On the agenda: Brighton meeting — data center (Aug 13)

City of Brighton
Planning Commission
Agenda
August 13, 2026
6:00 p.m.

Located in the 1st Floor Council Chambers at City Hall
500 South 4th Avenue, Brighton, CO 80601

Chair:
Vice Chair:
Commissioners:

Mark Rawlings
Blaine Nickeson
Stephanie Ohm
Kylie Parks
Kathryn LeDonne
Jolene Cohen-McCoy
Kevin Wieland
Alan Marraudino

Ward I
At Large
Ward II
Ward III
Ward IV
Alternate
Alternate
Youth

ATTENTION TO ALL ATTENDING PUBLIC HEARING
Please leave all cell phones out of the Commission Chambers or make sure that they are turned off before
entering. Thank you!
Por favor apage todos teléfonos de celular y aparatos de busca personas antes de entrar al concejo municipal.
Muchas gracias!

I.

Call to Order at 6:00 p.m.

II.

Pledge of Allegiance

III.
IV.

Roll Call
Seating of Alternates

V.

Minutes from the July 9, 2026, Planning Commission Meeting Presented for
Approval

VI.

Public Invited to be Heard on Items Not on the Agenda

VII.

Agenda Items
1. Public Hearing: Bromley Park PUD 38th Amendment – Colton Guarini
Presenting
2. Public Hearing: Article 5 Community Benefits Incentives Code Amendments
(Adoption) – Shawn Weiman Presenting

VIII.

Old Business

IX.

New Business

X.

Reports
1. Assistant Director of Community Development
2. Next Meeting: August 27, 2026

XI.

Adjournment

Notice of Non-Discrimination
It is the policy of the City of Brighton to provide equal services, programs and
activities without regard to race, color, national origin, creed, religion, sex, sexual
orientation, disability, or age and without regard to the exercise of rights guaranteed
by state or federal law. The City of Brighton has a policy to provide language access
services at no charge to persons with limited English proficiency (LEP) and persons
with a disability who are served by the City.
For more information on non-discrimination or interpretation, please contact the
City’s Coordinator at [email protected] or 303-655-2096. The City will
make reasonable accommodations for citizens in accordance with the Americans
with Disabilities Act (ADA) or will arrange for an interpreter in accordance with Title VI
of the Civil Rights Act. Any request for an interpreter must be made by 9:00 a.m. on
the Thursday prior to the Planning Commission meeting.
Si desea traducción o acomodaciones de acuerdo con la Ley de Derechos de
Discapacitados (“ADA” en inglés) o Titulo VI, por favor comuníquese por correo
electrónico a [email protected] o 303-655-2096. Cualquier petición
para un intérprete debe ser pedido antes de las 9 a.m. el jueves anterior de la sesión
de la Comisión de Planificación.

CITY OF BRIGHTON
PLANNING COMMISSION
MINUTES
July 9, 2026
I.

CALL TO ORDER
Chair Rawlings called the meeting to order at 6:00 PM

II.

PLEDGE OF ALLEGIANCE
Vice Chair Nickeson led the Pledge of Allegiance.

III.

ROLL CALL
Roll call was taken with the following Commissioners in attendance: Mark
Rawlings, Blaine Nickeson, Kathryn LeDonne, Jolene Cohen-McCoy, Stephanie
Ohm; Alan Marraudino was excused; Kylie Parks, and Kevin Weiland were
absent.
STAFF PRESENT
Shannon McDowell, Assistant Director of Community Development; Yasmina
Gibbons, Deputy City Attorney; Greg Labrie, Director of Public Works; Kyle
Sylvester, Assistant Director of Parks & Open Space; Kim Bauer, Associate
Planner; Shawn Weiman, Affordable Housing Coordinator; Grey Shipman,
Associate Planner; and Jon Waines, Commission Secretary.

IV.

SEATING OF ALTERNATES
Jolene Cohen-McCoy was seated as a voting commissioner.

V.

MINUTES FROM May 14, 2026, PLANNING COMMISSION MEETING
PRESENTED FOR APPROVAL
Motion by Vice Chair Nickeson to approve the minutes from the May 14, 2026,
Planning Commission meeting.
Second by Commissioner Ohm.
Motion Passes: 5-0

VI.

PUBLIC INVITED TO BE HEARD ON ITEMS NOT ON THE AGENDA
None presented.

VII.

AGENDA ITEMS

1. Public Hearing: Case Farms Rezoning – Kim Bauer presenting
Chair Rawlings opened the Public Hearing at 6:03 PM.
Karen Henry representing the Henry Design Group presented on behalf
of the applicant, Clark Carlson with Bromley and Buckley LLC.
Associate Planner Kim Bauer presented about the history of the
property, the current zoning, and the proposed Case Farms Zoning
amendment. Finding the rezoning in compliance with the Land Use
and Development Code (LUDC) section 2.03B, the Comprehensive
Plan, and that the Development Review Committee recommended
approval, staff recommended approval of the amendments.
Chair Rawlings called for questions from the Commission of Staff.
Five questions were asked of Staff and were answered.
Chair Rawlings called for any member of the public to comment about the
item being presented.
Three members of the public made comments about the proposed
changes.
Chair Rawlings called for comments from the Commission.
Two comments were made by staff.
Chair Rawlings closed the Public Hearing at 6:43 PM.
Motion by Commissioner Nickeson to approve the resolution.
Second by Commissioner Ohm.
Motion Passes: 4-1.
2. Public Hearing: Parks & Open Space Code Amendments – Shawn Weiman
Presenting
Chair Rawlings opened the Public Hearing at 6:47 PM.
Affordable Housing Coordinator Shawn Weiman presented about the
proposed LUDC code amendments focusing on uniformity, consistency,
and clarity of wording in the code as well as updating the required open
space dedication obligations to assist with the development of more
affordable housing in the city. Finding the amendments meet the review
criteria of the code and meet the intent of the Comprehensive Plan, staff
recommended approval of the amendments.
Chair Rawlings called for questions from the Commission of Staff.
Three questions were asked of Staff and were answered.
Chair Rawlings called for any member of the public to comment about the
item being presented.

One member of the public made comments about the proposed
changes.
Chair Rawlings called for comments from the Commission.
Four comments were made by staff.
Chair Rawlings closed the Public Hearing at 7:12 PM.
Motion by Commissioner LeDonne to approve the resolution.
Second by Commissioner Nickeson.
Motion Passes: 5-0.
3. Study Session: Temporary Sign Code Amendments – Grey Shipman
Presenting
Associate Planner Grey Shipman presented regarding a necessary
correction to the code and a simplified process for issuing and enforcing
the appropriate use of temporary signs.
VIII.

OLD BUSINESS
No old business.

IX.

NEW BUSINESS
No new business.

X.

REPORTS
Chair Rawlings invited Staff to present, summarized:
1. Assistant Director Shannon McDowell presented regarding the recent
projects passed by the City Council that were previously presented to
the Planning Commission.
2. Next meetings: Joint Study Session with City Council on August 11 and
Planning Commission on August 13.

XI.

ADJOURNMENT
Meeting adjourned by Chair Rawlings at 7:29 PM

Recorded by: Commission Secretary Jon Waines

Department of Community Development
Reference: Bromley Park Planned Unit Development (PUD) 38th Amendment
To:

Chair Mark Rawlings and Members of the Planning Commission

Through:

Shannon McDowell, Assistant Director of Community Development

Prepared By:

Colton Guarini, Planner I

Date Prepared:

August 3, 2026

PURPOSE
The Major Planned Unit Development (“PUD”) Amendment application (the "Application” or the
“Amendment”) before the Planning Commission is for an approximately 13.401-acre property (the
“Property”), generally located to the northeast of the intersection of west bound Interstate 76
Frontage Road and North 60th Avenue. Sue Sibel is the project contact working on behalf of the
Property owner and Brighton Crossing LLC (the “Applicant”). The request proposes a zoning
change from the current split zoning of the property which is Single Family Attached and Office
Research & Development, to solely being zoned Office Research & Development within the PUD
and further defining permitted uses in the Office Research & Development zoning district as the
Bromley Park Land Use Regulations scope of permitted uses is very general. This request
requires approval of a Major PUD Amendment, which is a form of zoning map amendment,
commonly referred to as a rezoning.
PROCESS
A Zoning Map Amendment is the second step in the land development process with the City of
Brighton (the “City”) (Annexation > Zoning Map Amendment > Platting > Site Plan Review >
Permits). The Property is platted as Brighton Crossing Filing 10, however a subdivision plan will
be required due to the need for additional right of way dedication. All applications will be reviewed
using the City’s Land Use and Development Code (the “LUDC”) to ensure compliance with City
codes and policies.
Zoning dictates whether uses at a property are allowed by right or conditionally, and this, in turn,
allows owners, neighbors, and the community at large to have a reasonable expectation of what
can occur on a property. It establishes standards for construction including building height, lot
coverage, and building setbacks. There are a variety of zone districts within the City, including
residential, commercial, industrial, mixed-use, and PUD.
The Bromley Park Land Use Regulations are the standards set for all of the Bromley Park PUD
unless amended, the standards outline the amendment process for the subject PUD. Per these
regulations, the proposal does not meet the criteria for a Minor PUD Amendment, due to the
Application further defining of allowed uses having a substantial impact on the development
standards and requirements of Office Research & Development, and as such, must be processed
as a Major PUD Amendment and “subject to the review of the Planning Commission and approval
by the City Council after public hearings.” The Bromley Park Land Use Regulations do not include
specific review criteria for a Major PUD Amendment. The Planned Development process outlined
in the LUDC is most closely aligned with the PUD Amendment process. As such, Staff, the
Planning Commission, and the City Council should use the review criteria outlined in Section
2.04(C)(2) of the LUDC.

1

BACKGROUND
In 1985, the Property was annexed as part of the Bromley Park Annexation and was most recently
given the land use designation of Office Research & Development as well as Residential Single
Family Attached in 1997 under Bromley Park PUD 2nd Amendment. Previously, the Property was
zoned under the Bromley Park PUD 1st Amendment, which retains all of the development
standards for site development, including permitted uses. The Property is platted under the
Brighton Crossing Filing No. 10 Administrative Plat.
Surrounding Land Use(s):
Surrounding
Land Use(s)
Direction

Zoning

Annexation
Status

North

Single Family Detached

Ridgeline Vista PUD (Single
Family Detached)

City of Brighton

South

Industrial

City of Brighton

East

Storm Drainage

West

Single Family Detached

Bromley Park PUD 2nd
Amendment (Industrial)
Bromley Park PUD 2nd
Amendment (Office
Research and Development)
Bromley Park PUD 7th
Amendment (Single Family
Detached)

City of Brighton
City of Brighton

CRITERIA BY WHICH PLANNING COMMISSION MUST CONSIDER THE ITEM
Section 2.04(C)(2) of the LUDC outlines the review criteria upon which the Planning Commission
must consider the Application. Specifically, the Planning Commission must consider the following:
a. The plan proposes the most closely applicable base zoning district(s) for specific portions of
the property in terms of land use, development intensity, and building form and scale.
b. The proposed change is consistent with concepts or plans in the previously approved Planned
Unit Development and does not increase development beyond the capacity or impacts
proposed in that plan.
c. The proposed plan either meets the standards provided in this code, or where deviations from
the base zoning districts or other standards of this code are requested, they bring the project
closer to the intent or design objectives of this code than was otherwise anticipated under the
approved Planned Unit Development.
d. The plan meets all of the review criteria for a Zoning Map Amendment.
STAFF ANALYSIS OF THE APPLICATION
Proposed Uses:
Under the Bromley Park PUD, the allowed uses in Office Research & Development are generally
described to include office, medical, dental, professional and governmental activities, Light
Manufacturing, Fabrication, and Processing. The Applicant has provided a list of permitted uses
that resemble the Business Park (BP) zone district of the LUDC. The list includes a variety of
Residential, Public/Civic, Commercial, Industrial, Agricultural, and Wireless Communication
Facility uses that are all permitted or permitted with conditions in the BP zone district of the LUDC.
2

In addition, the Amendment introduces primary and secondary land uses. Primary land uses shall
occupy more than 50% of the land area within the property and are meant to establish the primary
character and function of the area. The secondary land uses must occupy less than 50% of the
land area within the property and are intended to support or complement the primary uses.
Secondary land uses shall not be permitted until a primary land use has been established.
The Amendment does not propose modifications to existing development standards, such as
building design standards, parking standards, and buffer design standards. Development
standards would revert back to the original Bromley Park Land Use Regulations, and anything
not specified in those standards would go to the LUDC.
Land Use & Development Code:
In making its recommendation, the Planning Commission shall use the criteria outlined in Section
2.04(C)(2). Below, Staff analyzes how the Application meets and/or exceeds the criteria.
a. The plan proposes the most closely applicable base zoning district(s) for specific
portions of the property in terms of land use, development intensity, and building form
and scale.
Per the Bromley Park PUD, the Office Research & Development zone district is described as, “a
campus-type technological park to serve as an easily accessible employment center for the
region. Office use shall include general, medical, dental, and professional and governmental
activities.” This closely resembles the Business Park zone district description in the LUDC, which
reads, “the BP district provides planned business, employment and light manufacturing uses, and
supporting services arranged in a campus development pattern around common amenities, welldesigned open space systems, and internal circulation systems.” Both descriptions describe
industrial, business, and employment centers designed in a campus style development. The BP
zone district’s permitted uses include all of the general uses described in the Office Research &
Development zone district.
b. The proposed change is consistent with concepts or plans in the previously approved
Planned Unit Development and does not increase development beyond the capacity or
impacts proposed in that plan.
The Application expands the existing zoning designation of Office Research & Development to
encompass the entire property. The different amendments to the Bromley Park PUD have
removed all other instances of Office Research & Development from Bromley Park. The proposal
expands the Office Research & Development zoning area due to the Single Family Attached area
being unable to meet the minimum lot standards of the Bromley Park Land Use Regulations and
rather than leave that area unable to be developed, the Application incorporates the remainder of
the Property into the Office Research & Development designation. The Application ensures that
future development of the Property will develop in a manner consistent with the intent of the
Bromley Park PUD.
c. The proposed plan either meets the standards provided in this code, or where
deviations from the base zoning districts or other standards of this code are requested,
they bring the project closer to the intent or design objectives of this code than was
otherwise anticipated under the approved Planned Unit Development.

3

As the Bromley Park Land Use Regulations are vague, the Application seeks to further define the
allowed uses in the Office Research & Development zone district. The Office Research &
Development zone district closely mirrors the BP zone district in the LUDC and will use the
development standards from the Bromley Park Land Use Regulations in conjunction with the
LUDC to fulfill the intent of the Bromley Park PUD.
d. The plan meets all of the review criteria for a Zoning Map Amendment.
The criteria for a Zoning Map Amendment is set out in Section 2.03(B) and outlined and analyzed
below:
d1. The proposal is in accordance with the goals and objectives of the Comprehensive Plan and
any other plan, policy or guidance adopted pursuant to that plan.
The future land use map of the Be Brighton Comprehensive Plan has designated the Property as
Medium Density Residential which aligns with a portion of the current zoning and permitted uses,
but the proposal for sole Office Research & Development contradicts this designation. While the
Application does not conform to the Future Land Use Map designation, it does comply with the
future land use chapter of the Comprehensive Plan containing Opportunity Areas, which
describes areas in Brighton that should focus on specified development opportunities in pursuit
of the goals and visions of the City. This section specifically calls out “I-76 Opportunities” as an
entrance into the community and that the development should be attracting businesses and
residential investors. The surrounding area has residential investment already but is currently
missing businesses. The Amendment seeks to fulfill the intent of the I-76 Opportunity area by
introducing new business opportunities while also furthering other policies and strategies of the
Comprehensive Plan. Within Chapter Four on ‘Citywide Principles, Policies & Strategies’, the
proposed Amendment advances a number of these goals:
Policy 1.1 – New Growth Should Favor Existing Areas of Infrastructure Investment and Planning
• The Property is located within an area that is primarily built out and has benefited from
previous planning and infrastructure investment.
Policy 2.1: Brighton Will Continue to Develop in a Self-Sufficient and Sustainable Manner (Live,
Learn, Work, Shop and Play) with an Appropriate Balance between Residential and NonResidential Uses
• The Application will seek to bring in diverse industries as expressed in the Comprehensive
Plan. The proposed Amendment will provide the only Office Research & Development in
the Bromley Park PUD, and this will be the last opportunity to introduce this unique
business park design that the original PUD intended.
Policy 5.2 – Support Brighton’s Non-Downtown Commercial Centers, Focusing Growth within
Existing Investment Areas Where Possible
• The proposed Amendment supports Brighton’s non-downtown commercial centers by
facilitating a compatible commercial use within an established Office Research &
Development area. The addition of a business park introduces a neighborhood service
that complements the surrounding commercial and residential development and focuses
growth within an existing investment area.
Policy 5.3 – Retain Sufficient and Suitable Land for Anticipated Employment and Industrial
Development as Part of an Overall Economic Development Program
4

•

This policy says to “[r]eserve employment and industrial lands for future primary jobs,
particularly along US 85, I-76, and E-470 and protect them from encroaching conflicting
uses.” The proposed Amendment seeks to create employment opportunities along I-76
that will help create a diverse balance between the residential uses and commercial
opportunities.

d2. The proposal will support development in character with existing or anticipated development
in the area, including the design of street, civic spaces and other open space; the pattern,
scale and format of buildings and sites; and the integration, transitions and compatibility of
other uses.
The proposed Amendment does not propose any development standards. The original Bromley
Park Land Use Regulations contain development standards including setbacks, buffering, and
screening that are consistent with the existing development framework and are intended to
mitigate potential impacts on adjacent uses. With the exception of building design, which is not
specified in the Regulations, the future buildings will be designed in accordance with current
LUDC standards.
d3. The City or other agencies have the ability to provide services or facilities that may be
necessary for anticipated uses in the proposed district.
The area around the Property has been built out with roads and utility lines to accommodate the
surrounding area’s development. The Property is adequately served by the existing road
infrastructure and any future site developer will pay applicable costs to connect to City
infrastructure.
d4. The change will serve a community need, amenity or development that is not possible under
the current zoning or that was not anticipated at the time of the initial zoning of the property.
The zoning designation that established the Office Research & Development areas was approved
in 1994. Since that time, there has been significant residential growth in the surrounding area.
Allowing the expanded uses on the Property would introduce new uses and services that support
nearby neighborhoods and families. The proposed Amendment enables this use while
maintaining compatibility with surrounding development through tailored development standards
set in the Bromley Park Land Use Regulations and the LUDC.
d5. The recommendations of any professional staff or advisory review bodies.
City staff finds this site appropriate for a business park given its specific location as expressed in
the Comprehensive Plan. Site development, including buffering and building design, will occur in
accordance with the applicable zone district standards as outlined in the LUDC and the Bromley
Park Land Use Regulations. Any development on the Property will only be permitted with a design
that ensures it fits in with the context and development patterns of the area.
The Development Review Committee (DRC) reviewed this project and recommends approval.
Note: A complete list of comments and the agencies who made them are available upon request.
PUBLIC NOTICE AND INQUIRY
Mailings were sent to all property owners within 1,000 feet of the subject Property, as required by
the LUDC. These mailings were sent on July 22, 2026, and included a letter describing the
proposed Application, the time and place for the public hearing, and a map of the subject Property.
5

A notice was published on the City’s website on the same day. City staff also posted public hearing
information on Facebook and NextDoor in the days leading up to the meeting. On July 29, 2026,
two signs were posted on the Property. As of the posting of this report, Planning staff has not
received any formal comments from the public regarding the rezoning.
On June 3, 2025, as required by Code prior to the submission of the Application to the City, the
Applicant held a virtual neighborhood meeting. The notification mailings, sent by the Applicant to
property owners within the applicable mailing radius of the Property, included information on the
meeting. The Applicant had multiple members of their team available to present their proposal,
field any questions, and take feedback from meeting participants. A copy of the neighborhood
meeting minutes is attached to this report.
SUMMARY OF FINDINGS AND STAFF RECOMMENDATION
Staff finds the Application is in general compliance with the requirements as outlined in Section
2.04(C)(2) of the LUDC and therefore recommends approval of the Bromley Park PUD 38th
Amendment. Staff has drafted a resolution for the recommendation of approval if the Planning
Commission agrees with this recommendation.
OPTIONS FOR COMMISSION CONSIDERATION
The Planning Commission has four options when reviewing this Application. The Planning
Commission may:
1.) Recommend approval of the Application;
2.) Recommend approval of the Application with changes to the drafted resolution;
3.) Recommend denial of the Application; or
4.) Continue the item to be heard at a later, specified date if the Commission feels it needs
additional information to ensure compliance with the approval criteria as set forth in the
Land Use & Development Code.
Note: The first three decisions would be a recommendation to the City Council, who will ultimately
make the decision on the Application.
ATTACHMENTS
● Draft Planning Commission Resolution
● Proposed Planned Unit Development Amendment (Exhibit to draft resolution)
● Aerial Map by City Staff
● Neighboring Area Property Owner Notification
● Buffer Map
● Neighborhood Meeting Minutes
● Affidavit of Sign Posting
● Public Notice on Website
● Website Posting Proof
● Draft Staff Presentation

6

RESOLUTION NO. __________
A RESOLUTION OF THE PLANNING COMMISSION OF THE CITY OF BRIGHTON,
COLORADO, CONSIDERING A RECOMMENDATION TO THE CITY COUNCIL
REGARDING THE BROMLEY PARK PLANNED UNIT DEVELOPMENT 38TH AMENDMENT
FOR AN APPROXIMATELY 13.401 ACRE PROPERTY, GENERALLY LOCATED TO THE
NORTHEAST OF THE INTERSECTION OF WEST BOUND INTERSTATE 76 FRONTAGE
ROAD AND NORTH 60TH AVENUE, MORE PARTICULARLY LOCATED IN A PORTION OF
SECTION 1, TOWNSHIP 1 SOUTH, RANGE 66 WEST OF THE SIXTH PRINCIPAL MERIDIAN,
CITY OF BRIGHTON, COUNTY OF ADAMS, STATE OF COLORADO
WHEREAS, Brighton Crossings LLC (the “Owner”) is the owner of
approximately 13.401 acres of real property located in the City of Brighton (the
“City”), attached hereto as Exhibit A (the “Property”); and
WHEREAS, the Owner has requested approval of the Bromley Park Planned
Unit Development 38th Amendment, attached hereto as EXHIBIT B (the “PUD
Amendment”); and
WHEREAS, the Planning Commission finds it appropriate to review the PUD
Amendment as a Major PUD Amendment, as outlined in the adopted Bromley
Park Land Use Regulations, and to use the criteria outlined for the amendment of
a Planned Development in the Land Use & Development Code (the “LUDC”) in
considering the PUD Amendment; and
WHEREAS, the Planning Commission conducted a public hearing on August
13, 2026, to review and consider the PUD Amendment pursuant to the applicable
provisions and criteria set forth in the LUDC Section 2.04(C)(2); and
WHEREAS, in accordance with the public notice requirements of the LUDC,
a notice of public hearing was mailed to all property owners within 1,000 feet of
the Property, a public notice was published on the City’s website, and a sign was
posted on the Property, all for no less than fifteen (15) days prior to the Planning
Commission public hearing; and
WHEREAS, at the public hearing, the Planning Commission received and
considered all relevant evidence and testimony from City staff, the Applicant,
and other interested parties, including the public at large.
NOW THEREFORE, BE IT RESOLVED by the Planning Commission of the City of
Brighton, Colorado, as follows:
Section 1. Findings. The Planning Commission finds and determines that
the proposed PUD Amendment: (a) is consistent with the Office Research &

Development designation under the Bromley Park Land Use Regulations; (b) does
not increase development capacity or impact on adjacent infrastructure; (c)
meets the standards of the Land Use and Development Code and/or aligns
development standards with the existing surrounding subdivision; and (d) meets
all of the review criteria for a zoning map amendment.
Section 2. Recommendation.
The Planning Commission hereby
recommends to City Council the approval of the Bromley Park PUD 38th
Amendment.
Section 3.

This Resolution is effective as of the date of its adoption.

RESOLVED this 13th day of August 2026.
CITY OF BRIGHTON, COLORADO
PLANNING COMMISSION

Mark Rawlings, Chairperson
ATTEST:

Jon Waines, Secretary
APPROVED AS TO FORM:

James Gallagher, Assistant City Attorney

EXHIBIT A
Legal Description of the Property
Lot 1, Tract A, and Tract B Brighton Crossing Filing No. 10, as recorded July 8th,
2026, at Reception No. 2026000040091, County of Adams, State of Colorado.

EXHIBIT B
PUD Amendment

Community Development

500 South 4th Avenue
Brighton, CO 80601
303-655-2072
www.brightonco.gov

July 27, 2026
Dear Interested Party:
I am writing this letter to inform you of upcoming public hearings, which you may be inclined to attend.
The hearings provide an opportunity for interested parties to voice their opinion on the proposed
project to the Planning Commission and City Council. The input and opinions of residents and
neighboring property owners provides valuable feedback to the Planning Commission, City Council,
City staff, and the applicant. The following is some basic information that pertains to the project.
Application Type:

Planned Unit Development (PUD) Amendment: A request to amend the
previously approved Bromley Park PUD, to be known as the 38th Amendment
(the “Application”).

Summary:

The request proposes a zoning change from the current split zoning of the
property which is Single Family Attached and Office Research & Development,
to solely being zoned Office Research & Development within the PUD and
modifying permitted uses in the Office Research & Development zoning district.

Location/Site Plan:

The property is generally located to the northeast of the intersection of west
bound I-76 Frontage Road and North 60th Avenue.

The abbreviated legal description is as follows: A portion of Section 1, Township 1 South, Range 66 West
of the 6th Principal Meridian, City of Brighton, County of Adams, State of
Colorado. See the reverse side for a vicinity map.
Reviewing Bodies:

The Planning Commission makes a recommendation on the Application. The
City Council will make a final decision after a Public Hearing (details below)
has been held.

Public Hearings:

Planning Commission
Thursday, August 13, 2026 at 6:00 p.m.
City Council
Tuesday, September 15, 2026 at 6:00 p.m.

Official Notice
Publication:
City Staff Project

Both hearings are held in the Council Chambers on the first floor of City Hall
Located at 500 S 4th Avenue, Brighton, CO 80601
Information continues on the reverse side.
July 27, 2026 posted on the City’s Website.

Page 1 of 2

Manager:

Colton Guarini
Planner I
(303) 655 - 2290
[email protected]

Property Owner:

Brighton Crossing LLC

Additional Info:

The review process allows the Planning Commission and the City Council to
determine the completeness of the application and its adherence to City
Codes and policies.

Please do not hesitate to contact me if you have any questions on this project or if you are unable to
attend the hearing but would like to submit a comment into the record. Public comments must be
received at least 24 hours prior to the meeting time. Thank you for your time.
Best regards,
Colton Guarini
Planner I

Page 2 of 2

MEETING MINUTES
DATE: June 3, 2025
TIME: 6-7 pm
LOCATION: Virtual – Zoom Meeting
PURPOSE: Neighborhood Meeting for Brighton Crossings Planning Area 14 (PA14)

In Attendance


NAME
Sue Sibel
Will Zerkus



Dewberry

Paul Shoukas



PCS

[email protected]

Matt Haley



Brookfield Residential

[email protected]

David Hicks & Lampert

[email protected]

Woody Boyd
Sherry M
Erin Himelright
Kurt
NA



ORGANIZATION

PHONE

EMAIL
[email protected]
[email protected]

Attendees

Summary
•

Meeting started at 6:05 PM

•

Paul commented that this meeting is being recorded at City of Brighton’s request

•

Paul with PCS provided a short introduction, went through agenda for neighborhood
meeting, introduced the project partners.

•

Paul discussed the development process relative to the City of Brighton and where we are
in the process.

•

Paul showed the overall Bromley Park PUD map and explained at a high level that this
zoning document outlines broad land uses that are more specifically defined by a
regulating document, the Bromley Park Land Use Regulations specifically.

•

Paul showed a colored, zoomed-in look at the land uses including and immediately
surrounding the project. He discussed current use by right and mentioned the City is
requesting we change the allowable land use for the Site to only Office – Research and
Development since we have less than the 5-acre requirement for a Single-Family
Attached project.

•

Paul showed an access plan with surrounding roadways and developments to depict
future vehicular and pedestrian access and routing. Paul explained that the definition for
the Office – Research/Development land use within the Bromley Park Land Use
Regulations is extremely vague. He mentioned that the City has requested we utilize the
City’s prescribed Business Park zoning to further specify potential land uses for this Site.

•

Paul shared a list and discussed permitted uses within the City of Brighton’s prescribed
Business Park zoning

•

Paul discussed conditional uses within the City of Brighton’s prescribed Business Park
zoning. These uses would require additional approval by the City’s governing body.

•

Paul showed a conceptual bubble plan to illustrate what a campus-style Office – Research
and Development site could look like, acknowledging that zoning documents without
MEETING MINUTES

1 OF 2

illustration can be difficult to comprehend. He disclaimed that this bubble plan is purely
conceptual and is not a true indication of what may be proposed for this site at a later
date.
•

•

Questions/Neighbor Comments
o

Sherry asked a clarifying question that any of the listed land uses could be
proposed with this zoning/PUD Amendment application. Answer: Paul reiterated
that the land uses listed in the Bromley Park Land Use Regulations are so vague
that we must rely on the City’s prescribed land uses in the Business Park zoning
to guide potential development.

o

Sherry voiced concerns with traffic and undesirable types of land
uses/developments.

o

Sherry asked if homeowners will be notified of future public meetings. Yes –
homeowners will receive notices for future public meetings.

o

Sherry asked who all will receive mailed notifications. Answer: Paul stated that
mailed notifications are delivered to a 1,000-ft radius of the site. Matt also stated
that signs will be posted on either end of the site that spell out details of upcoming
public meetings.

Meeting ended at 6:30PM

Action Items
DESCRIPTION

BALL-IN-COURT

DUE DATE

COMPLETE? (Y/N)

None

We believe the foregoing record to be an accurate summary of the meeting and related decisions. We
would appreciate notification of exceptions or corrections to these Minutes within five (5) days of receipt.
Without notification, we will consider these minutes to be a record of fact.
COPIED: Brookfield, PCS, DHLB, City of Brighton

Sincerely,
Sue Sibel
Dewberry Engineers

MEETING MINUTES

2 OF 2

Bromley Park Planned Unit
Development 38th Amendment
Planning Commission – August 13, 2026

City Staff Representative:
Department:
Applicant:
Project Contact:

Colton Guarini, Planner I
Community Development
BRIGHTON CROSSING LLC
Sue Sibel

Subject Property
Location
The property is generally
located to the northeast of
the intersection of West
bound I-76 Frontage Road
and North 60th Ave.

Aerial Map
2

Background
The Property:
● Is currently zoned Bromley Park

PUD 2nd Amendment.

● Is currently platted Brighton

Crossing Filing 10.

Zoning Map
3

Purpose
● The request proposes a zoning change from the current split zoning of

the property from Single Family Attached and Office Research &
Development, to solely being zoned Office Research and Development
and further defining the permitted uses in the Office Research &
Development zoning district.

Annexation

Zoning

Process

Platting –
Subdivision
Plan

Platting
- Final
Plat

Site Plan
Review

Building
Permits

● The Bromley Park Land Use Regulations allow for a Major PUD

Amendment.

● Staff used the conversions of PUDs criteria from the Land Use &

Development Code to review the proposal.

4

Proposed Amendment – Subject Property

5

Proposed Amendment – Further Definition of Uses

6

Bromley Parking Zoning vs LUDC
• Office - Research & Development Zoning:
• A campus-type technological park to serve as an easily accessible
employment center for the region. Office use shall include general,
medical, dental, and professional and governmental activities.

• Business Park (BP) Zoning:
• The BP district provides planned business, employment and light
manufacturing uses, and supporting services arranged in a campus
development pattern around common amenities, well-designed open
space systems, and internal circulation systems.
7

Staff Analysis – Proposed Amendment
• Provisions of the Office Research & Development Zoning:
• The Application seeks to incorporate the remainder of the Property
into this Office Research and Development opportunity.
• The proposed list of allowed uses in the Office Research &
Development zoning closely reflects the Business Park's allowed
uses in the LUDC.
• Building design and development standards will not be
modified by this Amendment.
8

Staff Analysis – Review Criteria Slide 1
The proposal shall meet the review criteria for a Planned Unit
Development Amendment (LUDC Sec. 2.04 C.)
a)

The plan proposes the most closely applicable base zoning district(s) for
specific portions of the property in terms of land use, development intensity,
and building form and scale.

b)

The proposed change is consistent with concepts or plans in the previously
approved Planned Unit Development and does not increase development
beyond the capacity or impacts proposed in that plan.

c)

The proposed plan either meets the standards provided in this code, or where
deviations from the base zoning districts or other standards of this code are
requested, they bring the project closer to the intent of this code than was
otherwise anticipated under the approved Planned Unit Development.

9

Staff Analysis – Review Criteria Slide 2
The plan meets the review criteria for a Planned Unit
Development Amendment (LUDC Sec. 2.04 C.)
d)

The plan meets the review criteria for a Zoning Map Amendment.
1.

The proposal is in accordance with the goals and objectives of
the Comprehensive Plan and any other plan, policy, or guidance
adopted pursuant to that plan.

10

Staff Analysis – Comprehensive Plan:
Future Land Use Designation
The Subject Property is
designated as Medium Density
Residential.

Future Land Use Map

11

Staff Analysis – Comprehensive Plan:
Principles, Policies & Strategies
Chapter Four: Citywide Principles, Policies & Strategies
● Policy 1.1 – New Growth Should Favor Existing Areas of Infrastructure

Investment and Planning

● Policy 2.1 – Brighton Will Continue to Develop in a Self-Sufficient and

Sustainable Manner (Live, Learn, Work, Shop and Play) With an
Appropriate balance Between Residential and Non-Residential Uses

● Policy 5.2 – Support Brighton’s Non-Downtown Commercial Centers,

Focusing Growth within Existing Investment Areas Where Possible

● Policy 5.3 – Retain Sufficient and Suitable Land for Anticipated

Employment and Industrial Development as Part of an Overall
Economic Development Program

12

Staff Analysis – Review Criteria Slide 3
2.

The proposal will support development in character with existing or
anticipated development in the area, including the design of street,
civic spaces and other open spaces; the pattern, scale and format of
buildings and sites; and the integration, transitions and compatibility
of other uses.

3.

The City or other agencies can provide services or facilities that may
be necessary for anticipated uses in the proposed district.

4.

The change will serve a community need, amenity, or development
that is not possible under the current zoning or that was not
anticipated at the time of the initial zoning of the property.

5.

The recommendations of any professional staff or advisory review
bodies.

13

Public Notice and Comment
● Public Notice was provided in accordance with the Land Use &

Development Code.

● On July 22nd
 Notice was published on the City’s Website.
 Written notice was mailed to all property owners within 1,000 feet of the Property.
● On July 29th
 Two public hearing sign was posted on the Property.
● City staff posted information for the public hearing on Facebook and

NextDoor.

● A neighborhood meeting was held on June 3, 2025.
● Planning staff has received no formal comments in advance of this

hearing.

14

Summary of Findings
 The Development Review Committee has reviewed this project and
recommends approval.

 Staff finds the Major PUD Amendment meets the requirements as outlined in the
Land Use & Development Code.

City Staff Recommendation
 Staff recommends approval of the Bromley Park Planned Unit Development 38th
Amendment.

15

Options for Planning Commission
 Recommend approval of the Planned Unit Development Amendment

as presented;
 Recommend approval of the Planned Unit Development Amendment

with changes to the drafted resolution;
 Recommend denial of the Planned Unit Development Amendment; or
 Continue the Planned Unit Development Amendment to be heard at a

later specified date.
16

Dear Planning Commissioners and City Staff:
Please accept this email as my written public comment concerning the Bromley Park PUD 38th
Amendment. Please include this email and the attached supporting materials in the official
record for the August 13, 2026 Planning Commission hearing and retain them with the
application materials for consideration by the City Council.
My purpose in submitting these comments and supporting materials is to provide the
Commission with reliable information relevant to the decision before it and to ask that significant
development rights not be granted before the intended uses and their foreseeable impacts can
be thoroughly evaluated.
I request that the Planning Commission recommend denial of the Bromley Park PUD 38th
Amendment as presently submitted and noticed. At minimum, I request that the application be
continued until the exact permitted use changes, the purpose of those changes, and sufficient
information about the development those changes are intended to accommodate are fully
disclosed.
The City's public notice states that the property is currently divided between Single Family
Attached and Office Research & Development zoning. The proposed amendment would
eliminate the Single Family Attached designation, make the entire property Office Research &
Development, and "modify permitted uses."
What has not been clearly disclosed to the public is exactly what permitted uses are being
added, removed, or modified and what use or development is prompting those changes. That
information is fundamental to the zoning decision now before the Commission.
Brighton's Land Use and Development Code requires a zoning amendment to be evaluated
based on criteria that include consistency with the Comprehensive Plan, compatibility with
existing and anticipated development, the ability of the City and other agencies to provide the
services and facilities necessary for anticipated uses, and whether the change serves a
community need or development that is not possible under the existing zoning.
Based on the information presently available to the public, I do not believe there is sufficient
information to make those findings. Before recommending approval, I respectfully ask the
Commission to require clear answers to the following:
1. What exact permitted use language is being added, removed, or modified by the 38th
Amendment?
2. What use or development is prompting the requested amendment?
3. Is a data center, AI computing facility, server farm, high load computing facility, or similar use
currently contemplated for this property by the owner, a prospective purchaser, tenant, or
operator?
4. Would approval of this amendment allow such a facility as a permitted or by right use, or
would it require a later discretionary public hearing?

5. What evidence demonstrates that the full range of uses made possible by this amendment
will be compatible with nearby residential development?
6. What evidence establishes that the City, utilities, and other service providers have adequate
electrical, water, wastewater, emergency-response, transportation, and other infrastructure
capacity for the anticipated uses?
7. What community need requires this zoning change, and why can that need not be met under
the property's existing zoning?
These questions are particularly important because the City of Brighton is currently seeking
professional consulting services to develop enforceable noise standards related to the
introduction of data centers within the community. I have attached the City's data-center-noise
solicitation as supporting information.
I support Brighton taking the time to develop appropriate data-center standards. However, if this
amendment could authorize or facilitate a data center, particularly as a permitted or by right use,
I believe it would be premature to grant that zoning entitlement while the City is still determining
what enforceable protections are necessary.
I am not asking the Commission to assume that a data center on this property will necessarily
cause a particular impact. There is not enough project specific information available to make
that determination. That lack of information is precisely why I believe this zoning amendment
should not be approved at this stage.
Data centers can involve continuously operating cooling equipment, fans, transformers,
substations, backup generators, substantial electrical loads, and significant cooling and water
requirements. Those characteristics raise legitimate land-use questions concerning compatibility
with surrounding properties, noise, emissions, utility capacity, water use, and infrastructure.
I have attached complete governmental source documents addressing several of these issues
so their source, authorship, context, findings, methodology, and limitations are available for
review. I have identified the most relevant pages below so staff and commissioners do not have
to search through the complete publications.
Low frequency and continuous noise
The attached CDC/NIOSH Health Hazard Evaluation illustrates why low-frequency sound
should not necessarily be evaluated only through a general A-weighted noise limit.
In the facility NIOSH evaluated, low-frequency sound materially influenced the indoor sound
environment. NIOSH also found that an imbalance between lower- and higher-frequency sound
increased the likelihood of annoyance.
NIOSH did not conclude that the sound levels measured during its visit were likely to cause
adverse health effects, and I do not suggest otherwise. The relevance of the report to land-use
planning is that it demonstrates why frequency-specific analysis may be necessary to properly
characterize a low-frequency sound environment.

See the attached CDC/NIOSH report, Evaluation of Low Frequency Noise, Infrasound, and
Health Symptoms at an Administrative Building and Men's Shelter, HHE Report No. 2019-01193362 (2019), especially PDF pp. 5–6 for the key findings and PDF p. 31, Table C2, for the
dBA/dBC measurements.
For any future data center proposal, Brighton should require baseline sound measurements,
predictive acoustic modeling based on the actual proposed equipment, dBA and dBC
measurements, appropriate low-frequency or frequency specific analysis, evaluation of tonal
noise, nighttime limits, post construction testing, continuing monitoring, and enforceable
corrective action.
Backup generators and air emissions
Backup generation equipment also deserves project specific review.
EPA regulates hazardous air emissions from stationary reciprocating internal combustion
engines and identifies pollutants associated with those engines including formaldehyde,
acrolein, methanol, and acetaldehyde.
See the attached U.S. EPA Final Rule to Reduce Hazardous Air Emissions from Reciprocating
Internal Combustion Engines fact sheet, especially PDF pp. 1–2.
The International Agency for Research on Cancer (IARC), which is part of the World Health
Organization, classifies diesel engine exhaust as carcinogenic to humans (Group 1), based on
sufficient evidence of an increased risk of lung cancer. IARC also specifically identifies power
generators as a potential source of diesel-exhaust exposure.
See the attached IARC/WHO, IARC: Diesel Engine Exhaust Carcinogenic, Press Release No.
213 (June 12, 2012), especially PDF pp. 1–2.
These documents do not establish what a future facility on this property would emit. They
demonstrate why the number, size, fuel type, emissions controls, testing schedules, operating
limitations, and applicable permitting requirements of backup generators should be disclosed
and evaluated before a data center use is authorized.
Electricity, cooling, and water requirements
Electrical and water capacity are directly relevant to whether adequate services and facilities
exist for an anticipated use. Lawrence Berkeley National Laboratory’s 2024 United States Data
Center Energy Usage Report, LBNL-2001637, DOI 10.71468/P1WC7Q, was prepared in
response to a congressional directive through the U.S. Department of Energy.
The report estimates that US data centers consumed approximately 176 TWh of electricity in
2023, representing approximately 4.4 percent of total U.S. electricity consumption. See report p.
6. The report also discusses how different data-center cooling technologies affect energy and
water requirements. See report pp. 44-46. Its analysis of water consumption estimates
approximately 66 billion liters of direct water consumption by U.S. data centers in 2023 and
discusses nearly 800 billion liters of indirect water consumption associated with the electricity

used by data centers. See report pp. 55–57.
I am not offering these national figures as an estimate of what a facility on this property would
consume. They demonstrate why the actual electrical load, cooling technology, water source,
anticipated water consumption, wastewater impacts, substation or transmission requirements,
and other utility infrastructure should be known before the City determines that adequate
services and facilities exist for an anticipated data center use.
I intended to include the complete Berkeley Lab report with my supporting materials; however,
the file is too large to transmit through email even after compression. I have therefore provided
the report’s complete title, publication number, DOI, and the specific page references relied
upon above so that the source can be readily located and reviewed. If the Commission or City
staff would like a complete copy for the application record, I am happy to provide a printed copy
or another acceptable format upon request.

My earlier comments
I previously submitted a public comment to the Planning Commission in May 2026 concerning
the need for data center specific regulation. I also submitted comments through Brighton's
Comprehensive Plan process addressing data centers and high load computing facilities as a
long range land use issue.
Those comments were submitted before this Bromley Park amendment was publicly noticed. I
am attaching both comments again so there is no uncertainty about their inclusion with my
comments on this application.
What I am asking the City to do
If the 38th Amendment is intended to accommodate a data center, or if the amended permitteduse language would allow a data center, I respectfully ask Brighton not to make that use
permitted by right through this amendment.
At minimum, any future data-center proposal should remain subject to a discretionary, project
specific public review after the actual operator, site plan, building size, mechanical and electrical
equipment, cooling system, transformers, substations, generators, electrical demand, water
requirements, and surrounding-property impacts are known.
Before authorizing such a use, Brighton should adopt measurable and enforceable standards
addressing at minimum:
•

continuous and nighttime operational noise;

•

dBA and dBC measurements and appropriate frequency-specific or low-frequency
analysis;

•

tonal and impulsive noise and cumulative noise from mechanical and electrical
equipment;

•

pre-construction baseline measurements and predictive acoustic modeling;

•

post-construction testing and continuing compliance monitoring;

•

generator number, size, fuel type, emissions controls, testing schedules, and operating
limits;

•

residential setbacks, equipment orientation, acoustic enclosures, and barriers;

•

cooling technology, water source, anticipated water use, and wastewater impacts;

•

electrical demand and required substations, transmission, or other utility infrastructure;

•

emergency-response and fire-safety requirements; and

•

a clear complaint process, independent verification, and enforceable corrective action.

These protections should be objective requirements that can actually be measured and
enforced, rather than general assurances that a future operator will comply with whatever
standards happen to apply later.
Whether data centers should be allowed in Brighton, where they should be located, whether
they should ever be permitted by right, and what standards should govern them are important
citywide land-use policy decisions.
A property-specific PUD amendment should not answer those larger questions indirectly by
creating new development rights before Brighton has completed that policy and regulatory work.
If no data center or high load computing use is contemplated for this property, I ask the
applicant and City to state that clearly in the public record and disclose exactly which permitted
uses are being modified, what development those changes are intended to accommodate, and
why the existing zoning is insufficient.
If material information concerning the intended use, a prospective purchaser or operator, the
exact permitted use language, utility requirements, or other information necessary to evaluate
the zoning criteria is disclosed at or shortly before the hearing, I request that the Commission
continue the hearing and allow the public a reasonable opportunity to review and respond
before a recommendation is made.
I am not asking the City to reject economic development or to assume impacts that have not
been demonstrated. I am asking the City to preserve meaningful review until it knows what use
is being enabled and has enforceable standards appropriate to that use.
The decision before the Commission is whether this requested zoning change satisfies
Brighton's approval criteria. The Commission and the public should not have to speculate about
what use is being enabled and then attempt to address foreseeable impacts after the zoning
change has already been approved.
For these reasons, I respectfully request that the Planning Commission recommend denial of
the Bromley Park PUD 38th Amendment as presently submitted or, at minimum, continue the
application until the exact permitted use changes, intended development, infrastructure
requirements, and information necessary to evaluate Brighton's zoning criteria are fully

disclosed.
Supporting materials attached:
•

May 2026 Planning Commission Comment

•

Comprehensive Plan Comment

•

CDC/NIOSH - Evaluation of Low Frequency Noise, Infrasound, and Health Symptoms at
an Administrative Building and Men's Shelter, HHE Report No. 2019-0119-3362; see
PDF pp. 5–6 and PDF p. 31, Table C2

•

US EPA - Final Rule to Reduce Hazardous Air Emissions from Reciprocating Internal
Combustion Engines - see PDF pp. 1–2

•

IARC/World Health Organization - IARC: Diesel Engine Exhaust Carcinogenic, Press
Release No. 213; see especially PDF pp. 1–2

•

City of Brighton — Consulting Services for Data Center Noise Standards, Owner
Reference No. 26500329

Additional supporting source referenced above but not attached due to email file size
limitations:
•

Lawrence Berkeley National Laboratory — 2024 United States Data Center Energy
Usage Report, LBNL-2001637, DOI 10.71468/P1WC7Q. See especially report p. 6, pp.
44-46, and pp. 55-57. A complete copy can be provided in another format upon
request.

Please confirm that this comment and the attached supporting materials were received and
associated with the Bromley Park PUD 38th Amendment.
I also respectfully request that my physical address and email address be redacted from any
version of this public comment or its attachments that is published online or otherwise made
publicly accessible, while retaining that information in the City's internal records as necessary.
Thank you for your time and consideration.
Sincerely,
Angela Pirrone

Dear Mr. Waines and Planning Commission Members,

Tue, Apr 28, 2026 at 4:16 PM

Please accept this written public comment for the May 14, 2026 Planning Commission hearing regarding the proposed
Wireless Communication Facilities Code Amendment.
My comment is limited to citywide land-use policy, code clarity, and future standards for emerging high-load technology
uses.
I understand from the public notice that this hearing concerns amendments to Article 10 of the Land Use and
Development Code related to Wireless Communication Facilities, including changes intended to comply with state law
and clarify existing WCF regulations.
Because this is a citywide technology-infrastructure code amendment, I respectfully request that the Planning
Commission and staff clarify on the record that this WCF amendment does not authorize, classify, regulate, or create a
review path for data centers, Al compute facilities, server farms, modular data centers, high-load computing facilities, or
similar high-resource industrial technology uses.
I am raising this because data centers and high-load computing facilities can raise land-use impacts that are different from
ordinary wireless communication facilities, including continuous mechanical cooling noise, low-frequency hum, backupgenerator noise, backup-generator emissions, high electrical demand, fire-safety issues, and compatibility concerns near
residential areas and other sensitive receptors.
If data centers or high-load computing facilities are not addressed by this WCF amendment, I respectfully ask that the
Planning Commission refer this issue to City staff and Long Range Planning for consideration as a separate citywide landuse-code topic. I also ask that the City not rely on broad existing use categories, such as industrial, warehouse,
manufacturing, technology, utility, or wireless communication categories, to process such uses without clear definitions,
public notice, public review, and enforceable performance standards.
For any future citywide code work, I ask the City to consider requiring:
1. A specific Land Use and Development Code definition for data centers, Al compute facilities, server farms, modular
data centers, and high-load computing facilities;
2. Conditional Use Permit, special-use, or other discretionary public-review approval for such facilities above defined
thresholds;
3. Public notice and neighborhood meeting requirements;
4. Noise studies evaluating continuous operations, nighttime conditions, cumulative equipment noise, and both dBA
and dBC/low-frequency impacts;
5. One-third-octave-band frequency analysis where low-frequency mechanical noise may be present;
6. Disclosure and review of backup generators, including number, fuel type, testing schedule, emissions controls, and
applicable air permits;
7. Residential setbacks, acoustic screening, and buffering from homes, schools, parks, and other sensitive receptors;
8. Enforceable operational limits and ongoing compliance monitoring, rather than relying only on initial site-plan
review.
I am particularly concerned that dBA-only noise standards may be inadequate for facilities that generate continuous lowfrequency mechanical noise from cooling equipment, fans, transformers, or backup generators. Some foundational publichealth guidance on low-frequency noise is older, but its core technical point remains relevant: dBA-only measurements
can understate low-frequency noise. The World Health Organization's Guidelines for Community Noise states that when
prominent low-frequency components are present, A-weighted measures are inappropriate, and that the difference
between dB(C) and dB(A) can provide information about low-frequency components. WHO further recommends
frequency analysis when the difference between dB(C) and dB(A) is more than 10 dB.
More recent federal sources support this concern. A CDC/NIOSH low-frequency-noise evaluation documented conditions

where measured indoor levels were only 26.5-39.8 dBA, while C-weighted levels were 55.9-67.2 dBC, demonstrating
how dBA-only measurements can understate low-frequency noise impacts.
I am submitting a limited set of public-health references for the record to support a citywide policy request for future datacenter and high-load-computing standards.
I respectfully request that this comment and the attached materials be included in the public record for the May 14
Planning Commission hearing.
Thank you for your time and consideration.
Sincerely,
Angela Pirrone

Dear City of Brighton Planning Staff and Comprehensive Plan Project Team,

Tue, Apr 28, 2026 at 4:18 PM

Please accept this written comment for the City of Brighton Comprehensive Plan update and any related future citywide
land-use policy or Land Use and Development Code implementation work.
Please forward this comment to the appropriate Long Range Planning / Comprehensive Plan project staff and include it in
the public-input record for any remaining plan-sharing, Planning Commission, City Council, adoption, or implementation
phases.
My comment is limited to citywide land-use policy, Comprehensive Plan implementation, and future standards for
emerging high-load technology uses.
As Brighton updates its Comprehensive Plan and future land-use framework, I ask the City to specifically address data
centers, Al compute facilities, server farms, modular data centers, and other high-load computing facilities as a distinct
citywide land-use issue.
These facilities may provide economic benefits, but they can also create impacts that are materially different from ordinary
warehousing, office, light industrial, manufacturing, utility, or wireless-communication uses. Potential impacts include
continuous 24/7 mechanical cooling noise, low-frequency hum, backup-generator testing, diesel or gas generator
emissions, high electrical demand, water or cooling impacts, fire-safety concerns, utility-infrastructure impacts, and
compatibility issues near residential areas or other sensitive receptors.
I respectfully request that the Comprehensive Plan and implementation framework include a policy direction stating that
Brighton should not process data centers or high-load computing facilities under broad existing land-use categories
without specific public review standards.
I ask the City to consider including the following policy language, or similar language, in the Comprehensive Plan:
"Data centers, Al compute facilities, server farms, modular data centers, and high-load computing facilities should be
defined and regulated as distinct land uses. The City should require public notice, appropriate discretionary review,
health-based noise and air-quality analysis, residential buffering, generator-emissions review, utility-capacity evaluation,
fire-safety review, and enforceable operating standards before such uses are approved."
I also ask that the City consider a future Land Use and Development Code amendment that would:
1. Define data centers and high-load computing facilities as separate land uses;
2. Identify where such uses are allowed, conditional, or prohibited;
3. Require Conditional Use Permit, special-use, or other discretionary public-review approval above defined
thresholds;
4. Require public notice and neighborhood meeting procedures;
5. Require noise studies that evaluate continuous operation, nighttime impacts, cumulative equipment noise, and
both dBA and dBC/low-frequency sound;
6. Require one-third-octave-band frequency analysis where low-frequency mechanical noise may be present;
7. Require disclosure of backup generators, including number, fuel type, testing schedule, emissions controls, and
applicable air-permit status;
8. Establish setbacks, acoustic screening, and buffering from residential areas, schools, parks, and other sensitive
receptors;
9. Require enforceable operational conditions and ongoing compliance monitoring.
I am particularly concerned that dBA-only noise standards may be inadequate for facilities that generate continuous lowfrequency mechanical noise from cooling systems, fans, transformers, and backup generators. Some foundational publichealth guidance on low-frequency noise is older, but its core technical point remains relevant: dBA-only measurements

can understate low-frequency noise. The World Health Organization's Guidelines for Community Noise states that when
prominent low-frequency components are present, A-weighted measures are inappropriate, and that the difference
between dB(C) and dB(A) can provide information about low-frequency components. WHO further recommends
frequency analysis when the difference between dB(C) and dB(A) is more than 10 dB.
More recent sources support the need for low-frequency analysis. A CDC/NIOSH evaluation of low-frequency noise
documented measured indoor levels of only 26.5-39.8 dBA while C-weighted levels were 55.9-67.2 dBC, showing that
dBA-only measurements may understate low-frequency impacts. A 2020 peer-reviewed literature review, Low-Frequency
Noise and Its Main Effects on Human Health-A Review of the Literature between 2016 and 2019, also supports the need
to evaluate low-frequency noise exposure as a specific public-health and land-use compatibility concern.
I am submitting a limited set of public-health references for the record to support a citywide policy request for future datacenter and high-load-computing standards.
Thank you for considering this citywide policy comment as part of Brighton's Comprehensive Plan update and future Land
Use and Development Code implementation work.
Sincerely,
Angela Pirrone

FACT SHEET
FINAL RULE TO REDUCE HAZARDOUS AIR EMISSIONS FROM RECIPROCATING
INTERNAL COMBUSTION ENGINES
TODAY=S ACTION
!

On February 26, 2004, the Environmental Protection Agency (EPA) issued final
requirements to reduce toxic air emissions from stationary reciprocating internal
combustion engines (RICE). These requirements apply to RICE used at facilities such as
pipeline compressor stations, chemical and manufacturing plants, and power plants.

!

The final rule will reduce emissions of a number of toxic air pollutants such as
formaldehyde, acrolein, methanol, and acetaldehyde by 5,6000 tons in the fifth year after
promulgation. These pollutants, also known as air toxics, are known or suspected to
cause adverse health and environmental effects. Formaldehyde and acetaldehyde are
probable human carcinogens.

!

The final rule limits the amount of air pollution that may be released from exhaust stacks
of all new (built after December 19, 2002), and certain existing, stationary RICE above
500 horsepower that are located at major industrial sources of air toxics. According to
the Clean Air Act, a major source emits 10 tons a year or more of a single toxic air
pollutant, or 25 tons a year or more of a combination of toxic air pollutants.

!

Existing stationary RICE must comply with the final rule no later than 3 years after the
final rule is published. New stationary RICE must comply with the final rule when they
are brought on line. These units have up to 6 months after the rule is final, or 6 months
after startup, whichever is later, to demonstrate compliance with the new standards.

!

The final rule requires that:
¾ Existing and new 4-stroke rich burn (4SRB) engines either reduce formaldehyde by
76 percent or limit the formaldehyde concentration to 350 parts per billion.
¾ New 2-stroke lean burn (2SLB) engines either reduce carbon monoxide (CO) by 58
percent or limit the formaldehyde concentration to 12 parts per million.
¾ New 4-stroke lean burn (4SLB) engines either reduce CO by 93 percent or limit the
formaldehyde concentration to 14 parts per million.
¾ New compression ignition (CI) engines either reduce CO by 70 percent or limit the
formaldehyde concentration to 580 parts per billion.
Formaldehyde and CO are surrogates for reducing the air toxics of concern from RICE.
Therefore, by reducing formaldehyde and CO, facilities also will reduce the other air
toxics to similar levels.

!

EPA expects owners or operators of 4SRB engines to install air pollution control devices
known as Anon-selective catalyst reduction.@ These systems not only reduce CO
emissions, they also reduce air toxics emissions such as formaldehyde, acrolein,

methanol, and acetaldehyde. Sources are free to comply with either compliance option,
irrespective of the control technique applied.
!

Owners or operators of 2SLB, 4SLB, and CI engines likely will install devices known as
ACO catalytic oxidation systems@ to meet the formaldehyde and CO requirements.

!

EPA estimates that approximately 8,120 new stationary RICE will be built at major
sources of air toxic emissions by the end of the 5th year after this rule takes effect. In
addition, about 1,800 existing stationary RICE located at major sources may potentially
be subject to the rule.

!

When proposing this rule, EPA requested comment on three options that could reduce the
cost of complying with the final rule requirements. These options focused regulatory
controls on facilities that pose significant human health risks from their toxic air
emissions. Facilities that could show their air toxic emissions fall below certain
thresholds could have been exempt from this air toxics rule if EPA adopted one or more
of these options.

!

EPA received comments on these risk-based approaches. After considering the complex
issues raised and evaluating the effort required to finalize this rule by the court ordered
deadline, EPA did not adopt any of these options in the final rule.

HEALTH/ENVIRONMENTAL BENEFITS
!

The final rule will provide improvements in protecting human health and the environment
by reducing air toxics emissions by 5,600 tons per year in the fifth year after the rule is
final. Emissions of formaldehyde, acrolein, acetaldehyde and methanol will be reduced
by 40 to 90 percent, depending on the type of stationary RICE.

!

Exposure to emissions of these air toxics may produce a wide variety of human health
effects including irritation of the eyes, skin and mucous membranes, dysfunction of the
central nervous system, and narcosis. Formaldehyde exposure has been associated with
reproductive effects such as menstrual disorders and pregnancy problems. EPA has
classified formaldehyde and acetaldehyde as probable human carcinogens.
In addition, the controls that will be used to reduce air toxic emissions will also reduce
carbon monoxide (CO), nitrogen oxides (NOx), volatile organic compounds (VOC), and
particulate matter (PM). The total annualized benefits for the final rule are $280 million
in the fifth year due to the NOx reductions. Benefits would be greater if we were able to
quantify the effects of the air toxics and pollutants other than NOx.

COST
!

EPA estimates the total nationwide capital costs for the final rule to be $440 million
within the first five years, with an annualized cost of $247 million in the fifth year.

3
BACKGROUND
!

The Clean Air Act requires EPA to develop standards for categories of facilities that emit
one or more of 188 listed toxic air pollutants. These standards require the application of
strict controls known as maximum achievable control technology (MACT).

!

EPA identified stationary RICE as a category of sources that emit one or more of the
listed air toxics.

!

The Clean Air Act requires EPA to identify MACT controls based on the emissions levels
achieved by the best-performing facilities. This baseline for controls, or MACT floor, is
established differently for existing and new sources. In the case of existing stationary
RICE, there were not enough existing 2SLB, 4SLB, and CI engines with controls to
establish an emission reduction for the MACT floor. Requiring these facilities to add
controls required for new engines would be cost prohibitive.

FOR MORE INFORMATION
!

To download the final standards from EPA=s web site, go to ARecent Actions@ at the
following address: http://www.epa.gov/ttn/oarpg.

!

For further information about the final rule, contact Mr. Sims Roy at EPA=s Office of Air
Quality Planning and Standards at 919-541-5263.

!

For information regarding stationary RICE, visit EPA=s web site at:
http://www.epa.gov/ttn/atw/combust/engine/ricepg.html. For other combustion-related
regulations, visit EPA=s Combustion Related Rules page at:
http://www.epa.gov/ttn/atw/combust/list.html.

Evaluation of Low Frequency
Noise, Infrasound, and Health
Symptoms at an Administrative
Building and Men’s Shelter
HHE Report No. 2019-0119-3362
October 2019

Authors:

Sophia Chiu, MD, MPH
Scott E. Brueck, MS, CIH, COHC
Douglas M. Wiegand, PhD
Hannah Free, MPH

Desktop Publisher: Jennifer Tyrawski
Editor: Cheryl Hamilton
Logistics: Donald Booher, Kevin Moore
Data Support: Hannah Echt
Keywords: North American Industry Classification System (NAICS) 624190 (Other Individual and
Family Services), Low Frequency Sound, Low Frequency Noise, LFN, Infrasound, Methane
Flare, Maryland, Vertigo, Auditory Symptoms, Vestibular Symptoms, Psychological Contract

Disclaimer
The Health Hazard Evaluation Program investigates possible health hazards in the workplace under
the authority of the Occupational Safety and Health Act of 1970 [29 USC 669a(6)]. The Health
Hazard Evaluation Program also provides, upon request, technical assistance to federal, state, and
local agencies to investigate occupational health hazards and to prevent occupational disease or
injury. Regulations guiding the Program can be found in Title 42, Code of Federal Regulations,
Part 85; Requests for Health Hazard Evaluations [42 CFR Part 85].

Availability of Report
Copies of this report have been sent to the employer and employees at the nonprofit organization
and mobile clinic. The state and local health departments and the Occupational Safety and Health
Administration Regional Office have also received a copy. This report is not copyrighted and may
be freely reproduced.

Recommended Citation
NIOSH [2019]. Evaluation of low frequency noise, infrasound, and health symptoms at an
administrative building and men’s shelter. By Chiu S, Brueck SE, Wiegand DM, Free H. Cincinnati,
OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention,
National Institute for Occupational Safety and Health, Health Hazard Evaluation Report 20190119-3362, https://www.cdc.gov/niosh/hhe/reports/pdfs/2019-0119-3362.pdf.

Table of Contents
Main Report
Introduction ....................................................................................................................................................... 1
Our Approach ................................................................................................................................................... 1
Our Key Findings.............................................................................................................................................. 1
Our Recommendations .................................................................................................................................... 4

Supporting Technical Information
Section A: Workplace Information............................................................................................................ A-1
Workplace.................................................................................................................................................. A-1
Employee Information ............................................................................................................................ A-2
History of Issue at Workplace ................................................................................................................ A-2
Section B: Methods, Results, and Discussion .......................................................................................... B-1
Methods: Noise Assessment ................................................................................................................... B-1
Results: Noise Assessment ...................................................................................................................... B-2
Methods: Employee Health Assessment .............................................................................................. B-6
Results: Employee Health Assessment ................................................................................................. B-7
Methods: Employee Perceptions of the Handling of the Loud Noise Situation ............................ B-8
Results: Employee Perceptions of the Handling of the Loud Noise Situation ............................... B-9
Discussion ............................................................................................................................................... B-10
Limitations............................................................................................................................................... B-14
Conclusions ............................................................................................................................................. B-15
Section C: Tables .......................................................................................................................................... C-1
Section D: References.................................................................................................................................. D-1

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Introduction
Request
Employer representatives of a nonprofit organization and a mobile health services provider (mobile
clinic) as well as county health department officials requested a health hazard evaluation. The request
concerned low frequency noise, infrasound, and health symptoms among employees who work at the
nonprofit organization’s campus. Two events, in February and May 2019, caused particular concern
because of the perceived noise intensity and symptoms among some employees, which lead to the
campus being vacated.

Workplace
The nonprofit organization and mobile clinic provided services to homeless persons. The campus
included an administrative building and a men’s shelter, which were located near an inactive landfill with
methane flares. The campus and the landfill were owned by the county. The requesters were concerned
that sound and vibrations originating from the methane flares could be associated with health effects
among employees.
To learn more about the workplace, go to Section A in the Supporting Technical Information

Our Approach
In June 2019, we visited the nonprofit organization. For this evaluation, we completed the
following activities:
• Measured sound levels and took noise frequency measurements (one-third octave band noise
measurements) inside and outside the campus buildings and near the methane flares and
motor-operated blowers.
• Interviewed employees who worked in the administrative building and men’s shelter about
unusual sounds or vibrations, personal health, and their perceptions of the nonprofit
organization and the county’s response.
To learn more about our methods, go to Section B in the Supporting Technical Information

Our Key Findings
Sound level and noise frequency measurements during the site visit were well below
levels likely to cause adverse health effects
• The highest one-third octave band levels when a flare was operating were at 20 hertz. The
highest level at this frequency was about 71 decibels in the administrative building, 66 decibels in
1

the men’s shelter, and 85 decibels in the parking lot between the methane flare area and the
buildings. These were well below the American Conference of Governmental Industrial
Hygienists’ ceiling limit of 145 decibels for low frequency noise below 80 hertz.
• The highest overall unweighted noise levels (added across all frequencies) were about 73 decibels
in the administrative building, 69 decibels in the men’s shelter, and 87 decibels in the parking lot.
These were well below the American Conference of Governmental Industrial Hygienists’
frequency-specific ceiling limit of 150 decibels for low frequency noise below 80 hertz.
• The sound levels during the reported loud noise events in February and May 2019 were higher
than those we measured based on employees’ descriptions and reported sensory experiences.
However, the actual sound levels and frequency characteristics during these events are unknown.
• The low frequency noise (sound at frequencies below 200 hertz) generated by the flares,
especially in the frequencies 16 to 25 hertz, influenced sound levels in the buildings. In the
administrative building, one-third octave band levels were 12 to 17 decibels higher when a
methane flare was operating compared to when flares were not operating.
• The noise levels in the low frequencies were relatively greater than noise levels in higher
frequencies, creating an unbalanced noise spectrum.
o This imbalance between low and high frequencies increases the likelihood of being
annoyed by the noise, particularly in the administrative building.
o The low frequency noise levels we measured were above some European guidelines for
low frequency noise and infrasound (sound at frequencies below 20 hertz).

Most interviewed employees reported unusual sounds or vibrations occurring at
other times, not just in February and May 2019
• Of the 46 employees interviewed, 37 (80%) reported unusual sounds or vibrations at some point
since beginning to work on the campus. Descriptions of the frequency, duration, and intensity
of the unusual sounds or vibrations varied.
• By location, 28 (61%) employees reported experiencing unusual sounds or vibrations in the
administrative building and 11 (24%) employees reported experiencing them in the men’s
shelter. This includes two employees (4%) who reported experiencing them in both locations.
• Most employees (89%) who reported experiencing unusual sounds or vibrations in the
administrative building stated that they had first occurred before the February 2019 incident.
Three of 11 employees (27%) who reported experiencing unusual sounds or vibrations in the
men’s shelter stated they had first occurred before the May 2019 incident.

2

Interviewed employees reported different types of symptoms as well as different
times when those symptoms first appeared. The symptoms among different
employees could have different causes.
• Twenty-four of the 46 (52%) interviewed employees reported experiencing symptoms that they
thought were related to unusual sounds or vibrations at the site.
• Nine of the 24 (38%) employees who reported symptoms saw a health care provider about
them. One employee reported being hospitalized. Relevant medical records for five (56%) of
these employees were available for review.
• Many of the symptoms reported by employees were common, nonspecific, and could have
multiple causes. Some of the employees had baseline medical conditions that could be associated
with their symptoms.
• In general, information about symptom onset, duration, and timing relative to the incidents
was incomplete.
• Some employees reported that their symptoms occurred before the incident in their primary
work area. Some symptoms that predated the incident are consistent with symptoms reported in
studies about background low frequency noise.
• Some employees reported developing symptoms during or after the February and May 2019
incidents. Auditory symptoms, such as hearing loss, ear pain, tinnitus, and ear pressure, can
occur after exposure to loud noise. However, measurements of the actual noise levels or octave
band frequency levels during the February and May 2019 incidents are not available.

Over half of the employees did not feel comfortable with returning to the
vacated campus
• Over half of the employees (25/44; 57%) reported that they did not feel comfortable returning
to the vacated campus.
To learn more about our results, go to Section B in the Supporting Technical Information

3

Our Recommendations
The Occupational Safety and Health Act requires employers to provide a safe workplace.
Benefits of Improving Workplace Health and Safety:
 Improved employee health and well-being



Enhanced image and reputation

 Better workplace morale



Superior products, processes, and services

 Easier employee recruiting and retention



May increase overall cost savings

The recommendations below are based on the findings of our evaluation. For each recommendation,
we list a series of actions you can take to address the issue at your workplace. The actions at the
beginning of each list are prioritized over the ones listed later. The list order is based on a well-accepted
approach called the “hierarchy of controls.” The hierarchy of controls groups actions by their likely
effectiveness in reducing or removing hazards. In most cases, the preferred approach is to eliminate
hazardous materials or processes and install engineering controls to reduce exposure or shield
employees. Until such controls are in place, or if they are not effective or practical, administrative
measures and personal protective equipment might be needed. Read more about the hierarchy of
controls at https://www.cdc.gov/niosh/topics/hierarchy/.
We encourage the nonprofit organization, county, and mobile clinic to use a health and
safety committee to discuss our recommendations and develop an action plan. Both
employee representatives and management representatives should be included on the
committee. Helpful guidance can be found in “Recommended Practices for Safety and Health
Programs” at https://www.osha.gov/shpguidelines/index.html.

Recommendation 1: Reduce low frequency noise generated by the methane flares
Why? Low frequency noise generated by the flares, especially in the frequencies 16 to 25 hertz, is
likely related to turbulence during flare operation. Noise at these frequencies influences sound levels
in the buildings, leading to an unbalanced noise spectrum (greater noise levels at low frequencies
compared to higher frequencies) and a greater likelihood of employees experiencing annoyance
because of the low frequency noise.

How? At your workplace, we recommend these specific actions:
Reduce turbulence generated by the methane flares.
• Optimize the waste methane gas and air mixture to continually maintain a proper ratio
and decrease combustion instability or combustion roar.
• Use flare burners designed to generate the least amount of noise.
• Reduce the velocity of waste gas stream, when feasible.
4

Consult with a noise control engineer about the possible use of building
treatments such as double-glazed windows to decrease noise
transmission into the building.
Recommendation 2: Encourage employees to report health concerns they think are
work-related to their supervisors
Why? Information about symptoms in this evaluation was incomplete. Going forward, the nonprofit
organization can periodically review information reported by employees to determine whether further
action is needed.

How? At your workplace, we recommend these specific actions:
Formalize a symptom reporting procedure so that information about
health concerns is documented.
Encourage employees with health concerns to seek an evaluation from a
healthcare provider with occupational medicine expertise and familiar
with the types of exposures employees have and their health effects.
• Resources for locating occupational medicine physicians include the Association of
Occupational and Environmental Clinics (http://www.aoec.org) and the American
College of Occupational and Environmental Medicine (http://www.acoem.org).

Recommendation 3: Improve communication to all nonprofit organization and
mobile clinic employees
Why? Open communication improves employees’ sense of control and may help eliminate confusion,
misinformation, and rumors related to building concerns.

How? At your workplace, we recommend these specific actions:
Improve communication by documenting employees’ concerns regarding
the vacated campus. Discuss what is or is not being done to address the
concerns and why, and what is being planned for the future.
• Joint meetings among nonprofit organization and mobile clinic employees,
management, and representatives of the county may be the best way to improve
communication. This will improve transparency and give all involved the opportunity to
discuss their concerns and have their questions answered.
• Employee input and distribution of information (for example, meeting minutes) should
be equal across all employees and employer representatives.
5

Recommendation 4: Take employees’ perceptions of risk and willingness to return
to work at the vacated campus into serious consideration
Why? If employees return to work in a setting that they believe is unhealthy or unsafe, it will likely
have an undesirable impact on turnover, absenteeism, job satisfaction, productivity, and quality
of work.

How? At your workplace, we recommend these specific actions:
Take time to speak with individual employees to understand their
concerns about the vacated campus and their willingness to return to
work there.
• Consider this information when deciding whether to return to work at the
vacated campus.

6

Supporting Technical Information
Evaluation of Low Frequency Noise, Infrasound, and
Health Symptoms at an Administrative Building and
Men’s Shelter
HHE Report No. 2019-0119-3362
October 2019

Section A: Workplace Information
Workplace
A diagram of the campus is shown in Figure A1. The campus included an administrative building and a
men’s shelter. The campus was adjacent to a landfill that closed in 1982. Two large methane flares
(Figure A2), located within a fenced area across the parking lot from the administrative building, burned
off excess methane from the adjacent landfill. Each flare had three automated air intake louvers equally
spaced around the perimeter of the cylindrical flare stack. Within each flare stack, four burners were
equally spaced in a spoke-like fashion about 5 feet (ft) above ground level. The site had three motoroperated blowers that pulled methane from the landfill at approximately 40 inches of vacuum pressure.
Typically, only one flare and one blower operated at any given time.
The methane burning system was computer-controlled and the automated air intake louvers could be
adjusted (fully open, partially open, or closed) depending on the concentration of methane pulled from
the landfill in order to maintain an optimal flare temperature of 1,650 degrees Fahrenheit. Although the
system was designed to adjust quickly as necessary (on the basis of continuing feedback to the computer
control system) to consistently keep the flare system within optimal operating parameters,
environmental or other factors can potentially disrupt the system. A wall perpendicular to the parking
lot was built reportedly to reduce noise transmission to the former methane plant that generated energy.
This wall was slightly shorter than the flares.
The administrative building had several wings. The one occupied by the nonprofit organization was
L-shaped. The main entrance and several offices faced directly toward the methane flares. A hallway
with offices along both sides extended from the main entrance straight toward the back of the building,
perpendicular to the flares. The men’s shelter building also had several rooms facing the flares,
including a main office and examination rooms. A large common room also faced the flares. A city road
was located on the opposite side of both buildings.
The nonprofit organization was contracted by the county to provide services for homeless persons.
Employees of the mobile clinic served clients at the men’s shelter. The county owned the campus,
landfill, and flares.

A-1

Figure A1. Schematic of the
campus and methane flares. Not
drawn to scale. Employees
worked in the administrative
building or the men’s shelter.
Yellow circles with A–D refer to
parking lot locations where we
made noise measurements. The
closed landfill extends from the
top edge of the fenced area to
beyond the top of the diagram.

Figure A2. Large methane flares
adjacent to the municipal landfill.

Employee Information
At the time of the evaluation, there were 59 nonprofit employees plus 1 volunteer: 31 worked in the
administrative building, 26 worked in the men’s shelter, and 3 worked for the mobile clinic.
Administrative building staff reported working 8–10 hours a day, while men’s shelter employees worked
8 hours a day.

History of Issue at Workplace
Request Basis
On February 4, 2019, employees reported unusually loud noise and strong vibrations in the
administrative building coming from the direction of the methane flares. During this loud noise event,
some employees also reported emotional discomfort and physical symptoms such as vertigo, dizziness,
and ear pressure. Prior to this loud noise event, the local area had received substantial heavy rain.
A-2

According to staff familiar with flare operation, heavy rainfall conditions can affect the composition of
methane and increase the amount of methane released within the landfill. It was likely that the
combination of these factors required greater input of air at the flare stack. Because the flare system did
not respond and adjust quickly enough to the changing air requirements, an imbalance in the air-tomethane gas ratio occurred, leading to an increase in combustion instability and combustion roar. These
conditions led to a subsequent increase in noise. To reduce the likelihood of additional loud noise
events, an additional air intake louver was added to each of the flare stacks (for a total of three equally
distributed automated louvers around the base of each flare) to bring additional air into the stacks, if
needed. Additional adjustments in the computer control systems were also completed to help keep the
air-to-gas ratio properly balanced.
As a result of the loud noise event, employees in the administrative building were relocated to an
off-campus building within 1 week. On May 17, 2019, loud noise and vibrations were reported at the
men’s shelter. Some nonprofit organization and mobile clinic employees and shelter clients reported not
feeling well during or soon after the incident. On the same day, the men’s shelter was relocated to a
building normally used for client overflow during colder months.
Other Issues
Some employees reported a strong, persistent odor in the administrative building. The nonprofit
organization hired a consultant to evaluate the odor in late 2017. The consultant took an ambient air
sample (via a whole air canister) and bulk samples of carpet and wood laminate. Air sampling and
headspace analysis of the bulk samples were done to identify volatile organic compounds (VOCs). The
VOC concentrations detected in the samples (39 VOCs in the air sample, 32 VOCs in the wood floor
laminate headspace sample, and 28 VOCs in the carpet headspace sample) were well below
occupational exposure limits. The consultant concluded that the most likely cause of the odor was one
of the VOCs identified in the samples, 2-methyl-1,3,butadiene (isoprene), from the duct mastic/sealant
used for the heating, ventilation, and air-conditioning ductwork. This VOC is a component of natural
and synthetic rubber.

A-3

Section B: Methods, Results, and Discussion
Our evaluation objectives were to characterize the following:
• One-third octave band noise frequency levels
• Health symptoms among employees
• Employee perceptions of how the loud noise situations were handled by the nonprofit
organization and the county

Methods: Noise Assessment
We gathered information about noise through (1) noise measurements and (2) confidential
employee interviews.
Sound Level and One-third Octave Band Measurement
We used a Larson Davis Model 831 integrating sound level meter and sound frequency analyzer and a
Model 377B20 ½ inch random incidence microphone for octave band frequency measurements. The
sound level meter and microphone met American National Standards Institute (ANSI) S1.4 2014 Type
1 standards and the octave band frequency filter met ANSI S1.11-2004 Class 1 standards. The
instrument and microphone were calibrated together before and after each day of measurements using a
Larson Davis CAL200 calibrator. We measured one-third octave band noise frequency levels at each
one-third octave band center frequency from 6.3 to 20,000 hertz (Hz) (corresponding to frequencies of
5.62–22,400 Hz).
The instrument sampled at a rate of 51,200 Hz (i.e., 51,200 measurements per second) and integrated
using linear averaging at 1-second time history intervals. One-third octave band levels were measured
using a slow weighting (1,000 millisecond) time constant and the Z-weighting (flat or unweighted)
response. During measurements, the instrument was either hand-held or positioned on a tripod at a
height of approximately 5 ft above floor or ground level. We took several measurements within rooms
inside the administrative building and the men’s shelter. We took measurements outside at six locations
between the flare areas and the administrative building and men’s shelters (identified as Locations A, B,
C, and D; grill area; and smoking hut in Figure A1). We also took some measurements offsite along the
city road that was behind the administrative building and men’s shelter. At each location, most
measurements were taken for a duration of approximately 30–45 seconds. Following measurements, the
one-third octave band frequency data stored on the instrument were downloaded, exported, and
analyzed using Larson Davis G4® software and Microsoft® Excel® for Office 365®.
Confidential Interviews: Perceptions of Noise
We invited all current employees of the nonprofit organization who (1) had been working during the
February 2019 incident, May 2019 incident, or both, and (2) were working during our site visit for
confidential interviews. We also invited all three mobile clinic employees who provide services at the
men’s shelter as part of their rotating schedule. We interviewed 46 employees, 43 employees in person

B-1

and 3 employees by phone. Our convenience sample included 45 current employees and 1 former
employee who had been employed during the February 2019 incident.
During the interviews, we discussed work characteristics and demographic information. We also asked
about perceptions of sounds or vibrations experienced in the administrative building or men’s shelter.
We categorized employees as administrative building employees or men’s shelter employees based on
their self-reported primary work area prior to the relocations. Mobile clinic employees were categorized
as men’s shelter employees. Administrative building employees were asked about their primary work
area within the building. Using a blueprint as a reference, we categorized employees as working
primarily in rooms facing the flares based on a reported room number for their office or working in a
room with a window facing the methane flares, as reported by employees.
We asked employees whether they heard any unusual sounds or experienced any unusual vibrations
since starting to work on the campus. For “yes” responses, we asked employees about when they first
heard unusual sounds or felt unusual vibrations in the administrative building or men’s shelter. We also
asked employees to describe the unusual sounds and vibrations. We grouped unusual sounds and
vibrations together for analysis.
We summarized results using descriptive statistics. We compared the proportion of employees working
primarily in rooms facing the flares who reported unusual sounds or vibrations to the proportion of all
other interviewed employees who reported unusual sounds or vibrations using a two-side Fisher’s exact
test where P < 0.05 was considered to indicate statistical significance. We used R version 3.5.1 to
perform statistical analyses.
Other interview topics and results are presented later in this report.

Results: Noise Assessment
Noise Measurement
The primary external sources for noise near the administrative building and men’s shelter were the
operating methane flare(s) and blower(s). Figure B1 shows the one-third octave band noise levels at an
operating flare and at an operating blower. The highest sound levels in the vicinity of the operating
methane flare occurred in frequencies below 50 Hz and ranged from 70.8 to 101.2 decibels (dB),
depending on frequency and distance from the flares. The highest levels (95.0 to 101.2 dB), measured
approximately 2 to 3 ft away from an air intake louver of the flare stack, were at a frequency of 20 Hz.
At 12.5 Hz, 16 Hz, and 25 Hz the levels ranged from 84.9 to 93.5 dB. At 10 ft from a flare in operation,
the sound level at 20 Hz was 91.2 dB, and at the adjacent frequencies of 12.5 Hz, 16 Hz, and 25 Hz, the
sound levels were at or slightly above 80 dB. The highest sound levels generated by an operating blower
were in the frequencies from 500 to 6,300 Hz, ranging from 68.6 to 76.2 dB. The measurements near
the blower also showed high sound levels in frequencies below 50 Hz, but these were due to the sound
generated by the nearby operating methane flare.

B-2

One-third octave band noise level (dB)

100.0
90.0
80.0
70.0
60.0
50.0
40.0
30.0

Flare #1

20.0

Blower #3

10.0
6.3
8.0
10.0
12.5
16.0
20.0
25.0
31.5
40.0
50.0
63.0
80.0
100
125
160
200
250
315
400
500
630
800
1000
1250
1600
2000
2500
3150
4000
5000
6300
8000
10000
12500
16000
20000

0.0

Frequency (Hz)

Figure B1. One-third octave band noise levels measured approximately 8 to 10 feet from an operating
methane flare and blower.
Table C1 provides the one-third octave band measurement results (up to 80 Hz) and overall sound
levels while one of the methane flares was in operation for comparison to occupational infrasound and
low frequency noise threshold limit values (TLVs) established by the American Conference of
Governmental Industrial Hygienists (ACGIH) [ACGIH 2019]. The highest one-third octave band levels
we measured across these frequencies (as well as for frequencies up to 20,000 Hz) at each location was
at 20 Hz, except for measurements taken along the city road behind the administrative and men’s
shelter buildings, where the levels were highest at 63 Hz. One-third octave band noise levels at 20 Hz
ranged from 60.5 to 71.4 dB in the administrative building, 60.4 to 65.6 dB in the men’s shelter, 75.8 to
84.9 dB at the four outdoor locations in the parking lot, grill area, and smoking hut. These results show
that the sound levels we measured were well below the ACGIH frequency-specific TLV ceiling value of
145 dB and the overall TLV ceiling limit of 150 dB.
Because relative sound levels were greater in lower frequencies relative to higher frequencies, Table C2
provides the overall C-weighted decibel (dBC) and A-weighted decibel (dBA) measurements results
within the administrative building and men’s shelter. The overall C-weighted sound levels ranged from
55.9 to 67.2 dBC in the administrative building and from 58.7 to 62.4 dBC in the men’s shelter.
A-weighted sound levels ranged from 26.5 to 39.8 dBA in the administrative building and 42.6 to
48.0 dBA in the men’s shelter.
During our site visit, the flares were shut down to complete some adjustments to the flare and
blower-motor computer control systems. During this shutdown, we took several one-third octave band
measurements for comparison to levels when a flare was operating. Within the administrative building
we took measurements in eight different rooms. All of the rooms had exterior windows, but five of the
rooms faced toward the flares. The other three rooms had windows facing out toward a side or toward
the rear (roadside) of the building. The highest one-third octave band noise levels across these eight
B-3

rooms when the flares were on occurred at 20 Hz, ranging from 62.1 to 71.4 dB. When the flares were
off the highest one-third octave band noise levels occurred at 8 Hz, ranging from 50.5 to 59.6 dB. In
general, our measurements did not show a substantial difference in the one-third octave band levels for
rooms facing the flares versus the rooms not facing the flares. Overall, the levels were slightly higher in
the rooms facing the flares across the frequencies of 10 to 100 Hz, but were slightly lower at all other
frequencies (and nearly the same from 10,000 to 20,000 Hz)
Figure B2 compares median one-third octave band frequency levels in the administrative building when
the flares were on versus when the flares were off. The greatest difference in one-third octave band
noise levels between flare on versus flare off conditions occurred across the frequencies of 16 Hz,
20 Hz, and 25 Hz. The differences in the median dB levels at these three one-third octave band
frequencies were 17.4 dB at 20 Hz, 15.2 dB at 25 Hz, and 12.2 dB at 16 Hz. At all other frequencies, the
median differences between flare on versus flare off conditions ranged from –4.6 to 6.1 dB, with a
negative difference indicating that octave band noise levels were higher when the flares were off.
70.0
median octave band sound level with the methane flare on

One-third octave band noise level (dB)

60.0
median octave band sound level with the methane flare off
50.0

40.0

30.0

20.0

10.0

6.3
8.0
10.0
12.5
16.0
20.0
25.0
31.5
40.0
50.0
63.0
80.0
100
125
160
200
250
315
400
500
630
800
1000
1250
1600
2000
2500
3150
4000
5000
6300
8000
10000
12500
16000
20000

0.0

Frequency (Hz)

Figure B2. One-third octave band noise levels across eight rooms in the administrative building when a
methane flare was on versus when the flare was off.
Figure B3 compares the median one-third octave band frequency levels in the administrative building
when a flare was on and off to four different European guidelines suggested for assessing indoor low
frequency noise and infrasound following complaints of annoyance. When the flare was on, our
measured levels exceeded the Polish guidelines at frequencies of 20 Hz, 25 Hz, and 50 to 250 Hz, and
exceeded German and Dutch guidelines at frequencies of 50 to 100 Hz. The highest exceedance was at
250 Hz when compared to Polish guidelines and was at 100 Hz when compared to German and Dutch
guidelines. None of the measured levels were above British guidelines. When the flare was off, we
similarly found that levels were above German and Dutch guidelines from 63 to 100 Hz and above
Polish guidelines from 100 to 250 Hz.
B-4

110.0
100.0

110.0
median 1/3 octave band sound level with the flare on
100.0

median 1/3 octave band sound level with the flare off
90.0

90.0

80.0

80.0

70.0

70.0

60.0

60.0

dB

dB

German guidelines

50.0

40.0

30.0

30.0

20.0

20.0

10.0

10.0

0.0

0.0

110.0
median 1/3 octave band sound level with the flare on

100.0

median 1/3 octave band sound level with the flare off

90.0

Dutch guidelines

80.0

70.0

70.0

60.0

60.0

dB

dB

80.0

Polish guidelines

Hz

Hz
110.0

90.0

median 1/3 octave band sound level with the flare off

50.0

40.0

100.0

median 1/3 octave band sound level with the flare on

50.0

50.0

40.0

40.0

30.0

30.0

20.0

20.0

10.0

10.0

0.0

0.0

Hz

median 1/3 octave band sound level with the flare on
median 1/3 octave band sound level with the flare off
British guidelines

Hz

Figure B3. Comparison of median one-third octave band noise levels in the administrative building with a flare on versus off to European
low frequency and infrasound guidelines
B-5

Confidential Interviews: Perceptions of Noise
Of the 48 employees invited for interviews, 46 employees (96%) participated. Interviewed employees
consisted of 44 nonprofit organization employees and 2 mobile clinic employees. The median job
tenure was 3 years (range: 5 months–14 years). Nonprofit organization employees worked for a median
of 40 hours per week (range: 30–65 hours per week). Mobile clinic employees were on site 2–3 partial
days per week. Based on the reported primary work area before the relocations, there were 29 (63%)
administrative building employees and 17 (37%) men’s shelter employees. Of the 46 interviewed
employees, 30 (65%) were female. The median age was 44 years (range: 24–69 years).
Thirty-seven (80%) interviewed employees reported either unusual sounds or vibrations. Descriptions
of the frequency, duration, and intensity of unusual sounds or vibrations varied. Some employees
described a rumbling, analogous to a large truck driving by, or a jackhammer, that can be heard or felt
prior to the incidents. Some employees described vibrating windows or objects or a sensation that the
building was shaking.
Regarding the location of sounds or vibrations, 28 (61%) employees reported experiencing them in the
administrative building and 11 (24%) employees reported experiencing them in the men’s shelter. These
numbers included 2 (4%) employees who reported experiencing unusual sounds or vibrations in
both locations.
Regarding when unusual sounds or vibrations were first noticed, responses ranged from the beginning
of employment to the day of the incident at the location where the incident occurred. Of the
28 employees who reported experiencing unusual sounds or vibrations in the administrative building,
25 (89%) reported that they noticed them occurring before the February 2019 incident. Of the
11 employees who reported experiencing unusual sounds or vibrations in the men’s shelter, 3 (27%)
reported that they noticed them occurring before the May 2019 incident.
The proportion of employees working primarily in rooms facing the flares who reported unusual
sounds or vibrations was similar to the proportion of other interviewed employees who reported
unusual sounds or vibrations (P = 0.69).

Methods: Employee Health Assessment
We gathered information about employee health through (1) interviews and (2) medical record review.
During confidential interviews with 46 employees, we asked about their medical histories. We also asked
about the following:
• Symptoms that employees thought were related to unusual sounds or vibrations.
• Medical care sought for symptoms that employees thought were related to unusual sounds
or vibrations.
We asked all interviewed employees whether they experienced any symptoms that they thought were
related to unusual sounds or vibrations at the site. Employees who answered “yes” or “not sure” were
asked additional questions about symptoms. If an employee reported seeking medical care for
symptoms, we attempted to obtain relevant medical records.

B-6

We summarized descriptive statistics for health information. We grouped tinnitus (sensation of noise or
ringing in the ears when there is no sound), ear pain, ear pressure, and hearing loss as auditory
symptoms. We grouped vertigo (sensation of movement when there is no movement) and balance
problems as vestibular symptoms (i.e., symptoms related to balance or the inner ear). We considered an
auditory or vestibular symptom to have a plausible (i.e., possible and medically reasonable) alternative
explanation if an employee reported (1) having a history of that symptom, (2) having a medical
condition for which that symptom is characteristic, (3) taking an over-the-counter or prescription
medication known to induce the symptom, or (4) basing it on medical record review, if available.
To assess the distribution of symptoms across groups, we compared the prevalence of symptoms
reported by employees working primarily in rooms facing the flares to the prevalence of symptoms
reported by other interviewed employees using a two-sided Fisher’s exact test. We also used the exact
binomial test to assess whether the percentages of administrative building versus men’s shelter
employees with a given symptom were similar to the percentages of employees who primarily worked in
those two areas.
Statistical significance was set at P < 0.05. We used R version 3.5.1 to perform statistical analyses.

Results: Employee Health Assessment
Twenty-four (52%) employees responded “yes” or “unsure” when asked whether they experienced any
symptoms that they thought were related to unusual sounds or vibrations at the site (Figure B4). The
most common symptom was headache (n = 19), followed by anxiety (n = 14), and lightheadedness
(n = 12). Six employees described one or more sources of their anxiety: uncertainty related to the
incidents and subsequent relocation (n = 4), whether the campus was safe (n = 2), noise (n = 1), and
methane gas (n = 1). Of the 46 interviewed employees, 14 (30%) reported auditory symptoms and
9 (20%) reported vestibular symptoms.
In general, information about symptom onset, duration, and timing relative to the incidents was
incomplete. When responses about symptom onset were available, the percentage of employees who
reported that symptoms occurred before the incident in their primary area ranged from 0% for ear pain,
body vibrations, vision problems, and irritability to 44% for vertigo and 50% for hearing loss.
Of the 24 employees who reported symptoms that they thought were related to unusual sounds or
vibrations at the site, 9 (38%) saw a health care provider. One employee reported being hospitalized.
Of the nine employees who saw a health care provider, we reviewed the relevant medical records of five
(56%) employees who agreed to making them available for review.
Some employees had plausible (i.e., possible and medically reasonable) alternative explanations for
auditory or vestibular symptoms. Of the 14 employees who reported auditory symptoms, 2 (14%) had a
plausible alternative explanation for their auditory symptoms. Of the 9 employees who reported
vestibular symptoms, 3 (33%) had a plausible alternative explanation for their vestibular symptoms.
The proportion of employees working primarily in rooms facing the flares who reported symptoms was
similar to the proportion of other interviewed employees who reported symptoms (P = 0.21). Similar
results were obtained for auditory symptoms (P = 0.60) and vestibular symptoms (P = 0.64).

B-7

The 24 employees who reported symptoms that they thought were related to unusual sounds or
vibrations consisted of 19 (79%) administrative building employees and 5 (21%) men’s shelter
employees. This breakdown was not statistically different from the proportion of administrative
building employees (63%) and men’s shelter employees (37%) interviewed (P = 0.13). Similar results
were obtained when comparing each symptom individually.

Headache
Anxiety
Lightheadedness
Ear pressure
Difficulty with concentration
Tinnitus
Nausea
Vertigo
Irritability
Fatigue
Ear pain
Chest pressure
Balance problems
Vibrations in the body
Hearing loss
Nasal congestion or sinus pressure
Malaise
Vision problems
Vomiting
Other

19
14
12
11
9
9
9
9

Symptom

6
6
6
4
4
4
4
3
2
2
1
4
0

5

10

15

20

Number of employees reporting symptom

Figure B4. Bar graph showing that among the symptoms reported by employees as being related to
unusual sounds or vibrations at work, headache, anxiety, and lightheadedness were the most common.

Methods: Employee Perceptions of the Handling of the Loud Noise Situation
We asked employees several questions about their perceptions and experience of the events that led to
their workplace being evacuated/relocated. Employees were asked each question twice, once focusing
on the nonprofit organization, and once focusing on the county. These questions included, “Do you
have any concerns about how the situation was handled by the nonprofit organization/the county,”
“Are you satisfied with the nonprofit organization/the county’s communication to employees about the
B-8

situation,” and “Do you trust the nonprofit organization/the county to care for your health and safety
at work?” Each response was recorded as yes, no, or unsure, and was followed by an open-ended
question asking for an explanation of the response. We also asked employees a yes/no question about
whether they were comfortable with returning to work at the vacated locations. If the response was
“no” or “unsure,” it was followed by an open-ended question: “what would be needed for you to feel
comfortable returning to work [at the site]?”
Open-ended responses were analyzed to report common themes, which were then tallied to report the
number of employees expressing similar concerns. Employees’ responses may have been tallied into one
or more themes. If fewer than three employees reported a particular concern, it is not reported in order
to protect employee confidentiality.

Results: Employee Perceptions of the Handling of the Loud Noise Situation
Table C3 shows the yes/no/unsure responses to questions about employee perceptions of how the
situation was handled by the nonprofit organization and the county.
When asked if they had concerns about how the situation was handled by the nonprofit organization,
12 (26%) replied “yes.” When interviewed employees were given the opportunity to explain their
response, 25 employees provided more detail. Eight (32%) employees replied with a positive comment
about how the nonprofit organization handled the situation. The most common concern (n = 7; 28%)
was that the men’s shelter was not evacuated until months after the administrative building was
evacuated. When asked if they had concerns about how the situation was handled by the county,
27 (59%) employees replied “yes.” When given the opportunity to explain their response, 32 employees
provided more detail. The most common concerns being a perception that the county did not take the
situation seriously (n = 10; 31%); a lack of communication about the situation (n = 9; 28%); and the
length of time it took to evacuate the men’s shelter (n = 7; 22%).
Most interviewed employees (n = 35; 76%) reported that they were satisfied with communication from
the nonprofit organization. Twenty-eight employees provided more detail about their response, and a
quarter of the responses (n = 7) were positive in nature. The most common concerns reported were
being unsure of what plans were moving forward (n = 6; 21%); a perceived lack of transparency from
the nonprofit organization (n = 4; 14%); wanting more information about how the situation was being
assessed (n = 3; 11%), and a perception that the information was being shared informally (e.g., “office
gossip”; n = 3; 11%). Most of the interviewed employees (n = 28; 61%) were not satisfied with
communication from the county, and another 14 (30%) were unsure. Thirty-five employees provided
more detail about their response, with the most common response (n = 27; 77%) being that there was
no communication from the county. The next most frequent response (n = 4; 11%) was that the county
was taking too long to share information.
Most of the interviewed employees (n = 42; 91%) reported that they trusted the nonprofit organization
to care for their health and safety at work. Twenty-eight employees provided more detail about their
response, with the most common responses (n = 21; 75%) being positive in nature (e.g., “they look out
for us and are supportive”). One-third (n = 15; 33%) of the interviewed employees reported that they
trusted the county to care for their safety and health, while another four (9%) said they were unsure.

B-9

Thirty-two employees provided more detail about their response, with the most common responses
being that nothing was being done because the situation was not being taken seriously (n = 8; 25%) and
the perception that the county does not care about the nonprofit organization (n = 7; 22%). Six (19%)
of the comments were positive in nature.
When asked whether they would be comfortable returning to work at the vacated campus, 25 of
44 interviewed employees (57%) said “no,” and 19 (43%) said “yes.” Thirty-two employees provided a
response when asked what it would take to make them comfortable enough to return, with the most
common responses being that there is nothing that could be done to alleviate their concerns (n = 12;
38%); if testing is completed that shows the campus is objectively “safe” (n = 9; 28%); or if the
problem is “fixed” (n = 8; 25%). Others mentioned they would be comfortable returning if the
vibrations stopped (n = 5; 16%) or if the odor in the administrative building was no longer present
(n = 5; 16%).

Discussion
Low frequency noise is usually defined as sound occurring at frequencies below 200 Hz. Sound in
frequencies below 20 Hz is referred to as infrasound. Although audible sound for humans is generally
considered to range from 20 to 20,000 Hz, with the greatest sensitivities across frequencies of 500 to
8,000 Hz, research has shown that sounds below 20 Hz are audible if the sound pressure level is high
enough. Watanabe and Moller [1990] showed that hearing thresholds in the infrasound frequencies
ranged from 107 dB at 4 Hz to 88 dB at 16 Hz. In contrast, hearing thresholds at 200 Hz are under
20 dB and may be at or near audiometric 0 dB for people with no hearing loss in frequencies from
1,000 to 6,000 Hz.
Low frequency noise and infrasound are omnipresent and rarely, if ever, occur without the concurrent
presence of sound in higher frequencies. Infrasound, particularly at frequencies of 1 Hz or less, is
generated in nature by volcanos, earthquakes, thunder, waterfalls, waves, and wind. Infrasound levels of
up to 110 dB have been measured at wind speeds of approximately 16 miles per hour [Nowacki et al.
2008]. Human activities such as running can generate infrasound levels up to 90 dB, and swimming can
generate infrasound up to 140 dB (both at frequencies < 2 Hz) [von Gierke and Parker 1976].
Infrasound levels in cars have been found to range up to 120 dB, and in helicopters or fixed-wing
aircraft, infrasound levels can range from 120 to 145 dB [Integrated Laboratory Systems 2001].
In workplaces, sources of infrasound and low frequency noise include ventilation systems, air
compressors, turbines, and heavy machinery or equipment. Diesel engines have been shown to generate
sound levels of 110 dB across frequencies of 10 to 20 Hz [Integrated Laboratory Systems 2001]. We
found no information in the research literature on octave band noise levels generated by methane flares.
However, a guidance report on landfill gas flaring for the Scottish Environmental Protection Agency
(SEPA) reported that noise generated by combustion in methane flares was predominately found at
frequencies around 17 Hz [SEPA 2002].
A literature review by Johnson [1982] assessing hearing damage risk from infrasound did not find
evidence of hearing threshold shifts from continuous exposure to infrasound at 140 dB for 30 minutes
nor from continuous exposures to levels of 118 dB or less for 24 hours. However, a sense of pressure

B-10

in the middle ear has been reported to occur at infrasound levels ranging from 127 to 133 dB [Broner
1978]. Subjects in a laboratory study perceived sensations through infrasound vibrations at sound levels
of approximately 130 dB at 4 Hz and 110 dB at 20 Hz [Landstrom et al. 1983].
Tsunekawa et al. [1987] reported perception to a lower level of infrasound (50% response to a threshold
level of 94 dB at 10 Hz) during a field study evaluating perceptions to exposures occurring underneath a
bridge, in an automobile, and near a cooling tower. An early study found that employees exposed for
15 minutes to simulated industrial infrasound at frequencies of 5 Hz and 10 Hz and levels of 100 dB
and 135 dB reported symptoms such as fatigue, ear pressure, poor concentration, drowsiness, and
perception of vibration in internal organs [Integrated Laboratory Systems 2001]. Research has also
reported that symptoms such as headache, sensation of body sway, fatigue, tinnitus, and respiratory
difficulties following exposure to infrasound levels ranging from 100 to 120 dB [Storm 2009]. In
contrast, a study of 145 long-haul truck drivers exposed infrasound of 115 dB did not find that reported
symptoms such as fatigue, vertigo, tinnitus, hearing impairment, headache, abdominal symptoms, or
hypertension were statistically significantly more common when analyzed with respect to exposure and
hours of work, driving, and rest [Kawano et al. 1991].
The ACGIH TLVs are the only U.S. occupational exposure limits established specifically for low
frequency noise and infrasound. TLVs are recommended limits, not enforceable regulatory limits,
established to protect against auditory pain and other auditory, respiratory, and cardiac responses. They
represent sound exposures to which it is believed that nearly all workers may be exposed without
adverse effects that do not involve hearing [ACGIH 2019]. The ACGIH has established two TLVs:
(1) a ceiling limit of 145 dB for one-third octave band frequencies from 1 to 80 Hz and (2) a ceiling
limit of 150 dB for overall sound pressure levels for frequencies from 1 to 80 Hz. A ceiling limit should
not be exceeded at any time. The TLV documentation further notes that low frequency noise exposure
across frequencies of 50 to 60 Hz are in the chest resonance range and can cause whole-body vibration
which could lead to discomfort and annoyance. ACGIH advises that under these conditions, the sound
pressure level may need to be reduced to a level to where these problems are alleviated [ACGIH 2019].
Though only applicable to infrasound exposures for space craft and space stations, the National Air and
Space Administration (NASA) has established an exposure limit of 120 dB across the frequency range
of 1 to 16 Hz for 24-hour exposure [NASA 1995].
Our one-third octave band noise level measurement results clearly show that the predominant noise
frequencies generated by an operating methane flare were at the one-third octave band center
frequencies of 20 Hz and secondarily at the adjacent center band frequencies of 16 Hz and 25 Hz.
These results were similar to the predominant frequency (17 Hz) reported in a guidance document on
landfill gas flaring prepared for SEPA [SEPA 2002]. The wavelength of sound waves is inversely
proportional to frequency, with high frequencies having short wavelengths and low frequencies having
long wavelengths. Because of the exceptionally long wavelength of low frequency noise (e.g., sound at
20 Hz has a wavelength of almost 56 ft), it is able travel long distances, is difficult to stop with barriers
or enclosures because of diffraction and surface propagation, and is minimally attenuated by common
building structures.

B-11

The predominance of noise from the flares across these low frequencies is a function of the turbulence
generated by the combination of methane gas and air-flow through the flare burners, the combustion
process (combustion roar and combustion instability), and the effect of the hollow flare stack
configuration (resonant acoustic characteristics) as heated air moves upward toward the top of the
stack. Combustion roar is related to how much fuel is burned and the rate of burn. Combustion
instability is related to an imbalance that occurs when too much air is introduced relative to the waste
gas stream, which can periodically disrupt the flame, resulting in generation of low frequency
rumbling-type noise [Fleifil et al. 2011]. Noise from combustion roar and combustion instability are
characteristically generated at low frequencies, with combustion instability typically at lower frequencies
than combustion roar. The factors leading to both combustion roar and combustion instability create
turbulence. As turbulence increases, sound levels also tend to increase. Combustion roar and
combustion instability can potentially be reduced by optimizing the waste gas and air mixture, using low
noise burners or flare tips, and reducing the velocity of the waste gas stream, when feasible.
All of our indoor and outdoor measurements were well below the ACGIH TLV ceiling values for low
frequency noise. All of our measurement results were also well below levels reported in the research
literature as likely to cause adverse health effects.
While several case studies have reported subjective symptoms such as headaches, feelings of pressure in
the head or ears, body vibration, concentration difficulties, or fatigue [Waye 2011] associated with
infrasound, many research studies have shown noise-related annoyance is one of the main effects from
exposure to infrasound [Andresen and Moller 1984; Broner 1978; Moller 1984; Pawlaczyk-Luszczynska
et al. 2009; Waye and Rylander 2001]. In contrast, some researchers have reported that high sound
levels in the frequencies of 30 to 80 Hz [Broner and Levanthall 1983; Levanthall 2003] or 25 to 63 Hz
[Waye 2011] may have a greater influence on annoyance than high levels of infrasound or at frequencies
above these ranges. Waye et al. [2001] reported that annoyance was correlated with subjective
estimation of symptoms such as tiredness, dizziness, poor concentration, and sensation of pressure on
the head when low frequency noise conditions occurred in the workplace. Although unrelated to
workplace exposure, a more recent systematic review and evaluation of observational studies of an adult
population living near a source of low frequency noise and infrasound suggests an association between
self-reported annoyance and symptoms such as sleep-related problems, difficulty concentrating, and
headaches [Baliatsas et al. 2016].
Our comparison of one-third octave band measurements when a flare was operating versus when a flare
was not operating showed the influence of noise generated by the flares within the buildings on the
campus, particularly across the frequencies 16 to 25 Hz. The levels across these frequencies in the
administrative building were 12 to 17 dB higher when the flares were operating compared to when the
flares were not operating. The frequency-specific or overall sound levels we measured are not known to
cause adverse health effects. However, complaints of annoyance due to low frequency noise tend to be
associated with an unbalanced noise spectrum [Broner 2010; Broner and Leventhall 1983], which can
occur when sound levels in the low frequencies are higher relative to the sound levels in the
higher frequencies.

B-12

One method for assessing the potential for the likelihood of annoyance complaints due to low
frequency noise is a comparison of overall C-weighted to A-weighted sound pressure levels.
C-weighting and A-weighting refer to different metrics for measuring and integrating noise across the
frequency spectrum. Because humans do not perceive loudness equally across all frequencies and have
diminished perception of loudness at low frequencies, A-weighted sound level measurements
approximate equal loudness characteristics of human hearing for pure tones relative to a reference of
40 dB at 1,000 Hz [Earshen 2000]. C-weighting is a measure of noise across all frequencies, similar to
linear weighting, except for slight attenuation at frequencies below 50 Hz and above 5,000 Hz. At
frequencies above 500 Hz, A- and C-weighting are quite similar. Researchers have suggested that a
C-A difference of 20 dB or more is indicative of an unbalanced noise spectrum and potential low
frequency noise problems and low frequency noise annoyance complaints [Broner 2010; Broner and
Leventhall 1983].
Our results showed that the C-A differences in the administrative building ranged from 17 to 38 dB
(median: 29 dB). The C-A differences in the shelter ranged from 12 to 20 dB (median: 16 dB). These
results indicate that annoyance may be more likely for occupants of the administrative building than for
occupants of the men’s shelter. During interviews, 89% of employees who reported experiencing
unusual sounds or vibration in the administrative building stated they occurred before the February
2019 incident, whereas 27% of employees who reported experiencing unusual sounds or vibrations in
the men’s shelter stated they noticed them before the May 2019 incident. It is important to note that
during our measurements, the administrative and men’s shelter buildings were unoccupied. If these
buildings had been fully occupied, it is highly likely that the sound levels, particularly in frequencies
above 500 Hz, would have been higher due to the occurrence of conversation (which is generally in the
500 to 2,000 Hz range) and other daily activities. This would likely have the effect of diminishing the
C-A differences.
In addition to our comparison of overall C-A differences suggesting that annoyance due to low
frequency noise might be likely in the administrative building, we also compared our results to
European guidelines for assessing low frequency noise and infrasound in indoor environments
(Figure B3). We found that one-third octave band levels when a flare was in operation were below
British guidelines (Note: The Swedish guidelines, which cover 31.5 to 200 Hz, are identical to the
British guidelines). However, levels were above Polish guidelines at 20 Hz, 25 Hz, and 50–250 Hz.
These findings provide additional support to the potential for annoyance from low frequency noise.
Interestingly, at some of the low frequencies above 63 Hz we found that levels exceeded German,
Dutch, and Polish guidelines, even when the flares were off. Contribution of low frequency noise from
nearby city traffic could be a factor in these results.
Our measurements only provide sound level results and noise frequency characteristics during normal
operating conditions of the flares at the time of our site visit. During the reported loud noise events, it
is possible that the frequency characteristics of the noise may have been similar to those we measured,
with the highest levels around 20 Hz and adjacent one-third octave band frequencies. However, the
actual sound levels and frequency characteristics are unknown in the absence of measurements using
proper instruments. Based on employees’ descriptions and reported sensory experiences, sound levels
were likely higher during those events than those we measured during the site visit.
B-13

Approximately half of the employees we interviewed reported symptoms that they thought were related
to unusual sounds or vibrations. It is likely that different subsets of employees have different
explanations for their symptoms. First, some employees might have developed symptoms during or
after the February and May 2019 incidents, which were described as loud sounds or intense vibrations.
Auditory symptoms, such as hearing loss, ear pain, tinnitus, and ear pressure, can occur after exposure
to loud noise, such as after a concert. Vestibular symptoms after exposure to low frequency sound or
infrasound are less commonly reported in the scientific literature. One study found exposure to noise at
5 Hz and 16 Hz at 95 dB for 5 minutes affected body sway, suggesting that infrasound might affect
inner ear function and balance [Takigawa et al. 1988]. Superior semicircular canal dehiscence syndrome
is a rare condition in which patients experience vertigo induced by sound or pressure. Patients also have
other signs and symptoms such as nystagmus (abnormal eye movements), pulsatile tinnitus, and hearing
internal body sounds. Superior semicircular canal dehiscence syndrome is caused by an abnormal
thinning or opening in one of the bony canals of the inner ear. While the exact cause of this syndrome
is unknown, those who discovered it believe it is congenital; exposure to sound or pressure has not
been posited as a cause [Ward et al. 2017]. The interviews and medical records reviewed did not suggest
that vestibular symptoms among employees were due to this condition.
Second, some symptoms reported by interviewed employees as predating the incident in their primary
area are consistent with symptoms reported in studies about background low frequency noise, such as
headache, fatigue, difficulties with concentration, vibrations in the body, and ear pressure in the absence
of specific incidents [Pawlaczyk-Luszczynska et al. 2009; Waye 2011]. However, many of these
symptoms are also common, nonspecific, and might have multiple causes. Third, some employees with
auditory or vestibular symptoms had a plausible alternative explanation for their symptoms based on
their medical history. Most employees did not undergo medical evaluation and medical records for
some evaluated employees were not available, which might have led to missed opportunities to identify
plausible alternative explanations.
Over half (57%) of the interviewed employees reported that they were uncomfortable with returning to
work at the vacated campus. Their perceived risk and lack of willingness to return should be considered
when the nonprofit organization and county are discussing whether to return to work at the vacated
campus. Having employees return to work at a location that they perceive as unsafe may represent a
breach of psychological contract, or the implicit agreement that the employer will value and care for the
worker in exchange for good work [Morrison and Robinson 1997; Rousseau 1995]. Breach in
psychological contract often results in employees feeling violated, and it diminishes trust in an
organization. Further, such breaches in psychological contract are associated with undesirable
organizational outcomes, such as increased turnover intentions and absenteeism, counterproductive
behaviors, decreased willingness to go “above and beyond” one’s role to benefit an organization,
decreased job satisfaction, and decreased in-role performance [Shen et al. 2019; Zhao et al. 2007].

Limitations
It was not possible during our site visit to characterize sound levels or noise frequency characteristics
that occurred at the time of the February and May 2019 incidents. Our measurements were done during
normal flare operations and in campus buildings that were unoccupied because employees and shelter
B-14

clients had been relocated, and no similar loud noise events occurred during the site visit. However, we
were able to measure differences and estimate the effects of a methane flare being on and off without
background noise. Employees’ interview responses were based on self-report and occurred
approximately 1–4 months after the incident, which may have resulted in decreased recall. In addition,
the incidents might have influenced employees’ perceptions of whether symptoms were related to
unusual sounds or vibrations. Not all relevant medical records for employees who reported symptoms
were available for review. Statistical tests might not have been able to detect significant differences due
to the relatively small number of employees.

Conclusions
We found that the overall and one-third octave band noise frequency measurement results during the
site visit were well below levels reported in the research literature as likely to cause adverse health
effects. The operating flares generated noise primarily in the low frequencies, particularly across the
frequencies of 16 to 25 Hz, which influenced frequency-specific sound levels in the nearby buildings.
The relatively greater noise levels in low frequencies compared to levels in higher frequencies resulted in
a spectrum imbalance that exceeded some European guidelines. This imbalance also increased the
likelihood of noise-related annoyance concerns, particularly in the administrative building. Many
employees reported symptoms that they thought were related to unusual sounds and vibrations at the
workplace, but different explanations for symptoms among different employees were likely. Employees
were concerned about communication issues surrounding the incidents, and over half of the employees
reported that they were uncomfortable returning to work at the vacated campus.

B-15

Section C: Tables
Table C1. Low frequency noise and infrasound levels across one-third octave band frequencies 6.3 to 80 Hz (dB) while flares were operating
Measurement location

6.3 Hz

8.0 Hz

10.0 Hz

12.5 Hz

16.0 Hz

20.0 Hz

25.0 Hz

31.5 Hz

40.0 Hz

50.0 Hz

63.0 Hz

80.0 Hz

Overall sound
pressure level

Admin bldg. Room 100

51.5

52.0

52.2

55.4

60.4

62.9

60.5

45.6

36.5

39.5

35.4

35.0

67.0

Admin bldg. Room 101

52.6

53.0

57.5

56.8

59.2

71.4

66.9

47.3

39.1

41.4

40.3

35.5

73.2

Admin bldg. Room 102

50.8

50.1

58.9

62.6

56.4

63.0

60.8

47.0

35.0

41.3

33.1

34.5

68.1

Admin bldg. Room 103

49.6

51.1

57.0

56.2

62.6

65.5

62.9

48.8

41.9

43.6

45.2

39.7

69.3

Admin bldg. Room 105

55.8

56.0

54.4

55.1

56.9

70.0

57.9

50.2

46.6

44.1

44.9

41.5

71.0

Admin bldg. Room 108

55.0

57.9

58.5

55.0

53.8

68.9

59.4

46.5

40.9

40.6

39.5

31.9

70.4

Admin bldg. Room 109

59.7

59.3

59.9

57.6

54.2

63.7

57.9

46.0

40.9

41.2

42.6

36.0

68.2

Admin bldg. Room 110

54.3

57.0

51.5

60.1

53.4

63.0

59.1

42.5

33.7

35.2

36.5

33.1

67.0

Admin bldg. Room 113

54.9

55.8

54.2

51.6

49.6

60.5

51.5

43.7

37.4

37.4

32.3

29.0

63.9

Admin bldg. Room 117

57.1

56.7

53.1

53.4

57.3

60.9

53.9

45.0

38.6

33.8

37.5

37.9

65.4

Admin bldg. Room 118

49.9

51.4

51.3

52.5

48.9

62.1

60.1

44.5

35.7

38.2

33.3

33.1

65.2

Admin bldg. Room 121

50.7

54.6

54.3

50.3

56.2

64.7

58.8

50.3

41.5

42.2

38.7

35.5

67.0

Admin bldg. Room 123

55.9

55.3

58.1

56.1

59.5

63.3

53.8

46.6

44.5

43.4

46.7

47.4

67.2

Shelter bldg. Main room

48.3

52.0

53.8

53.1

50.5

64.6

62.9

52.3

47.8

48.7

46.9

46.1

67.8

Shelter bldg. Socializing room

56.7

56.8

53.7

54.3

54.2

60.4

51.4

48.4

50.3

49.5

46.3

45.6

65.2

Shelter bldg. Check-in desk

52.0

52.2

52.1

53.2

59.5

63.2

60.7

51.6

48.3

47.1

43.3

41.6

67.1

Shelter bldg. Office area

54.0

58.5

60.8

58.2

56.7

65.6

58.4

48.6

44.8

38.4

40.7

36.0

68.9

Shelter bldg. Intake office

47.8

49.7

52.9

54.5

55.2

62.9

58.6

48.3

43.7

37.0

41.1

38.9

65.7

Parking lot - Location A

60.2

62.9

68.9

72.0

76.2

84.9

79.7

68.1

66.8

62.2

63.1

62.9

86.9

Parking lot - Location B

61.3

61.5

61.3

63.2

67.6

76.9

77.1

61.2

59.8

58.3

57.7

54.9

80.6

Parking lot - Location C

62.0

60.4

64.3

69.8

73.8

80.3

75.0

67.6

60.6

61.4

61.2

57.7

82.7

Parking lot - Location D

60.5

62.4

62.1

64.8

68.7

78.1

72.4

63.1

62.4

57.9

58.4

57.4

80.1

Grill area

53.4

55.0

57.8

60.4

64.8

75.8

70.7

60.2

61.2

56.9

57.1

56.1

77.7

Smoking hut

56.0

57.7

63.8

67.4

68.3

81.3

74.1

65.9

63.2

59.1

58.0

55.9

82.6

Blower #2 (6 ft from blower)

65.0

70.6

75.3

76.5

71.8

84.6

80.4

68.3

76.5

72.5

72.6

61.1

87.7

Flare #1 (10 ft from flare)

69.1

72.3

76.5

81.1

79.7

91.2

83.5

71.3

74.4

70.8

67.6

67.1

92.8

At flare control panel

63.2

68.1

74.5

80.2

82.4

94.2

87.7

76.5

74.7

66.6

66.4

53.1

95.6

City road behind shelter

70.4

69.3

71.6

69.4

67.3

71.5

66.2

66.6

65.1

68.1

80.3

71.5

83.0

City road across from public
storage business

64.2

62.4

60.4

60.1

60.6

66.0

61.9

61.5

63.0

65.2

69.9

67.3

75.5

ACGIH ceiling limits

145 (frequency dependent)

C-1

150 (overall)

Table C2. C-weighted and A-weighted sound level measurement results and their differences in the
administrative and shelter buildings
Measurement location

C-weighted
sound level (dBC)

A-weighted
sound level (dBA)

dBC-dBA difference
(dB)

Admin bldg. Room 100

60.4

27.1

33.3

Admin bldg. Room 101

67.2

28.8

38.4

Admin bldg. Room 102

60.7

26.5

34.2

Admin bldg. Room 103

63.1

39.8

23.3

Admin bldg. Room 105

64.6

30.5

34.1

Admin bldg. Room 108

63.7

28.3

35.4

Admin bldg. Room 109

59.9

29.0

30.9

Admin bldg. Room 110

59.7

37.7

22

Admin bldg. Room 113

55.9

39.2

16.7

Admin bldg. Room 117

57.3

36.1

21.2

Admin bldg. Room 118

59.1

31.3

27.8

Admin bldg. Room 121

60.8

31.8

29

Admin bldg. Room 123

59.8

34.6

25.2

Shelter bldg. Main room

62.4

42.6

19.8

Shelter bldg. Socializing room

58.7

43.8

14.9

Shelter bldg. Check-in desk

61.4

45.2

16.2

Shelter bldg. Office area

61.9

45.6

16.3

Shelter bldg. Intake office

60.2

48.0

12.2

C-2

Table C3. Employee perceptions of how the loud noise situation was handled by the nonprofit organization
and the county (n = 46)
Question

Nonprofit organization
Number
(%)

County
Number
(%)

Unsure

Yes

No

Unsure

Yes

No

Do you have concerns about how the
situation was handled by the ____?

3
(7)

12
(26)

31
(67)

7
(15)

27
(59)

12
(26)

Are you satisfied with ____’s communication
to employees about the situation?

1
(2)

35
(76)

10
(22)

14
(30)

4
(9)

28
(61)

Do you trust _____ to care for your health
and safety at work?

0
(0)

42
(91)

4
(9)

4
(9)

15
(33)

27
(59)

C-3

Section D: References
Low Frequency Noise and Infrasound
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LH, Royster JD, Driscoll DP, Layne M, eds. The noise manual. 5th rev. ed. Fairfax, VA: American
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D-1

NASA [1995]. Man-systems integration standards: NASA-STD-3000. Vol. 1, Sec. 5. Natural and
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D-2

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D-3

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PRESS RELEASE
N° 213
12 June 2012

IARC: DIESEL ENGINE EXHAUST CARCINOGENIC
Lyon, France, June 12, 2012 ‐‐ After a week-long meeting of international experts, the International
Agency for Research on Cancer (IARC), which is part of the World Health Organization (WHO), today
classified diesel engine exhaust as carcinogenic to humans (Group 1), based on sufficient evidence
that exposure is associated with an increased risk for lung cancer.
Background
In 1988, IARC classified diesel exhaust as probably carcinogenic to humans (Group 2A). An Advisory Group
which reviews and recommends future priorities for the IARC Monographs Program had recommended
diesel exhaust as a high priority for re-evaluation since 1998.
There has been mounting concern about the cancer-causing potential of diesel exhaust, particularly based
on findings in epidemiological studies of workers exposed in various settings. This was re-emphasized by
the publication in March 2012 of the results of a large US National Cancer Institute/National Institute for
Occupational Safety and Health study of occupational exposure to such emissions in underground miners,
which showed an increased risk of death from lung cancer in exposed workers (1).
Evaluation
The scientific evidence was reviewed thoroughly by the Working Group and overall it was concluded that
there was sufficient evidence in humans for the carcinogenicity of diesel exhaust. The Working Group
found that diesel exhaust is a cause of lung cancer (sufficient evidence) and also noted a positive
association (limited evidence) with an increased risk of bladder cancer (Group 1).
The Working Group concluded that gasoline exhaust was possibly carcinogenic to humans (Group 2B), a
finding unchanged from the previous evaluation in 1989.
Public health
Large populations are exposed to diesel exhaust in everyday life, whether through their occupation or
through the ambient air. People are exposed not only to motor vehicle exhausts but also to exhausts from
other diesel engines, including from other modes of transport (e.g. diesel trains and ships) and from power
generators.
Given the Working Group’s rigorous, independent assessment of the science, governments and other
decision-makers have a valuable evidence-base on which to consider environmental standards for diesel
exhaust emissions and to continue to work with the engine and fuel manufacturers towards those goals.
Increasing environmental concerns over the past two decades have resulted in regulatory action in North
America, Europe and elsewhere with successively tighter emission standards for both diesel and gasoline
engines. There is a strong interplay between standards and technology – standards drive technology and
new technology enables more stringent standards. For diesel engines, this required changes in the fuel
such as marked decreases in sulfur content, changes in engine design to burn diesel fuel more efficiently
and reductions in emissions through exhaust control technology.
However, while the amount of particulates and chemicals are reduced with these changes, it is not yet
clear how the quantitative and qualitative changes may translate into altered health effects; research into

Page 2

IARC: Diesel engines exhaust carcinogenic
this question is needed. In addition, existing fuels and vehicles without these modifications will take many
years to be replaced, particularly in less developed countries, where regulatory measures are currently
also less stringent. It is notable that many parts of the developing world lack regulatory standards, and
data on the occurrence and impact of diesel exhaust are limited.
Conclusions
Dr Christopher Portier, Chairman of the IARC working Group, stated that “The scientific evidence was
compelling and the Working Group’s conclusion was unanimous: diesel engine exhaust causes lung
cancer in humans.” Dr Portier continued: “Given the additional health impacts from diesel particulates,
exposure to this mixture of chemicals should be reduced worldwide.“(2)
Dr Kurt Straif, Head of the IARC Monographs Program, indicated that “The main studies that led to this
conclusion were in highly exposed workers. However, we have learned from other carcinogens, such as
radon, that initial studies showing a risk in heavily exposed occupational groups were followed by positive
findings for the general population. Therefore actions to reduce exposures should encompass workers
and the general population.”
Dr Christopher Wild, Director, IARC, said that “while IARC’s remit is to establish the evidence-base for
regulatory decisions at national and international level, today’s conclusion sends a strong signal that
public health action is warranted. This emphasis is needed globally, including among the more vulnerable
populations in developing countries where new technology and protective measures may otherwise take
many years to be adopted.”
Summary evaluation
The summary of the evaluation will appear in The Lancet Oncology as an online publication ahead of print
on June 15, 2012.
(1) JNCI J Natl Cancer Inst (2012) doi:10.1093/jnci/djs034
http://jnci.oxfordjournals.org/content/early/2012/03/05/jnci.djs034.abstract; and
JNCI J Natl Cancer Inst (2012) doi: 10.1093/jnci/djs035
http://jnci.oxfordjournals.org/content/early/2012/03/05/jnci.djs035.abstract
(2) Dr Portier is Director of the National Center for Environmental Health and the Agency for Toxic
Substances and Disease Registry at the Centers for Disease Control and Prevention (USA).

For more information, please contact
Dr Kurt Straif, IARC Monographs Section, at +33 472 738 507, or [email protected];
Dr Lamia Tallaa, IARC Monographs Section, at +33 472 738 385, or [email protected];
Nicolas Gaudin, IARC Communications Group, at +33 472 738 478, or [email protected];
Fadela Chaib, WHO News Team, at +41 79 475 55 56, or [email protected].
Link to the audio file posted shortly after the media briefing:
http://terrance.who.int/mediacentre/audio/press_briefings/

About IARC
The International Agency for Research on Cancer (IARC) is part of the World Health Organization. Its
mission is to coordinate and conduct research on the causes of human cancer, the mechanisms of
carcinogenesis, and to develop scientific strategies for cancer control. The Agency is involved in both
epidemiological and laboratory research and disseminates scientific information through publications,
meetings, courses, and fellowships.

IARC, 150 Cours Albert Thomas, 69372 Lyon CEDEX 08, France - Tel: +33 (0)4 72 73 84 85 - Fax: +33 (0)4 72 73 85 75
© IARC 2012 - All Rights Reserved.

Page 3

IARC: Diesel engines exhaust carcinogenic
Annexes

Evaluation groups - Definitions
Group 1: The agent is carcinogenic to humans.
This category is used when there is sufficient evidence of carcinogenicity in humans. Exceptionally, an
agent may be placed in this category when evidence of carcinogenicity in humans is less than sufficient
but there is sufficient evidence of carcinogenicity in experimental animals and strong evidence in exposed
humans that the agent acts through a relevant mechanism of carcinogenicity.
Group 2.
This category includes agents for which, at one extreme, the degree of evidence of carcinogenicity in
humans is almost sufficient, as well as those for which, at the other extreme, there are no human data but
for which there is evidence of carcinogenicity in experimental animals. Agents are assigned to either
Group 2A (probably carcinogenic to humans) or Group 2B (possibly carcinogenic to humans) on the basis
of epidemiological and experimental evidence of carcinogenicity and mechanistic and other relevant data.
The terms probably carcinogenic and possibly carcinogenic have no quantitative significance and are
used simply as descriptors of different levels of evidence of human carcinogenicity, with probably
carcinogenic signifying a higher level of evidence than possibly carcinogenic.


Group 2A: The agent is probably carcinogenic to humans.
This category is used when there is limited evidence of carcinogenicity in humans and sufficient
evidence of carcinogenicity in experimental animals. In some cases, an agent may be classified in
this category when there is inadequate evidence of carcinogenicity in humans and sufficient
evidence of carcinogenicity in experimental animals and strong evidence that the carcinogenesis
is mediated by a mechanism that also operates in humans. Exceptionally, an agent may be
classified in this category solely on the basis of limited evidence of carcinogenicity in humans. An
agent may be assigned to this category if it clearly belongs, based on mechanistic considerations,
to a class of agents for which one or more members have been classified in Group 1 or Group 2A.



Group 2B: The agent is possibly carcinogenic to humans.
This category is used for agents for which there is limited evidence of carcinogenicity in humans
and less than sufficient evidence of carcinogenicity in experimental animals. It may also be used
when there is inadequate evidence of carcinogenicity in humans but there is sufficient evidence of
carcinogenicity in experimental animals. In some instances, an agent for which there is
inadequate evidence of carcinogenicity in humans and less than sufficient evidence of
carcinogenicity in experimental animals together with supporting evidence from mechanistic and
other relevant data may be placed in this group. An agent may be classified in this category solely
on the basis of strong evidence from mechanistic and other relevant data.

Group 3: The agent is not classifiable as to its carcinogenicity to humans.
This category is used most commonly for agents for which the evidence of carcinogenicity is inadequate in
humans and inadequate or limited in experimental animals.
Exceptionally, agents for which the evidence of carcinogenicity is inadequate in humans but sufficient in
experimental animals may be placed in this category when there is strong evidence that the mechanism of
carcinogenicity in experimental animals does not operate in humans.
Agents that do not fall into any other group are also placed in this category.
An evaluation in Group 3 is not a determination of non‐carcinogenicity or overall safety. It often means that
further research is needed, especially when exposures are widespread or the cancer data are consistent
with differing interpretations.

IARC, 150 Cours Albert Thomas, 69372 Lyon CEDEX 08, France - Tel: +33 (0)4 72 73 84 85 - Fax: +33 (0)4 72 73 85 75
© IARC 2012 - All Rights Reserved.

Page 4

IARC: Diesel engines exhaust carcinogenic
Group 4: The agent is probably not carcinogenic to humans.
This category is used for agents for which there is evidence suggesting lack of carcinogenicity in humans
and in experimental animals. In some instances, agents for which there is inadequate evidence of
carcinogenicity in humans but evidence suggesting lack of carcinogenicity in experimental animals,
consistently and strongly supported by a broad range of mechanistic and other relevant data, may be
classified in this group.

Evidence for studies in humans - Definition
As shown previously, the evidence relevant to carcinogenicity is evaluated using standard terms. For
studies in humans, evidence is defined into one of the following categories:
Sufficient evidence of carcinogenicity: The Working Group considers that a causal relationship has
been established between exposure to the agent and human cancer. That is, a positive relationship has
been observed between the exposure and cancer in studies in which chance, bias and confounding could
be ruled out with reasonable confidence. A statement that there is sufficient evidence is followed by a
separate sentence that identifies the target organ(s) or tissue(s) where an increased risk of cancer was
observed in humans. Identification of a specific target organ or tissue does not preclude the possibility that
the agent may cause cancer at other sites.
Limited evidence of carcinogenicity: A positive association has been observed between exposure to
the agent and cancer for which a causal interpretation is considered by the Working Group to be credible,
but chance, bias or confounding could not be ruled out with reasonable confidence.
Inadequate evidence of carcinogenicity: The available studies are of insufficient quality, consistency or
statistical power to permit a conclusion regarding the presence or absence of a causal association
between exposure and cancer, or no data on cancer in humans are available.
Evidence suggesting lack of carcinogenicity: There are several adequate studies covering the full
range of levels of exposure that humans are known to encounter, which are mutually consistent in not
showing a positive association between exposure to the agent and any studied cancer at any observed
level of exposure. The results from these studies alone or combined should have narrow confidence
intervals with an upper limit close to the null value (e.g. a relative risk of 1.0). Bias and confounding should
be ruled out with reasonable confidence, and the studies should have an adequate length of follow‐up. A
conclusion of evidence suggesting lack of carcinogenicity is inevitably limited to the cancer sites,
conditions and levels of exposure, and length of observation covered by the available studies. In addition,
the possibility of a very small risk at the levels of exposure studied can never be excluded.

In some instances, the above categories may be used to classify the degree of evidence related to
carcinogenicity in specific organs or tissues.

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Department of Community Development
Reference: Community Benefit Incentives Land Use and Development Code
Amendment
To:

Mark Rawlings & Members of the Planning Commission

Through:

Shannon McDowell, Asst. Dir. of Community Development

Prepared By:

Shawn Weiman, Affordable Housing Coordinator

Date Prepared:

June 29, 2026

PURPOSE
To propose an amendment to the City of Brighton (the “City”) Land Use &
Development Code (the “Code”) regarding incentives to promote development of
certain types of housing.
BACKGROUND
The Code under Section 5.08 Community Benefit Incentives promotes housing that
accommodates different abilities and stages of life and that is offered for sale at a
wide range of price points including below the median income. However, the
eligibility criteria and incentives are either obsolete, do not adequately incentivize
the desired housing, are unclear, or are inapplicable. It was also discovered that
the incentives have not been utilized since 2020 when they were included in the
current Code.
During a June 9, 2026, study session with the City Council and the Planning
Commission, City staff recommended housing strategies required by the State of
Colorado for inclusion in a Housing Action Plan (the “HAP”). Also, it was pointed out
that the recommended strategies are identical or closely aligned with strategies
outlined in the City Housing Needs Assessment (the “HNA”). In addition, the HNA
recommends that Code Section 5.08 be rewritten to:
1. Provide zoning-related concessions for affordable housing,
2. Significantly reduce the objectives of diverse housing since development
constraints prohibit eligibility,
3. Provide lot open space (also referred to as open lot area) reductions, and
4. Provide incentives that can be approved on an administrative level.
Reorganizing housing incentives so they can be more quickly adapted to changing
conditions was also proposed during the June 9, 2026, study session. This approach
removes housing incentives from the Code and puts them in a format that can be
adopted and then amended from time to time by the City Council.
1

SUMMARY OF THE AMENDMENT
The following modification is proposed: Delete Section 5.08 Community Benefit
Incentives in its entirety and replace it with Section 5.08 Housing Incentives that does
not outline eligibility or incentives but allows for the establishment of incentives by
the City Council via resolution that may reduce, remove, or modify requirements of
the Code.
CODE AMENDMENT PROCESS
The Code amendment process allows for the initiation of amendments by the City
Council, Planning Commission, and City Staff on behalf of these entities. Proposed
Code amendments are first introduced at a study session to understand whether
they should be refined and brought forward for consideration. Code amendments
are then reviewed at a public hearing before the Planning Commission, who make
a recommendation to the City Council. The City Council holds a public hearing to
consider the amendments. Code amendments are approved by ordinance.
In considering the proposed amendments, the Planning Commission should use the
review criteria outlined in Code Section 2.10(B): (1) the amendment furthers the
purposes of the Code; (2) the amendment is in accordance with the
Comprehensive Plan and has been considered for both its long-range effects and
immediate impacts; (3) the amendment promotes the health, safety, and welfare
of the community of the City of Brighton; and (4) the amendment improves the
effectiveness and efficiency of administering the Code.
CRITERIA BY WHICH THE PLANNING COMMISSION MUST CONSIDER THE ITEM
Code amendments shall be reviewed according to the criteria appearing below;
Staff analysis of the amendments’ compliance follows each criterion.
1. The amendment furthers the purposes of the Code listed in Section 1.01(C).
The amendment furthers the purposes of the Code by implementing the
Comprehensive Plan, namely by providing a diversity of housing types for the full
spectrum of incomes and needs including homes that allow aging-in-place (Plan
pages #3-18, #4-9, and #4-21) and by creating incentives for infill development
(Plan page #4-6).
2. The amendment is in accordance with the Comprehensive Plan and has been
considered for both its long-range effects as well as immediate impacts.
The amendment is consistent with the Comprehensive Plan by supporting the
development of diverse and accessible housing that is available to a wide range of
incomes.
2

3. The amendment promotes the public safety, health, and general welfare of
the community of the City.
The amendment promotes the health, safety, and welfare of the community by
promoting housing that is more affordable and accessible to more residents and
that benefits from existing street and utility infrastructure.
4. The amendment improves the effectiveness and efficiency of administering
the Code.
The amendment improves the effectiveness of administering the Code by replacing
the current ineffective incentives with a means by which a housing incentive
program can be adopted and adapted more easily.
STAFF RECOMMENDATION
Staff find that the proposed Code amendment generally meets the review criteria
outlined in Section 2.10(B) of the Code, enables implementation of Comprehensive
Plan, HNA, and HAP strategies and, therefore, recommend approval of the Code
amendment.
PUBLIC NOTICE AND INQUIRY
Notice of the public hearing was published on the City website on July 21, 2026, at
least 15 days prior to the public hearing, as required by Section 2.01(F) of the
Code.
OPTIONS FOR PLANNING COMMISSION CONSIDERATION
The Planning Commission has four options when reviewing the Code Amendment
application and may:
1. Approve the resolution recommending approval of the Code amendment;
2. Deny the resolution recommending approval of the Code amendment;
3. Approve the resolution recommending approval of the Code amendment
with changes; or
4. Continue the item to be heard at a later, specified date if the Planning
Commission feels it needs additional information to ensure compliance with
the approval criteria as set forth in the Code.
ATTACHMENTS
● Draft Planning Commission Resolution
● Website Notice
● Website Publication Proof
● Draft PowerPoint Presentation
● Draft Code Amendment

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RESOLUTION NO. ______________
A RESOLUTION OF THE PLANNING COMMISSION OF THE CITY OF BRIGHTON,
COLORADO, CONSIDERING A RECOMMENDATION TO THE CITY COUNCIL TO
AMEND ARTICLE 5 OF THE LAND USE AND DEVELOPMENT CODE RELATING TO
HOUSING INCENTIVES
WHEREAS, the City of Brighton (the “City”) Land Use and Development
Code (the “LUDC”) includes housing incentives which are designed to encourage
the development of housing that serves a range of life stages and income levels,
including housing that is affordable to households earning below the area
median income; and
WHEREAS, the housing incentives are intended to advance broader citywide housing policies and help achieve regional housing goals; and
WHEREAS, City staff have examined the current housing incentives and
have found that the eligibility criteria and incentives are obsolete, do not
adequately incentivize the desired housing, are unclear, or are inapplicable; and
WHEREAS, during a June 9, 2026, joint study session with the City Council
and the Planning Commission, City staff presented recommendations to amend
the LUDC to align the housing incentives with the State of Colorado Housing
Action Plan and the City’s Housing Needs Assessment; and
WHEREAS, the Planning Commission held a duly noticed public hearing on
August 13, 2026, to consider the proposed amendments to the housing incentives;
and
WHEREAS, in accordance with the public notice requirements of the LUDC,
a notice of public hearing was published on the City’s website for no less than
fifteen (15) days prior to the Planning Commission public hearing; and
WHEREAS, at the public hearing, the Planning Commission received and
considered all relevant evidence and testimony from City staff and other
interested parties, including the public at large; and
WHEREAS, the Planning Commission has reviewed the proposed
amendments to the LUDC and has found that the amendments, as provided
herein, are in the best interest of the public health, safety, and welfare of the
residents of the City.
NOW THEREFORE, BE IT RESOLVED by the Planning Commission of the City of
Brighton, Colorado, as follows:

Section 1. The Planning Commission hereby recommends that Section
5.08 of the LUDC be amended as follows:
5.08 - Housing Incentives
The City may approve incentives for the development of certain housing types.
Any such incentives shall be set forth by resolution by the City Council, may be
amended from time to time, and may reduce, remove, or modify requirements in
this Code. Housing incentives may be subject to administrative or City Council
approval.
Section 2. The Planning Commission finds and determines that the
proposed amendments set forth herein: (i) further the purpose of the LUDC; (ii) are
in accordance with the Comprehensive Plan and have been considered for both
their long-range effects and immediate impacts; (iii) promote the public safety,
health, and general welfare of the community of the City of Brighton; and (iv)
improve the effectiveness and efficiency of administering the LUDC.
Section 3.

This Resolution is effective as of the date of its adoption.

RESOLVED this 13th day of August 2026.
CITY OF BRIGHTON, COLORADO
PLANNING COMMISSION

Mark Rawlings, Chairperson
ATTEST:

Jon Waines, Secretary
APPROVED AS TO FORM:

James Gallagher, Assistant City Attorney

NOTICE OF PUBLIC HEARING
PLANNING COMMISSION
CITY OF BRIGHTON
COMMUNITY BENEFIT INCENTIVES AMENDMENTS
Notice is hereby given that the Planning Commission of the City of Brighton will hold a
public hearing regarding Land Use and Development Code amendments related to
incentives for accessible, affordable, and diverse housing, referred to in the Code as
community benefit incentives.
The Planning Commission will hold a public hearing to consider the amendments at 6:00
p.m. on Thursday, August 13, 2026. The hearing will take place in the City Council
Chambers, located on the first floor of City Hall, 500 South 4th Avenue in Brighton, CO.
The Planning Commission will hear evidence from City staff and any interested parties and
will make a recommendation on the amendments thereafter.
Further information may be obtained from the City of Brighton Planning Division located
at the above address or by calling (303) 655-2072.
Public comments must be received at least 24 hours prior to the hearing time.
For publication: Before Wednesday, July 29, 2026

5.08 Community Benefit Incentives
A.

Design Objective. Community Benefits Incentives have the following design objectives:
1.

Ensure that housing for different stages of life are integrated into neighborhoods in a
manner that provides the opportunity for aging populations to participate in activities
of the broader community.

2.

Provide a wide variety of price points within neighborhoods such that entry-level and
move-up housing options are available to meet housing needs, and neighborhoods
are more resilient to changing demographic or economic conditions.

3.

Meet housing needs for populations earning below the median income.

4.

Disperse and diversify a variety of housing types, including community benefit
housing, throughout the community and in some cases within neighborhoods.

B.

Applicability. This section offers guidance to meeting broader city-wide housing policies
and achieving regional housing benchmarks. It is primarily guidance for potential
incentives when projects achieve critical benchmarks when analyzing projects within their
surrounding context, or for projects with significant capacity and critical mass of units that
could meet them within the project.

C.

Accessibility, Diversity and Affordability Thresholds. The following are thresholds for
housing mixes that achieve the design objectives and provide a mix of accessible and
affordable housing.
1.

Accessible Housing. Within a neighborhood (or approximately ½-mile area), or within
a specific project proposing accessible housing, at least 10% of total units should be
accessible. Accessible units may be reduced to 5% of the total if at least 10% percent
are visitable or constructed under a universal design standard. Accessible units shall
include:
a.

At least one external entrance at grade or accessible by wheelchair. Note front
entry features meeting the design standards should integrate access ramps in
subtle ways that meet the streetscape design objectives, and these strategies
may be justifications for deviations to the frontage type and entry feature
standards. Additionally side or rear at grade access, or access with lifts may be
acceptable if it has the same convenience relative to the overall site layout.

b.

The main floor has at least 1 bedroom and a laundry and bathroom.

c.

The floor plan and unit design has all doorways at least 3 feet wide,

d.

Fixtures and service areas with grab bars, light switches, thermostats and other
environmental controls are placed in accessible locations.

e.

Other features that are wheelchair compatible for routine daily living as may be
recommended by the latest version of the American National Standards for
buildings and facilities providing accessibility and usability for physically
handicapped people.

2.

3.

D.

Diverse Housing. Within a neighborhood (or approximately ½ mile area), or within a
specific project proposing attainable housing, there should be a diversity of housing
stock to meet different housing needs, different demographic preferences and
different price points. Diverse housing should include:
a.

At least 4 distinct housing types within the neighborhood. Each category should
be at least 10% of the overall mix and no single type should be more than 60% of
the overall mix.

b.

At least 3 different price points, one of which is considered "attainable." Unless
specifically defined in an official report or study, attainable is generally housing
that is available to households between 80% and 100% of the area median
income, through financing or rent that is no more than 40% of that monthly
income. At least 25% of the mix should be "attainable."

c.

Different types should be integrated into a neighborhood pattern so that all
housing has access to the same level of amenity and quality of neighborhood
design.

Affordable Housing. Within a neighborhood (or approximately ½-mile area), or within
a specific project proposing affordable housing, at least 15% of total units should be
affordable. Affordable units shall include:
a.

Units meeting the parameters for household size, income levels and a maximum
housing expenditure defined by the City Council.

b.

The City Council may determine that this criteria is met by projects with a wide
variety of price points and housing types in the same project or neighborhood, in
a manner that adequately supports entry-level, market rate housing, and where
no housing type comprises more than 30% of units in the entire project.

c.

A statement shall be included with market research, applicable price points of
units and housing types in relation to that research, and a strategy to ensure that
the units are developed in a manner to hit various price points and affordability
thresholds shown in the data and market research.

Incentives. Projects meeting these thresholds may receive the following incentives, in
addition to any additional incentive defined by official policy or project-specific approval of
the City Council.
1.

A density bonus of at least 15% in units above what is allowed for the district or
building type; with site plan review by the Planning Commission and City Council, this
increase may be up to 25%.

2.

An increase in the allowed building height of up to 2 stories; however, additional
setbacks or step-backs of upper stories may be required.

3.

Reduction in the open space requirements or fees by 20%; with site plan review by
the Planning Commission and City Council, this may be reduced further up to 50%.

E.

4.

When any of these incentives are used in combination, the project shall require
Planning Commission and City Council review of the application.

5.

If incentives are granted for a mix of attainable housing, the City may require by
contract or other restriction that assures for specific thresholds for accessible,
attainable or affordable housing are met.

Accessibility Requirements. Accessible housing units shall be provided for all residential
developments containing duplexes, multi-unit houses, row houses, apartments or mixeduse residential buildings. The rate of accessible units shall be 1 accessible unit for every 7
units in the development. Any phasing of construction shall not affect the required
accessible housing ration.

5.08 Housing Incentives
The City may approve incentives for the development of certain housing types. Any such
incentives shall be set forth by resolution by the City Council, may be amended from time
to time, and may reduce, remove, or modify requirements in this Code. Housing
incentives may be subject to administrative or City Council approval.

Community Benefit Incentives
Land Use & Development Code
Amendments
PLANNING COMMISSION PUBLIC HEARING
August 13, 2026
City Staff Representative:

Shawn Weiman, Affordable Housing Coordinator

Purpose
To propose an amendment to the Land Use & Development Code
(the “Code”) regarding community benefit incentives.

2

Background
During a joint study session
before the City Council and the
Planning Commission on June 9,
2026, Code amendment
concepts regarding housing
incentives were presented.

3

Background – Housing Strategy
●

The City Housing Needs Assessment recommends revising the
Community Benefit Incentives to encourage affordable housing
production and remove barriers to diverse housing
development.

●

Housing Action Plan strategies include adding a density bonus,
incentivizing accessible units, and supporting housing for larger
households.

●

The Comprehensive Plan strategies include incentivizing infill
development.
4

Staff Analysis
Staff found that:
1. The current Community Benefit Incentives have not been utilized
since 2020 when they were included in the current code.
2. The incentives are either obsolete, subject to interpretation, or
inapplicable.
3. Affordable housing impact fee reduction incentives adopted by
resolution currently function outside of the Code.

5

Staff Recommendations
Staff recommend rewriting the current Community Benefit
Incentives and bundling the incentives into a Housing
Incentives program adopted and revised by resolution.

• Incentives can be adapted to changing conditions
more quickly.

• Incentives will be consolidated into one document.
• A Housing Incentives program will enable
implementation of Comprehensive Plan, Housing
Needs Assessment, and Housing Action Plan
strategies.

6

Functions of the Amendment
1. Removes the current obsolete, unclear, and unused
incentives.
2. Puts in place a provision for adopting housing incentives
that may reduce, remove, or modify requirements of the
Code.
3. Establishing new housing incentives is not a function of the
amendment. This is planned as a separate process to be
proposed at a later time.

7

Housing Incentives Concept
“Community Benefits Incentives”
include Accessible, Diverse,
and Affordable Housing

Infill Housing

Lower-Cost New Housing

HOUSING INCENTIVES
8

Code Amendment Processes
●

Code allows City Staff to initiate amendments on behalf of the City Council
and Planning Commission.

●

Code states that an amendment shall be reviewed according to the
following criteria:
1.

The amendment furthers the purposes of these regulations in Section
1.01.C.

2.

The amendment is in accordance with the Comprehensive Plan and
has been considered for both its long-range effects as well as
immediate impacts.

3.

The amendment promotes the public safety, health, and general
welfare of the community in the City of Brighton.

4.

The amendment improves the effectiveness and efficiency of
administering the Land Development Code.

9

Code Amendment Criteria
The amendments meet the review criteria by:

•

Furthering the purpose of the Code by implementing the Comprehensive Plan,
namely by providing a diversity of housing types for the full spectrum of incomes
and needs including homes that allow aging-in-place and by creating incentives
for infill development;

•

Being in accordance with the Comprehensive Plan by supporting the
development of diverse and accessible housing that is available to a wide range
of incomes;

•

Promoting the health, safety, and general welfare of the community by promoting
housing that is more affordable and accessible to more residents and that
benefits from existing street and utility infrastructure; and

•

Improving the effectiveness and efficiency of administering the Code by
replacing the current ineffective incentives with a means by which a housing
incentive program can be adopted and adapted more easily.
10

City Staff Recommendation
Staff find that the presented code amendments
generally meet the review criteria outlined in Section
2.10.B Review Criteria of the LUDC as well as
enables implementation of Comprehensive Plan,
HNA and HAP strategies and recommend approval
of the code amendments.

Public Notice & Comment
Notice of the public hearing was published on the City of Brighton
website on July 21, 2026, at least 15 days prior to the public
hearing, as required by Section 2.01.F of the LUDC.

11

Options for Planning Commission
1.

Approve the resolution recommending approval of the code
amendment;

2.

Deny the resolution recommending approval of the code
amendment;

3.

Approve the resolution recommending approval of the code
amendment with changes; or

4.

Continue the item to be heard at a later, specified date if the
Planning Commission feels it needs additional information to
ensure compliance with the approval criteria as set forth in
the Land Use & Development Code.
12

THANK YOU
Questions?

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