Arcata City Council
June 3, 2026

CITY OF ARCATA

CITY COUNCIL MEETING
AGENDA

Wednesday, June 3, 2026, 6:00 p.m.

Council Chamber
736 F Street, Arcata
Special accommodations for the disabled who attend City meetings can be made in advance by contacting the City Clerk at 822-5953. Assistive listening devices are available. _____________________________________________________________________________________ Pursuant to Government Code section 54957.5, all writings or documents relating to any item on this agenda which have been provided to a majority of the City Council, including those received less than 72 hours prior to the City Council meeting, will be made available for public inspection in the agenda binder located on the counter in the lobby at Arcata City Hall, 736 F Street, during normal business hours, and on the City's website at www.cityofarcata.org.

PLEASE NOTE: Speakers wishing to distribute materials to the City Council at the meeting are requested to provide 10 copies to the City Clerk.
_____________________________________________________________________________________ How to Observe and Participate in the Meeting:

Observe:

Members of the public can attend the meeting in person or observe the meeting on Zoom (see below), on Access Humboldt Channel 10, online by visiting www.cityofarcata.org and clicking on the See Live Meetings, Agendas, and Archives button on the home page, or on the City’s YouTube channel at https://www.youtube.com/c/CityofArcataCA
Public Comment Participation in Person and on Zoom:

Members of the public may attend the meeting in person and give public comment. Or, they may access the meeting via Zoom to provide public comment.

Join from a PC, Mac, iPad, iPhone or Android device: Please use this URL:
https://us06web.zoom.us/j/86773627430

1. If you want to comment during the public comment portion of any item, click on raise your hand on the right-hand side of your screen. When it is time for public comment on the item on which you wish to speak, the Clerk will unmute you. You will have 3 minutes to comment (2 minutes for Early Oral Communications), subject to the Mayor’s discretion.

2. Or join by phone:

1. *67 1-669-900-6833

2. Enter Meeting ID: 867 7362 7430
If you are accessing the meeting via telephone and want to comment during the public comment portion of any item, press star (*) 9 on your phone. This will raise your hand. When it is time for public comment on the item on which you wish to speak, the Clerk will unmute your phone. You will

3. hear a prompt that will indicate your phone is unmuted. You will have 3 minutes to comment (2 minutes for Early Oral Communications), subject to the Mayor’s discretion.

1. LAND ACKNOWLEDGMENT

2. FLAG SALUTE

3. ROLL CALL

4. CEREMONIAL MATTERS
a. Proclamation in Recognition of World Oceans Day, June 8, 2026. b. Proclamation in Celebration of the Fourth of July Jubilee, July 4, 2026. c. Proclamation Designating June 7–13, 2026, as the Week of the Oyster. d. Proclamation Recognizing June 2026 as National Alzheimer's and Brain Awareness Month. e. Proclamation Recognizing June 2026 as Pride Month.

5. REPORT BY COMMISSION/COMMITTEE

6. STAFF REPORTS
All reports shall be specifically limited to City business and shall not request or lead to action by the Council at this meeting.
a. Receive an Update Regarding the City's Excessive Residential Electricity Users Tax from Deputy Director of Environmental Services—Community Services Emily Benvie.

7. ORAL AND WRITTEN COMMUNICATIONS [EARLY - TIME LIMITED] The City Council values your comments. The public comment period allows people to address the Council on matters not on the agenda. This early section of public comment is limited to 15-minutes and speakers are limited to 2 minutes each. If you prefer to have a full 3 minutes of time for your public comment, this item is continued at the end of the meeting under item 12 where speakers are granted 3 minutes. Please know that pursuant to the Brown Act, the Council cannot discuss or take action on items not listed on the agenda. The Council may respond to statements. There will also be a time to provide public comment specific to each item when that item is being reviewed by the Council.

8. N/A

9. CONSENT CALENDAR
All matters on the Consent Calendar are considered to be routine by the City Council and are enacted in one motion. There is no separate discussion of any of these items. If discussion is required, that item is removed from the Consent Calendar and considered separately. At the end of the reading of the Consent Calendar, Council members can request that an item be removed for separate discussion.

Members of the public may comment on any items remaining on the consent calendar in the comment period before the vote.
a. Approval to Waive Reading of the Text and Consent to Read by Title Only for Any Ordinance on this Agenda.
b. Approve the Minutes of the City Council Special Meeting Study Session of May 13, 2026.

June 3, 2026 - City Council Agenda

c. Approve the Minutes of the City Council Special Meeting of May 20, 2026. d. Approve the Minutes of the City Council Meeting of May 20, 2026. e. Bi-Weekly Report on Disbursements.
f. Award a Contract for the 2026 Digester Cleaning Project to Synagro-WWT, Inc. in the Amount of $462,885.80; and Approve Necessary and Associated Related Actions. g. Make a Continued Finding that Emergency Procurement to Repair Failed Culverts at 4700 West End Road is Necessary; and Authorize the City Manager to Execute All Applicable Documents.
h. Approve an Amendment to the Contract with Civic Possible for the Economic Strategic Plan Update to Add $13,000 for Additional Scope – Not Subject to the California Environmental Quality Act.
i. Approve the Purchase of Solar Trail Lights from Fonroche for the Arcata Annie and Mary Trail Project in the Amount of $99,544.54; and Approve Necessary and Associated Related Actions.
j. Adopt Resolution No. 256-67 Designating the City Manager, Assistant City Manager, or City Engineer as the City’s Agents Authorized to Submit Applications for Federal Financial Assistance for Any Future or Existing Grant Program.
k. Adopt Resolution No. 256-71 Approving a Temporary Hiring Freeze for Vacant Positions to Address Fiscal Conditions, Reduce the Current Budget Deficit, and Preserve General Fund Reserves; and Approve Necessary and Associated Related Actions. l. Adopt Resolution No. 256-68 Approving a Voluntary Retirement Health Incentive Program for City of Arcata Employees; and Approve Necessary and Associated Related Actions. m. Adopt Resolution No. 256-69 Approving A Corrected Letter of Agreement Between the City of Arcata and Arcata Police Association to Amend the 2024–2027 Memorandum of Understanding Regarding Medical Benefits; and Authorize City Manager to Execute Documents.

10. OLD BUSINESS
a. Hold a Hearing to Consider Abatement for the Properties Located at 4600 West End Road, Arcata, CA 95521, Assessor's Parcel No. 507-081-055; and Terminate Abatement Proceedings Due to the Property Owner Having Successfully Abated the Nuisance. b. Receive a Presentation on the Final Arcata Wastewater Treatment Facility (AWTF) Feasibility Study and Potential Future Projects at the AWTF; and Provide Direction to Staff on a Preferred Alternative.

11. NEW BUSINESS
a. Appoint One New Member to the Energy Committee for a Term Expiring on Either September 30, 2027, or September 30, 2028; Appoint One New Member to the Forest Management Committee for a Term Expiring March 31, 2029; and Appoint Two New Members to the Wetlands and Creeks Committee for Terms Expiring March 31, 2028, and March 31, 2029.
b. Hold a Public Hearing to Review the City of Arcata 2025 Updated Urban Water Management Plan and Water Shortage Contingency Plan.
c. Hold a Public Hearing to Consider Adopting Resolution No. 256-65 Adopting the City of June 3, 2026 - City Council Agenda

Arcata 2025 Updated Urban Water Management Plan and Water Shortage Contingency Plan.

12. ORAL AND WRITTEN COMMUNICATIONS [CONTINUED]
The City Council values your comments. The public comment period allows people to address the Council on matters not on the agenda. Speakers will be limited to 3 minutes each. Please know that pursuant to the Brown Act, the Council cannot discuss or take action on items not listed on the agenda. The Council may respond to statements.

13. CITY MANAGER'S REPORT

14. COUNCIL REPORTS
All reports shall be specifically limited to items relating to City business and shall not request or lead to action by the Council at this meeting.

15. DATES OF FUTURE MEETINGS AND FUTURE AGENDA ITEMS
a. Confirm a Special Meeting Study Session with the Planning Commission Regarding a Land Use Code Update for June 8, 2026, at 5:00 p.m. in the Council Chamber. b. Schedule a Special Meeting Study Session to Discuss the City's Economic Strategic Plan on Monday, June 15, 2026, at 2:00 p.m. in the Council Chamber.

16. CLOSED SESSION

17. CLOSED SESSION REPORTS

18. ADJOURNMENT
Other than items continued or tabled to a date certain, the Council may, by majority vote, continue all matters not completed by 10:30 p.m.

June 3, 2026 - City Council Agenda

Proclamation
in Recognition of

WORLD OCEANS DAY
June 8, 2026
WHEREAS, the ocean provides one half of the oxygen we breathe, regulates our climate and provides us with food, water and economic support. World Oceans Day is an annual opportunity to honor the world's oceans by building awareness of the crucial role the ocean plays in our lives; and
WHEREAS, the people of Humboldt County can help protect our ocean’s future by partnering and volunteering with local schools and organizations such as Surfrider Humboldt, Humboldt Waterkeeper, Friends of the Dunes, and the Environmental Protection Information Center; and WHEREAS, the City of Arcata’s Environmental Services Department also organizes opportunities year round to help clean our creeks and improve watershed health by keeping trash from entering Humboldt Bay, thus reducing the impact of marine debris on ocean ecosystems.

NOW, THEREFORE, BE IT PROCLAIMED that the City Council of the City of Arcata hereby recognizes June 8, 2026, to be WORLD OCEANS DAY in Arcata and encourages the community to participate in coastal and watershed clean-up days throughout the year.

Dated: June 3, 2026
_______________________________
Stacy Atkins-Salzar
Vice-Mayor

Proclamation
in Celebration of the

FOURTH OF JULY JUBILEE
July 4, 2026
WHEREAS, the City of Arcata, known for its vibrant community spirit and commitment to fostering local businesses, recognizes the importance of celebrating our nation’s independence and the contributions of our local commerce; and WHEREAS, the Arcata Chamber of Commerce has organized a grand event to commemorate this significant day with a festive celebration that brings together businesses, residents, and visitors alike; and
WHEREAS, the Jubilee promises to be a day filled with joy, camaraderie, and entertainment, featuring activities, live music, local artisans, and food vendors that highlight the diverse talents of our local community; and WHEREAS, this event not only provides an opportunity for our community members to come together and enjoy the festive atmosphere but also acts as a catalyst for the growth and success of our local economy, creating a platform for businesses to showcase their offerings and gain exposure to a wider audience; and
WHEREAS, the Jubilee is the longest-running event on the Arcata Plaza dating back over 150 years.

THEREFORE, BE IT RESOLVED that the City Council of the City of Arcata encourages all residents to attend the Arcata Chamber of Commerce’s FOURTH OF JULY JUBILEE on the Arcata Plaza on Saturday, July 4, 2026.

Dated: June 3, 2026

Stacy Atkins-Salzar
Vice-Mayor

Proclamation
Designating June 7–13, 2026
The week of the Oyster
WHEREAS, the Arcata Chamber of Commerce, to showcase Arcata’s relationship to its highquality water resources and Arcata and Humboldt Bays, is producing the 36th Annual Arcata Bay Oyster Festival on Saturday, June 13, 2025, to be held on the Plaza and throughout Arcata. The Arcata Chamber of Commerce recognizes the City of Arcata and the City of Eureka’s significant efforts to improve and maintain water quality in Humboldt Bay, which supports aquaculture, plant and fish populations, and many recreational activities; and WHEREAS, our local aquaculture industry farms over 450 acres of Arcata Bay to produce the highest quality and largest quantity of oysters in the State of California; and WHEREAS, the Arcata Chamber of Commerce’s Arcata Bay Oyster Festival attracts visitors from all over the nation and the State of California to enjoy our natural bounty, culinary talent, entertainers, and downtown ambiance. This event is an important showcase for the community and contributes significantly to the local economy through tourism while increasing awareness of local resource conservation and our City’s unique identity and varied hospitality services; and WHEREAS, this year, the entire community is invited to attend this event on the Plaza featuring live music from 10 a.m.–5 p.m. on Saturday, June 13th. Participants are encouraged to dance the day away, taste the unique culinary creations, join the Oyster Calling and Shuck and Swallow Contests, check out the Black Humboldt Block, and more! There will also be a map showcasing where to find your favorite oysters and artisans, local wines and spirits, and thousands of fellow revelers celebrating our wonderful town.

NOW, THEREFORE, BE IT PROCLAIMED that the City Council of the City of Arcata hereby designates June 7–13, 2026, as THE WEEK OF THE OYSTER and encourages all community members to enjoy the food, fun, music, and frolic at The Arcata Chamber of Commerce’s 36th Annual Oyster Festival on the Arcata Plaza on Saturday, June 13.

Dated: June 3,2026
__________________________________
Stacy Atkins-Salzar
Vice-Mayor

Proclamation
Recognizing June 2026 as
National Alzheimer’s and

BRAIN AWARENESS MONTH
WHEREAS, the Alzheimer’s Association is encouraging people of all ages to take charge of their brain health through positive daily actions. As research advances, it’s increasingly clear that taking proactive steps early — and consistently — can make a meaningful difference; and WHEREAS, while awareness is high, a gap remains in understanding what to do. Nearly 9 in 10 Americans say brain health is important, yet only 1 in 10 know how to maintain it. Evidence shows that healthy habits — including regular physical activity, a balanced diet, social and cognitive engagement and routine health monitoring — may help reduce the risk of cognitive decline; and
WHEREAS, the importance of early detection is also growing. Only about half of people living with Alzheimer’s are diagnosed, limiting access to care and support. New advances, including emerging blood tests and treatments that can slow disease progression in early stages, highlight why timely diagnosis matters more than ever; and
WHEREAS, Alzheimer’s disease is a local issue. Our friends and neighbors need access to support services and resources to lessen the disease’s impact. In Humboldt County, it is estimated that 3,589 people currently live with Alzheimer’s and related dementia. There are another 8,500 caregivers who are caring for a loved one with Alzheimer's; and WHEREAS, throughout June, the Alzheimer’s Association invites individuals and partners to take action — whether by learning about brain health, adopting healthy habits, raising awareness by going purple, supporting fundraising efforts, volunteering, or advocating for early detection and research. Together, these efforts can help drive progress and support families impacted by Alzheimer’s.

NOW, THEREFORE, BE IT PROCLAIMED by the City Council of the City of Arcata recognizes June 2026 as ALZHEIMER’S AND BRAIN AWARENESS MONTH. The Council thanksthe Alzheimer’s Association for providing services to people and families coping with dementia.

Dated: June 3, 2026
______________________________
Stacy Atkins-Salzar
Vice-Mayor

Proclamation
Recognizing June 2026 as

PRIDE MONTH
WHEREAS, the City of Arcata recognizes the month of June as Pride Month, honoring the rich histories, contributions, and ongoing struggles of Two-Spirit, Lesbian, Gay, Bisexual, Transgender, Queer, Intersex, Asexual, and all gender-expansive individuals (2S/LGBTQIA+); and
WHEREAS, Pride Month commemorates the 1969 Stonewall Uprising—an act of resistance against police brutality led by Black and Brown trans women, femmes, and queer youth, including trailblazers such as Marsha P. Johnson and Sylvia Rivera—whose courage ignited a global movement for liberation and dignity; and
WHEREAS, the legacy of Pride is rooted in protest, mutual aid, and collective resilience in the face of criminalization, state violence, and societal exclusion, especially for those most marginalized within our communities; and
WHEREAS, today, 2S/LGBTQIA+ people—especially transgender and gender non-conforming individuals, youth, and Black, Indigenous, and People of Color (BIPOC) community members— face escalating threats to their safety, bodily autonomy, and rights under a growing wave of antiLGBTQ+ legislation and rhetoric across the country; and WHEREAS, in the face of this rising hostility, the City of Arcata reaffirms its unwavering commitment to the safety, rights, visibility, and joy of 2S/LGBTQIA+ communities. We recognize that there is no equity without trans liberation, and we stand firmly with our trans comrades and all queer community members as they demand dignity, protection, and full inclusion in public life; and
WHEREAS, the City honors the invaluable contributions of 2S/LGBTQIA+ people in the arts, education, public service, business, and social justice movements, and commits to amplifying these voices through policy, funding, celebration, and community-driven change.

NOW, THEREFORE, BE IT PROCLAIMED, that the City Council of the City of Arcata hereby recognizes June as Pride Month, and urges all residents to uplift and celebrate the resilience, brilliance, and leadership of 2S/LGBTQIA+ people. We call on our community to not only celebrate Pride, but to defend it—through action, solidarity, and a shared commitment to justice for all.

Dated: June 3, 2026
Stacy Atkins-Salazar
Vice-Mayor

1 CITY OF ARCATA

SPECIAL CITY COUNCIL MEETING STUDY SESSION

MINUTES
May 13, 2026, 3:30 p.m.

Council Chamber
736 F Street, Arcata

Present: Mayor White, Vice Mayor Atkins-Salazar, Councilmember Matthews, Councilmember Schaefer

Absent: Councilmember Stillman
Staff Present: City Manager Perry, Assistant City Manager Miller, Chief of Police Ortega, City Engineer Khatri, Director of Community Development Loya, Human Resources/Administrative Services Director Vink, Assistant City Engineer Caisse, Deputy Director of Community Development Dart, Deputy Director of Environmental Services— Community Services Benvie, Deputy Director of Environmental Services—Streets and Utilities Culbert, Deputy Director of Information Technology Savage, Police Business Manager Brazil, City Clerk Varley, Executive Assistant/Deputy City Clerk Redfern
A special meeting of the City Council of the City of Arcata was held on the above date at 3:33 p.m. with Mayor White presiding. Notice of this meeting was posted on May 11, 2026. _____________________________________________________________________

1. CALL TO ORDER
Mayor White called the meeting to order at 3:33 p.m.

2. LAND ACKNOWLEDGMENT
Mayor White read a statement acknowledging that Arcata sat on ancestral Wiyot land.

3. ROLL CALL
City Clerk Varley called roll.

4. PUBLIC COMMENT
Mayor White invited public comment.

Public Comment: Joanne McGarry.

Mayor White closed the public comment period.

2 5. DISCUSSION
a. Review the General Fund Fiscal Year 2026-27 Proposed Budget; Evaluate Options to Close the Projected Deficit; and Provide Direction to Staff.

Assistant City Manager Miller provided an overview of the proposed budget and potential options to close the projected deficit.

Staff responded to inquiries and comments from the Council.

No action was taken. There was a presentation and discussion only for this item.
b. Review the Transactions and Use Tax (TUTOC) Committee's Recommendation for Measure H Supplemental Budget Requests for Fiscal Year 2026-27; and Provide Direction to Staff.

Assistant City Manager Milller led the Council in Reviewing the Transactions and Use Tax Oversight Committee's recommendations for supplemental budget requests and City Manager recommended reductions.

Staff responded to inquiries and comments from the Council.

No action was taken. There was a presentation and discussion only for this item.
c. Review the City of Arcata Fiscal Year 2026-27 Schedule for Public Hearing and Possible Adoption at the June 17, 2026, Regular City Council Meeting; and Provide Direction to Staff.

Assistant City Manager Miller provided a report
Staff responded to inquiries and comments from the Council.

BY GENERAL CONSENSUS, THE COUNCIL DIRECTED STAFF TO
PROCEED WITH A HIRING FREEZE; TO MOVE FORWARD WITH

THE RECONNECT ARCATA PROJECT WHILE USING A SMALLER
DOLLAR AMOUNT OF $150,000; TO USE THE UNRESERVED FUND
BALANCE TO BALANCE THE FISCAL YEAR 2026/2027 BUDGET; AND TO ADD A POLICY TO INCREASE GENERAL FUND RESERVES TO 50 PERCENT OF OPERATING EXPENSES.

Certain direction was given, but no Council action was taken. There was a presentation and discussion only for this item.

6. ADJOURNMENT
The meeting was adjourned at 4:27 p.m.

Respectfully submmitted,

3 Rhea Varley
City Clerk

1 CITY OF ARCATA

SPECIAL CITY COUNCIL MEETING

MINUTES
Date:

Location:

May 20, 2026, 5:15 p.m.

City Manager's Conference Room
736 F Street, Arcata

Present: Mayor White, Vice Mayor Atkins-Salazar, Councilmember Matthews, Councilmember Schaefer

Absent: Councilmember Stillman
Staff Present: Assistant City Manager Miller, City Engineer Khatri, Director of Community Development Loya, Human Resources/Administrative Services Director Vink, Attorney Schrimp de la Vergne (via teleconference)
A special meeting of the City Council of the City of Arcata was held on the above date at 5:15 p.m. with Mayor White presiding. Notice of this meeting was posted on May 14, 2026. _____________________________________________________________________

1. CALL TO ORDER
Mayor White called the meeting to order at 5:15 p.m.

2. PUBLIC COMMENT
Mayor White invited public comment.

There being none, Mayor White closed the public comment period.

3. CLOSED SESSION
a. CONFERENCE WITH LEGAL COUNSEL––EXISTING LITIGATION,
Pursuant to Government Code Section 54956.9(d)(1). Name of Case: City of Arcata v. AO Kiriki Ben TutMalik Silkiss; and Marc Delany, et al., Humboldt County Superior Court, Case number: CV2401719.

The Council met in closed session in the City Manager's Conference Room. b. CONFERENCE WITH REAL PROPERTY NEGOTIATORS, Pursuant to Government Code Section 54956.8. Property: Assessor's Parcel Nos. 507-251- 039 and -040. Agency Negotiator: City Manager Merritt Perry. Negotiating Party: Emran Essa. Under Negotiation:

2 Price and Terms.

The Council met in closed session in the City Manager's Conference Room. c. CONFERENCE WITH LABOR NEGOTIATORS, Pursuant to Government Code Section 54957.6. Employee Organizations: International Union of Operating Engineers Local No. 3; Arcata Police Association; and Management/Mid-Management/Confidential
Employees. Agency Negotiator: Keira Vink.

The Council met in closed session in the City Manager's Conference Room.

4. CLOSED SESSION REPORTS
a. CONFERENCE WITH LEGAL COUNSEL––EXISTING LITIGATION,
Pursuant to Government Code Section 54956.9(d)(1). Name of Case: City of Arcata v. AO Kiriki Ben TutMalik Silkiss; and Marc Delany, et al., Humboldt County Superior Court, Case number: CV2401719.

The Council entered the Chamber at 5:55 p.m.

RECESS: The Council recessed from 5:55 p.m. to 6:01 p.m.

Mayor White stated that there was nothing to report out from this closed session item.
b. CONFERENCE WITH REAL PROPERTY NEGOTIATORS, Pursuant to Government Code Section 54956.8. Property: Assessor's Parcel Nos. 507-251- 039 and -040. Agency Negotiator: City Manager Merritt Perry. Negotiating Party: Emran Essa. Under Negotiation:

Price and Terms.

Mayor White stated that there was nothing to report out from this closed session item.
c. CONFERENCE WITH LABOR NEGOTIATORS, Pursuant to Government Code Section 54957.6. Employee Organizations: International Union of Operating Engineers Local No. 3; Arcata Police Association; and Management/Mid-Management/Confidential
Employees. Agency Negotiator: Keira Vink.

Mayor White stated that there was nothing to report out from this closed session item.

5. ADJOURNMENT
The meeting was adjourned at 6:01 p.m.

Respectfully submitted,

3 Rhea Varley
City Clerk

1 CITY OF ARCATA

CITY COUNCIL MEETING

MINUTES
May 20, 2026, 6:00 p.m.

Council Chamber
736 F Street, Arcata

Present: Mayor White, Vice Mayor Atkins-Salazar, Councilmember Matthews, Councilmember Schaefer

Absent: Councilmember Stillman
Staff Present: Assistant City Manager Miller, City Engineer Khatri, Director of Community Development Loya, Deputy Director of Environmental Services—Streets and Utilities Culbert, Building Official Bishop, Code Compliance/Permit Technician Garcia, IT and Digital Media Specialist Carrillo, City Clerk Varley
A regular meeting of the City Council of the City of Arcata was held on the above date at 6:01 p.m. as a hybrid meeting, via teleconference utilizing Zoom Video Communications and in person, with Mayor White presiding. Notice of this meeting was posted on May 14, 2026.
_____________________________________________________________________

1. LAND ACKNOWLEDGMENT
Mayor White read a statement acknowledging that Arcata sat on ancestral Wiyot land.

2. FLAG SALUTE
Mayor White led the Pledge of Allegiance.

3. ROLL CALL
City Clerk Varley called roll.

4. CEREMONIAL MATTERS
a. Proclamation in Honor of Kinetic Sculpture Racing, May 23, 2026.

Goosetoph Waddlesworth, Rudabega Queen for the 2026 Kinetic Racing Championship, accepted the proclamation. The proclamation was read by Councilmember Schaefer.

5. REPORT BY COMMISSION/COMMITTEE

2 There was none.

6. STAFF REPORTS
a. Receive an Annual Report from the Arcata Chamber of Commerce.

Meredith Maier, Executive Director of the Arcata Chamber of Commerce, presented the Chamber's annual report.

Arcata Chamber of Commerce Operations & Event Manager, Gloria Baker, and Media Director, Zach Lathouris, presented a Visit Arcata website draft to the Council.

7. ORAL AND WRITTEN COMMUNICATIONS [EARLY - TIME LIMITED] Mayor White invited public comment.

Public Comment: Pat Kanzler, and an unidentified member of the audience.

Mayor White closed the oral and written communications [early - time limited] period.

8. N/A
None.

9. CONSENT CALENDAR
Mayor White invited public comment.

Public Comment: Joanne McGarry.

Mayor White closed the public comment period.

ON MOTION BY MATTHEWS, SECONDED BY SCHAEFER, AND WITH A

FOUR-TO-ZERO VOICE VOTE WITH ONE ABSENCE, THE COUNCIL
ADOPTED THE CONSENT CALENDAR [FOR MAY 20, 2026, AS PRESENTED, ITEMS A THROUGH G]. AYES: WHITE, ATKINS-SALAZAR, MATTHEWS, SCHAEFER. NOES: NONE. ABSENT: STILLMAN. ABSTENTIONS: NONE. a. Approval to Waive Reading of the Text and Consent to Read by Title Only for Any Ordinance on this Agenda.
b. Approve the Minutes of the City Council Special Meeting of May 6, 2026. c. Approve the Minutes of the City Council Meeting of May 6, 2026. d. Bi-Weekly Report on Disbursements.
e. Make a Finding that it is Necessary to Continue Emergency Procurement to Repair Failed Culverts at 4700 West End Road; and Authorize the City Manager to Execute All Applicable Documents.
f. Approve a Letter of Support for Assembly Bill 1821, California Public Records Act: Agency Response Time; and Authorize the Mayor to Sign the Letter.

3 g. Adopt Resolution No. 256-64 Proclaiming June as Lesbian, Gay, Bisexual, Transgender, Queer + Pride Month in the City of Arcata and Authorizing the Two-Spirit Pride Flag to be Flown on the Flagpole at Arcata City Hall During the Month of June.

10. OLD BUSINESS
a. Hold a Hearing to Consider Abatement for the Properties Located at 4600 West End Road, Arcata, CA 95521, Assessor's Parcel No. 507-081-055; and Adopt Resolution No. 256-55 Authorizing the City to Abate Nuisance Conditions and Recover Costs.

Mayor White opened the hearing.

Deputy Director of Environmental Services—Streets & Utilities Culbert provided a report.

Property Owner, Bob Figas, provided testimony.

MATTHEWS MOVED AND SCHAEFER SECONDED TO CONTINUE
THE HEARING TO THE NEXT COUNCIL MEETING ON JUNE 3 AT
6:00 P.M. IN THE COUNCIL CHAMBER.

Mayor White invited public comment.

There being none, Mayor White closed the public comment period.

THE MOTION PASSED ON A FOUR-TO-ZERO VOICE VOTE WITH
ONE ABSENCE. AYES: WHITE, ATKINS-SALAZAR, MATTHEWS,
SCHAEFER. NOES: NONE. ABSENT: STILLMAN. ABSTENTIONS:

NONE.

11. NEW BUSINESS
a. Receive an Update on the Current Status of the City’s Residential Rental Inspection Program and Next Steps.

Building Official Bishop provided an update regarding the City's Residential Rental Inspection Program (RRIP) and proposed changes to the program.

Building Official Bishop discussed proposed changes to the RRIP fee structure and responded to inquiries and comments from the Council.

The Council deliberated regarding the proposed fee structure options.

Mayor White invited public comment.

Public Comment: Joanne McGarry.

Mayor White closed the public comment period.

Acting City Manager Loya, Building Official Bishop, and Code Compliance/Permit Technician Garcia responded to inquiries and comments from the Council.

4 BY GENERAL CONSENSUS, THE COUNCIL AGREED THAT STAFF

SHOULD COME BACK AT A FUTURE MEETING WITH A DRAFT

ORDINANCE REFLECTING PROPOSED CHANGES TO THE RRIP
PROGRAM.

Certain direction was given, but no Council action was taken. There was a presentation and discussion only for this item.

12. ORAL AND WRITTEN COMMUNICATIONS [CONTINUED]
Mayor White invited public comment.

Public Comment: An unidentified member of the audience who provided a written communication to the Council, and Joanne McGarry.

Mayor White closed the oral and written communications [continued] period.

13. CITY MANAGER'S REPORT
There was none.

14. COUNCIL REPORTS
Presenters: Matthews, Schaefer, Atkins-Salazar, and White.

15. DATES OF FUTURE MEETINGS AND FUTURE AGENDA ITEMS
a. Cancel the July 1, 2026, City Council Meeting.

BY GENERAL CONSENSUS, THE COUNCIL CANCELLED THE JULY
1, 2026, CITY COUNCIL MEETING.
b. Confirm a Special Meeting Study Session with the Planning Commission Regarding a Land Use Code Update for June 8, 2026, at 5:00 p.m. in the Council Chamber.

BY GENERAL CONSENSUS, THE COUNCIL CONFIRMED A SPECIAL

MEETING STUDY SESSION WITH THE PLANNING COMMISSION
REGARDING A LAND USE CODE UPDATE FOR JUNE 8, 2026, AT 5:00 P.M. IN THE COUNCIL CHAMBER.

16. CLOSED SESSION
There was none.

17. CLOSED SESSION REPORTS
There were none.

18. ADJOURNMENT
The meeting was adjourned at 7:24 p.m.

Respectfully submitted,

5 Rhea Varley
City Clerk

STAFF REPORT – CITY COUNCIL MEETING
TO: Honorable Mayor and City Council Members
FROM: Tabatha Miller, Assistant City Manager/Finance Director PREPARER: Tabatha Miller, Assistant City Manager/Finance Director DATE: June 3, 2026
TITLE: Bi-Weekly Report on Disbursements.

RECOMMENDATION:

It is recommended that the Council approve the report on disbursements listing for the period May 9, 2026, through May 22, 2026
INTRODUCTION:

Pursuant to Section 37208 of the California Government Code, checks drawn in payment of demands certified by the City Finance Director as conforming to the authorized expenditures set forth in the City Council adopted budget need not be audited by the City Council prior to payment but may be presented to the City Council at the first meeting after delivery.

DISCUSSION:

The attached Disbursements Listing lists the checks and electronic payments that have been paid for the period identified above. The Finance Director certifies that the disbursements were drawn in payment of demands conforming to the adopted budget and that these demands are being presented to the City Council at its first meeting after the delivery of the checks and electronic payments.

BUDGET/FISCAL IMPACT:

The disbursements presented were drawn in payment of demands included within the adopted budget.

RECOMMENDED COUNCIL ACTION:

Approve the report on disbursements listing for the period of May 9, 2026, through May 22, 2026.

Consent Calendar vote.

ATTACHMENTS:

A. Cash Disbursements 5.9.2026-5.22.2026

City of Arcata Bi-Weekly Report on Cash Distributions 5/9/2026-5/22/2026 Check # Vendor Name GL Account Amount Date Description
262890 Ault Jared 204-40-21-51420 $ 322.00 5/13/2026
POST Use of Force Trainer Santa Rosa CA 5/27-
5/29/26
262891 Rogers Christopher 204-40-21-51420 $ 322.00 5/13/2026 POST Use of Force Trainer Santa Rosa CA 5/27-
5/29/26
262892 US Bank 662-60-67-51770 $ 400.00 5/13/2026
262892 US Bank 101-30-31-53300 $ 38.53 5/13/2026
262892 US Bank 209-50-55-54200 $ 36.11 5/13/2026
262892 US Bank 101-40-21-51600 $ 55.12 5/13/2026
262892 US Bank 101-10-03-54200 $ 39.68 5/13/2026
262892 US Bank 662-60-67-51400 $ 1,126.24 5/13/2026
262892 US Bank 101-60-89-54200 $ 22.97 5/13/2026
262892 US Bank 771-50-57-54700 $ 5.40 5/13/2026
262892 US Bank 101-40-21-54200 $ 87.27 5/13/2026
262892 US Bank 550-00-00-24100 $ 500.00 5/13/2026
262892 US Bank 662-60-67-55400 $ 103.24 5/13/2026
262892 US Bank 101-20-07-54200 $ 19.99 5/13/2026
262892 US Bank 101-50-61-57300 $ 40.65 5/13/2026
262892 US Bank 207-50-45-53800 $ 1,114.10 5/13/2026
262892 US Bank 207-50-45-53600 $ 42.28 5/13/2026
262892 US Bank 209-50-55-54200 $ 29.49 5/13/2026
262892 US Bank 662-50-65-51400 $ 977.22 5/13/2026
262892 US Bank 771-50-57-55100 $ 150.80 5/13/2026
262892 US Bank 101-50-41-51400 $ 15.98 5/13/2026
262892 US Bank 662-60-67-51600 $ 0.99 5/13/2026
262892 US Bank 661-50-63-54200 $ 0.99 5/13/2026
262892 US Bank 101-50-81-54200 $ 774.88 5/13/2026
262892 US Bank 661-60-64-53500 $ 277.87 5/13/2026
262892 US Bank 101-40-21-54200 $ 45.19 5/13/2026
262892 US Bank 662-60-67-53300 $ 5.08 5/13/2026
262892 US Bank 204-40-21-51420 $ 820.72 5/13/2026
262892 US Bank 101-40-21-54200 $ 6.16 5/13/2026
262892 US Bank 101-10-15-51430 $ 2,876.50 5/13/2026
262892 US Bank 662-60-67-54200 $ 409.33 5/13/2026
262892 US Bank 101-40-21-51600 $ 158.00 5/13/2026
262892 US Bank 661-50-63-51600 $ 90.00 5/13/2026
262892 US Bank 662-60-67-55300 $ 51.81 5/13/2026
262892 US Bank 771-50-57-54400 $ 35.43 5/13/2026
262892 US Bank 101-50-81-54200 $ 339.72 5/13/2026
262892 US Bank 101-20-07-54200 $ 23.99 5/13/2026
262892 US Bank 101-40-21-54200 $ 66.09 5/13/2026
262892 US Bank 101-50-81-55400 $ 552.92 5/13/2026
262892 US Bank 662-60-67-55300 $ 75.49 5/13/2026
262892 US Bank 101-50-81-51400 $ 900.00 5/13/2026
262892 US Bank 775-10-71-51200 $ 629.16 5/13/2026
262892 US Bank 771-50-57-54700 $ 68.11 5/13/2026
262892 US Bank 101-10-15-51430 $ 29.77 5/13/2026
262892 US Bank 207-50-45-54300 $ 16.53 5/13/2026
262892 US Bank 205-60-87-54200 $ 16.47 5/13/2026
262892 US Bank 771-50-57-54400 $ 88.19 5/13/2026
262892 US Bank 101-50-41-54200 $ 55.05 5/13/2026
262892 US Bank 662-50-65-51500 $ 187.41 5/13/2026
262892 US Bank 101-40-21-51400 $ 53.22 5/13/2026
262892 US Bank 662-60-67-51600 $ 19.99 5/13/2026
262892 US Bank 101-40-21-51500 $ 193.02 5/13/2026
262892 US Bank 661-60-64-54200 $ 80.00 5/13/2026
262892 US Bank 771-50-57-55300 $ 122.45 5/13/2026
262892 US Bank 771-50-57-54400 $ 32.60 5/13/2026
262892 US Bank 661-60-64-53300 $ 18.71 5/13/2026
262892 US Bank 775-10-71-55300 $ 273.38 5/13/2026
262892 US Bank 775-10-71-51770 $ 456.13 5/13/2026
262892 US Bank 771-50-57-55100 $ 450.00 5/13/2026
262892 US Bank 204-40-21-51420 $ 12.00 5/13/2026
262892 US Bank 775-10-71-55300 $ 70.14 5/13/2026
262892 US Bank 662-60-67-57800 $ 16.84 5/13/2026
262892 US Bank 771-50-57-55300 $ 162.03 5/13/2026
262892 US Bank 662-60-67-53300 $ 64.93 5/13/2026

262892 US Bank 662-60-67-54300 $ 15.42 5/13/2026
262892 US Bank 101-60-89-54200 $ 117.95 5/13/2026
262892 US Bank 204-40-21-51420 $ 59.79 5/13/2026
262892 US Bank 101-60-89-54200 $ 170.01 5/13/2026
262892 US Bank 661-60-64-55300 $ 19.58 5/13/2026
262892 US Bank 662-60-67-55300 $ 26.42 5/13/2026
262892 US Bank 771-50-57-54400 $ 34.11 5/13/2026
262892 US Bank 775-10-71-51770 $ 92.76 5/13/2026
262892 US Bank 101-10-15-53100 $ 4.84 5/13/2026
262892 US Bank 101-40-21-53100 $ 23.01 5/13/2026
262892 US Bank 101-40-21-54200 $ 485.08 5/13/2026
262892 US Bank 101-40-21-54200 $ 197.51 5/13/2026
262892 US Bank 101-40-21-51400 $ 441.93 5/13/2026
262892 US Bank 101-40-21-51400 $ 56.12 5/13/2026
262892 US Bank 661-60-64-54300 $ 7.71 5/13/2026
262892 US Bank 101-20-07-53110 $ 6.08 5/13/2026
262892 US Bank 771-50-57-51770 $ 165.00 5/13/2026
262892 US Bank 101-40-21-51400 $ 13.00 5/13/2026
262892 US Bank 101-40-21-51770 $ 336.40 5/13/2026
262892 US Bank 662-60-67-55300 $ 73.44 5/13/2026
262892 US Bank 662-60-67-51400 $ 71.10 5/13/2026
262892 US Bank 101-00-00-13100 $ 890.00 5/13/2026
262892 US Bank 101-40-21-51400 $ 10.00 5/13/2026
262892 US Bank 207-50-45-54300 $ 90.37 5/13/2026
262892 US Bank 662-60-67-51400 $ 25.00 5/13/2026
262892 US Bank 771-50-57-54400 $ 286.65 5/13/2026
262892 US Bank 662-60-67-51500 $ 19.83 5/13/2026
262892 US Bank 101-50-41-54200 $ 24.98 5/13/2026
262892 US Bank 662-60-67-55300 $ 78.69 5/13/2026
262892 US Bank 662-60-67-55300 $ 130.87 5/13/2026
262892 US Bank 101-10-15-51300 $ 60.00 5/13/2026
262892 US Bank 662-60-67-54200 $ 26.44 5/13/2026
262892 US Bank 101-10-03-51770 $ 81.00 5/13/2026
262892 US Bank 775-10-71-55300 $ 201.09 5/13/2026
262892 US Bank 771-50-57-54700 $ 167.56 5/13/2026
262892 US Bank 101-10-03-51770 $ 33.35 5/13/2026
262892 US Bank 101-50-41-54200 $ 22.04 5/13/2026
262892 US Bank 775-10-71-55300 $ 99.20 5/13/2026
262892 US Bank 661-50-63-54200 $ 0.99 5/13/2026
262892 US Bank 209-50-55-54200 $ 30.85 5/13/2026
262892 US Bank 662-60-67-51770 $ 335.00 5/13/2026
262892 US Bank 771-50-57-54400 $ 63.26 5/13/2026
262892 US Bank 662-60-67-54200 $ 31.94 5/13/2026
262892 US Bank 101-50-81-57614 $ 542.15 5/13/2026
262892 US Bank 771-50-57-54400 $ 50.00 5/13/2026
262892 US Bank 771-50-57-55300 $ 680.96 5/13/2026
262892 US Bank 101-60-89-54200 $ 15.88 5/13/2026
262892 US Bank 771-50-57-54700 $ 84.00 5/13/2026
262892 US Bank 101-10-03-51770 $ 55.78 5/13/2026
262892 US Bank 771-50-57-53500 $ 208.57 5/13/2026
262892 US Bank 101-50-81-57614 $ 542.15 5/13/2026
262892 US Bank 662-60-67-53500 $ 15.41 5/13/2026
262892 US Bank 204-40-21-51420 $ 915.15 5/13/2026
262892 US Bank 101-40-21-54200 $ 52.42 5/13/2026
262892 US Bank 662-60-67-57800 $ 432.00 5/13/2026
262892 US Bank 661-50-63-51600 $ 2.48 5/13/2026
262892 US Bank 101-40-21-53100 $ 19.50 5/13/2026
262892 US Bank 101-10-15-51430 $ 26.46 5/13/2026
262892 US Bank 101-10-03-53300 $ 24.80 5/13/2026
262892 US Bank 101-10-15-54200 $ 116.10 5/13/2026
262892 US Bank 207-50-45-51500 $ 1,311.98 5/13/2026
262892 US Bank 101-50-81-54200 $ 336.54 5/13/2026
262892 US Bank 207-50-45-54200 $ 2.99 5/13/2026
262892 US Bank 101-10-03-51770 $ 35.09 5/13/2026
262892 US Bank 771-50-57-51400 $ 21.49 5/13/2026
262892 US Bank 101-40-21-54200 $ 158.61 5/13/2026
262892 US Bank 207-50-45-54300 $ 173.40 5/13/2026
262892 US Bank 550-00-00-24100 $ 200.00 5/13/2026

262892 US Bank 101-40-21-53100 $ 22.85 5/13/2026
262892 US Bank 662-60-67-55400 $ 116.56 5/13/2026
262892 US Bank 207-50-45-54300 $ 29.88 5/13/2026
262892 US Bank 101-40-21-51400 $ 28.61 5/13/2026
262892 US Bank 771-50-57-54400 $ 363.09 5/13/2026
262892 US Bank 101-40-21-51500 $ 28.17 5/13/2026
262892 US Bank 101-40-21-51400 $ 650.00 5/13/2026
262892 US Bank 211-30-13-58222 $ 150.00 5/13/2026
262892 US Bank 775-10-71-51210 $ 65.00 5/13/2026
262892 US Bank 205-60-87-54200 $ 16.47 5/13/2026
262892 US Bank 775-10-71-57800 $ 229.31 5/13/2026
262892 US Bank 101-10-03-54200 $ 24.96 5/13/2026
262892 US Bank 101-40-21-54200 $ 5.59 5/13/2026
262892 US Bank 101-40-21-51500 $ (193.02) 5/13/2026
262892 US Bank 101-40-21-51770 $ 44.72 5/13/2026
262892 US Bank 101-10-03-51770 $ 50.00 5/13/2026
262892 US Bank 101-40-21-51770 $ 56.75 5/13/2026
262892 US Bank 101-10-15-51430 $ 46.31 5/13/2026
262892 US Bank 771-50-57-51400 $ 21.49 5/13/2026
262892 US Bank 771-50-57-55300 $ 28.65 5/13/2026
262892 US Bank 101-40-21-54200 $ 148.82 5/13/2026
262892 US Bank 661-60-64-54200 $ 40.00 5/13/2026
262892 US Bank 771-50-57-53500 $ 156.15 5/13/2026
262892 US Bank 662-60-67-54200 $ 45.64 5/13/2026
262892 US Bank 771-50-57-55300 $ 1,202.62 5/13/2026
262892 US Bank 101-40-21-54200 $ 122.84 5/13/2026
262892 US Bank 101-40-21-51600 $ 79.00 5/13/2026
262892 US Bank 101-40-21-51770 $ 84.29 5/13/2026
262892 US Bank 209-50-55-54200 $ 164.00 5/13/2026
262892 US Bank 101-10-15-51430 $ 475.00 5/13/2026
262892 US Bank 662-60-67-53500 $ 137.07 5/13/2026
262892 US Bank 101-30-31-55800 $ 0.99 5/13/2026
262892 US Bank 101-40-21-51770 $ 169.15 5/13/2026
262892 US Bank 771-50-57-54200 $ 813.20 5/13/2026
262892 US Bank 661-50-63-54200 $ 33.00 5/13/2026
262892 US Bank 550-00-00-24100 $ 199.00 5/13/2026
262892 US Bank 771-50-57-53500 $ 15.32 5/13/2026
262892 US Bank 771-50-57-54200 $ 25.18 5/13/2026
262892 US Bank 771-50-57-51400 $ 786.90 5/13/2026
262892 US Bank 771-50-57-51400 $ 786.90 5/13/2026
262892 US Bank 661-50-63-54200 $ 282.84 5/13/2026
262892 US Bank 101-10-15-51400 $ 30.00 5/13/2026
262892 US Bank 101-50-85-55400 $ 227.58 5/13/2026
262892 US Bank 101-50-41-54300 $ 360.00 5/13/2026
262892 US Bank 662-60-67-53500 $ 6.60 5/13/2026
262892 US Bank 101-50-61-57300 $ 274.52 5/13/2026
262892 US Bank 101-40-21-54200 $ 13.11 5/13/2026
262892 US Bank 101-40-21-54200 $ 24.21 5/13/2026
262892 US Bank 662-60-67-51400 $ 1,026.24 5/13/2026
262892 US Bank 101-30-31-53300 $ 26.74 5/13/2026
262892 US Bank 775-10-71-55300 $ 431.97 5/13/2026
262892 US Bank 561-00-00-24056 $ 90.00 5/13/2026
262892 US Bank 661-50-63-54200 $ 398.34 5/13/2026
262892 US Bank 662-60-67-55300 $ 31.53 5/13/2026
262892 US Bank 207-50-45-54300 $ 164.29 5/13/2026
262892 US Bank 662-60-67-55400 $ 13.22 5/13/2026
262892 US Bank 101-20-07-54200 $ 284.16 5/13/2026
262892 US Bank 661-50-63-54200 $ 44.16 5/13/2026
262892 US Bank 771-50-57-54700 $ 144.30 5/13/2026
262892 US Bank 101-40-21-54200 $ 82.05 5/13/2026
262892 US Bank 101-50-85-55400 $ 11.00 5/13/2026
262892 US Bank 662-60-67-55300 $ 56.55 5/13/2026
262892 US Bank 101-10-03-51770 $ 33.31 5/13/2026
262892 US Bank 101-60-89-54200 $ 211.90 5/13/2026
262892 US Bank 101-60-89-54200 $ 135.65 5/13/2026
262892 US Bank 101-10-03-54200 $ 29.06 5/13/2026
262892 US Bank 662-60-67-53500 $ 1,171.00 5/13/2026
262892 US Bank 771-50-57-54400 $ 146.33 5/13/2026

262892 US Bank 771-50-57-54400 $ 434.42 5/13/2026
262892 US Bank 661-60-64-55400 $ 16.50 5/13/2026
262892 US Bank 204-40-21-51420 $ 38.40 5/13/2026
262892 US Bank 202-60-51-51770 $ 244.08 5/13/2026
262892 US Bank 101-30-31-53300 $ 20.00 5/13/2026
262892 US Bank 662-50-65-54300 $ 23.97 5/13/2026
262892 US Bank 662-50-65-51500 $ 72.21 5/13/2026
262892 US Bank 771-50-57-54400 $ 19.83 5/13/2026
262892 US Bank 204-40-21-51420 $ 40.37 5/13/2026
262892 US Bank 662-60-67-55300 $ 102.75 5/13/2026
262892 US Bank 101-40-21-54200 $ 122.50 5/13/2026
262892 US Bank 550-00-00-24100 $ 500.00 5/13/2026
262892 US Bank 101-50-85-55300 $ 236.72 5/13/2026
262892 US Bank 662-60-67-55300 $ 305.60 5/13/2026
262892 US Bank 101-20-07-53110 $ 165.00 5/13/2026
262892 US Bank 662-60-67-51770 $ 476.02 5/13/2026
262892 US Bank 101-50-41-54300 $ 0.99 5/13/2026
262892 US Bank 207-50-45-54300 $ 11.01 5/13/2026
262892 US Bank 101-50-85-51500 $ 507.09 5/13/2026
262893 AmWINS Group Benefits Inc./REMIF 101-00-00-22203 $ 1,701.51 5/15/2026 AMWINS PLAN PREMIUM STATEMENT; JUN26 262894 Arcata Stationers 662-60-67-51720 $ 518.13 5/15/2026 AMIC CHAIRS 262895 Arcata Little League 101-00-00-23070 $ 500.00 5/15/2026 DEPOSIT REFUND ACC RENTAL 4/25/26 262896 A. T. & T. 775-10-71-51200 $ 34.61 5/15/2026 STANDARD PHONE CHARGES; MAY26 262897 Bauer Denise 101-00-00-46318 $ 175.00 5/15/2026

REFUND DUE TO RECEIVING PAYMENT FROM

CHANGING TIDES
262897 Bauer Denise 101-00-00-46365 $ 13.50 5/15/2026

REFUND DUE TO RECEIVING PAYMENT FROM

CHANGING TIDES
262898 Wilkinson & Associates Baldwin Blomstrom 205-60-87-51720 $ 3,637.75 5/15/2026 FSC ANNUAL AUDIT - 2026 262899 Bergman Jandy 101-60-89-51710 $ 409.20 5/15/2026 FELDENKRAIS MAR-APR26 (151350-B & C) 262900 Berman Kassi 101-00-00-46360 $ 24.00 5/15/2026 REFUND FOR CREATIVE DANCE CANCELLATION 262900 Berman Kassi 101-00-00-23075 $ 8.00 5/15/2026 REFUND FOR CREATIVE DANCE CANCELLATION 262901 Black Humboldt 101-00-00-23070 $ 50.00 5/15/2026 DEPOSIT REFUND PICNIC AREA 5/2/26 262902 Bug Press 101-20-07-53300 $ 418.95 5/15/2026 CUSTOM #10 WINDOW ENVELOPES 30%PCW 262903 CDWG 775-10-71-51770 $ 207.36 5/15/2026 ADOBE ACROBAT LICENSES (SOFTWARE NO TAX) 262904 Diamond Nancy 101-10-09-51771 $ 1,708.00 5/15/2026 INVOICE 2935 (4/9/26-4/30/26) 262905 Flippen Susan 101-00-00-46335 $ 105.00 5/15/2026 CAMP CANCELLATION 262905 Flippen Susan 101-00-00-46365 $ 13.50 5/15/2026 CAMP CANCELLATION 262906 Franchise Tax Board 101-00-00-22109 $ 75.39 5/15/2026 PR Batch 00009.05.2026 Franchise Tax Board 262907 Franchise Tax Board 101-00-00-22109 $ 157.01 5/15/2026 PR Batch 00009.05.2026 Franchise Tax Board 262908 Harris Bridgett 101-50-81-52070 $ 1,508.15 5/15/2026

PAYMENT TO SETTLE CLAIM FOR CRACKED
WINDSHIELD 4/23/26
262909 Humboldt County Association of Governments 663-00-00-45747 $ 18,009.00 5/15/2026 REFUND FY24-25 ARCATA SGR CLAIM PAYMENT 262910 Hinderliter De Llamas & Associ 101-20-07-51778 $ 900.00 5/15/2026 CONTRACT SERVICES TRANSACTIONS TAX APRJUN26
262910 Hinderliter De Llamas & Associ 101-20-07-51778 $ 1,412.32 5/15/2026 CONTRACT SERVICES TRANSACTIONS TAX APRJUN26; AUDIT SERVICES TAX 262911 Humboldt Crabs 101-40-21-51400 $ 360.00 5/15/2026 RIGHT FIELD RESERVATION DEPOSIT 06242026 262912 Cal Poly Sponsored Programs Foundation 101-00-00-23070 $ 500.00 5/15/2026 DEPOSIT REFUND ACC RENTAL 4/23/26 262913 IT Management Corp. 775-10-71-51200 $ 1,312.95 5/15/2026 PHONE SERVICE; MAY26 262914 Keller Stacey 101-00-00-23070 $ 50.00 5/15/2026 DEPOSIT REFUND PICNIC AREA 5/3/26 262915 Mattison Kinsey 101-00-00-23070 $ 50.00 5/15/2026 DEPOSIT REFUND PICNIC AREA 4/25/26 262916 Mosher Riley 771-50-57-51500 $ 15.00 5/15/2026
MEAL ALLOWANCE FOR 14-HR SHIFT WORKED
4/29/26
262917 Pacific Gas & Electric Co 212-30-11-51100 $ 7,493.44 5/15/2026 ACCT: 9015588019-9; APR26 262917 Pacific Gas & Electric Co 662-60-67-51100 $ 43.95 5/15/2026 ACCT: 3863988117-6; MAY26 262917 Pacific Gas & Electric Co 101-50-41-51100 $ 77.17 5/15/2026 ACCT: 7561752578-9; MAY26 262917 Pacific Gas & Electric Co 662-60-67-51100 $ 19,972.60 5/15/2026 ACCT: 7687817960-5; MAY26 262917 Pacific Gas & Electric Co 101-50-41-51100 $ 39.13 5/15/2026 ACCT: 8191325790-3; MAY26 262918 Purcell Nick 771-50-57-51500 $ 15.00 5/15/2026
MEAL ALLOWANCE FOR 14-HR SHIFT WORKED
4/29/26
262919 UBEO West LLC 101-20-07-53210 $ 54.22 5/15/2026

PRINTER MAINTENANCE CONTRACT CHARGES
CONSUMABLES; MAY26

262919 UBEO West LLC 101-40-21-53300 $ 352.43 5/15/2026

PRINTER MAINTENANCE CONTRACT CHARGES
CONSUMABLES; MAY26
262919 UBEO West LLC 775-10-71-53300 $ 1,007.23 5/15/2026

PRINTER MAINTENANCE CONTRACT CHARGES
CONSUMABLES; MAY26
262920 Snyder Rose 101-00-00-46360 $ 40.00 5/15/2026 REFUND FOR CREATIVE DANCE CANCELLATION 262920 Snyder Rose 101-00-00-46365 $ 13.50 5/15/2026 REFUND FOR CREATIVE DANCE CANCELLATION 262921 Optimum 775-10-71-51210 $ 77.15 5/15/2026 CITY HALL/APD INTERNET; MAY26 262922 Optimum 101-40-21-51200 $ 500.00 5/15/2026 CITY HALL/PD INTERNET (FIBER); MAY26 262922 Optimum 775-10-71-51210 $ 950.00 5/15/2026 CITY HALL/PD INTERNET (FIBER); MAY26 262923 Neff Josh 661-00-00-21000 $ 14.29 5/15/2026 Refund Check 007714-011 1037 H St Apt H 262924 Marmolejo-Hurtado Angel 661-00-00-21000 $ 41.54 5/15/2026 Refund Check 037161-000 1270 Foster Ave Apt K 262925 Castruita Cassandra 661-00-00-21000 $ 22.40 5/15/2026 Refund Check 032443-000 3122 Janes Rd 262926 Smith Wyatt 661-00-00-21000 $ 29.44 5/15/2026 Refund Check 036339-000 261 E 11th St 262927 Sutter John 661-00-00-21000 $ 28.40 5/15/2026 Refund Check 037017-000 605 Diamond Dr Apt H 262928 Columbia Bank 101-00-00-27200 $ 5,097.42 5/15/2026 DEBT SERVICE PAYMENT; CALPERS UAL
REFINANCE; 6/1/26
262928 Columbia Bank 101-00-00-27200 $ 71,000.00 5/15/2026 DEBT SERVICE PAYMENT; CALPERS UAL
REFINANCE; 6/1/26
262929 Yang Laura 101-00-00-23070 $ 50.00 5/15/2026 DEPOSIT REFUND PICNIC AREA 4/26/26 262930 American Backflow Products Co. 661-60-64-55300 $ 141.81 5/15/2026 OPO Backflow Parts and Kits 262931 Arcata Used Tire & Wheel 771-50-57-54600 $ 20.00 5/15/2026 open po for tire repair 262932 B & B Portable Toilets 101-50-81-55600 $ 252.16 5/15/2026 Parks OPO FY25/26 262932 B & B Portable Toilets 101-50-81-55600 $ 240.04 5/15/2026 Parks OPO FY25/26 262932 B & B Portable Toilets 662-60-67-55400 $ 482.11 5/15/2026 Parks OPO FY25/26 262932 B & B Portable Toilets 101-50-81-55600 $ 473.11 5/15/2026 Parks OPO FY25/26 262932 B & B Portable Toilets 101-50-81-55600 $ 261.35 5/15/2026 Parks OPO FY25/26 262932 B & B Portable Toilets 662-60-67-55400 $ 176.88 5/15/2026 Parks OPO FY25/26 262932 B & B Portable Toilets 101-50-81-55600 $ 482.11 5/15/2026 Parks OPO FY25/26 262932 B & B Portable Toilets 662-60-67-55400 $ 124.06 5/15/2026 Parks OPO FY25/26 262933 CA Dep Of Justice 101-60-89-52524 $ 392.00 5/15/2026 Fingerprinting for Part-Time Recreation Staff 262934 Caltest Analytical Lab 662-60-67-51742 $ 356.25 5/15/2026 OPO WW lab testing 262934 Caltest Analytical Lab 662-60-67-51742 $ 532.95 5/15/2026 OPO WW lab testing 262934 Caltest Analytical Lab 662-60-67-51742 $ 356.25 5/15/2026 OPO WW lab testing 262935 Carollo Engineers Inc. 662-70-67-57601 $ 7,465.85 5/15/2026 Engineering Services for Ph1 of WWTF
Improvements Project. Contr
262936 CDT Inc 101-10-15-51705 $ 465.00 5/15/2026 CDT - DOT Drug Program REMIF 262937 Chandler Asset Management 101-00-00-44100 $ 2,491.56 5/15/2026 City of Arcata Investment Management 262937 Chandler Asset Management 245-00-00-44100 $ 330.86 5/15/2026 Arcata 2003 Public Imporvement Projects 262938 Confab Manufacturing Company LLC 662-60-67-55400 $ 3,001.46 5/15/2026 (2) 2 Yd Pitch Top Dumpsters 262939 CSG Consultants Inc 664-60-73-54455 $ 1,800.00 5/15/2026 262940 Eureka Ready Mix Concrete Co Inc 661-50-63-53800 $ 249.84 5/15/2026 open po for aggregate 262941 Fedex 662-60-67-53100 $ 153.40 5/15/2026 OPO Shipping 262942 GHD Inc. 210-70-45-51770 $ 31,148.32 5/15/2026
Phase 2 / PS&E for Sunset Ave. & US 101
Interchange Improvements
262942 GHD Inc. 210-70-45-51770 $ 10,822.33 5/15/2026
Phase 2 / PS&E for Sunset Ave. & US 101
Interchange Improvements
262942 GHD Inc. 661-70-64-57600 $ 6,778.50 5/15/2026 Heindon Pump Well Review 262943 Genuine Parts Company Inc 771-50-57-54400 $ 14.75 5/15/2026 open po for atuo parts 262944 Harper Ford Country 771-50-57-54400 $ 441.51 5/15/2026 open po for parts 262945 HELIX Environmental Planning Inc. 101-30-11-51790 $ 15,692.50 5/15/2026 CEQA/NEPA Services for the Roger's Garage
Affordable Housing Pro
262946 Hensels Hardware 212-30-11-55400 $ 55.89 5/15/2026 Hardware and Supplies (Foodworks) 262946 Hensels Hardware 212-30-11-55400 $ 119.89 5/15/2026 Hardware and Supplies (Foodworks) 262947 Humboldt Bay Municipal Water District 661-60-64-54000 $ 133,461.43 5/15/2026 FY25/26 OPO Water Purchases 262948 Humboldt Termite & Pest Control 101-50-61-57300 $ 111.18 5/15/2026 open po for pest service 262948 Humboldt Termite & Pest Control 101-50-85-51770 $ 67.58 5/15/2026 BUILDINGS OPO FY25/26 262949 IBS Of The Redwoods 771-50-57-54400 $ 165.69 5/15/2026 open po for batteries 262950 InSource Software Solutions Inc 662-60-67-51600 $ 6,015.00 5/15/2026 Aveva CF #46732 Flex #F25107-6K459-RL Credits
#300 - Preumium
262951 Kernen Construction 207-50-45-53800 $ 9.43 5/15/2026 open po for aggregate 262951 Kernen Construction 207-50-45-53800 $ 683.74 5/15/2026 open po for aggregate 262951 Kernen Construction 101-00-00-21090 $ (9.43) 5/15/2026 open po for aggregate 262951 Kernen Construction 101-00-00-21090 $ (7.95) 5/15/2026 open po for aggregate 262951 Kernen Construction 207-50-45-53800 $ 575.99 5/15/2026 open po for aggregate

262951 Kernen Construction 207-50-45-53800 $ 7.95 5/15/2026 open po for aggregate 262952 Mad River Union 101-30-11-51300 $ 200.00 5/15/2026 Notices for Passthrough Projects 262953 Mendes Supply Co 212-30-11-55400 $ 172.94 5/15/2026 Cleaning Supplies and Services (Foodworks) 262954 Microbac Laboratories Inc 661-60-64-51742 $ 80.00 5/15/2026 OPO W Lab Testing and Analysis 262954 Microbac Laboratories Inc 662-60-67-53500 $ 66.00 5/15/2026 OPO Wastewater QC Standards 262955 The Mill Yard 101-50-81-55400 $ 31.82 5/15/2026 Parks OPO FY25/26 262956 Mission Linen Ind.Inc. 212-30-11-55400 $ 94.24 5/15/2026 Mop/Rag Service (Foodworks) 262956 Mission Linen Ind.Inc. 661-50-63-51770 $ 11.03 5/15/2026 open po for first aid supply 262956 Mission Linen Ind.Inc. 771-50-57-51500 $ 90.78 5/15/2026 open po for linens 262956 Mission Linen Ind.Inc. 212-30-11-55400 $ 94.24 5/15/2026 Mop/Rag Service (Foodworks) 262956 Mission Linen Ind.Inc. 661-50-63-51770 $ 11.03 5/15/2026 open po for first aid supply 262956 Mission Linen Ind.Inc. 771-50-57-51500 $ 87.53 5/15/2026 open po for linens 262957 North Coast Journal Inc 101-10-15-51300 $ 112.00 5/15/2026 North Coast Journal 262958 American Hospital Management 101-10-15-51702 $ 341.25 5/15/2026 Occupational Health - Physicals 262958 American Hospital Management 101-10-15-51702 $ 227.50 5/15/2026 Occupational Health - Physicals 262959 Pace Engineering INC 661-60-64-57300 $ 1,035.50 5/15/2026 Engineering Design and Project Management
Services for Alliance
262960 Peterson Power Systems Inc 662-60-67-55300 $ 18.19 5/15/2026 CAT Generator PM 262960 Peterson Power Systems Inc 101-00-00-21090 $ (18.19) 5/15/2026 CAT Generator PM 262960 Peterson Power Systems Inc 662-60-67-55300 $ 3,396.92 5/15/2026 CAT Generator PM 262961 Post-Haste Mail Center Inc 101-60-89-52524 $ 245.00 5/15/2026 Fingerprinting for Part-Time Rec Staff 262962 Blue Star Gas Associates 662-60-67-51770 $ 103.39 5/15/2026 OPO Hazmat/Propane Drop off 262963 Shelter John 101-70-81-57613 $ 852.12 5/15/2026
Annual Contract Clean-up & Monitoring - Carlson
Park
262964 SHN Consulting Engineers & Geologists Inc 662-60-67-57300 $ 192.50 5/15/2026 Klopp Lake Soil Sampling - Field Implementation 262964 SHN Consulting Engineers & Geologists Inc 666-60-51-51770 $ 302.50 5/15/2026 Post-Fire 2026 Water Quality Sampling 262964 SHN Consulting Engineers & Geologists Inc 205-60-87-51770 $ 860.00 5/15/2026 JCF NTO 26 Geotech Support 262965 Sunbelt Rentals Inc 101-50-85-55400 $ 4,263.55 5/15/2026 generator rental community center 262966 USA Blue Book 662-60-67-53500 $ 663.17 5/15/2026 OPO Lab Supplies 262966 USA Blue Book 661-60-64-53500 $ 45.82 5/15/2026 OPO Lab Supplies 262966 USA Blue Book 662-60-67-53500 $ 107.13 5/15/2026 OPO Lab Supplies 262966 USA Blue Book 662-60-67-51728 $ 193.44 5/15/2026 OPO AMRI Lab Supplies 262966 USA Blue Book 661-60-64-53500 $ 103.59 5/15/2026 OPO Lab Supplies 262967 Wahlund Construction Inc. 662-60-67-55400 $ 5,678.87 5/15/2026 Gearheart Leak Repair 262968 Crandell Wesley 101-50-81-51400 $ 217.00 5/22/2026 CPSI Training Rohnert Park CA 6/2-6/4/26 262969 Jansen Abraham 204-40-21-51420 $ 1,058.00 5/22/2026 POST Supervisor Course Dublin CA 6/1-6/12/26 262970 Rodriguez Marcela 661-60-64-51400 $ 92.00 5/22/2026 Drinking Water Distribution Exam Redding CA
6/2/26
262971 Advanced Security Systems 101-50-85-51770 $ 309.97 5/22/2026 BUILDINGS OPO FY25/26 262971 Advanced Security Systems 101-50-85-51770 $ 607.95 5/22/2026 BUILDINGS OPO FY25/26 262972 Applied River Sciences 662-70-67-57601 $ 4,768.00 5/22/2026 AWTF Monitoring Stations - AWTF Phase I 262973 Arcata Stationers 101-40-21-53300 $ 398.54 5/22/2026 OFFICE SUPPLIES 262973 Arcata Stationers 101-60-70-53300 $ 42.80 5/22/2026 ES FY25/26 OPO - energy acct 262974 Arcata Used Tire & Wheel 771-50-57-51770 $ 120.00 5/22/2026 open po for tire disposal 262975 Brant Electric 101-50-85-51770 $ 725.00 5/22/2026 BUILDINGS OPO FY25/26 262976 Buddy's Auto Center 101-40-23-51762 $ 100.00 5/22/2026 AV REMOVAL 262976 Buddy's Auto Center 101-40-23-51762 $ 100.00 5/22/2026 AV REMOVAL 262976 Buddy's Auto Center 101-40-23-51762 $ 100.00 5/22/2026 AV REMOVAL 262977 CA Dep Of Justice 101-40-21-52524 $ 714.00 5/22/2026 FINGERPRINTING SERVICES 262977 CA Dep Of Justice 101-40-21-52524 $ 343.00 5/22/2026 FINGERPRINTING SERVICES 262977 CA Dep Of Justice 101-40-21-52522 $ 1,876.98 5/22/2026 CLETS LINE 262978 Code Publishing Company 101-10-05-51770 $ 579.00 5/22/2026 Code Publishing 262979 Eureka Rubber Stamp 101-40-21-51500 $ 42.57 5/22/2026 NAME TAGS/MISC 262979 Eureka Rubber Stamp 101-40-21-51500 $ 54.19 5/22/2026 NAME TAGS/MISC 262980 Fedex 662-60-67-53100 $ 153.40 5/22/2026 OPO Shipping 262981 GHD Inc. 666-70-51-57600 $ 2,499.56 5/22/2026
Sensitive Species Clearance Work - 4700 West End
Rd
262982 Genuine Parts Company Inc 771-50-57-54400 $ 15.41 5/22/2026 open po for atuo parts 262982 Genuine Parts Company Inc 771-50-57-54400 $ 23.12 5/22/2026 open po for atuo parts 262982 Genuine Parts Company Inc 771-50-57-54400 $ 27.77 5/22/2026 open po for atuo parts 262982 Genuine Parts Company Inc 771-50-57-54400 $ 11.40 5/22/2026 open po for atuo parts 262982 Genuine Parts Company Inc 771-50-57-54400 $ 180.46 5/22/2026 open po for atuo parts 262982 Genuine Parts Company Inc 771-50-57-54400 $ 65.48 5/22/2026 open po for atuo parts 262982 Genuine Parts Company Inc 771-50-57-54400 $ 83.55 5/22/2026 open po for atuo parts 262982 Genuine Parts Company Inc 771-50-57-54400 $ 33.60 5/22/2026 open po for atuo parts 262982 Genuine Parts Company Inc 771-50-57-54400 $ 3.66 5/22/2026 open po for atuo parts

262982 Genuine Parts Company Inc 771-50-57-54400 $ 264.58 5/22/2026 open po for atuo parts 262982 Genuine Parts Company Inc 771-50-57-54400 $ (147.54) 5/22/2026 open po for atuo parts 262983 Hensels Hardware 212-30-11-55400 $ 34.81 5/22/2026 Hardware and Supplies (Foodworks) 262983 Hensels Hardware 212-30-11-55400 $ 93.65 5/22/2026 Hardware and Supplies (Foodworks) 262983 Hensels Hardware 212-30-11-55400 $ 12.99 5/22/2026 Hardware and Supplies (Foodworks) 262983 Hensels Hardware 212-30-11-55400 $ 92.04 5/22/2026 Hardware and Supplies (Foodworks) 262984 Hensell Materials Inc 101-50-81-53800 $ 1,068.16 5/22/2026 Parks OPO FY25/26 262985 Humboldt Termite & Pest Control 101-50-85-51770 $ 89.38 5/22/2026 BUILDINGS OPO FY25/26 262986 InSource Software Solutions Inc 662-60-67-51600 $ 1,155.00 5/22/2026 TopView Software Support Agreement
#ARCATAWWTP
262987 Kens Auto Parts 101-00-00-21090 $ (72.78) 5/22/2026 set up maverick 552 for compliance Scott S 262987 Kens Auto Parts 661-60-64-55300 $ 3,584.82 5/22/2026 set up maverick 552 for compliance Scott S 262987 Kens Auto Parts 662-60-67-55300 $ 3,566.03 5/22/2026 set up maverick 552 for compliance Scott S 262987 Kens Auto Parts 661-60-64-55300 $ 36.39 5/22/2026 set up maverick 552 for compliance Scott S 262987 Kens Auto Parts 662-60-67-55300 $ 36.39 5/22/2026 set up maverick 552 for compliance Scott S 262988 LexisNexis Risk Data Management Inc 101-40-21-52522 $ 819.55 5/22/2026 ONLINE REPORTING 262989 American Hospital Management 101-40-21-51770 $ 140.00 5/22/2026 BLOOD DRAWS/TASER REMOVAL 262990 Mad River Union 101-10-05-51300 $ 110.00 5/22/2026 Mad River Union - Legal Ads 262991 Maple Service Inc. 212-30-11-55400 $ 640.50 5/22/2026 Plumbing and Sewer Service (Foodworks) 262992 McCullough Construction Inc 661-70-63-57500 $ 941,114.15 5/22/2026 Steel Waterline Replacement Project 262993 McKinleyville Community Servic 661-60-64-54000 $ 188.79 5/22/2026 FY 25/26 Water Purchases - Wymore Rd 262994 Mendes Supply Co 212-30-11-55400 $ 178.61 5/22/2026 Cleaning Supplies and Services (Foodworks) 262994 Mendes Supply Co 212-30-11-55400 $ 3,452.40 5/22/2026 Cleaning Supplies and Services (Foodworks) 262994 Mendes Supply Co 212-30-11-55400 $ 407.28 5/22/2026 Cleaning Supplies and Services (Foodworks) 262994 Mendes Supply Co 212-30-11-55400 $ 236.31 5/22/2026 Cleaning Supplies and Services (Foodworks) 262994 Mendes Supply Co 101-50-85-55300 $ 196.88 5/22/2026 BUILDINGS OPO FY25/26 - equip. maint. 262995 The Mill Yard 101-50-85-55400 $ 69.39 5/22/2026 BUILDINGS OPO FY25/26 262995 The Mill Yard 101-50-85-55400 $ 7.86 5/22/2026 BUILDINGS OPO FY25/26 262995 The Mill Yard 101-50-85-55400 $ 166.53 5/22/2026 BUILDINGS OPO FY25/26 262996 Mission Linen Ind.Inc. 662-60-67-51500 $ 133.51 5/22/2026 OPO Weekly Linens 262996 Mission Linen Ind.Inc. 212-30-11-55400 $ 94.24 5/22/2026 Mop/Rag Service (Foodworks) 262996 Mission Linen Ind.Inc. 212-30-11-55400 $ 20.84 5/22/2026 Mop/Rag Service (Foodworks) 262996 Mission Linen Ind.Inc. 771-50-57-51500 $ 90.78 5/22/2026 open po for linens 262996 Mission Linen Ind.Inc. 661-50-63-51770 $ 11.03 5/22/2026 open po for first aid supply 262996 Mission Linen Ind.Inc. 662-60-67-54200 $ 11.03 5/22/2026 OPO 1st Aid Cabinet Service 262997 Motorola Solutions Inc 101-40-21-55300 $ 15,677.55 5/22/2026 WATCHGUARD MAINTENANCE CONTRACT 262997 Motorola Solutions Inc 101-40-21-55300 $ 9,344.70 5/22/2026 WATCHGUARD MAINTENANCE CONTRACT 262998 Munimetrix Inc 101-10-05-51770 $ 99.80 5/22/2026 Munimetrix Systems 262999 Norman's Dry Cleaners 101-40-21-51500 $ 209.75 5/22/2026 DRY CLEARNING SERVICES 262999 Norman's Dry Cleaners 101-40-21-51500 $ 186.25 5/22/2026 DRY CLEARNING SERVICES 262999 Norman's Dry Cleaners 101-40-21-51500 $ 24.50 5/22/2026 DRY CLEARNING SERVICES 262999 Norman's Dry Cleaners 101-40-21-51500 $ 258.50 5/22/2026 DRY CLEARNING SERVICES 262999 Norman's Dry Cleaners 101-40-21-51500 $ 19.75 5/22/2026 DRY CLEARNING SERVICES 262999 Norman's Dry Cleaners 101-40-21-51500 $ 44.00 5/22/2026 DRY CLEARNING SERVICES 262999 Norman's Dry Cleaners 101-40-21-51500 $ 19.75 5/22/2026 DRY CLEARNING SERVICES 262999 Norman's Dry Cleaners 101-40-21-51500 $ 17.75 5/22/2026 DRY CLEARNING SERVICES 262999 Norman's Dry Cleaners 101-40-21-51500 $ 14.75 5/22/2026 262999 Norman's Dry Cleaners 101-40-21-51500 $ 43.70 5/22/2026 DRY CLEARNING SERVICES 262999 Norman's Dry Cleaners 101-40-21-51500 $ 131.75 5/22/2026 DRY CLEARNING SERVICES 262999 Norman's Dry Cleaners 101-40-21-51500 $ 122.00 5/22/2026 DRY CLEARNING SERVICES 262999 Norman's Dry Cleaners 101-40-21-51500 $ 73.25 5/22/2026 DRY CLEARNING SERVICES 262999 Norman's Dry Cleaners 101-40-21-51500 $ 24.50 5/22/2026 DRY CLEARNING SERVICES 262999 Norman's Dry Cleaners 101-40-21-51500 $ 40.00 5/22/2026 DRY CLEARNING SERVICES 262999 Norman's Dry Cleaners 101-40-21-51500 $ 19.75 5/22/2026 DRY CLEARNING SERVICES 262999 Norman's Dry Cleaners 101-40-21-51500 $ 19.75 5/22/2026 DRY CLEARNING SERVICES 262999 Norman's Dry Cleaners 101-40-21-51500 $ 19.75 5/22/2026 DRY CLEARNING SERVICES 263000 Norman's Dry Cleaners 101-40-21-51500 $ 122.00 5/22/2026 DRY CLEARNING SERVICES 263000 Norman's Dry Cleaners 101-40-21-51500 $ 14.75 5/22/2026 DRY CLEARNING SERVICES 263000 Norman's Dry Cleaners 101-40-21-51500 $ 63.50 5/22/2026 DRY CLEARNING SERVICES 263000 Norman's Dry Cleaners 101-40-21-51500 $ 100.00 5/22/2026 DRY CLEARNING SERVICES 263000 Norman's Dry Cleaners 101-40-21-51500 $ 151.25 5/22/2026 DRY CLEARNING SERVICES 263000 Norman's Dry Cleaners 101-40-21-51500 $ 209.75 5/22/2026 DRY CLEARNING SERVICES 263000 Norman's Dry Cleaners 101-40-21-51500 $ 161.00 5/22/2026 DRY CLEARNING SERVICES 263000 Norman's Dry Cleaners 101-40-21-51500 $ 31.50 5/22/2026 DRY CLEARNING SERVICES 263000 Norman's Dry Cleaners 101-40-21-51500 $ 36.50 5/22/2026 DRY CLEARNING SERVICES 263001 Northern CA Gloves 101-50-81-51500 $ 141.12 5/22/2026 Parks OPO FY25/26 263002 American Hospital Management 101-10-15-51702 $ 422.50 5/22/2026 Occupational Health - Physicals 263003 Paper Direct Inc. 101-10-05-54200 $ 189.02 5/22/2026 Paper Direct - Certificate Supplies

263003 Paper Direct Inc. 101-10-05-54200 $ 221.34 5/22/2026 Paper Direct - Certificate Supplies 263004 Phoenix Group Information Systems 101-40-23-54200 $ 295.00 5/22/2026 263005 Penn Valley Pump Co 662-60-67-55300 $ 591.70 5/22/2026 Est. Tax and Shipping 263005 Penn Valley Pump Co 662-60-67-55300 $ 3,879.00 5/22/2026 Double Disk Pump Replacement Parts - PC1 263006 Service First Information Solutions LLC 211-30-13-58221 $ 244.00 5/22/2026 Credit Reporting for CalHome 263007 SmithGroup Inc 101-70-45-51770 $ 17,610.00 5/22/2026 Planning and Public Engagement Efforts for the
Reconnect Arcata
263008 Shelter John 662-60-67-55400 $ 600.00 5/22/2026 Arcata Marsh Clean up 263008 Shelter John 101-70-81-57613 $ 2,032.73 5/22/2026 Annual Contract Clean-up & Monitoring - Carlson
Park
263009 SHN Consulting Engineers & Geologists Inc 662-70-67-57601 $ 3,377.48 5/22/2026 WWTF Ph 1 Improvements - Source Water pH
Control
263010 Tehama Tire 771-50-57-54600 $ 66.51 5/22/2026 open po for tires 263011 Trinity Diesel Inc. 771-50-57-57900 $ 29,710.59 5/22/2026 Kubota D1105 RTVX2CSKLH1 Sourcewell QUOTE
#2920283
263012 USA Blue Book 661-60-64-53500 $ 276.74 5/22/2026 OPO Lab Supplies 263013 Valley Pacific Petroleum Services Inc 771-50-57-54700 $ 36.46 5/22/2026 open po for fuel 263013 Valley Pacific Petroleum Services Inc 771-50-57-54700 $ 606.14 5/22/2026 open po for fuel 263013 Valley Pacific Petroleum Services Inc 771-50-57-54700 $ 107.79 5/22/2026 open po for fuel 263013 Valley Pacific Petroleum Services Inc 771-50-57-54700 $ 1,392.89 5/22/2026 open po for fuel 263013 Valley Pacific Petroleum Services Inc 771-50-57-54700 $ 361.53 5/22/2026 open po for fuel 263013 Valley Pacific Petroleum Services Inc 771-50-57-54700 $ 1,971.93 5/22/2026 open po for fuel 263014 Wahlund Construction Inc. 662-70-67-57601 $ 198,527.51 5/22/2026 AWTF Improvements Phase I - Construction
Contract
263015 Zumar Industries Inc 209-50-55-54200 $ 5,254.40 5/22/2026 opne po for signs 263016 Alameda Co Sheriff's Office 204-40-21-51420 $ 207.00 5/22/2026 POST SUPERVISORY SCHOOL TUITION - JANSEN 263017 Corbett Danielle 101-00-00-46331 $ 620.00 5/22/2026 REFUND DUE TO CAMP CANCELLATIONS 263018 Cutshall Charles 570-00-00-24157 $ 177.00 5/22/2026

CASH SEIZED DURING ARREST BELONGING TO
CHARLES; REFER 25-0963
263019 Harris Bridgett 101-50-81-52070 $ 354.35 5/22/2026 PAYMENT TO SETTLE CLAIM RECEIVED ON 5/13/26
FOR 5/12/26 INCIDENT
263020 Humboldt County Office of Education 561-00-00-24057 $ 178.72 5/22/2026 ORDER #36968 & 36969 EQUITY ARCATA HAFH
FLYERS
263021 Humboldt Moving & Storage Company Inc. 211-30-13-58222 $ 825.00 5/22/2026 MOVING COSTS FOR TIM MILLS FROM 611 1ST ST
TO 1185 TROJAN ST
263022 Humboldt Pet Supply 664-60-73-54200 $ 901.94 5/22/2026 DOG POO BAGS 263023 Maxwell Brian 661-50-63-53800 $ 1,590.00 5/22/2026

TRUCKING FEE FOR DELIVERING COLD MIX FROM

MOUNTAIN VIEW PAVING
263024 North Coast Rape Crisis Team 101-00-00-23070 $ 500.00 5/22/2026 DEPOSIT REFUND ACC RENTAL 5/2/26 263025 Olson Matthew 101-60-89-51710 $ 141.00 5/22/2026 SPRING JUJITSU (APR26) - 151206_DA 263026 Pacific Gas & Electric Co 101-50-81-51100 $ 51.41 5/22/2026 COST OF OWNERSHIP @ARCATA SPORTS

COMPLEX
263026 Pacific Gas & Electric Co 101-50-81-51100 $ 270.49 5/22/2026 ACCT: 6236826977-5; MAY26 263027 REMIF 101-00-00-22206 $ 552.05 5/22/2026 EAP INSURANCE PREMIUMS; JUN26 263028 Ruiz Dinorah 101-00-00-23070 $ 500.00 5/22/2026 DEPOSIT REFUND DUE TO D ST CANCELLATION 263029 SWRCB 662-60-67-51600 $ 665.00 5/22/2026 CHAD SCOTT WASTEWATER GRADE IV EXAM FEES 263030 Optimum 775-10-71-51210 $ 382.43 5/22/2026 COMMUNITY CENTER; MAY26 263031 The Briefing Room 101-40-21-51600 $ 1,505.98 5/22/2026

ONLINE LAW ENFORECEMENT TRAINING

PLATFORM - ANNUAL SUBSCRIPTION
263032 ZD Inc 771-50-57-51770 $ 45.00 5/22/2026 PATROL CAR WASHES 263033 US Bank Equipment Finance 101-40-21-53300 $ 234.70 5/22/2026 COPIER FINANCE; JUN26 263034 Vero Broadband LLC 775-10-71-51210 $ 90.92 5/22/2026 ALLIANCE LIFT STATION (FIBER); APRIL/MAY26 263034 Vero Broadband LLC 775-10-71-51210 $ 85.00 5/22/2026 ALLIANCE LIFT STATION (FIBER); APRIL/MAY26 312345 Payroll Misc $ 1,710.80 5/15/2026
312346 Payroll Misc $ 623.45 5/15/2026
312347 Payroll Misc $ 278.93 5/15/2026
312348 Payroll Misc $ 2,074.31 5/15/2026
312349 Payroll Misc $ 4,781.25 5/15/2026
312350 Payroll Misc $ 151.59 5/15/2026
312351 Payroll Misc $ 466.69 5/15/2026
312352 Payroll Misc $ 46.82 5/15/2026
312353 Payroll Misc $ 193.33 5/15/2026
312354 Payroll Misc $ 39.02 5/15/2026

312355 Payroll Misc $ 95.29 5/15/2026
312356 Payroll Misc $ 444.02 5/15/2026
312357 Payroll Misc $ 43.32 5/15/2026
312358 Payroll Misc $ 33.81 5/15/2026
ACH PERS Misc $ 81,187.76 5/15/2026
ACH Payroll Deductions ACH Misc $ 196,118.16 5/15/2026
ACH CA State Disbursement Unit 101-00-00-22109 $ 119.07 5/15/2026 PR Batch 00009.05.2026 California Child Support
Order
ACH Operating Engineers No 3 101-00-00-22113 $ 1,227.78 5/15/2026 PR Batch 00009.05.2026 Union Dues ACH HealthEquity HAS Misc $ 1,221.92 5/15/2026
ACH Payroll Misc $ 370,526.01 5/15/2026
Total $ 2,370,175.53

STAFF REPORT – CITY COUNCIL MEETING
TO: Honorable Mayor and City Council Members
FROM: Emily Sinkhorn, Director of Environmental Services PREPARER: Doug Culbert, Deputy Director of Environmental Services – Streets & Utilities DATE: June 3, 2026
TITLE: Award a Contract for the 2026 Digester Cleaning Project to Synagro-WWT, Inc. in the Amount of $462,885.80; and Approve Necessary and Associated Related Actions.

RECOMMENDATION:

It is recommended that the Council:
1) Award a contract for the 2026 Digester Cleaning Project to Synagro-WWT, Inc. in the amount of $462,885.80;
2) Authorize the City Engineer to increase the contract price by up to 10% ($46,288.58, for a total amount not to exceed $509,174.38) to allow for unforeseen contingencies and additional work as necessary; and
3) Authorize the City Manager to execute all applicable documents.

INTRODUCTION:

The Arcata Wastewater Treatment Facility (AWTF) utilizes anaerobic digestion as part of its solids handling and biosolids management process. Over time, solids accumulation within the Primary Digester reduces operational capacity and treatment efficiency. Periodic cleaning of the digester is necessary to maintain reliable operations, preserve treatment performance, and support ongoing biosolids processing activities. The digester was last cleaned in 2014.

This project includes complete cleaning and removal of accumulated material from the existing 0.3- million-gallon Primary Digester located at the Arcata Wastewater Treatment Facility at 600 S G Street, Arcata, CA 95521.

BACKGROUND:

The City of Arcata owns and operates the Arcata Wastewater Treatment Facility, which provides wastewater treatment and biosolids management services for the community. The facility includes anaerobic digestion infrastructure used to stabilize sludge generated through the wastewater treatment process.

The Primary Digester has accumulated solids over time and requires cleaning to restore operational capacity and maintain efficient treatment processes. This large maintenance project was planned and budgeted for in the 2025-26 fiscal year budget. The project scope generally includes removal,

dewatering, handling, and disposal or on-site management of digested biosolids and cleaning of the digester interior.

On April 29, 2026, the City published a Notice Inviting Bids for the 2026 Digester Cleaning Project.

The project was publicly bid in accordance with California public contracting requirements. The bid documents required contractors to possess either a Class A General Engineering Contractor License or a Class C-42 Sanitation System Contractor License and maintain active registration with the California Department of Industrial Relations (DIR).

A non-mandatory pre-bid conference was held on May 7, 2026. Questions raised during the bidding period resulted in issuance of Addendum No. 1 on May 14, 2026. Addendum No. 1 included clarifications regarding project operations, staging, contractor coordination, biosolids handling requirements, and revisions to the screening requirements to reduce project costs.

DISCUSSION:

Sealed bids for the 2026 Digester Cleaning Project were received until 11 AM on May 21, 2026.

One responsive bid was received before the deadline:

No. Name of Contractor Total = Base Bid
1 Synagro-MMT, Inc. $462,885.80
Staff reviewed the bid received from Synagro-MMT, Inc. and determined it to be responsive. The engineer’s estimate for the project was approximately $300,000. The City of Eureka recently implemented a digester cleaning project which cost approximately $425,000.

It is recommended that the Council award the construction contract to Synagro-MMT, Inc. in the amount of $462,885.80, and authorize the City Engineer to increase the contract price by 10% for unforeseen contingencies If awarded, work is anticipated to begin on or about June 15, 2026, and be completed within thirty (30) working days in accordance with the contract documents.

The project will support continued reliable operation of the wastewater treatment facility by restoring digester storage capacity and improving biosolids handling operations ENVIRONMENTAL REVIEW (CEQA):

The project is categorically exempt from the California Environmental Quality Act (CEQA) pursuant to CEQA Guidelines Section 15301 (Existing Facilities), which applies to the maintenance, repair, and minor alteration of existing public facilities involving negligible or no expansion of existing use.

BUDGET/FISCAL IMPACT:

Funding for the 2026 Digester Cleaning Project is included in the Fiscal Year 2025/26 Wastewater Fund budget.

Account Number Amount Account Name
662-60-67-57600 $207,914.58 Wastewater Fund – Other Improvements 662-60-67-57300 $185,702.25 Wastewater Fund – Buildings & Structures 662-60-67-55400 $69,268.97 Wastewater Fund – Buildings & Ground Maintenance

Staff recommend inclusion of a contingency allowance of 10% to address unforeseen conditions or additional work that may be discovered during cleaning operations. Funds for contingency are available under GL 662-60-67-55400.

RECOMMENDED COUNCIL ACTION:

Motion to:

1. Award a contract for the 2026 Digester Cleaning Project to Synagro-MT, Inc., in the amount of $462,885.80;

2. Authorize the City Engineer to increase the contract price by up to 10% ($46,288.58, for a total amount not to exceed $509,174.38) to allow for unforeseen contingencies and additional work as necessary; and

3. Authorize the City Manager to execute all applicable documents.

Consent Calendar vote.

ATTACHMENTS:

A. Digester Cleaning Project Bid Summary

Bid Summary
Agency: City of Arcata
Project: 2026 Primary Digester Cleaning
Bid Opening Date: Thursday, May 21st, 2026 11 a.m.
1 Mobilization 1 LS $22,500.00 $22,500.00
2 Digester Cleaning 1 LS $432,500.00 $432,500.00
3 Thickened Sludge Transport and Disposal (if needed) 20 TN $394.29 $7,885.80 MATCH $462,885.80
$462,885.80
Unit Price Total
Actual Total Base Bid (Calculated based on submitted unit price for each item.) Total Base Bid As Written on Submitted Bid Schedule
Item No. Description Quantity Units
Synagro-WWT, Inc.

STAFF REPORT – CITY COUNCIL MEETING
June 3, 2026
TO: Honorable Mayor and City Council Members
FROM: Netra Khatri, City Engineer
PREPARER: Mara Grow, Administrative Specialist
DATE: May 26, 2026
TITLE: Make a Continued Finding that Emergency Procurement to Repair Failed Culverts at 4700 West End Road is Necessary; and Authorize the City Manager to Execute All Applicable Documents.

RECOMMENDATION:

It is recommended that the Council:
1) Continue to find that emergency procurement to repair failed culverts at 4700 West End Road is necessary; and
2) Authorize the City Manager to execute all applicable documents.

BACKGROUND:

City staff recently identified the failure of existing 30-inch and 18-inch culverts located at 4700 West End Road, which is City-owned property that serves as the City’s ancillary corporation yard.

The failure has resulted int the formation of two sinkholes, posing a potential risk to public safety, nearby infrastructure, and aquatic resources within North Fork Janes Creek.

Due to the nature of the failure, immediate action is necessary to prevent further deterioration and to ensure safe conditions at the site.

DISCUSSION:

City staff conducted a site evaluation and confirmed that both culverts have structurally failed and are no longer functioning as intended. The resulting sinkhole indicates subsurface instability that may worsen if not addressed promptly.

These culverts convey a segment of North Fork Janes Creek under the City property and were likely installed many decades ago as part of prior lumber and plywood mill development.

City staff met with the applicable permitting agencies on April 22, 2026, to discuss the proposed emergency repairs. The agencies expressed support for expediting the work under emergency permits given the urgency and potential risks associated with delay.

Due to the emergency nature of the project, a streamlined procurement process is being utilized in accordance with City policies. This staff report serves as the recorded explanation required pursuant to the City’s emergency procurement policy. Staff requests the Council receive this report and make a determination that the proposed emergency repairs are necessary.

Update as of May 27, 2026:

Last week, crews completed installation of the 48” culvert. Currently the work is on pause until Granite Construction installs the bridge footings in mid-June. Remaining excavation for next phases is anticipated to occur early to mid-July, approximately two to three weeks after the footings are poured. Coordination efforts will continue, including working with City consultants and permitting agencies to ensure any required fish relocation is completed before final plugging and grouting of the old culverts (final phase).

To date, nesting birds have not been impacted by construction activities. Once birds have fledged, vegetation within the work area will be trimmed or removed to prevent future nesting conflicts.

ENVIRONMENTAL REVIEW (CEQA):

The proposed action qualifies for an exemption under the California Environmental Quality Act (CEQA) under 14 CCR § 15269(c) Emergency Repair: Specific actions to prevent or mitigate an emergency, including those necessary to prevent imminent loss of life or property.

BUDGET/FISCAL IMPACT:

There are currently no funds allocated in the adopted Fiscal Year 2025-26 budget for this repair.

Staff are requesting authorization to utilize reserve funds to cover the cost of the emergency repair.

The final cost will be determined upon receipt of bids; however, staff will make efforts to ensure cost-effective delivery of the project.

Use of reserve funds is justified due to the unforeseen nature of the infrastructure failure and the need for immediate corrective action.

RECOMMENDED COUNCIL ACTION:

Motion to:

1. Make a continued finding that emergency procurement to repair failed culverts at 4700 West End Road is necessary; and

2. Authorize the City Manager to execute all applicable documents.

Consent Calendar vote.

ATTACHMENTS:

A. Image of new Culvert getting installed

STAFF REPORT – CITY COUNCIL MEETING
TO: Honorable Mayor and City Council Members
FROM: David Loya, Community Development Director
PREPARER: David Loya, Community Development Director
DATE: June 3, 2026
TITLE: Approve an Amendment to the Contract with Civic Possible for the Economic Strategic Plan Update to Add $13,000 for Additional Scope – Not Subject to the California Environmental Quality Act.

RECOMMENDATION:

Staff recommends the Council approve an amendment to the contract with Civic Possible for the Economic Strategic Plan Update to add $13,000 for additional scope – not subject to the California Environmental Quality Act.

INTRODUCTION:

Civic Possible has been working with City staff to develop an economic plan. The plan approaches economic vitality through a network lens that focuses on facilitating progress on community goals through partnerships and collaboration. The implementation requires broad buy in. Staff propose to add two on-site engagements specifically for Councilmembers and staff. This amendment will add these two meetings to Civic Possible’s scope of work and increase the contract price by $13,000.

BACKGROUND:

The Council approved a contract with Civic Possible on July 30, 2025, for an amount not to exceed $140,904 with contingency. The work proposed to broaden understanding and buy in among the Council and staff was not envisioned in the original contract. Based on the nature of the proposed plan, staff believe that broadening the reach of the plan throughout the City is critical to its success.

DISCUSSION:

The proposed contract amendment will add two on-site visits for the Civic Possible team to facilitate conversations with staff and Council to improve depth and breadth of understanding.

ENVIRONMENTAL REVIEW (CEQA):

This action is not a project as defined by CEQA.

BUDGET/FISCAL IMPACT:

The additional $13,000 will be funded from the Successor Agency and will not have an impact on the General Fund.

RECOMMENDED COUNCIL ACTION:

Motion to approve an amendment to the contract for the Economic Strategic Plan Update with Civic Possible to add $13,000 for additional scope, not subject to the California Environmental Quality Act. Consent Calendar vote.

ATTACHMENTS:

A. Civic Possible Workshop Facilitation Proposal

Background
Civic* Possible is currently engaged by the City of Arcata to develop the 2026–2031 Economic Strategic Plan. The engagement has proceeded through a rigorous Discovery phase and is now concluding the Planning phase. The work has been grounded throughout in a community-centered approach and an ecosystem lens that treats economic development as a shared endeavor, sustained by the coordinated action of multiple actors across sectors and over time.

At the request of the City Manager, this proposal presents two additional services for the City's consideration: a Staff and Key Partner Workshop and a City Council Work Session. Both reflect a direct extension of the ecosystem approach that has defined this engagement. Durable implementation of the plan requires City staff, key partners, and elected leadership to develop a shared understanding of the plan's priorities and their respective roles in advancing them. These services are designed to build that foundation.

The original Professional Services Agreement was approved by Council at its July 30, 2025 special session in the amount of $122,525, with authorization for the City Manager to increase the contract by up to fifteen percent, establishing a not-to-exceed ceiling of $140,904, to address unforeseen contingencies. In October 2025, the parties executed Amendment No. 1, expanding the scope of stakeholder interviews from 25 to 60 one-on-one engagements and adding $13,125 to the contract, bringing the current total to $135,650 and leaving $5,254 within the City Manager's authorized ceiling. Pricing options for the services presented here range from $8,000 to $18,500 depending on format and staffing. Each option exceeds that remaining balance, and Council action to appropriate additional funds will be required. Upon Council direction, the parties would execute Amendment No. 2 to the Professional Services Agreement to authorize the additional scope and associated compensation.

Deliverable 1: Staff and Key Partner Workshop
Purpose
The community-centered, ecosystem-based approach that shaped this plan has a direct consequence for implementation. No single department, office, or stakeholder can carry it forward alone. Implementation will require coordinated action across city departments and with key external partners. This workshop will establish that foundation.

Civic* Possible will facilitate an in-person working session that brings together City staff and identified key partners to walk through the draft Economic Strategic Plan, examine how each participant connects to its goals, and begin building the shared ownership that sustainable implementation requires.

Scope
Civic* Possible will develop all session materials, including a facilitation guide, presentation of the draft plan, and supporting reference documents. The workshop is estimated at four hours.

Staffing Options
The City may select one, two, or three Civic* Possible team members to be present for this session. Additional team members expand facilitation depth and allow for more substantive engagement across participant groups. All pricing is flat fee and inclusive of preparation, facilitation, and travel.

Option Team Present Flat Fee
A One team member (Jason Schneider) $5,500
B Two team members $9,500
C Three team members $13,500
Deliverable 2: City Council Work Session
Purpose
Effective adoption of the Economic Strategic Plan requires that City Council members have a substantive understanding of its findings, strategic framework, and proposed priorities. This work session is designed to provide that foundation and to ensure that Council’s own perspectives, local knowledge, and policy priorities are reflected in the plan before it is finalized.

Civic* Possible will present the draft plan to Council, walk through key findings and strategic directions, and facilitate a working conversation that grounds Council members in the community and partner perspectives that shaped the plan's priorities. The goal is to ensure that Council understands how the strategy is designed to work, and what their role will be in sustaining its success over time.

Scope
Civic* Possible will prepare a Council-ready presentation and facilitate the work session. The session is estimated at two hours.

Format and Staffing Options
This session may be conducted via Zoom or in person. If conducted in person, it may be scheduled during the same site visit as the Staff and Key Partner Workshop (Deliverable 1), which substantially reduces cost, or during a separate trip. All options are presented below.

Option Format and Staffing Flat Fee
A Zoom — All team members $5,500
B In person, same trip as Workshop — one team member $2,500 C In person, same trip as Workshop — two team members $3,500 D In person, same trip as Workshop — three team members $5,000

E In person, separate trip — one team member $3,500
F In person, separate trip — two team members $6,500
G In person, separate trip — three team members $9,500
Options B through D assume this session is coordinated with the Deliverable 1 site visit.

Consolidating both deliverables into a single trip represents a meaningful reduction in total cost.

Combined Pricing
The table below presents total costs for common combinations of Deliverable 1 and Deliverable 2 selections.

Combination Total
Workshop Option A + Council Option A (Zoom) $11,000
Workshop Option A + Council Option B (same trip, 1 person) $8,000 Workshop Option B + Council Option C (same trip, 2 people) $13,000 Workshop Option C + Council Option D (same trip, 3 people) $18,500 Workshop Option A + Council Option E (separate trip, 1 person) $9,000 Next Steps
Upon selection of preferred options or shaping a separate path, the City may initiate Amendment No. 2 to the existing Professional Services Agreement to authorize and fund this additional scope of work.

STAFF REPORT – CITY COUNCIL MEETING
TO: Honorable Mayor and City Council Members
FROM: Emily Sinkhorn, Director of Environmental Services PREPARER: Emily Sinkhorn, Director of Environmental Services DATE: June 3, 2026
TITLE: Approve the Purchase of Solar Trail Lights from Fonroche for the Arcata Annie and Mary Trail Project in the Amount of $99,544.54; and Approve Necessary and Associated Related Actions.

RECOMMENDATION:

It is recommended that the Council:
1) Approve the purchase of solar trail lights from Fonroche in the amount of $99,544.54; 2) Authorize City Manager to increase the purchasing amount by up to 10% (for total not to exceed $109,498.99) to allow for any unforeseen contingencies; and 3) Authorize the City Manager to execute all applicable documents.

INTRODUCTION/BACKGROUND:

Construction is well underway on the Arcata Annie & Mary Trail Connectivity Project to provide a safe walking and biking route from the existing northern terminus of the Humboldt Bay Trail at the Arcata Skate Park to the Valley West neighborhood, the Aldergrove business park, and the Mad River at the Humboldt Bay Municipal Water District’s Park 1. While a significant portion of the trail between Sunset Ave. and north of Aldergrove Rd. is paved, active construction continues.

Completion of the Arcata Annie & Mary Trail has been a City Council priority for many years and has been a priority Capital Improvement Project. Lighting is an essential component in the design of key segments of the trail project such as between the Hinarr Hu Moulik student housing and Sunset Avenue. While the construction contract was put out to bid, the City had planned to procure trail lighting separately through cooperative purchasing agreements.

DISCUSSION:

During the planning phase for the Arcata Annie & Mary Trail project, City staff received comments to include lighting along key segments of the planned trail, particularly where students would be actively commuting between housing and the Cal Poly Humboldt campus. During the design phase it was determined that designing and installing electrical connections along the linear trail for trail lighting would greatly increase costs. In 2024, the City purchased a solar light on a 14’ pole from Fonroche and installed the light at the D Street Linear Park along a well-traveled sidewalk. Over the last year plus, City staff have monitored the effectiveness of the light and have been very satisfied with the product’s reliability and effectiveness of lighting the pedestrian travel way.

The City used Sourcewell cooperative purchasing to obtain the attached quote, which is based on a competitively bid contract. Per the City of Arcata Municipal Code, the City shall have the authority

to join with other units of government in cooperative purchasing. This procurement method satisfies public contracting requirements while allowing the City to expedite purchase of equipment.

ENVIRONMENTAL REVIEW (CEQA):

An Initial Study and Mitigated Negative Declaration (IS/MND) was prepared for the Arcata Annie & Mary Trail project and adopted by the City Council on December 9, 2022. On August 20, 2025, the Council adopted an addendum to the IS/MND. The Project changes, detailed in the addendum, did not result in new significant environmental effects or a substantial increase in the severity of effects related to the mandatory findings of significance previously addressed in the 2022 IS/MND.

BUDGET/FISCAL IMPACT:

Funding for these purchases is included within the approved Capital Improvement Program budget for the Arcata Annie & Mary Trail Project under Fund 210.

Account Number Amount Account Purpose
210-70-48-51770 $99,544.54 Arcata Annie & Mary Trail Project RECOMMENDED COUNCIL ACTION:

Motion to:

1. Approve purchase of solar lights from Fonroche in the amount of $99,544.54;

2. Authorize the City Manager to increase the purchasing amount by up to 10% (for total not to exceed $109,498.99) to allow for any unforeseen contingencies; and

3. Authorize the City Manager to execute all applicable documents.

Consent Calendar vote.

ATTACHMENTS:

A. Fonroche Quote

Fonroche Lighting America
2224 SE Loop 820, Building C
Fort Worth, TX 76140
339-225-4530
Shipping fees do not include offloading at the delivery site. It is the customer’s responsibility to arrange for any necessary equipment or personnel to unload the shipment upon arrival.

Fonroche is not in charge of or responsible for utility lines. Fonroche positions its lights on each layout to provide the proper photometric results. It is solely the responsibility of the customer to do their own due diligence in cooperation with the local utility to determine easement/spacing requirements from the utility lines, as well as any other requirements of the local utility.

Beware of Fraud: Any advance payment request will only be made on the basis of a proforma invoice sent by Fonroche Lighting America.

Shipping estimated; final cost determined on day of shipping and added to invoice.

Ship To United States
Ship To Name City of Arcata, CA
Est. Lead Time Within 6 Weeks
Quote Expiration 9/30/2026
Date
Quote Date 5/22/2026
Quote Name G9541 - Arcata CA - Annie & Mary Phase 2
Quote Number 00087415
Shipping Terms Prices are FOB Origin
50% deposit, 50% Net 30 from Ship
Date-contingent on credit approval
Payment Terms
Opportunity Owner Dale Curtis
Contract ID Sourcewell Contract: 041525-FNR
Fonroche Model Number Fonroche Product Description Price System Quantity Amount
[T54-CK16B-3K-CK16B]
[P190F-2P]HW-MC-Fixture
Color: Black
POLE: 14Ft. Round
Tapered Pole-Direct
Burial-1-4 FT Arm --Pole
Color: Black
SmartLight Assembly with 624Wh-24V NiMH Battery , special extreme temperature (from -40F to +158F), 1 x 190W solar module with Top of Pole assembly and Intelligent management/control system. Provisioned for Single Fixture configuration. Single Essential (Formerly CK16B) Fixture -Color Temp 3K -Dist. Type CK16B-Fixture Color: Black. Power Assembly color is black. Mount:

High wind and enhanced marine coating.
14Ft. Round Tapered Pole-Direct Burial-1-4 FT Arm --Pole Color is Black 8 Year Warranty All Night Lighting 365 Days a Year - Full Battery Replacement Assumes No Shading | Assumes little or no snow
10 Degrees Tilt
100% =20 Watts worst case conditions.T-PM: 5 hrs. @100% | T-N (Balance of night) @50% | T-AM: 2 hrs. @100%
USD
3,535.00 16.00 USD56,560.00
[T54-CK16B-3K-CK16B]
[P190F-2P]HW-MC-Fixture
Color: Black
POLE: 20Ft. Round
Tapered Pole-Anchor
Base-1-4 FT Arm --Pole
Color: Black
SmartLight Assembly with 624Wh-24V NiMH Battery , special extreme temperature (from -40F to +158F), 1 x 190W solar module with Top of Pole assembly and Intelligent management/control system. Provisioned for Single Fixture configuration. Single Essential (Formerly CK16B) Fixture -Color Temp 3K -Dist. Type CK16B-Fixture Color: Black. Power Assembly color is black. Mount:

High wind and enhanced marine coating.
20Ft. Round Tapered Pole-Anchor Base-1-4 FT Arm --Pole Color is Black 8 Year Warranty All Night Lighting 365 Days a Year - Full Battery Replacement Assumes No Shading | Assumes little or no snow
10 Degrees Tilt
USD
3,885.00 6.00 USD23,310.00

Fonroche Lighting America
2224 SE Loop 820, Building C
Fort Worth, TX 76140
339-225-4530
Seller's Terms and Conditions of Sale in effect on the date of this order shall apply to this quote and are hereby incorporated by reference.

Seller's Terms and Conditions of Sale may be viewed at https://www.fonrochesolarlighting.com/about-us/terms/.

Pricing is based on Fonroche Lighting America's Standard Terms & Conditions and any additional terms stipulated herein. It is the Representative's responsibility to convey these terms to the customer. Without prior written approval from Fonroche Lighting America's Sales Director, any deviation from these terms may constitute a change in this pricing at the time of order.

Quote Total USD 99,544.54
Tax USD 8,471.22
Programming,Pkg, USD 8,427.32
Ship & Handling Est.

Total Line Items USD 82,646.00
100% =20 Watts worst case conditions.T-PM: 5 hrs. @100% | T-N (Balance of night) @50% | T-AM: 2 hrs. @100%

GATEWAY
Fonroche Connect Gateway enables optional wireless networking and customer portal access. With long-range LoRA communication, you can connect one or more SmartLight Projects for monitoring and reporting. Communications included, NO MONTHLY FEES. *Requires 3G/4G/5G*
USD
1,388.00 2.00 USD2,776.00
This quotation is subject to the following terms and conditions

STAFF REPORT – CITY COUNCIL MEETING
TO: Honorable Mayor and City Council Members
FROM: Merritt Perry, City Manager’s Office
PREPARER: Danielle Allred, Contracts & Special Projects Manager DATE: May 20, 2026
TITLE: Adopt Resolution No. 256-67 Designating the City Manager, Assistant City Manager, or City Engineer as the City’s Agents Authorized to Submit Applications for Federal Financial Assistance for Any Future or Existing Grant Program.

RECOMMENDATION:

It is recommended that the Council adopt Resolution No. 256-67 designating the City Manager, Assistant City Manager, or City Engineer as the City’s agents authorized to submit applications for Federal Financial Assistance for any future or existing grant program.

INTRODUCTION:

The California Office of Emergency Services (Cal OES) requires the governing bodies of non-state agencies applying for grant programs to adopt a resolution designating which agents of the City shall be authorized to submit applications on behalf of the City of Arcata. The Resolution shall utilize Cal OES’s Financial Processing Division’s Form 130, and it shall be effective for all open and future disaster/grants declared up to three years following the date of approval. The prior Resolution No. 189-08 was adopted in 2018 and expired in 2021; therefore, a new resolution is needed for the City to apply for financial assistance opportunities available through Cal OES.

BACKGROUND:

The California Disaster Assistance Act (CDAA) authorizes the Director of the Cal OES to administer a disaster assistance program that provides financial assistance from the state for costs incurred by local governments as a result of a disaster event. Funding for the repair, restoration, or replacement of public real property damaged or destroyed by a disaster is made available when the Director concurs with a local emergency proclamation requesting state disaster assistance. The program also provides for the reimbursement of local government costs associated with certain emergency activities undertaken in response to a state of emergency proclaimed by the Governor. In addition, the program may provide matching fund assistance for cost sharing required under federal public assistance programs in response to a Presidential Major Disaster or Emergency Declaration.

On January 2, 2026, a structural fire comprised of three interconnected fires damaged multiple commercial and residential buildings, resulting in the collapse of several large structures, as well as damage to roads and sidewalks in the downtown area of Arcata. On January 3rd, the City Manager proclaimed a Local Emergency; and on April 17, 2026, the California Governor’s Office proclaimed a State of Emergency to exist in the City of Arcata due to the Arcata Fire.

DISCUSSION:

This state of emergency declaration opens the door for the City of Arcata to recuperate some of its costs for emergency response efforts in the wake of the Arcata Fire, and to apply for future funding assistance for mitigation measures that are cost-effective and substantially reduce the risk of future damage, hardship, loss or suffering in the area where the state of emergency has been proclaimed.

The proposed resolution is a necessary prerequisite to the City’s application for reimbursement for emergency response expenses and for funding assistance for mitigation measures through CDAA.

This resolution would remain in effect for three years, and would give the City Manager, Assistant City Manager, or City Engineer authority to submit applications for any other existing or future grant program as well, including, but not limited to any of the following: Federally declared Disaster; Fire Mitigation Assistance Grant; Immediate Services Program; Hazard Mitigation Grant Program; Building Resilient Infrastructure and Communities; Legislative Pre-Disaster Mitigation Program; Flood Mitigation Assistance Program; National Earthquake Hazards Reduction Program; and the California Early Earthquake Warning program.

POLICY IMPLICATIONS:

Adoption of this resolution will open doors for the City to apply for financial assistance opportunities that support the Council’s policy objective to “Implement the Capital Improvements Program to City infrastructure” and the Council’s Facilities and Infrastructure goal to provide services for residents’ safety and comfort.

BUDGET/FISCAL IMPACT:

The State share may cover up to 75 percent of the eligible costs; the City’s must satisfy a 25 percent match of the total eligible costs.

RECOMMENDED COUNCIL ACTION:

Motion to adopt Resolution No. 256-67 designating the City Manager, Assistant City Manager, or City Engineer as the City’s agents authorized to submit applications for Federal Financial Assistance for any future or existing grant program. Consent Calendar vote.

ATTACHMENTS:

A. Resolution No. 256-67 (utilizing the OES-FPD-130 form).

DESIGNATION OF APPLICANT'S AGENT RESOLUTION FOR NON-STATE AGENCIES

BE IT RESOLVED BY THE OF THE
(Governing Body) (Name of Applicant)

THAT , OR
(Title of Authorized Agent)
, OR
(Title of Authorized Agent)
(Title of Authorized Agent)
is hereby authorized to execute for and on behalf of the , (Name of Applicant)
a public entity established under the laws of the State of California, this application and to file it with the California Governor’s Office of Emergency Services for the purpose of obtaining federal financial assistance for any existing or future grant program, including, but not limited to any of the following:
- Federally declared Disaster (DR), Fire Mitigation Assistance Grant (FMAG), California State Only Disaster (CDAA), Immediate Services Program (ISP), Hazard Mitigation Grant Program (HMGP), Building Resilient Infrastructure and Communities (BRIC), Legislative Pre-Disaster Mitigation Program (LPDM), under - Public Law 93-288 as amended by the Robert T. Stafford Disaster Relief and Emergency Assistance Act of 1988, and/or state financial assistance under the California Disaster Assistance Act.
- Flood Mitigation Assistance Program (FMA), under Section 1366 of the National Flood Insurance Act of 1968.
- National Earthquake Hazards Reduction Program (NEHRP) 42 U.S. Code 7704 (b) ((2) (A) (ix) and 42 U.S. Code 7704 (b) (2) (B) National Earthquake Hazards Reduction Program, and also The Consolidated Appropriations Act, 2018, Div. F, Department of Homeland Security Appropriations Act, 2018, Pub. L. No. 115-141 - California Early Earthquake Warning (CEEW) under CA Gov Code – Gov, Title 2, Div. 1, Chapter 7, Article 5, Sections 8587.8, 8587.11, 8587.12 That the , a public entity established under the
(Name of Applicant)
laws of the State of California, hereby authorizes its agent(s) to provide to the Governor’s Office of Emergency Services for all matters pertaining to such state disaster assistance the assurances and agreements required.

STATE OF CALIFORNIA

CALIFORNIA GOVERNOR'S OFFICE OF EMERGENCY SERVICES

DESIGNATION OF APPLICANT'S AGENT RESOLUTION

NON-STATE AGENCIES
OES-FPD-130 (Rev. 10-2022)

RECOVERY DIRECTORATE

FINANCIAL PROCESSING DIVISION
Cal OES ID No: _____________
Rev. 10-2022 Page 1 of 4 OES-FPD-130
Resolution No. 256-67
023-02476 CITY COUNCIL CITY OF ARCATA CITY OF ARCATA CITY OF ARCATA THE CITY MANAGER THE ASSISTANT CITY MANAGER THE CITY ENGINEER

Please check the appropriate box below
This is a universal resolution and is effective for all open and future disasters/grants declared up to three (3) years following the date of approval.

This is a disaster/grant specific resolution and is effective for only disaster/grant number(s):

Passed and approved this __day of , 20
(Name and Title of Governing Body Representative)
(Name and Title of Governing Body Representative)
(Name and Title of Governing Body Representative)

CERTIFICATION
I, , duly appointed and of
(Name) (Title)
, do hereby certify that the above is a true and
(Name of Applicant)
correct copy of a resolution passed and approved by the (Governing Body)
of the on the day of , 20 .
(Name of Applicant)
(Signature) (Title)

STATE OF CALIFORNIA

CALIFORNIA GOVERNOR'S OFFICE OF EMERGENCY SERVICES

DESIGNATION OF APPLICANT'S AGENT RESOLUTION

NON-STATE AGENCIES
OES-FPD-130 (Rev. 10-2022)

RECOVERY DIRECTORATE

FINANCIAL PROCESSING DIVISION
Rev. 10-2022 Page 2 of 4 OES-FPD-130 CITY COUNCIL CITY OF ARCATA CITY OF ARCATA ✔ 3rd June 26 Rhea Varley City Clerk City Clerk 3rd June 26

STAFF REPORT – CITY COUNCIL MEETING
TO: Honorable Mayor and City Council Members
FROM: Keira A. Vink, Human Resources and Administrative Services Director PREPARER: Keira A. Vink, Human Resources and Administrative Services Director DATE: June 3, 2026
TITLE: Adopt Resolution No. 256-71 Approving a Temporary Hiring Freeze for Vacant Positions to Address Fiscal Conditions, Reduce the Current Budget Deficit, and Preserve General Fund Reserves; and Approve Necessary and Associated Related Actions.

RECOMMENDATION:

It is recommended that the Council:
1) Adopt Resolution No. 256-71 Approving a Temporary Hiring Freeze for Vacant Positions to Address Fiscal Conditions, Reduce the Current Budget Deficit, and Preserve General Fund Reserves; and
2) Authorize City Manager or their designee to execute all applicable documents.

BACKGROUND:

The City Council of the City of Arcata is responsible for the adoption of the annual Fiscal Year budget. City staff are currently preparing the Fiscal Year 2026-2027 Operating Budget based upon guidance and priorities of the City Council.

DISCUSSION:

The City of Arcata revenue streams are declining and the cost for personnel, services, and supplies are going up. This has created increased fiscal pressures for the City, and the City Council has found it necessary to implement temporary expenditure controls. One way to control costs and achieve fiscal savings is to reduce staffing. In an effort to avoid a reduction in force, the City is recommending an approach by holding vacancies open to achieve salary and benefit savings instead of reducing current staff. A temporary hiring freeze is one solution of many the City will implement throughout the Fiscal Year 2026-2027.

The hiring freeze will remain in effect until rescinded by the City Council of the City of Arcata.

POLICY IMPLICATIONS:

All vacant positions shall be reviewed to determine if the position will be filled or remain vacant.

There will be a consistent process implemented with a thorough examination of each vacant position as to whether the position will remain vacant and when it will be filled.

BUDGET/FISCAL IMPACT:

For each position which is held vacant the City could realize salary and benefit savings of $75,000 to $150,000 on an annual basis.

RECOMMENDED COUNCIL ACTION:

Motion to:

1. Adopt Resolution 256-71 Approving a Temporary Hiring Freeze for Vacant Positions to Address Fiscal Conditions, Reduce the Current Budget Deficit, and Preserve General Fund Reserves. Consent Calendar vote; and

2. Authorize City Manager or designee to execute all applicable documents.

Consent Calendar vote.

ATTACHMENTS:

A. Resolution 256-71 Temporary Hiring Freeze of Vacant Positions

RESOLUTION NO. 256-71

A RESOLUTION OF THE CITY COUNCIL OF THE CITY OF ARCATA

ESTABLISHING A TEMPORARY HIRING FREEZE FOR VACANT POSITIONS TO

ADDRESS FISCAL CONDITIONS, REDUCE THE CURRENT BUDGET DEFICIT

AND PRESERVE GENERAL FUND RESERVES
WHEREAS, the City Council of the City of Arcata is responsible for adopting the annual Fiscal Year (FY) budget before July 1st each year; and WHEREAS, maintaining the fiscal stability and long-term financial sustainability of the City is a priority and goal of the City Council; and WHEREAS, the City Council finds it necessary to implement temporary expenditure controls in order to protect essential public services, maintain adequate reserve levels, and reduce projected budget deficits; and
WHEREAS, the Arcata is currently preparing and considering the Fiscal Year 2026– 27 Operating Budget; and
WHEREAS, the City is experiencing increasing fiscal pressures resulting from inflationary impacts, increased costs for salaries and benefits, rising insurance premiums, escalating costs for goods and services, infrastructure needs, and slowing or uncertain revenue growth; and
WHEREAS, the City Council finds that prudent fiscal management requires the implementation of temporary expenditure controls in order to preserve essential public services, maintain fiscal stability, and protect the long-term financial health of the City; and WHEREAS, personnel costs represent the City’s largest General Fund expenditure and temporary vacancy controls can assist the City in reducing projected deficit spending while allowing the City Manager and City Council additional time to evaluate long-term staffing and service level needs; and
WHEREAS, the City Council recognizes the need to maintain staffing for critical public safety, legally mandated, revenue-supported, and operationally essential services; and WHEREAS, the City Council desires to implement a temporary hiring freeze applicable to vacant positions while allowing limited exemptions where necessary to protect public health, safety, welfare, and continuity of essential City operations.

NOW, THEREFORE, BE IT RESOLVED by the City Council of the City of Arcata as follows:

Section 1. Purpose
The purpose of this Resolution is to implement a temporary hiring freeze for vacant positions in order to reduce expenditures and preserve fiscal stability during the current budget period.

Section 2. Hiring Freeze Established
Effective immediately upon adoption of this Resolution, all recruitment, hiring, and filling of vacant full-time, part-time, temporary, seasonal, and retired-annuitant positions are suspended unless specifically exempted under this Resolution.

Section 3. Exempt Positions
The following positions or categories may be exempt from the hiring freeze upon approval by the City Manager:

1. Positions necessary for public health and safety;

2. Positions required to maintain minimum staffing levels for emergency response;

3. Positions necessary to comply with federal or state law, court order, permit requirement, or regulatory mandate;

4. Positions funded entirely by restricted grants or external funding sources;

5. Positions determined by the City Manager to be critical to essential City operations or revenue generation;

6. Internal promotions or reassignments that do not increase overall staffing levels or budgeted costs.

Section 4. Review of Vacancies
All currently vacant positions shall be reviewed by the City Manager, Assistant City Manager/Finance Director, and HR/Administrative Services Director to determine:
• Whether the position is essential;
• Whether duties may be reassigned;
• Whether the position should remain vacant; and/or
• Whether the position should be eliminated through a future budget process.

Section 5. Duration
This hiring freeze shall remain in effect until rescinded by the City Council.

Section 6. Reporting
The City Manager shall periodically report to the City Council regarding:
• Positions held vacant;
• Estimated salary and benefit savings;
• Operational impacts resulting from the hiring freeze; • Any exemptions approved under this Resolution.

Section 7. Implementation Authority
The City Manager is authorized to implement administrative procedures necessary to carry out this Resolution.

Section 8. Severability
If any section, subsection, sentence, clause, or phrase of this Resolution is for any reason held invalid or unconstitutional, such decision shall not affect the validity of the remaining portions of this Resolution.

SECTION 9. This Resolution shall become effective upon its adoption.

DATED:

ATTEST: APPROVED:

City Clerk, City of Arcata Mayor, City of Arcata

CLERK'S CERTIFICATE
I hereby certify that the foregoing is a true and correct copy of Resolution No.256-71, passed and adopted at a regular meeting of the City Council of the City of Arcata, Humboldt County, California, held on the ____ day of June 3, 2026 by the following vote:

AYES:

NOES:

ABSENT:

ABSTENTIONS:

City Clerk, City of Arcata

STAFF REPORT – CITY COUNCIL MEETING
TO: Honorable Mayor and City Council Members
FROM: Keira Vink, Human Resources and Administrative Services Director PREPARER: Keira Vink, Human Resources and Administrative Services Director DATE: June 3, 2026
TITLE: Adopt Resolution No. 256-68 Approving a Voluntary Retirement Health Incentive Program for City of Arcata Employees; and Approve Necessary and Associated Related Actions.

RECOMMENDATION:

It is recommended that the Council:
1) Adopt Resolution No. 256-68 Approving a Voluntary Retirement Health Incentive Program for City of Arcata Employees; and
2) Authorize City Manager or designee to execute all applicable documents.

INTRODUCTION:

The City of Arcata is entering into a tight economic climate due to a variety of reasons. Personnel costs are the largest expenditure for the General Fund, and the City is looking to implement a number of strategies to reduce expenditures. A reduction in staffing is one strategy which can be effective. The City is proposing an incentive for those who wish to retire, and this allows for reduced staffing costs which may prevent the City from having to reduce City staffing through a reduction in force.

BACKGROUND:

City of Arcata employees participate in the CalPERS retirement system, and their retirement formula is based upon their date of hire. In order to receive the maximum benefit, there are age limits as to when an employee is eligible for their full retirement which ranges from age fifty to age sixty-two.

In addition, there is a minimum age to retire which the employee may retire and receive a reduced benefit. All of the City of Arcata formulas have a minimum retirement age of fifty or fifty-two.

Most City of Arcata employees who retire will not qualify for Medicare until they turn age 65 leaving an extended period of time which the retiree has to pay for insurance on the private individual market if they are not covered by a family member.

DISCUSSION:

Staff propose to give a cash incentive to those employees who wish to retire but have chosen not to due to medical insurance. By giving a lump sum to the retiree with their final paycheck, the retiree would have a safety net to pay for medical premiums while they are contemplating other available options for medical insurance.

To allow the City to continue appropriate budget planning, employees would need to submit their committed retirement date no later than Friday, July 31, 2026.

Retirees who qualify and are approved for the retirement incentive shall receive a lump sum cash payment included in their final paycheck equal to six (6), nine (9), or twelve (12) months of the monthly medical premium depending on their retirement date and level of coverage (i.e. Employee Only, Employee + 1, Family) selected at open enrollment for the 2026 Plan Year.

Retirement Date Cash Incentive Amount
On or Before September 1, 2026 12 months of Medical Premiums On or Before November 1, 2026 9 months of Medical Premiums After November 1, 2026, and On or Before
December 31, 2026
6 months of Medical Premiums
POLICY IMPLICATIONS:

A defined program gives all employees who are eligible to retire an opportunity to apply for the Voluntary Retirement Health Incentive Program and be considered for approval.

The City reserves the right to administer layoffs as determined necessary.

BUDGET/FISCAL IMPACT:

For each position which is held vacant the City could realize salary and benefit savings of $75,000 to $150,000 on an annual basis.

RECOMMENDED COUNCIL ACTION:

Motion to:

1. Motion to Adopt Resolution No. 256-68 Approving a Voluntary Retirement Health Incentive Program for City of Arcata Employees; and

2. Authorize City Manager or designee to execute all applicable documents.

Consent Calendar vote.

ATTACHMENTS:

A. Resolution 256-68 Voluntary Retirement Health Incentive Program

RESOLUTION NO. 256-68

A RESOLUTION OF THE CITY COUNCIL OF THE CITY OF ARCATA

APPROVING THE CITY OF ARCATA

VOLUNTARY RETIREMENT HEALTH INCENTIVE PROGAM
WHEREAS, City of Arcata employees participate in the CalPERS retirement system and the minimum age to retire in the existing formulas is age 50 or age 52; and, WHEREAS, most City of Arcata employees who retire will not qualify for Medicare until they turn age 65 leaving an extended period of time which the retiree has to pay for insurance on the private individual market; and,
WHEREAS, the cost of health insurance on the employer market or the private individual market has risen considerably in the last five years making it very difficult for individuals to retire prior to reaching age 65 unless they find other benefitted employment or are covered on a family member’s plan: and,
WHEREAS, as the City is entering into a tight economic climate with personnel costs being the largest expenditure for the General Fund, creating an incentive for those who wish to retire allows for reduced staffing costs which may prevent the City from having to reduce City staffing through a reduction in force.

NOW, THEREFORE, BE IT RESOLVED by the City Council of the City of Arcata does hereby approve and establish the attached Administrative Policy and Procedure for the Voluntary Retirement Health Incentive Program, effective upon adoption.

DATED: June 3, 2026
ATTEST: APPROVED:

Rhea Varley, City Clerk, City of Arcata Kimberley White, Mayor, City of Arcata

Clerk’s Certificate
I hereby certify that the foregoing is a true and correct copy of Resolution 256-68, passed and adopted at a regular meeting of the City Council of the City of Arcata, Humboldt County, California, held on the 3rd of June in the year 2026, by the following vote:

AYES:

NOES:

ABSENT:

ABSTENTIONS:

Rhea Varley, City Clerk

1 VOLUNTARY RETIREMENT HEALTH INCENTIVE PROGRAM
(July 1, 2026 – December 31, 2026)
I. Eligibility and Participation
A. Classifications eligible for the Voluntary Retirement Incentive Program will be determined by the City Manager or designee and will consider the position’s impact to the General Fund and/or General Fund savings that can be realized by potential organization restructure as a result of the vacancy created by the retirement.

B. Employee must currently be employed by the City of Arcata and occupy a full-time regular allocated position that is participating in the CalPERS retirement system and must be able to retire under the CalPERS retirement system.

C. Must be vested with CalPERS and meet the minimum age requirement to be eligible for retirement from CalPERS:

D. The voluntary retirement date must be on or before December 31, 2026. To allow the City to continue appropriate budget planning, employees shall submit the Voluntary Retirement Health Incentive Form to Human Resources indicating the retirement date no later than Friday, July 31, 2026.

Retirement Date Cash Incentive Amount
On or Before September 1, 2026 12 months of Medical Premiums On or Before November 1, 2026 9 months of Medical Premiums After November 1, 2026, and On or Before
December 31, 2026
6 months of Medical Premiums
Formula Minimum Retirement Age
Miscellaneous

2.7%@55 50
2%@55 50
2%@62 52
Safety 3%@50 50
3%@55 50

2.7%@57 50

2 E. The City reserves the right to administer layoffs as determined necessary. If an involuntary layoff precedes an employee’s committed retirement date, the employee will no longer be eligible for the Retirement Health Incentive. By mutual agreement between the employee and the City, an employee may elect to modify their retirement date prior to being laid off in order to exercise the Voluntary Retirement Incentive agreement, and forego their lay off rights and associated benefits.

F. If the employee is approved for the Voluntary Retirement Incentive but is released from employment prior to their retirement date, the retirement cash incentive will be null and void.

G. The City Manager or in his absence the Assistant City Manager or the Human Resources and Administrative Services Director have the authority to change the terms and conditions of the Voluntary Retirement Health Incentive Program including but not limited to reducing participation, changing program deadlines, and/or extending the program into Fiscal Year 2027-2028.

II. Cash Payment Incentive
A. Retirees who qualify and are approved for the retirement incentive shall receive a lump sum cash payment included in their final paycheck equal to six (6), nine (9), or twelve (12) months of the monthly premium depending on their retirement date and level of coverage (i.e. Employee Only, Employee + 1, Family) selected at open enrollment for the 2026 Plan Year.

Description Coverage Benefit Six Months Nine Months Twelve Months Blue Cross Traditional HMO Single $ 1,612.08 $ 9,672.48 $ 14,508.72 $ 19,344.96 Blue Cross Traditional HMO 2-Party $ 3,224.16 $ 19,344.96 $ 29,017.44 $ 38,689.92 Blue Cross Traditional HMO Family $ 4,191.41 $ 25,148.46 $ 37,722.69 $ 50,296.92 Blue Shield Access+ Single $ 1,301.95 $ 7,811.70 $ 11,717.55 $ 15,623.40 Blue Shield Access+ 2-Party $ 2,603.90 $ 15,623.40 $ 23,435.10 $ 31,246.80 Blue Shield Access+ Family $ 3,385.07 $ 20,310.42 $ 30,465.63 $ 40,620.84 Western Health Advantage Single $ 969.58 $ 5,817.48 $ 8,726.22 $ 11,634.96 Western Health Advantage 2-Party $ 1,939.16 $ 11,634.96 $ 17,452.44 $ 23,269.92 Western Health Advantage Family $ 2,520.91 $ 15,125.46 $ 22,688.19 $ 30,250.92 PERS Gold Single $ 1,120.58 $ 6,723.48 $ 10,085.22 $ 13,446.96 PERS Gold 2-Party $ 2,241.16 $ 13,446.96 $ 20,170.44 $ 26,893.92 PERS Gold Family $ 2,913.51 $ 17,481.06 $ 26,221.59 $ 34,962.12 PERS Platinum Single $ 1,670.14 $ 10,020.84 $ 15,031.26 $ 20,041.68 PERS Platinum 2-Party $ 3,340.28 $ 20,041.68 $ 30,062.52 $ 40,083.36 PERS Platinum Family $ 4,342.36 $ 26,054.16 $ 39,081.24 $ 52,108.32 PORAC Single $ 1,063.00 $ 6,378.00 $ 9,567.00 $ 12,756.00 PORAC 2-Party $ 2,418.00 $ 14,508.00 $ 21,762.00 $ 29,016.00 PORAC Family $ 3,027.00 $ 18,162.00 $ 27,243.00 $ 36,324.00

3 B. Opting for the retirement health incentive does not restrict the employee from electing COBRA medical coverage at their full cost; or the applicable Retiree Health benefit as provided in the employee’s current applicable MOU or Resolution, at the defined cost share amounts for the Retiree and the City.

C. Employee may elect to receive the lump sum payment as a deferred compensation contribution. Should the lump sum payment be more than what is allowed for the employee to contribution, the remainder will be paid out.

D. All cash payments will be considered reportable income by the IRS and will be required to be included on your W-2.

E. Lump sum payments are not eligible to be considered as part of final compensation for CalPERS purposes.

STAFF REPORT – CITY COUNCIL MEETING
TO: Honorable Mayor and City Council Members
FROM: Keira A. Vink, Human Resources and Administrative Services Director PREPARER: Keira A. Vink, Human Resources and Administrative Services Director DATE: June 3, 2026
TITLE: Adopt Resolution No. 256-69 Approving A Corrected Letter of Agreement Between the City of Arcata and Arcata Police Association to Amend the 2024– 2027 Memorandum of Understanding Regarding Medical Benefits; and Authorize City Manager to Execute Documents.

RECOMMENDATION:

It is recommended that the Council:
1) Adopt Resolution No. 256-69 to approve a Corrected Letter of Agreement between City of Arcata and the Arcata Police Association to Amend Article 10, Section 10.1 of the 2024-2027 Memorandum of Understanding; and
2) Authorize the City Manager to execute all applicable documents.

INTRODUCTION:

The Meyers-Milias-Brown Act (MMBA) is the law in California that establishes mandatory rights and duties by which all local agencies must abide with regard to labor relations. Within the requirements of the MMBA, the City’s negotiators received authority from the City Council on matters within the scope of representation and then proceeded to meet and confer with the Arcata Police Association to reach an agreement on the subject. The agreement is formalized by a signed Memorandum of Understanding or Letter of Agreement (side letter) which is then brought before the governing body for final approval.

BACKGROUND:

The City of Arcata has had a long-term partnership with the Redwood Empire Municipal Insurance Fund (REMIF) to offer medical insurance to the City of Arcata full-time employees and select annuitants. This plan has served the City well for more than fifteen years. As the insurance market changes and medical costs increase, a smaller pool of municipalities is not able to survive the volatility of the market. The REMIF medical insurance plans will be terminating as of June 30, 2026.

DISCUSSION:

The City of Arcata has completed a diligent search for medical insurance plans to begin effective July 1, 2026, for all eligible employees and annuitants. CalPERS medical insurance plans were chosen by the City as the city sponsored medical insurance plans. Based on our local area, there will

be a choice of five medical plans for general members and six medical plans for safety members available to employees.

The City notified the Arcata Police Association as under MMBA payment of medical insurance premiums is a mandatory subject of bargaining. The parties met on one occasion and negotiated in good faith. The City of Arcata and the Arcata Police Association (APA) came to an agreement regarding the portion of the medical premiums which would be the responsibility of the City and the portion which would be the responsibility of employees represented by APA. A letter of agreement was signed by the City Manager and the President of the Arcata Police Association and originally approved by the City Council on May 6, 2026. It was discovered shortly afterwards that the Anthem Blue Cross medical plan name and premium were incorrected in the approved letter of agreement.

The corrected letter of agreement is before the City Council for approval.

BUDGET/FISCAL IMPACT:

Health benefits for employees including medical, dental, vision, EAP, and life insurance are included in salary costs for each Department’s operating budget.

RECOMMENDED COUNCIL ACTION:

Motion to:

1. Adopt Resolution No. 256-69 approving a Corrected Letter of Agreement between the City of Arcata and the Arcata Police Association to Amend Article 10, Section 10.1 of the 2024-2027 Memorandum of Understanding; and

2. Authorize the City Manager to execute all applicable documents.

Consent Calendar vote.

ATTACHMENTS:

A) Resolution 256-69 to Approve the Corrected Letter of Agreement Between City of Arcata and the Arcata Police Association to Amend Article 10, Section 10.1 of the 2024-2027 Memorandum of Understanding.

B) Corrected Letter of Agreement Between City of Arcata and the Arcata Police Association to Amend Article 10, Section 10.1 of the 2024-2027 Memorandum of Understanding.

RESOLUTION NO. 256-69

A RESOLUTION OF THE CITY COUNCIL OF THE CITY OF ARCATA

APPROVING A LETTER OF AGREEMENT BETWEEN THE CITY OF ARCATA

AND ARCATA POLICE ASSOCIATION
WHEREAS, on April 22, 2026, when the City Council of the City of Arcata adopted Resolution 256-58 the City of Arcata entered into an agreement with CalPERS to offer the CalPERS medical plans to the City of Arcata employees; and,
WHEREAS, the payment of medical plan premiums are a negotiated benefit under the MMBA (Meyer Milias Brown Act) and the Arcata Police Association is the exclusive representative for the police department employees; and,
WHEREAS, the City of Arcata and the Arcata Police Association came to an agreement in regard to the portion of the medical premiums the Arcata Police Association represented employees would pay and the portion of the medical premiums the City would pay; and, WHEREAS, a letter of agreement was signed by the Arcata Police Association President and the City Manager of the City of Arcata to modify Article 10, Section 10.1, of the Memorandum of Understanding between the City of Arcata and the Arcata Police Association in regards to medical benefits and it was approved at the May 6, 2026 City Council meeting; and,
WHEREAS, the letter of agreement brought before the City Council on May 6, 2026, contained the incorrect Anthem Blue Cross health plan and the incorrect plan premiums. In order to provide accurate information to the employee labor organizations and the general public a corrected letter of agreement is brought before the City Council; and,
NOW, THEREFORE, BE IT RESOLVED by the City Council of the City of Arcata does hereby approve the attached Letter of Agreement between the City of Arcata and the Arcata Police Association, effective upon adoption.

DATED: June 3, 2026
ATTEST: APPROVED:

City Clerk, City of Arcata Mayor, City of Arcata

Clerk’s Certificate
I hereby certify that the foregoing is a true and correct copy of Resolution 256-69, passed and adopted at a regular meeting of the City Council of the City of Arcata, Humboldt County, California, held on the 3rd day of June 2026, by the following vote:

AYES:

NOES:

ABSENT:

ABSTENTIONS:

City Clerk, City of Arcata

STAFF REPORT – CITY COUNCIL MEETING
TO: Honorable Mayor and City Council Members
FROM: Emily Sinkhorn, Director of Environmental Services PREPARER: Doug Culbert, Deputy Director of Environmental Services, Streets & Utilities DATE: June 3, 2026
TITLE: Hold a Hearing to Consider Abatement for the Properties Located at 4600 West End Road, Arcata, CA 95521, Assessor's Parcel No. 507-081-055; and Terminate Abatement Proceedings Due to the Property Owner Having Successfully Abated the Nuisance.

RECOMMENDATION:

It is recommended that the Council:

1. Open the hearing, receive testimony from the Deputy Director of Environmental Services, Streets & Utilities, and/or the Building Official, receive the property owner’s testimony, hear testimony of other persons, and close the hearing.

2. Close the hearing due to the property owner having successfully abated the nuisance at 4600 West End Road.

INTRODUCTION:

On February 19, 2026, the Building Official, at the request of Environmental Services, initiated enforcement proceedings regarding municipal code violations at 4600 West End Rd., by issuing a Notice of Nuisance to the property owner pursuant to Arcata Municipal Code (AMC) Section 5504 and causing notice of the nuisance to be recorded with the Humboldt County Clerk-Recorder.

On April 15, 2026, following a duly noticed public hearing, the City Council considered the matter and granted the property owner an additional thirty (30) days to complete abatement of the nuisance conditions. As of May 11, 2026, City staff confirmed that the nuisance conditions had not been abated, and the violations identified in the Notice of Nuisance remained unresolved.

The additional compliance period granted by the City Council has now expired, and the nuisance conditions have been abated by the property owner. The matter is only returning to the City Council due to the hearing being continued from the May 20, 2026, City Council meeting.

DISCUSSION:

In summary, due to the condition of the residence and property, notices were sent on the following dates:
 February 19, 2026 – Notice of Nuisance (Recorded)
 March 30,2026 – Notice to Abate Nuisance (by Certified Mail and Posted)

 April 15, 2026 – Public Hearing Scheduled; Council voted to give Property Owner 30 more days to abate
 May 5, 2026 – Second Notice to Abate Nuisance (by Certified Mail and Posted)  May 15, 2026 – Nuisance not abated
 May 20, 2026 – Council continued the hearing to the June 3, 2026, Council meeting  As of May 29, 2026, the property owner has abated the nuisance.

BUDGET/FISCAL IMPACT:

None given that the property owner has now abated the nuisance.

RECOMMENDED COUNCIL ACTION:

1. Open the hearing to consider abatement for the Properties Located at 4600 West End Rd., Arcata, CA 95521, Assessor’s Parcel No. 507-081-055;

2. Receive testimony from the Deputy Director of Environmental Services—Streets & Utilities, and/or the Building Official;

3. Receive the property owner’s testimony;

4. Open public comment;

5. Close public comment; and

6. Motion to close the hearing and terminate abatement proceedings due to the property owner having successfully abated the nuisance at 4600 West End Road.

STAFF REPORT – CITY COUNCIL MEETING
TO: Honorable Mayor and City Council Members
FROM: Emily Sinkhorn, Director of Environmental Services PREPARER: Emily Sinkhorn, Director of Environmental Services DATE: June 3, 2026
TITLE: Receive a Presentation on the Final Arcata Wastewater Treatment Facility (AWTF) Feasibility Study and Potential Future Projects at the AWTF; and Provide Direction to Staff on a Preferred Alternative.

RECOMMENDATION:

It is recommended that the Council:
1) Receive a presentation on the final Arcata Wastewater Treatment Facility (AWTF) Feasibility Study and potential future projects at the AWTF and review questions with staff. 2) Open public comment.
3) Close public comment.
4) Provide direction to staff on a preferred alternative.

INTRODUCTION:

While the Phase I Arcata Wastewater Treatment Facility (AWTF) Improvement Project was only recently completed with a ribbon cutting celebration planned for June 10, 2026, City staff continue to prepare for next steps at the AWTF to ensure high quality wastewater effluent, efficient operations and reliability for Arcata residents and rate payers.

A Feasibility Study was recently completed to evaluate strategies to protect, relocate, or otherwise adapt the City’s wastewater facilities to maintain safety and regulatory compliance and prepare for future sea level rise and coastal hazards beyond 2055 – the design life of the AWTF Improvement Phase I Project. Additionally, the City continues to advance multiple concurrent efforts related to the AWTF including the advancement of a sea level rise adaptation plan, conceptual designs for the Levee Augmentation Project and planning for additional wastewater treatment upgrades to ensure compliance with upcoming water quality standards.

BACKGROUND:

After over a decade of planning, the City has completed its largest ever capital improvement project, the AWTF Phase I Improvement Project which has replaced aging critical infrastructure, upgraded wastewater disinfection to an ultraviolet (UV) system, eliminated disinfection byproducts associated with the prior chlorine disinfection, created a new effluent outfall to Humboldt Bay, reconfigured to a single pass flow through the treatment facility and enhancement marshes and enhanced wastewater effluent water quality while protecting coastal resources. The City looks forward to celebrating these accomplishments with the Arcata community, state representatives, funders and stakeholders at a ribbon cutting event on June 10, 2026, at the AWTF. While there is much to celebrate with the

milestone of Phase I completion, additional needs remain at the AWTF to fully complete planned wastewater treatment upgrades and ensure reliability into the future for Arcata residents.

A special condition of the City’s Coastal Development Permit (CDP) for the Phase I Improvement Project required the City to formally assess alternatives to future levee augmentation at the core area of the AWTF in order to prepare the wastewater facilities for sea level rise beyond the design life of the Phase I improvements around 2055. The CDP special condition requested the City analyze a range of alternatives for AWTF treatment location and disposal mechanism including a retreat alternative and consolidation with another district/municipality.

The Feasibility Study commenced in summer 2024 with technical assistance funding from the State Water Board’s Division of Financial Assistance to third-party Rural Communities Assistance Corporation (RCAC). RCAC sought proposals for engineering and environmental support and selected GHD as a subcontractor. Over the course of the feasibility study process, City staff and the project team engaged monthly with Water Board and Coastal Commission staff, conducted targeted stakeholder outreach with other municipalities and districts in the Humboldt Bay area and throughout California, and provided multiple opportunities for community involvement. Project staff presented the draft Feasibility Study to the City Council on January 21, 2026, and the study was finalized in March 2026.

DISCUSSION:

Feasibility Study Summary
During the presentation on the draft Feasibility Study to the Council in January, staff shared that once the study was finalized, this item would be brought back to the Council for further direction.

The Final AWTF Feasibility Study has been completed and is attached to this staff report. The full document with appendices is located on the City’s webpage at https://www.cityofarcata.org/1099/Arcata-Wastewater-Treatment-Facility-Fea. The City is grateful for the participation of the project team, regulatory agencies, staff from other local municipalities and districts and members of the public in
In its CDP for the Phase I project, the City demonstrated operability and functionality of infrastructure improvements at the AWTF through the design life of the Phase I project – 2055. The Feasibility Study was intended to analyze options for the AWTF after 2055 if the City took no further action at the existing AWTF.

The Feasibility Study analyzed a range of alternatives for wastewater treatment location and disposal mechanism including retreat alternatives and consolidation with another district/municipality with some options determined to be infeasible for Arcata (e.g. groundwater injection, surface water discharge or a new ocean outfall). The alternatives utilized a range of and sometimes a combination of adaptation methodologies from accommodation of sea level rise to protection strategies and retreat strategies. Below is a table detailing AWTF adaptation alternatives deemed feasible and fully analyzed in the study:

The City held several opportunities for community involvement in this project including two public workshops with goals to inform the community on the AWTF Feasibility Study and efforts to address sea level rise and discuss and solicit input on adaptation strategies through envisioning future AWTF retreat and protection scenarios.

Community input on the project and potential adaptation alternatives spanned a wide range with key discussion points including:
 Need for attention to cost-effectiveness leveraging project phasing, grants, and potential consolidation opportunities to reduce impact on rate payers  Ensure maintenance of the ecological and recreation benefits of the Arcata Marsh which is integral to Arcata’s culture and values
 Consider land banking for future retreat for the wastewater treatment facility and careful attention to the future site characteristics and aesthetics

 Significant concern about sea level rise and its impact on marshlands and surrounding areas, with calls for measured retreat and improved protection strategies  Ensure alignment of AWTF adaptation with overall Arcata shoreline adaptation strategy The Feasibility Study developed criteria for assessing alternatives including non-negotiable criteria (such as constructability, meets regulatory requirement, minimal environmental impacts) and more flexible considerations informed through community input during the project’s first workshop in November 2024. The Feasibility Study also leveraged coastal hazard and sea level rise vulnerability and risk analyses from the Coastal Commission-funded Arcata Sea Level Rise Vulnerability & Risk Assessment (2024-2025).

The project team then developed feasibility level cost estimates for construction, annual ongoing operations and maintenance, and life cycle costs for each alternative which are detailed below:

Following a rigorous analysis utilizing community-prioritized criteria and identified constraints, estimated costs, and monthly consultation with Coastal Commission, Regional Board and State Water Board staff, three of these feasible adaptation alternatives were advanced as preferred alternatives:
 Alternative 1: Augment AWTF Levees and Maintain and Adaptive Management of the Enhancement Marshes
 Alternative 7: AWTF Retreat with Humboldt Bay Discharge: Relocate AWTF and Develop a New Enhancement Project

 Alternative 8: AWTF Retreat with Ocean Discharge: Relocate AWTF and utilize the Humboldt Bay Harbor, Recreation and Conservation District’s Redwood Marine Terminal II ocean outfall for discharge
Staff will present in further detail regarding each of these preferred alternatives. These preferred alternatives balanced the need for near-term protection, with long-term sustainability of treatment while providing options for the City to pursue around future uncertainties.

Previously Envisioned AWTF Phase II Project and Levee Augmentation Project The City initially planned to complete Phase I and II AWTF Improvements and Levee Augmentation together as one large, permitted project. The CEQA document (an Initial Study and Mitigated Negative Declaration) prepared in 2020 for these proposed AWTF Improvements analyzed potential environmental impacts of each of these phases.

While Phase I has neared completion, City staff recognize that additional improvements are still needed to ensure compliance with upcoming water quality standards and further protect the City’s investments at the AWTF up to federal standards for flood protection.

In 2022-23 the City received a grant from CalOES-FEMA for design and construction of levee augmentation around the core AWTF and oxidation ponds to ensure protection to a 100-year flood event. The City has been concurrently pursuing levee augment design through this grant while next steps were put on hold until the completion of the AWTF Feasibility Study. City staff anticipate CalOES will complete review of preliminary designs and environmental documentation in early 2027 and approve advancing to the full design phase.

Additionally as part of the City’s National Pollutant Discharge Elimination System (NPDES) permit to operate the AWTF, the City is required by the North Coast Regional Water Quality Control Board (Regional Board) to complete additional improvements at the AWTF through a Time Schedule Order (TSO) to comply with stricter water quality standards effective upon completion of Phase II Improvements.

As conceptually designed, the previously envisioned Phase II would require additional space within the existing core AWTF and Corporation Yard dedicated to wastewater treatment, which would include the construction of new oxidation ditches to augment the existing treatment train’s capacity to meet ammonia water quality standards for wastewater effluent implemented by the state. As such, City staff are concurrently planning for a measured retreat of some Corporation Yard functions out of 600 South G Street. With the mid-year 2025-26 budget update the City Council approved moving forward with a City-wide Facilities Assessment which would assess opportunities for existing City facilities and plan for future facility needs such as relocating the entirety of City Corporation Yard functions outside of the AWTF. Additionally, City staff are currently engaged in an emergency culvert repair at the 4700 West End ancillary Corp Yard to ensure this facility can continue to function for public works purposes.

The Coastal Commission’s requirement to remove Phase II and Levee Augmentation from the AWTF Improvement Project’s Coastal Development Permit and only proceed with Phase I did enable a third-party to analyze in detail the potential alternatives for the future of wastewater treatment in Arcata, ensure community members could be involved in the analysis and provide feedback, and develop clear considerations and criteria with which to analyze potential alternatives.

However, the requirement to complete this Feasibility Study, a process taking nearly three years, also greatly delayed the City in meeting the timelines for Phase II completion in the City’s TSO with the Regional Board, cost the City and ratepayers millions of dollars in grants and low interest loans

from the State Water Board’s Division of Financial Assistance that could have funded the City to design and implement Phase II and has resulted in cost escalations for any subsequent project at the AWTF.

While Regional Board staff were closely involved throughout the duration of this Feasibility Study, TSOs typically cannot be extended beyond a statutory time limit and may result in a future enforcement action against the City by the Regional Board as the furthest extended Proposed Compliance Dates (2027-2029) associated with progress towards completing Phase II are now not feasible to meet.

Completion of the Feasibility Study was a requirement from the Coastal Commission, and supported by Regional Board and State Water Board staff, before any new Coastal Development Permit associated with the AWTF would be considered. As such the Levee Augmentation Project and previously envisioned Phase II treatment upgrades have been on hold.

Next Steps and Staff Recommendation
City staff are seeking Council direction on next steps for the AWTF including the selection of a preferred alternative from the AWTF Feasibility Study in order to inform the direction of future action. The City needs to act soon to implement next steps for the AWTF as key compliance timelines with the Regional Board are already passing and to proactively adapt to sea level rise.

After careful consideration of the analyses in the Feasibility Study, staff recommend pursuing Alternative 1: Augment AWTF Levees and Maintain and Adaptive Management of the Enhancement Marshes. Alternative 1 and continuing to invest in the existing AWTF is in alignment with the recently adopted Local Coastal Program (LCP), is most protective of the environment and coastal resources and is most cost effective for Arcata ratepayers.

While selecting Alternative 1 would provide direction to continue to invest in the existing AWTF location, City staff also recommend continuing to monitor and plan for eventual measured retreat from the facility, just on a timeline further out from 2055. A phased approach with levee augmentation and additional required treatment upgrades in the next 3-7 years coupled with continual monitoring of water surface elevations and storm events and planning for measured retreat will buy time to implement long-term adaptation solutions for wastewater treatment in Arcata on a time frame more in alignment (80-100+ years) with the City’s LCP.

The existing AWTF is located in the adopted LCP’s Sea Level Rise Adaption Zone 1 where the City plans to continue to protect current development and potential redevelopment endangered from flooding. As the LCP notes, Zone 1 “includes residential, commercial, recreational, and industrial uses, as well as the City’s wastewater treatment plant. The economic, financial, and social impact of a hasty and early retreat from this area significantly outweighs the benefits of an early retreat.” As part of the City’s measured retreat strategy, by January 1, 2034 the City will establish specific triggers to initiate the retreat phase in Sea Level Rise Adaptation Zone 1, which will include identified triggers for retreat of the AWTF. Planning for this measured retreat in the long term (80- 100+ years) from the South G area will be supported by a Sea Level Rise Adaptation Pathways Grant awarded to the City by the Ocean Protection Council, anticipated to commence in late summer 2026.

If direction is provided to proceed with Alternative 1, staff would commence grant-funded design work and CDP preparation for Levee Augmentation once approved by CalOES at the end of 2026 and finalize an engineering design contract to re-envision and move forward Phase II treatment upgrades at the AWTF. While project development timelines are very preliminary, levee augmentation construction could potentially start by 2028-29 and Phase II treatment upgrade

construction by 2031-32. The recently completed five-year Water/Wastewater Rate Study and subsequent updated rate schedule factored in the potential costs for design and permitting of a next project phase at the AWTF.

The City has studied potential adaptation strategies for the AWTF for many years, even prior to this Feasibility Study. Staff is seeking direction to take action to proactively prepare the AWTF for sea level rise and to continue to comply with evolving water quality standards. As the longer it takes to initiate adaptation actions and construct additional treatment components being required by the Regional Board, the more these projects will ultimately cost and impact Arcata residents. The Feasibility Study and recently adopted LCP emphasize that continuing to invest in the existing AWTF is more beneficial ecologically and financially than an early retreat.

POLICY IMPLICATIONS:

The City Council has documented within its goals to maintain and improve infrastructure and facilities. Enhancing the City’s wastewater treatment is supported by the City’s General Plan 2045 Policy Public Facilities (PF)-2 the objective of which is to “Collect and treat wastewater to achieve safe water quality standards, utilizing the City’s internationally renowned marsh treatment facility.” As noted above, continuing to invest in the existing AWTF to ensure excellent water quality of wastewater effluent and protection from 100-year storm events for the existing AWTF is in alignment with the recently adopted Local Coastal Program. Planned improvements to the AWTF are located in the adopted LCP’s Sea Level Rise Adaption Zone 1 where the City plans to continue to protect current development and potential redevelopment endangered from flooding while planning for eventual measured retreat.

ENVIRONMENTAL REVIEW (CEQA):

While the AWTF Feasibility Study included a high-level Preliminary Environmental Memo (Appendix H), the study focused on developing several alternatives at the conceptual level and did not include any actions of land use change or physical construction and therefore qualifies for a common sense CEQA exemption. Should the Council provide direction on a preferred alternative for further study, City staff will ensure completion of environmental review.

An Initial Study and Mitigated Negative Declaration (IS/MND) was completed for the previously envisioned Arcata Wastewater Treatment Facility Improvement Project-Levee Augmentation which included the scope of the recently completed Phase I project, the envisioned Phase II project and proposed Levee Augmentation. The Notice of Determination was filed in December 2020 (State Clearinghouse 2020100483). A CEQA addendum was completed following design updates to the Levee Augmentation scope and filed with the State Clearinghouse in October 2025. Potential future updates to Phase II designs originally evaluated in the December 2020 IS/MND would be evaluated for any change in environmental impacts and either an addendum issued or other documentation completed to ensure compliance with CEQA.

BUDGET/FISCAL IMPACT:

Funding for the completion of the AWTF Feasibility Study was provided through technical assistance from the State Water Resources Control Board Division of Finance Assistance. Funding for the first phase of the AWTF Levee Augmentation Project was secured through the CalOES – FEMA Hazard Mitigation Grant Program with matching funds from the City’s Wastewater Fund.

City staff have proposed budgeting $1,000,000 in the fiscal year 2026-27 budget, funded by the City’s Wastewater Fund reserves intended for wastewater infrastructure improvements, towards design work to advance Phase II of the AWTF Improvement Project. The fiscal year 2026-27 is planned to be considered by the Council for adoption on June 17, 2026. City staff will continue to

pursue grants and low-cost loans to fund construction of future improvements as was fruitful for the Phase I AWTF Improvement Project.

RECOMMENDED COUNCIL ACTION:
1) Receive a presentation on the final Arcata Wastewater Treatment Facility (AWTF) Feasibility Study and potential future projects at the AWTF and review questions with staff. 2) Open public comment.
3) Close public comment.
4) Provide direction to staff on a preferred alternative.

ATTACHMENTS:

A. Arcata Wastewater Treatment Feasibility Study

Arcata Wastewater Treatment
Facility Sea Level Rise
Adaptation Feasibility Study
Rural Community Assistance Corp. & City
of Arcata
March 20, 2026
The Power of Commitment

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study i
Project name Design and Engineering Services for City of Arcata Wastewater Treatment Facilities Feasibility Study Document title Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study Project number 12616645
File name AWTF SLR Adaptation Feasibility Study 3.20.2026 Final.docx Status
Code
Revision Author Reviewer Approved for issue
Name Signature Name Signature Date
S3 Nick Black
Rebecca
Crow Jeremy
Svehla
5/30/2025
Brett Vivyan
S3 2
Nick Black Rebecca
Crow
Rebecca
Crow
10/1/2025
S4 3
Nick Black Brett Vivyan Rebecca
Crow
1/27/2026
S4 4
Nick Black Rebecca
Crow
Rebecca
Crow
3/20/2026
GHD Inc.

Contact: Nick Black, Staff Engineer | GHD
718 Third Street,
Eureka, California 95501, United States
T +1 707-267-2235 | E [email protected] | ghd.com
© GHD 2026
This document is and shall remain the property of GHD. The document may only be used for the purpose for which it was commissioned and in accordance with the Terms of Engagement for the commission. Unauthorized use of this document in any form whatsoever is prohibited.

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study ii
Executive Summary
Purpose
The Arcata Wastewater Treatment Facility (AWTF) and other City Wastewater Facilities are becoming more at risk to flooding from existing and future extreme tidal events and fluvial water levels, as well as extreme precipitation events. These events are predicted to become more frequent and severe with sea level rise (SLR) and changes to the climate. The AWTF Sea Level Rise Adaptation Feasibility Study (study) evaluates strategies to protect critical wastewater infrastructure from projected SLR, flooding, and coastal hazards through 2105. This study was initiated to comply with California Coastal Commission requirements to ensure long-term resilience of the City’s wastewater system.

Background
The AWTF serves approximately 19,000 residents and discharges treated effluent through the Enhancement Marshes to Humboldt Bay. The Enhancement Marshes support enhanced secondary treatment and provide auxiliary benefits to Humboldt Bay to comply with the City’s exception to Enclosed Bays and Estuaries Policy (EBEP) discharge prohibition. The recently completed Phase I upgrades (2023–2025) modernized the AWTF treatment systems to meet discharge limits and protect critical electrical infrastructure through 2055. The Coastal Development Permit (CDP) for the Phase I Upgrades required that adaptation strategies to address SLR impacts beyond 2055 be evaluated before further maintenance and upgrades at the facility are completed.

Current Vulnerabilities
Vulnerabilities for the City’s Collection System, Lift Stations, AWTF, and Enhancement Marshes were identified for current conditions through 2105 for multiple Ocean Protection Council (OPC) emission scenarios. The following vulnerabilities were identified for assets that would be impacted by the current 100-yr (10.7 ft tide) or less flood events. As water levels increase with SLR, impacts at these vulnerable locations are expected to become more frequent and severe:
– In low lying areas of the collection system, there are 44 manholes that are vulnerable to overtopping at a 10.7- foot tide. This would increase flows to the AWTF, increasing the volume of wastewater treated during the winter months, further exacerbating the I&I issues that the City already faces. – The floor of the First Street Lift Station is at an elevation of approximately 10.5 feet. The lift station is expected to experience nuisance flooding (less than 1 foot of flooding for 2 hours or less) at a 10.7-foot tide. This is not expected to impact the operation of the lift station.
– Access to the AWTF along South G Street is anticipated to experience nuisance flooding at a 9.5-foot tide. – The Enhancement Marshes levees have a minimum crest elevation of approximately 9.5 feet along South I Street and are currently vulnerable to overtopping during a 10-foot or greater tide. This may impact treatment effectiveness of the Enhancement Marshes and limit access to essential treatment facilities at the end of South I Street.
– The AWTF levees have a minimum crest elevation of less than 10.0 feet and are vulnerable to minor overtopping during a 10.1-foot tide. This would impact the headworks grit pump area and generator building with nuisance flooding which is not expected to disrupt treatment operations. This overtopping is expected to become disruptive by 2055.

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study iii
Future Risks
The OPC intermediate scenario was selected for the primary risk assessment for vulnerable assets. OPC Intermediate-High and High scenarios were discussed for the adaptation strategies and are presented in the main body of the report. The following risks were identified for City assets:
– By 2055, overtopping of Enhancement Marshes levees will occur multiple times per year, leading to erosion of the levees, disruption of treatment operations, and potential discharge of partially treated wastewater to Humboldt Bay. The AWTF will be vulnerable to extreme king tide events, potentially disrupting treatment operations and eroding levees, further increasing their vulnerability to overtopping. – By 2075 these levees are expected to overtop on a monthly basis, further exacerbating levee damage and treatment disruption.
– By 2105, most AWTF assets will see flooding on a monthly to daily basis, with severe to catastrophic consequences for treatment operations as critical infrastructure such as electrical panels, levees and pumps are impacted.

In addition to protecting treatment systems, the levees surrounding the AWTF facilities and Enhancement Marshes serve as trails which are extensively used by the community for recreation. The treatment marshes and wetlands also provide a unique freshwater habitat on the shore of Humboldt Bay, providing secondary benefits to local and migratory wildlife that frequent the area. If these facilities are not adapted, secondary benefits to the community and wildlife will be lost.

Adaptation Strategies
A suite of adaptation strategies was considered and were developed with progressively greater levels of protection to maintain continuous treatment operations. These strategies were split into two separate timelines: near-term (2025-2055) to provide protection for the current vulnerabilities identified, then mid-term to long term (2055-2105) strategies to address future risks to the facilities.

Near-Term (2025–2055)
– Continue inflow and infiltration (I&I) reduction projects to protect the collection system. – Complete Enhancement Marshes Levee Maintenance to elevate low points to the typical crest elevation 11.5 ft NAVD88, providing protection to treatment operations through 2055. – Complete AWTF Levee Maintenance to elevate low points to the typical crest elevation 11.5 ft NAVD88, reducing the occurrence of existing nuisance flooding and potential disruptive flooding at the facility through 2055.

Mid to Long-Term (2055–2105) Protect or Relocate:

Protect:
– AWTF Levee Augmentation Project (raise levees to 15 ft NAVD88, providing protection through 2105). – Enhancement Marshes Levee Augmentation Project (raise levees to 15 ft NAVD88, providing protection through 2105).

Relocate:
– Relocate the AWTF outside of the coastal flood hazard zone. This would make the facility resilient beyond 2105. – New Enhancement project to comply with the EBEP, likely a new Enhancement Marsh complex outside of the coastal flooding hazard zone. This strategy would allow for continued discharge to Humboldt Bay. – Utilize the Existing Harbor District Redwood Marine Terminal (RMTII) for discharge of treated effluent to the ocean.

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study iv
Adaptation Alternatives
Treatment and Disposal Adaptation strategies were combined resulting in eight feasible alternatives as follows:

Alternative Description Protection
Timeline
Adaptation
Methodology
Alternative 1: Augment
AWTF Levees and Maintain
and Adaptive Management
of the Enhancement
Marshes
This alternative would protect the AWTF with a new
levee system which could include both grey and green
infrastructure components. An adaptive management
approach would be taken with the Enhancement
Marshes and the effectiveness of the system under
increasing coastal flooding studied. This alternative
would include minor levee maintenances at critical low
spots around the Marsh. Discharge would continue to be
into Humboldt Bay.
~2055 Protect/
Accommodate
Alternative 2. Augment
AWTF Levees and Augment
Enhancement Marshes’
Levees
This alternative would protect both the AWTF and the
Enhancement Marshes with a new levee system which
could include both grey and green infrastructure
components. Discharge would continue to be into
Humboldt Bay.
~2105 Protect
Alternative 3. Augment
AWTF Levees and New
Enhancement
This alternative would protect the AWTF with a new
levee system which could include both grey and green
infrastructure components. The Enhancement Marshes
would be retreated/ modified and a new levee not
installed. Discharge would continue to be into Humboldt Bay.
~2105 Protect/ Retreat
Alternative 4: Augment
AWTF Levees and Ocean
Discharge
This alternative would protect the AWTF with a new
levee system which can include both grey and green
infrastructure components. A new connection to the
HBHRCD would be permitted for an Ocean Outfall.
~2105 Protect/ Retreat
Alternative 5. Retreat AWTF
and Maintain and Adaptive
Management of the
Enhancement Marshes
This alternative would retreat the AWTF to a new
location less susceptible to coastal flooding. An adaptive management approach would be taken with the
Enhancement Marshes and the effectiveness of the
system under increasing coastal flooding studied. This
alternative would include minor levee maintenances at
critical low spots around the Marsh. Discharge would
continue to be into Humboldt Bay.
~2055 Retreat/ Protect
Alternative 6. Retreat AWTF
and Augment Enhancement
Marshes’ Levees
This alternative would retreat the AWTF to a new
location less susceptible to coastal flooding. The
Enhancement Marshes would be protected with a new
levee system which could include both grey and green
infrastructure components. Discharge would continue to
be into Humboldt Bay.
~2105 Retreat/Protect
Alternative 7. Retreat AWTF
and New Enhancement
This alternative would retreat the AWTF to a new
location less susceptible to coastal flooding. The
Enhancement Marshes would be retreated/ modified and
a new levee not installed. Discharge would continue to
be into Humboldt Bay.
2105 and
beyond Retreat
Alternative 8. Retreat AWTF
and Ocean Discharge
This alternative would retreat the AWTF to a new
location less susceptible to coastal flooding. A new
connection to the HBHRCD outfall would be permitted for an Ocean Outfall.
2105 and
beyond
Retreat/
Accommodate
Alternatives which are based on maintenance or augmentation of levees considered implementation of Living Shorelines as an additive protection measure. Living shorelines can help extend the threshold of protection provided by the levee improvements by attenuating wind wave run up and overtopping, while also providing secondary ecosystem benefits through habitat restoration. Living shoreline costs are presented in the cost estimates as an additive item.

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study v
Cost Analysis
Class 5 cost estimates were developed for each of the alternatives presented above. These types of estimates are used for initial screening and feasibility of conceptual designs. There is a wide accuracy range for Class 5 estimates, and a range of -30% to +50% was used in this study. An average cost for each alternative is shown below, with full ranges and details provided in the main document. Further, an estimate of additional operations and maintenance (O&M) costs on top of existing costs was developed. Lastly, a life cycle cost was developed for each alternative for both an 80-year and 40-year planning period, also shown in the table below. All retreat alternatives include decommissioning costs of the existing facilities for relocated facilities.

Alternative Total Capital
Costs Cost
Total Additional
O&M Cost
Life Cycle Cost
(80-year)
Life Cycle Cost
(40-year)
Alternative 1: Augment AWTF Levees
and Maintain and Adaptive Management
of the Enhancement Marshes
$29,800,000 $0 $118 Million $57 Million
Alternative 2. Augment AWTF Levees
and Augment Enhancement Marshes’
Levees
$39,300,000 $0 $127 Million $66 Million
Alternative 3. Augment AWTF Levees
and New Enhancement $82,800,000 $200,000 $182 Million $115 Million Alternative 4: Augment AWTF Levees
and Ocean Discharge $122,100,000 $500,000 $226 Million $130 Million Alternative 5. Retreat AWTF and
Maintain and Adaptive Management of
the Enhancement Marshes
$177,800,000 $200,000 $210 Million $87 Million
Alternative 6. Retreat AWTF and
Augment Enhancement Marshes’
Levees
$187,300,000 $200,000 $219 Million $96 Million
Alternative 7. Retreat AWTF and New
Enhancement $230,800,000 $400,000 $274 Million $145 Million Alternative 8. Retreat AWTF and Ocean
Discharge $270,100,000 $700,000 $317 Million $161 Million Note: Life Cycle Costs include future treatment upgrades over the planning horizons.

Funding Opportunities
The City has several funding opportunities that could be used to support future projects including the following:
– State Water Resources Control Board (SWRCB) Clean Water State Revolving Fund (SRF) – USDA Rural Development programs
– EPA Water Infrastructure Finance and Innovation Act (WIFIA) loans – California Senate Bill 1 (SB1) SLR Adaptation Grants
The City should continue planning activities while looking for larger funding sources to create the most developed strategies possible to appeal to funding agencies.

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study vi
Priority Alternatives
From the strategies above, three priority alternatives were selected for further study. These alternatives balance the need for near term protection, with long term sustainability of treatment while providing options for the City to pursue around future uncertainties.
– Alternative 1: Augment AWTF Levees and Maintain and Adaptive Management of the Enhancement Marshes. – Alternative 7: AWTF Retreat with Humboldt Bay Discharge: Relocate AWTF and Develop a New Enhancement Project.
– Alternative 8: AWTF Retreat with Ocean Discharge: Relocate AWTF and utilize the RMTII ocean outfall for discharge.

Conclusion
Without proactive adaptation, AWTF faces escalating risks from SLR and flooding, threatening wastewater service reliability and environmental compliance. A phased approach combining near-term levee maintenance and asset floodproofing, with mid to long term levee augmentation, coupled with future relocation of treatment and discharge assets can address current flooding vulnerabilities while buying time to complete design, permitting and construction of long-term adaptation solutions for Arcata’s Wastewater assets.

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study vii
Contents

1. Introduction 1

2. Background 2

2.1 Project Area 2

2.1.1 Climate 2

2.1.2 Collection System and Service Area 3

2.1.3 Geologic Setting 4

2.1.4 Hydrogeologic Setting 6

2.2 Land Use 7

2.3 Wastewater System Characteristics 8

2.3.1 Existing Facilities 9

2.3.1.1 Headworks 9

2.3.1.2 Primary Clarifiers 9

2.3.1.3 Influent Bypass Pumping 10

2.3.1.4 Oxidation Ponds and Pond Pumping 10

2.3.1.5 Treatment Wetlands and Effluent Pumping 10

2.3.1.6 Disinfection 10

2.3.1.7 Enhancement Wetlands (Allen, Gearheart, and Hauser) 10

2.3.2 Phase I Facilities Upgrades 11

2.3.3 Phase II Facilities Upgrades 13

2.3.4 Wastewater Characteristics 14

2.3.5 Permitted Discharge Water Quality Requirements 14

2.3.6 Enclosed Bays and Estuaries Policy 15

2.4 Treatment Requirements for Discharge or Reuse 16

3. Vulnerability and Risk Assessment of AWTF Infrastructure to Sea Level Rise and Flooding 18

3.1 Tidal Water Levels 19

3.2 Wind Effects on Tidal Water Levels 20

3.2.1 Wind Setup 20

3.2.2 Wind Wave Conditions and Runup 22

3.3 Sea Level Rise and Climate Change 22

3.4 Reference Flood Design Criteria 24

3.5 Vulnerability Assessment of the Arcata Wastewater System 25

3.5.1 Collection System Vulnerability 25

3.5.2 Lift Station Vulnerability 27

3.5.3 Wastewater Treatment Facility Vulnerability 31

3.5.4 Enhancement Marsh System and Site Access Vulnerability 33

3.5.5 Current Vulnerabilities Identified 34

3.6 Coastal Hazards Risk Assessment 35

3.6.1 Qualitative Risk Analysis 37

3.6.2 Wastewater Collection Piping 38

3.6.3 Wastewater Lift Stations 39

3.6.4 Wastewater Treatment Facilities 40

3.6.5 Coastal Hazards Risk Assessment Summary 42

4. Case Studies 43

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4.1 McKinleyville CSD 44

4.1.1 System Description 44

4.1.2 Considerations for AWTF Planning 45

4.2 City of Fortuna 46

4.2.1 System Description 46

4.2.2 Considerations for AWTF 46

4.3 City of Rio Dell 47

4.3.1 System Description 47

4.3.2 Considerations for AWTF 47

4.4 Mendocino City CSD 48

4.4.1 System Description 48

4.4.2 Considerations for AWTF 48

4.5 Monterey One Regional WWTP, Ocean Outfall and Groundwater Enhancement 49

4.5.1 System Description 49

4.5.2 Considerations for AWTF 50

4.6 Gualala CSD 50

4.6.1 System Description 50

4.6.2 Considerations for AWTF 50

4.7 Tolowa Dee-Ni’ Nation 51

4.7.1 System Description 51

4.7.2 Considerations for AWTF 51

4.8 City of Healdsburg 52

4.8.1 System Description 52

4.8.2 Considerations for AWTF 52

4.9 Pelican Bay State Prison 53

4.9.1 System Description 53

4.9.2 Considerations for AWTF 53

4.10 Decentralized Systems 54

4.10.1 Small Scale Reuse Systems 54

4.10.2 Composting Toilets 54

4.10.3 Feasibility of Decentralized Systems 55

5. Adaptation Pathways and Options 56

5.1 Coastal Infrastructure and Wetland Resilience Case Study Projects to Support Adaptation 57

5.1.1 Natural Shoreline Infrastructure Project in Humboldt Bay 57

5.1.2 Oro Loma Living Laboratory 59

5.1.3 Bayshore Bikeway Resiliency Project in South San Diego Bay 60

5.2 Adaptation Feasibility Approach 61

5.3 Collection System 62

5.3.1 Near-Term Adaptation Strategies 62

5.3.1.1 I & I Reduction 62

5.3.2 Mid-Term and Long-Term Adaptation Strategies 64

5.3.2.1 Elevate Vulnerable Lift Station Components 64

5.3.2.2 Reroute Collection System for Treatment Plant Relocation 64

5.4 Treatment System 65

5.4.1 Implementation of Nature Based Protection Strategies 65

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5.4.1.1 Feasibility of Nature Based Protection Strategies 66

5.4.2 Near-Term Adaptation Strategies 67

5.4.2.1 Phase 1 Improvements 67

5.4.2.2 AWTF Levee Maintenance 68

5.4.3 Mid-Term to Long-Term Adaptation Strategies 69

5.4.3.1 AWTF Levee Augmentation Project 69

5.4.3.2 Decentralized Treatment 70

5.4.3.3 Relocate AWTF 71

5.5 Discharge/ Enhancement Marshes 73

5.5.1 Existing AWTF and Enhancement Marshes Ecological and Community Benefits 74

5.5.1.1 Freshwater Wetland Benefits 74

5.5.1.2 Brackish Wetland Benefits 74

5.5.1.3 Community Benefits 74

5.5.2 Near-Term Adaptation Strategies 75

5.5.2.1 Enhancement Marshes Protection Structures Maintenance 75

5.5.3 Mid-Term to Long-Term Adaptation Strategies 78

5.5.3.1 Determine Adaptative Capacity of Enhancement Marshes to Saltwater Intrusion 78

5.5.3.2 Enhancement Marshes Levee Augmentation 79

5.5.3.3 Enhancement Marshes Relocation 79

5.5.3.4 Alternative Enhancement for Bay Discharge 80

5.5.3.5 Ocean Discharge 81

5.5.3.6 Land Application and Reuse 86

5.5.3.7 Surface Water Discharge 90

5.5.3.8 Groundwater Injection 92

5.6 Consolidation 94

5.6.1 City of Eureka Ocean Outfall Consolidation 95

5.6.2 McKinleyville Consolidation 95

5.7 Alternative Development and Prioritization 96

5.7.1 Public Outreach and Input 96

5.7.1.1 November 2024 Public Meeting 96

5.7.1.2 August 28, 2025 Public Meeting 97

5.7.1.3 Other Public Engagement Events 98

5.7.2 Criteria for Alternative Prioritization 98

5.7.3 Summary of Adaptation Strategies 99

5.7.4 Priority Alternatives 102

6. Alternatives Analysis 103

6.1 AWTF Levee Augmentation 103

6.1.1 Levee Description 103

6.1.2 Living Shoreline Description 107

6.1.3 Project Costs 108

6.2 AWTF Relocation 108

6.2.1 Description 108

6.2.1.1 AWTF Levee Maintenance 108

6.2.1.2 Influent Transfer Pump Station and Pipeline 110

6.2.1.3 Treatment Overview 111

6.2.1.4 Conventional Activated Sludge (CAS) 111

6.2.1.5 Moving-Bed Biofilm Reactor (MBBR) 112

6.2.2 Project Costs 112

6.2.2.1 AWTF Levee Maintenance 112

6.2.2.2 Transfer Pipeline + Pump Station 112

6.2.2.3 New AWTF 112

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study x

6.2.2.4 Total Cost 112

6.2.2.5 Operations and Maintenance Costs 113

6.3 Enhancement Marshes Levee Maintenance and Adaptive Management 114

6.3.1 Levee Maintenance Description 114

6.3.2 Living Shoreline Description 115

6.3.3 Adaptive Management Description 115

6.3.4 Project Costs 115

6.4 Enhancement Marshes Levee Augmentation 118

6.4.1 Description 118

6.4.2 Project Costs 118

6.5 New Enhancement Project 118

6.5.1 Description 118

6.5.2 Project Costs 119

6.6 RMTII Ocean Outfall 120

6.6.1 Description 120

6.6.2 Project Costs 122

6.7 Alternative Cost Summary 123

6.8 Timeline 123

6.9 Cost Benefit Analysis 125

6.9.1 Financial Parameters and Assumptions 125

6.9.2 Life Cycle Cost Analysis 126

6.9.3 Summary of Costs and Benefits 127

6.10 Constraints Analysis 129

7. Funding and Financing Plan 130

7.1 Community Funding Factors 130

7.2 Funding Programs 130

7.2.1 State Water Resources Control Board (SWRCB), Clean Water State Revolving Fund (CWSRF) 130

7.2.2 USDA Rural Development Funding Programs 131

7.2.3 Environmental Protection Agency WIFIA 131

7.2.4 Ocean Protection Council Senate Bill 1 Sea Level Rise Adaptation Planning Grant Program – Track 2 132

7.2.5 California Bond funding 132

7.2.6 Federal Appropriation 132

7.3 Funding Strategy 133

8. Preliminary Project Report Findings 133

8.1 Summary of Existing and Future Vulnerabilities 133

8.2 Summary of Existing Projects, Planning, and Next Steps 134

8.3 Adaptation Alternatives Evaluated 135

8.4 Cost Comparison (Order-of-Magnitude, Class 5) 136

8.5 Constraints Affecting Alternatives 136

8.6 Overarching Conclusion 138

9. References 139

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study xi
Figure Index
Figure 1 City of Arcata Sewer Map 4
Figure 2 McKinleyville, Mad River and Fickle Hil Faults (Map Credit: USGS) 5 Figure 3 City of Arcata and Surrounding Areas Land Use Zoning 8 Figure 4 Phase I Improvements Site Plan 12
Figure 5 Conceptual representation of wind, wind waves and wave runup resulting in total water level (TWL). 20
Figure 6 Fetch directions relative to the Project shoreline adjacent to Klopp Lake in North Bay (NHE, 2024). 21
Figure 7 Example of Inundated Manhole Flooding Collection System 26 Figure 8 Typical Lift Station Components Consisting Of A) Lift Station Building on Concrete Slab B) Electrical Panels and C) Electrical Panels and Backup Generators 28 Figure 9 Risk Ratings of City Assets Based Likelihood and Consequence During the Planning Horizon (OPC Intermediate Scenario) 42
Figure 10 MCSD Recycled Water Land Application Area Just North of Hammond Bridge. 44 Figure 11 City of Rio Dell Irrigation Area West of Highway 101 Adjacent to Eel River (Source, City of Rio Dell) 47
Figure 12 Monterey One Treatment Plant and Ocean Outfall (Source: Monterey One) 49 Figure 13 Adaptation Strategies 56
Figure 14 Location of NSI Project Shoreline on North Humboldt Bay 57 Figure 15 Conceptual representation of wind wave dissipation on the rail prism pre-project (top), at the marsh edge following project implementation (middle) and with sea level rise (bottom). 58
Figure 16 Oro Loma Living Laboratory 59
Figure 17 Bayshore Bikeway Resiliency Project in South San Diego Bay 60 Figure 18 Still Water Datums and OPC Intermediate SLR Projection (Upper Bound of Most Likely Range of SLR by 2100). 61
Figure 19 2018 I&I Reduction Project. Orange = Replaced Piping, Purple = Pipe Rehab via Lining. 63
Figure 20 1870 Salt Marsh Extents at the AWTF Location. 66 Figure 21 Nuisance Flooding over Bay Trail into NW Corner of AWTF at approximately 10-foot NAVD88 tide on January 3rd, 2026 68
Figure 22 AWTF Potential Relocation Areas 72
Figure 23 Enhancement Marshes Levee Vulnerability 76
Figure 24 Approximately 10-foot NAVD88 Water Level briefly overtopping South I St into Hauser Marsh on January 3rd, 2026. 77
Figure 25 Approximately 10-foot NAVD88 Water Level flowing down South I St into Brackish Marsh on January 3rd, 2026. 77
Figure 26 Potential Pipelines and Oceans Outfall Locations Adjacent to the City of Arcata 84 Figure 27 Summer and Year-Round Required Irrigation Area Reference Scale. 88 Figure 28 Nearby Agricultural Parcels Over 30 Acres Outside of the 100-yr SLR Flood Zone. 89 Figure 29 Mad River Surface Water Discharge Areas of Limitations 91 Figure 30 Class I Injection Well (EPA) 92
Figure 31 Levee Augmentation Project with RSP 104
Figure 32 Typical Concrete floodwall for AWTF 105
Figure 33 Typical Floodgate Section 105

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Figure 34 Typical RSP and Sheet Pile Section 106
Figure 35 Typical Sheet pile and trail section 106
Figure 36 Levee Augmentation Project with Living Shoreline 107 Figure 37 Existing AWTF Crest Elevations. 109
Figure 38 Conceptual Design for Influent Transfer Pump Station and Pipeline to New AWTF Location 110
Figure 39 Enhancement Marsh Levee elevations sand conceptual living shoreline. 116 Figure 40 Concept Design for Levee Maintenance 117
Figure 41 Conceptual Design for Pipeline to RMTII 121

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Table Index
Table 1 Monthly Climate Summary for Arcata, CA (National Weather Service) 3 Table 2 Land Use Types and Area According to the City Of Arcata’s General Plan and Land Use Code 7
Table 3 AWTF Discharge Locations 9
Table 4 Wastewater Treatment Essential Facilities 13
Table 5 Wastewater Treatment and Operations Facilities 13 Table 6 Design Influent Wastewater Characteristics 14
Table 7 NPDES Permit Discharge Requirements for Discharge Point 001 After Completion of the Phase I Improvements. 14
Table 8 NPDES Permit Discharge Requirements for Discharge Point 002 After Completion of the Phase I Improvements. 15
Table 9 NPDES Permit Discharge Requirements for Discharge Point 003 After Completion of the Phase I Improvements. 15
Table 10 Treatment Level Required for Discharge 16
Table 11 Treatment Limits for Secondary, Enhanced Secondary and Tertiary Treatment Levels 17
Table 12 2023 Tidal water levels and still water return periods for the study area (NHE, 2024).19 Table 13 Estimated wind setup at project shoreline (NHE, 2024) 21 Table 14 Peak wave heights/period and wave runup at project location (NHE, 2024). 22 Table 15 SLR scenarios for Humboldt Bay North Spit (OPC, 2024) with vertical land motion for Mad River Slough in feet. 23
Table 16 Exceedance probabilities for the SLR Scenarios based on IPCC warming level – based GMSL projections (OPC, 2024). 23
Table 17 Reference Design Standards for Wastewater Asset Flood Protection 24 Table 18 Number of Wastewater Manholes Experiencing Flooding Greater Than 6 Times Per Year (MMMW) That Will Need to be Relocated or Replaced. 27 Table 19 Likelihood of flooding resulting in damage / failure of lift station facilities (OPC Intermediate Scenario). 29
Table 20 Likelihood of Flooding Resulting in Damage / Failure Of Lift Station Facilities (OPC Intermediate-High and High Scenario) 30
Table 21 Likelihood of Flooding Resulting in Damage / Failure at AWTF Facilities (OPC Intermediate Scenario). 31
Table 22 Likelihood of Flooding Resulting in Damage / Failure at AWTF Facilities (OPC Intermediate-High And High Scenarios). 32
Table 23 Likelihood of Shoreline Protection Overtopping Resulting in Erosion and Maintenance (OPC Intermediate Scenario) 33
Table 24 Likelihood of Shoreline Protection Overtopping Resulting in Erosion and Maintenance (OPC Intermediate-High and High Scenario). 34 Table 25 Likelihood Scale providing qualitative terms for numerical likelihoods for use in Risk Analysis 35
Table 26 Consequence Scale providing qualitative consequence terms, definitions and examples for use in Risk Analysis 35
Table 27 Risk Matrix Evaluation combining Consequence Scale and Likelihood Scale to assign a qualitative risk rating. 36

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Table 28 Assignment of Risk Consequence Scale to asset exposure based on anticipated impacts. 37
Table 29 Risk Rating for Flooding of Sewer Manholes Resulting in Sanitary Sewer Overflows and Reduced Treatment Capabilities 38
Table 30 Risk Rating for Flooding of Lift Stations That Affect the Building Access, Backup Power and Electrical Equipment 39
Table 31 Risk Rating for AWTF Facilities Affecting Treatment, Operations and Service 40 Table 32 Risk Rating for AWTF Facilities Affecting Treatment and Access 41 Table 33 Existing MCSD Recycled Water Irrigation Areas (acres) 45 Table 34 I & I Reduction Strategy 62
Table 35 Elevate Vulnerable Lift Stations Strategy 64
Table 36 Reroute Collection System for Treatment Plant Relocation Strategy 64 Table 37 Phase 1 Improvements Strategy 67
Table 38 Minor AWTF Levee Improvements Strategy 68
Table 39 Levee Augmentation Project 69
Table 40 Identify opportunities for decentralized treatment 70 Table 41 Relocate AWTF 71
Table 42 Planning Level Footprint Sizes for Wastewater Treatment Facilities Based on Technology Type 71
Table 43 Enhancement Marshes Protection Structures Maintenance Strategies 75 Table 44 Determine Adaptative Capacity of Enhancement Marshes to Saltwater Intrusion 78 Table 45 Enhancement Marshes Levee Augmentation 79
Table 46 Relocate Enhancement Marshes 79
Table 47 Alternative Enhancement 80
Table 48 Permits Required for Ocean Outfall 82
Table 49 Land Application and Reuse 86
Table 50 Water Balance Scenario Runs 87
Table 51 Surface Water Discharge 90
Table 52 Groundwater Injection 92
Table 53 Flexible Criteria Ranking 99
Table 54 Summary of SLR Adaptation Strategies for the Collection System 99 Table 55 Summary of SLR Adaptation Strategies for the Treatment System 100 Table 56 Summary of SLR Adaptation Strategies for Discharge and the Enhancement Marshes 100
Table 57 Summary of Alternatives 102
Table 58 Quantities for AWTF Levees to be raised. 109
Table 59 AWTF Relocation Costs 112
Table 60 Enhancement Marshes Levee Crest Elevation 114
Table 61 Enhancement Marshes Levee Maintenance Quantities 116 Table 62 Summary of Alternative Costs 123
Table 63 Timeline for Disruption of Treatment Operations by Asset. 124 Table 64 Approximate Years Needed to Implement Adaptation Strategies. 125 Table 65 Life Cycle Cost Assumptions. 126
Table 66 Adaptation Strategy Life Cycle Costs 127
Table 67 Adaptation Alternatives Life Cycle Costs 128

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Table 68 Alternatives Constraints Analysis 129
Table 69 Small DAC Construction Grant/ PF Eligibility Criteria (State of California, 2025) 131

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Table of Appendices
Appendix A Sea Level Rise Vulnerability and Capital Improvement Project Adaptation Plan Vulnerability & Risk Assessment
Appendix B Cost Estimates
Appendix C Preliminary Pumping Calculations
Appendix D Moving-Bed Biofilm Reactor Treatment Modeling Appendix E Conventional Activated Sludge Treatment Modeling Appendix F Public Outreach Summaries
Appendix G Life Cycle Cost Calculations
Appendix H Preliminary Environmental Memorandum

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 1

1. Introduction
The Arcata Wastewater Treatment Facility (AWTF) is owned and operated by the City of Arcata (City), serving residents within the City limits and the unincorporated community of Glendale. The AWTF has been discharging to Humboldt Bay since 1949. The AWTF currently discharges treated wastewater to Humboldt Bay after enhanced treatment occurs in the Arcata Marsh Wildlife Sanctuary (AMWS or Enhancement Marshes) constructed freshwater wetlands adjacent to the treatment facility. Discharges are regulated by the North Coast Regional Water Quality Control Board (RWQCB) through application of the National Pollutant Discharge Elimination System (NPDES) permit.

The AMWS provides secondary benefits to the local community with 5 miles of trails and open space for recreation, as well as wetland habitat for local and migratory wildlife. Over 300 bird species have been observed at the AM&WS, which serves as an important stopover site for migratory birds on the Pacific Flyway in the spring and fall, where migratory birds can rest, feed, and regain their strength. The Arcata Marsh Interpretive Center provides educational opportunities for visitors with information on the natural treatment system benefits, that include services provided to wildlife.

The City of Arcata is currently nearing completion of the Phase I Arcata Wastewater Treatment Plant Improvement Project (Phase I) which has replaced aging infrastructure, reconfigured to a single pass flow through the treatment facility and Enhancement Marshes, upgraded the disinfection system to ultraviolet light and developed a new treated effluent outfall location. This Phase I project is of critical importance to meet current water quality standards, eliminate disinfection byproducts associated with chlorine disinfection, protect coastal resources and produce a higher quality effluent for beneficial use within coastal habitats. Construction is anticipated to be fully complete by June 2026. The Phase I improvements will remain viable throughout its design life through 2055. In addition to the ongoing Phase I Upgrades, future Phase II upgrades are envisioned to comply with effluent limitations in the City’s NPDES permit, including construction of an oxidation ditch, secondary clarifiers, return activated sludge pump station, an alkalinity feed station and rehabilitation of the anaerobic digester.

Concurrently, the City is preparing to complete subsequent improvements to their Wastewater Treatment Facilities in preparation for sea level rise (SLR) adaptation. The City received funding from the Federal Emergency Management Agency (FEMA) Hazard Mitigation Grant Program (HMGP) for the Levee Augmentation Project design, to augment the existing perimeter levee elevation and erosion protection for enhanced flood protection due to existing and future extreme events and SLR. The California Coastal Commission issued a Coastal Development Permit for the Phase I project which requested that the City assess alternatives to levee construction in order to prepare the wastewater facilities for sea level rise beyond 2055 (CDP 1-20-0711 Special Condition 4). The purpose of this report is to present and assess the feasibility of alternatives to prepare the wastewater facilities for future sea level rise and coastal hazards. All elevations in this study are reported in the North American Vertical Datum of 1988 (NAVD88).

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 2

2. Background

2.1 Project Area
Arcata is located along the Northern California Coast in the west-central portion of Humboldt County, eleven miles north of Eureka and approximately 90 miles south of the Oregon border. Arcata is the second largest city in Humboldt County. The Arcata city limits encompass approximately 13 square miles of total area, almost two square miles of which is predominantly water. Arcata lies along the northern shoreline of Humboldt Bay. Humboldt Bay is the second largest estuary in California. The City of Arcata has 29 different watersheds, creeks, or sloughs that run through town.

There are approximately 2230 acres of wetlands within city limits. There are approximately 80 miles of sidewalks, 72 miles of bike accessible pathways within city limits, 65 miles of roads maintained by City of Arcata, and 63 miles of multi-use trails.

Arcata has a population of approximately 18,800 people and is principally a residential based community with nearly two-thirds of all households being renter occupied. Variations in population occur during Cal Poly Humboldt summer and holiday breaks. Arcata exhibits higher poverty rates among families and low-income students, and overall high housing costs relative to the statewide median household income (MHI). According to the 2020 Census, the MHI for Arcata is approximately $47,000 per year, roughly 60% of the statewide MHI which is currently approximately $78,000 per year. Cal Poly Humboldt and the Mad River Hospital are the two largest single employers in Arcata. As estimated 35% of Arcata citizens live at or below the poverty line. U.S. Census data for the City of Arcata between 2010 and 2020 shows a 6.2% population growth, or approximately 0.62% growth per year.

There are currently 16 neighborhoods and 5179 parcels within city limits. The 2020 U.S. Census data shows that there are 7,201 total households. The City is focused on infill development and select large-scale housing developments to address housing needs and costs for the off-campus university population. Arcata’s current sphere of influence (SOI) extends beyond its city limits and includes:
– A 40-acre subdivision of 175 residential low-density parcels between Upper Bay Road, Parton Lane, Ernest Way, and Janes Road.
– 375 acres of Agriculture Exclusive land West of Arcata between 27th Street, Jackson Ranch Road, and Vaissade Road.
– Approximately 2,500 acres between 547 parcels South-East of Arcata which comprises most of Bayside, Jacoby Creek, and the communities between Old Arcata Road and Baywood Golf & Country Club. – Approximately 185 acres between 84 parcels along Fickle Hill. – Approximately 210 acres between 66 parcels located in the Aldergrove, Boyd Road, and West End Road neighborhoods.

2.1.1 Climate
Moderate temperatures, frequent fog, and moderate to heavy precipitation primarily in the form of rain characterize local weather. Mean annual temperature for Arcata is 53 F with a yearly average range of 48 F to 55 F. Prevailing winds for California cities along the coast tend to be north or northwest during the summer months and south or southwest during winter months. Arcata lies within a coastal plains and heavy fog belt, characterized by low evapotranspiration (ETo) rates. Since 2016, ETo has increased for each month except for July. Similarly, the average cumulative rainfall has decreased since 2016 for each month except March, April, and July. Climate data was accessed through the National Weather Service and from the California Integrated Management Information System and is summarized in Table 1 below.

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 3
Table 1 Monthly Climate Summary for Arcata, CA (National Weather Service) Month Monthly Average Eto (Evapotranspiration)
(in/month)
Average Monthly Precipitation
(in)
Average Temperatures
min-max (F)
January 1.56 5.74 (31-66)
February 1.93 4.66 (31-65)
March 3.11 6.24 (34-65)
April 4.09 3.07 (37-67)
May 4.5 1.32 (41-67)
June 4.92 0.61 (44-70)
July 4.44 0.17 (49-68)
August 4.21 0.1 (49-72)
September 3.56 1.09 (45-76)
October 2.87 2.93 (39-75)
November 1.84 4.25 (33-69)
December 1.47 6.52 (30-64)

2.1.2 Collection System and Service Area
The City serves 5,661 active sewer connections, comprised of 5,067 residential and 594 commercial customers. The majority of sewer connections are single family residential units. The City provides wastewater service to California State Polytechnic University, Humboldt, with approximately 6,000 students. Within the City there are several parcels still using septic systems, which include parcels west of Alliance Road, on Fickle Hill Road, Grotzman Road, Anvick Road and Bayside Road. In addition, the City of Arcata also accepts wastewater from the Fieldbrook Glendale Community Services District (FGCSD) through a contractual agreement. FGCSD owns, maintains, and repairs its collection system, and fulfills all regulatory requirements for their collection system. FGCSD lies to the northeast of City limits. Figure 1 depicts a map of the City’s service area and shows the boundaries for the City.

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 4
Figure 1 City of Arcata Sewer Map

2.1.3 Geologic Setting
The Project is located in the United States Geological Survey (USGS) Arcata North and South Quadrangles. Regional geology is influenced by seismic activity related to the Cascadia Subduction Zone (CSZ) and Mendocino Triple Junction (MTJ). The MTJ is a very seismically active region where the oceanic Gorda and Pacific Plates meet the continental North American Plate. South of the MTJ, seismic activity is predominantly related to the transverse fault motion of the San Andreas Fault Zone. North of the MTJ, seismic activity is predominantly related to subduction occurring along the CSZ. The Project is located approximately 50 miles north of the MTJ, within the southern extent of the CSZ. The CSZ is capable of producing magnitude 9 earthquakes (RCTWG, 2022).

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 5
Active faults in the vicinity of the Project are discussed below. The Alquist Priolo definition of an active fault is one that has ruptured in the last 11,000 years (also referred to as a Holocene Fault). Older faults that have not been active in the Holocene exist in the area but are not discussed because rupture is extremely unlikely.

The Project is not mapped as being within an Alquist Priolo Fault Zone, however, Holocene faults are mapped near the Project. Fault names and positions relative to the Project are as follows (Figure ):
– The McKinleyville Fault is part of the Mad River Fault Zone, and a segment of the fault is located north of the Project. The fault segment is mapped as extending from the northern side of McKinleyville, along the eastern edge of McKinleyville, and south toward West End Road.
– The Mad River Fault is part of the Mad River Fault Zone and is located north of the Project. The fault is mapped as extending from the western portion of McKinleyville, south toward Giuntoli Lane, and curving east along the Mad River toward West End Road. The southeastern extent of the mapped fault ends on the northern side of Hwy 299.
– The Fickle Hill Fault is part of the Mad River Fault Zone and is mapped through the City of Arcata. The northern extent of the mapped fault ends at the intersection of Foster Avenue and Alliance Road. – Other Holocene faults in the local area include another segment of the McKinleyville Fault located southwest of the City of Blue Lake, the Trinidad Fault located through the City of Trinidad, and the Little Salmon Fault Zone located south of the City of Eureka.

Figure 2 McKinleyville, Mad River and Fickle Hil Faults (Map Credit: USGS)

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 6
The Project is situated within a seismically active area close to several seismic sources capable of generating moderate to strong ground motions. Because the Project is located within a seismically active area, there is potential for strong ground shaking associated with large magnitude earthquakes to occur during the design life of the Project.

For future implementation of adaptation projects, geotechnical investigations will need to be completed to determine site specific seismic design requirements.

2.1.4 Hydrogeologic Setting
The Project is located within the Mad River Groundwater Basin, Mad River Lowland Subbasin (DWR 2004). According to Bulletin 118 published by the Department of Water Resources (DWR), the Mad River floodplain is composed of alluvium and is underlain by the Hookton Formation. The upland areas to the north and the east that are above the alluvium of the river floodplain are comprised of Hookton Formation. Underlying the Hookton Formation are either Tertiary Wildcat group sediments or the basement rocks of the Jurassic and Cretaceous Franciscan Formation. There are sand dunes present along the coastline.

Water bearing formations include the Quaternary sand dune deposits, river channel deposits, and the Hookton Formation. The major aquifer in the basin is the alluvium that underlies the floodplain of the Mad River (DWR 2004).

Groundwater impairments listed for the basin include high iron concentrations and locally high manganese, fluoride, and phosphorus concentrations. Humboldt Bay Municipal Water District (HBMWD) supplies drinking water on a wholesale basis to Fieldbrook Glendale CSD and McKinleyville CSD in addition to Arcata, Eureka, Blue Lake, Humboldt CSD and Manila CSD.

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 7

2.2 Land Use
The City of Arcata has 25 different land use classifications stated under its General Plan and Land Use Code. Table 2 shows each land use code and total acres within Arcata. A map of land use areas is shown in Figure 3. The California Coastal Commission’s Local Coastal Program (LCP) Local Assistance Grant Program awarded the City funding to pursue the Arcata Sea Level Rise Vulnerability Assessment and Capital Improvement Project Adaptation Plan. The City recently updated the LCP with updates to the Local Coastal Element that reflect the most up to date understanding of the implications of projected SLR and precipitation. LCP updates are considered later in the document in the development of alternatives.

Table 2 Land Use Types and Area According to the City Of Arcata’s General Plan and Land Use Code Zoning (Land use Code) Acres
Agriculture - Exclusive 2092
Agriculture - Residential 429
Agriculture - Residential Planned Development 4
Commercial Central 25
Commercial General 59
Commercial General Planned Development 16
Commercial Mixed 16
Commercial Mixed Planned Development 1
Commercial Visitor Serving 38
Commercial Visitor Serving Planned Development 5
Industrial General 166
Industrial Limited 375
Industrial Limited Planned Development 11
Natural Resource 3239
Natural Resource Public Trust Planned Development 16
Public Facility 490
Public Facility Planned Development 35
Residential High Density 98
Residential High Density Planned Development 52
Residential Low Density 579
Residential Low Density Planned Development 27
Residential Medium Density 146
Residential Medium Density Planned Density 34
Residential Very Low Density 1046
Residential Very Low Density Planned Development 145

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Figure 3 City of Arcata and Surrounding Areas Land Use Zoning

2.3 Wastewater System Characteristics
The AWTF collects influent from the City of Arcata and the Fieldbrook-Glendale CSD. The collection system consists of approximately 65 miles of pipe ranging from 6 to 24 inches in diameter, with 12 sewer lift stations. The population served by the City’s sewer system is approximately 19,000 (US Census Bureau, 2024). Sewer service is provided to all businesses and residents within the City, as well as some residences located adjacent to City within the City’s sphere of influence. Since 1992, the sewer system has received flow from the Fieldbrook Glendale Community Services District of up to 71,200 gpd.

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 9

2.3.1 Existing Facilities
The collection system is comprised of 13 wastewater pump stations, 65 miles of sewer mainline, 1,114 manholes, and 5661 sewer laterals. With the completion of Phase I upgrades, AWTF facilities include headworks, primary clarifiers, 40 acres of oxidation ponds, 13 acres of treatment wetlands, 33 acres of enhancement wetlands, and UV disinfection.

Solids removed in the primary clarifiers are treated in anaerobic digesters, are placed into drying beds, and are composted to meet 40 CFR Part 503 Class A biosolid standards. Treated wastewater is ultimately discharged into Humboldt Bay after passing through the enhancement wetlands. Composted biosolids are used as a soil amendment and spread in select locations within the city owned forests or other designated areas. Table 3 summarizes the AWTF discharge locations within the treatment system. The following sections reflect treatment components with the completion of Phase I Upgrades.

Table 3 AWTF Discharge Locations
Discharge Point Effluent Description Discharge Point
Latitude (North)
Discharge Point
Longitude (West)
Receiving Water
001 Equivalent to
secondary treated
wastewater
40 51' 18" 124 5' 26" Humboldt Bay
002 Equivalent to
secondary treated
wastewater
40 51' 29" 124 5' 31" Enhancement
Marshes
003 Secondary treated
wastewater
40 51' 40" 124 5' 37" Brackish Marsh,
Humboldt Bay

2.3.1.1 Headworks
The headworks facility provides screening and grit removal of raw sewage from the collection system. The headworks treatment process was updated and rebuilt during Phase 1 Improvements. The headworks facility is comprised of the following:
– Two 2.5-million gallons per day (MGD) Archimedes screw pumps and a 0.9 MGD bypass pump. – Two 5.0-MGD mechanically cleaned bar screens that drop screenings into a single belt conveyor for transport to a roll-off bin.
– Headworks flow splitting structure with 2 magnetic flow meters. – A grit removal system including a mechanically induced vortex with grit pumping and grit classification.

2.3.1.2 Primary Clarifiers
The primary treatment facilities consist of two primary clarifiers and have a total treatment capacity of 5.9 MGD. Flow from the headworks is split between the two primary clarifiers after grit removal:
– Clarifier No. 1 has a 26-foot diameter and a design treatment capacity of 1.5 MGD. It is fed by a 12-inch diameter influent pipeline.
– Clarifier No. 2 has a 66-foot diameter and a design treatment capacity of 4.0 MGD. It is fed by a 24-inch diameter influent pipeline.

The clarifiers incorporate center-feed and peripheral withdrawal mechanisms to collect sludge. Suspended solids settle to the bottom of the tanks as primary sludge and are collected via mechanical scrapers and pumps. Skimmer arms collect residual floating sludge at the surface of the clarifiers. Settled solids are pumped from the bottom of primary clarifiers to the primary anaerobic digester. Scum collected on the surface of the primary clarifiers pass through a liquid/solid separator and the solids are transferred to a roll-off bin for disposal.

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 10

2.3.1.3 Influent Bypass Pumping
Influent flows greater than the 5.9 MGD headworks capacity bypass both the headworks facility and primary clarifiers, and are pumped, via the First Street Pump Station (located offsite) and the Influent Storm Pump (located at the headworks), directly to the oxidation ponds. These pumps allow for peak wet weather flow capacity and redundancy for the headworks screw pumps.

2.3.1.4 Oxidation Ponds and Pond Pumping
Primary effluent and influent bypass flows are conveyed by gravity to two facultative oxidation ponds for secondary treatment and stabilization. Secondary treatment is provided through a series of both biological and chemical reactions in both aerobic and anaerobic environments within the ponds. Oxidation Pond 2 has 24 mixer/blowers aerators. The two oxidation ponds have a total surface area of 40 acres and a total storage treatment volume of 89 million gallons.

The normal mode of operation is in series, where primary effluent is routed to Oxidation Pond 1 and then flows by gravity through transfer structures to Oxidation Pond 2. Pond influent and effluent piping are also set up to operate in parallel if needed. Additionally, there is a transfer structure between the Oxidation Ponds that allows for pumping between the two ponds. This allows Oxidation Pond 1 to be used as a retention pond in high flows while maintaining a high level of treatment in Oxidation Pond 2.

Dry weather effluent (flows less than 2.3 MGD) from Oxidation Pond 2 typically flows by gravity to the treatment wetlands for further secondary treatment. Flow in excess of the treatment wetlands capacity is piped to the wet well of the Pond Pump Station (PPS) for discharge to the UV basin. In high wet-weather flow scenarios, the Emergency Pond Pump Station (EPPS) can be used to redirect peak flows temporary from the oxidation ponds directly to disinfection.

2.3.1.5 Treatment Wetlands and Effluent Pumping
Effluent from the oxidation ponds flows by gravity in parallel to Treatment Wetlands 1 through 3 and 5 through 6 for further secondary treatment. A small portion of the oxidation pond effluent is also pumped to Treatment Wetland 4.

The 13 acres of treatment wetlands reportedly have a capacity to treat 3.3 MGD based on a minimum hydraulic retention time (HRT) of 4 days. Each treatment wetland has one or two influent distribution boxes with adjustable weir gates to control the flow distribution from the oxidation ponds.

Treatment wetlands effluent is pumped to the UV basin for disinfection. Pump Station 1 collects flow from the treatment wetlands and pumps to the UV basin.

2.3.1.6 Disinfection
Up to 9.8 MGD of effluent from the oxidation ponds and treatment wetlands is pumped to the UV basin. Disinfected effluent flows by gravity to the enhancement wetlands. Flows over 5.9 MGD may be routed directly to Humboldt Bay via emergency discharge at discharge point 001. A portion of the disinfected gravity flow from the UV basin is adaptively managed and discharged directly to discharge point 003. Flows greater than 9.8 MGD are diverted to the chlorine contact basin for disinfection via hypochlorite and dechlorination with sodium bisulfate. Chlorine disinfected effluent is discharged at discharge point-001.

2.3.1.7 Enhancement Wetlands (Allen, Gearheart, and Hauser) The three Enhancement Wetlands are hydraulically limited to 5.9 MGD, which is the capacity of the Enhancement Wetlands Pump Station. The three enhancement wetlands in series have a total surface area of 33 acres and allow for approximately 22 MG of storage. Enhancement wetlands effluent is pumped to discharge point-003.

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2.3.2 Phase I Facilities Upgrades
The City of Arcata is substantially complete with the construction of the Phase I Arcata Wastewater Treatment Plant Improvement Project (Phase I) which has replaced aging infrastructure, reconfigured to a single pass flow through the treatment facility and Enhancement Marshes, upgraded the disinfection system to ultraviolet light and added a new treated effluent outfall location, as shown in Figure 4. This Phase I project is of critical importance to meet current water quality standards, eliminate disinfection byproducts associated with chlorine disinfection, protect coastal resources, and produce a higher quality effluent for beneficial use within coastal habitats. Construction is anticipated to be fully complete by June 2026. The Phase I improvements will remain viable through 2055. In addition to the ongoing Phase I Upgrades, future Phase II upgrades are envisioned to comply with effluent limitations in the City’s NPDES permit, including construction of an oxidation ditch, secondary clarifiers, return activated sludge pump station, an alkalinity feed station and rehabilitation of the anaerobic digester.

Phase I upgrades include oxidation pond and wetland treatment system improvements, construction of a parallel oxidation ditch treatment system, construction of an Ultraviolet (UV) disinfection system upstream of the discharge to the enhancement wetlands, and an updated facility configuration allowing for discharges from the enhancement wetlands to the recently created Brackish Marsh in order to provide overall improvements to effluent quality discharged to Humboldt Bay, as shown in Figure 4.

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Figure 4 Phase I Improvements Site Plan
New Flow Schematic

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As a part of Phase I, new facilities, electrical equipment and backup power supply facilities are being elevated as shown in Table 4. Existing facilities related to treatment and operation and elevations are listed in Table 5.

Table 4 Wastewater Treatment Essential Facilities
Essential Facilities Grade Elevation
(feet)
Top of Slab
Elevation (feet)
Electrical Equipment
Elevation (feet)
Headworks 10-11 11.0 NA
Top Deck - 22.4 24.0
Lower Grit Pump Area - 6.8 14.0
Primary Clarifier No. 2 10 16.7 14.0
Pond Pump Station & Pump Station No. 1 11 11.4 14.0
Emergency Pond Pump Station 11 11.9 14.0
UV & Chlorine Contact Basins 11 15.7 14.0
Enhancement Wetlands Pump Station 14.4 14.9 14.0
Generator Building 10 10.4 12.4
Electrical Building 13 13.3 14.0
Table 5 Wastewater Treatment and Operations Facilities
Other Treatment and Operations Facilities Feature Grade Elevation (feet) Perimeter Levee around core treatment plant Perimeter Berm/Levee Lowest 10-11, Typical 11-14 Interior Site and Facility Access Various Driving Paths/Roads ~9.5-10.5 Office Facilities Adjacent Grade ~9.8
Oxidation Ponds Perimeter Berm/Levee 10.5 – 13.0
Treatment Wetlands Perimeter Berm/Levee 10.0 -12.5
Enhancement Marshes Perimeter Berm/Levee 10.0 -12.5
Sludge Drying Beds Adjacent Grade ~10.2

2.3.3 Phase II Facilities Upgrades
In addition to the ongoing Phase I Upgrades, future Phase II upgrades are envisioned to include construction of an oxidation ditch, secondary clarifiers, return activated sludge pump station, an alkalinity feed station and rehabilitation of the anaerobic digester. The rehabilitation of the anaerobic digester will include digester cleaning, replacing digester covers, replacing the boiler/heat exchanger, replacing the mixing and heating piping in the primary digester as needed, adding a sludge thickening system and relocating composting facilities to a new area on site. Completion of Phase II will allow the City to comply with final effluent limitations presented in RWQCB Order No. 1-2019-0006 for ammonia at Discharge Point 001 and Discharge Point 003 as well as more stringent Biochemical Oxygen Demand (BOD) and Total Suspended Solids (TSS) limitations at Discharge Point 002. The implementation of Phase II upgrades will be evaluated after Phase I improvements and this Feasibility Study are complete and treatment performance for regulatory compliance can be assessed.

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2.3.4 Wastewater Characteristics
The influent flows and loads used for the basis of design for the facility upgrades and for the NPDES Permit are presented in Table 6.

Table 6 Design Influent Wastewater Characteristics
Parameter Design Capacity
Average Dry Weather Flow (MGD) 2.3
Average Wet Weather Flow (MGD) 5.0
Peak Wet Weather Flow (MGD) 5.9
Peak Instantaneous Flow (MGD) 16.5
Design Influent BOD Load with 20% growth factor ppd 4800 Design Influent TSS Load with 20% growth factor ppd 6910 Design Influent Ammonia Load with 20% growth factor ppd 1060

2.3.5 Permitted Discharge Water Quality Requirements
The Discharge Requirements for the AWTF are regulated by the RWQCB Waste Discharge Requirements (WDR) Order No. R1-2019-0006 and Monitoring and Reporting Program (MRP) No. R1-2019-0006. Discharge points 001 and 003 presented in Table 3 have unique discharge requirements. The AWTF Phase I upgrades are in progress and the discharge limits presented in Table 7, Table 8 and Table 9 reflect Phase I completion. After the completion of Phase 1 Upgrades, discharge point 001 will is only permitted for emergency discharges when discharge point 003 is operating at capacity of 5.9 MGD.

Table 7 NPDES Permit Discharge Requirements for Discharge Point 001 After Completion of the Phase I Improvements.

Parameter Units Average
Monthly
Average
Weekly
Maximum
Daily
Instantaneous
Minimum
Instantaneous
Maximum
Biochemical Oxygen
Demand 5-day @ 20°C
(BOD5)
mg/L 38 57 -- -- --
Total Suspended Solids
(TSS)
mg/L 32 48 -- -- --
pH Standard units -- -- -- 6.0 8.5
Cyanide, Total (as CN) µg/L 0.43 -- 1.0 -- --
TCDD-Equivalents µg/L 1.4 x 10-8-- 3.3 x 10-8-- --
Ammonia Impact
Ratio
Ratio 1.0 -- 1.0 -- --
Settleable Solids ml/L 0.1 -- 0.2 -- --

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Table 8 NPDES Permit Discharge Requirements for Discharge Point 002 After Completion of the Phase I Improvements.

Parameter Units Average
Monthly
Average
Weekly
Maximum
Daily
Instantaneous
Minimum
Instantaneous
Maximum
Biochemical Oxygen Demand
5-day @ 20°C (BOD5)
mg/L 38 57 -- -- --
Total Suspended Solids
(TSS)
mg/L 32 48 -- -- --
pH standard
units
-- -- -- 6.0 8.5
Settleable Solids ml/L 0.1 -- 0.2 -- --
Table 9 NPDES Permit Discharge Requirements for Discharge Point 003 After Completion of the Phase I Improvements.

Parameter Units Average
Monthly
Average
Weekly
Maximum
Daily
Instantaneous
Minimum
Instantaneous
Maximum
Biochemical Oxygen Demand
5-day @ 20°C (BOD5)
mg/L 30 45 -- -- --
Total Suspended Solids
(TSS)
mg/L 30 45 -- -- --
pH standard
units
-- -- -- 6.0 8.5
Copper, Total
Recoverable
µg/L 3.3 -- 5.3 -- --
Cyanide, Total (as CN) µg/L 0.43 -- 1.0 -- --
TCDD-Equivalents µg/L 1.4 x 10-8-- 3.3 x 10-8-- --
Ammonia Impact
Ratio
Ratio 1.0 -- 1.0 -- --
Settleable Solids ml/L 0.1 -- 0.2 -- --

2.3.6 Enclosed Bays and Estuaries Policy
In 1974 the State Water Resources Control Board (State Board) adopted the Enclosed Bays and Estuaries Policy (EBEP). The EBEP prohibits the discharge of wastewater into enclosed bays and estuaries unless it can be shown that the wastewater will consistently be treated and discharged in a manner that would enhance the quality of the receiving waters above that which would occur in the absence of the discharge. The City currently complies with the EBEP through the use and maintenance of the Enhancement Marshes.

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2.4 Treatment Requirements for Discharge or Reuse
Currently, the AWTF discharges effluent into Humboldt Bay under their NPDES permit from 2019. With the Phase I upgrades to the AWTF in progress and future planning for Phase II upgrades and SLR adaptation at the plant in progress, the California Coastal Commission and State Board have requested that alternative disposal options be considered. Options include:
– Updated Bay Discharge
– Ocean Outfall
– New Surface Water Discharge
– Land Application
– Groundwater Infiltration/Injection
Each option has varying treatment levels (i.e. secondary, enhanced secondary, tertiary) for disposal of effluent based on State regulations (Table 10). Each treatment level has varying treatment limits which are defined in Table 11. The end use determines the level of treatment needed and the potential treatment upgrades that would be needed.

Recycled water for irrigation is regulated by the State Board and California Department of Health Services state-wide reclamation criteria in Title 22, California Code of Regulations (CCR), Section 60301. To meet discharge requirements, the treatment methods can be combined to meet disposal requirements. Further discussion of Alternative Discharge methods is included in Section 5.5.

Table 10 Treatment Level Required for Discharge
Discharge Type Treatment Level Special Considerations
Humboldt Bay Discharge Secondary w/Disinfection and
Enhancement
Must provide Water Quality “enhancement” to
receiving water
Ocean Outfall Secondary Lower effluent discharge limits under the regulatory framework of the Ocean Plan, which
allows for a dilution credit
Land Application Secondary/enhanced secondary/tertiary Treatment requirements are dependent on the final use, if there is human contact, or if a crop will be grown and for what purpose it will be used.

Surface Water Discharge Tertiary Discharge currently only allowed October 1st – May 14th
Groundwater
Infiltration/Injection
Tertiary Must provide groundwater enhancement, typically via aquifer recharge or seawater intrusion barrier

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Table 11 Treatment Limits for Secondary, Enhanced Secondary and Tertiary Treatment Levels Parameter
Treatment Level
Secondary
Secondary with
Enhancement for Bay
Discharge
Enhanced
Secondary for Land
Application
Tertiary
BOD, mg/L
Monthly Average 30 30 10 10
Weekly Average 45 45 15 15
TSS, mg/L
Monthly Average 30 30 10 10
Weekly Average 45 45 15 15
Settleable Solids, mg/L
Monthly Average 0.1 0.1 0.1 0.1
Weekly Average 0.2 - 0.2 0.2
pH

6.5 - 8.5 6.5 - 8.5 6.5 - 8.5 6.5 - 8.5
Total coliform MPN/100 mL
Monthly Average 23 - 22 2.2
Maximum Daily 240 - 23 23
Fecal coliform
Median Concentration, MPN/100ML - 14 - 2.2
Monthly Max, 10% of Samples - 43 - -
30-day Geometric Mean, CFU/100mL 200 - - -
Daily Maximum, CFU/100mL 400 - - -
Ammonia Impact Ratio (AIR)
AIR 1 1 1 1
Nitrate, mg/L
Monthly Average 8 - 1 1
Total Nitrogen, mg/L
Monthly Average 10 - 4 4
Total Phosphorus, mg/L
Monthly Average - - 1 0.3
Turbidity, NTU
Monthly Average - -
not more than 20%
above background
2 NTU
average
Maximum Daily - -
not more than 20%
above background
10 NTU
instantaneous
maximum

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3. Vulnerability and Risk Assessment of AWTF
Infrastructure to Sea Level Rise and
Flooding
The AWTF and surrounding areas are susceptible to flooding from existing and future extreme events of tidal and fluvial water levels and precipitation, which are predicted to become more frequent and severe with SLR and changes to the climate. This section describes the vulnerability and asset risk assessment for the AWTF and its associated systems to flooding. A detailed study of vulnerability for City assets within the City’s Coastal Zone is presented in the City’s Sea Level Rise Vulnerability Assessment and Capital Improvement Project Adaptation Plan Study (Appendix A).

To better understand potential impacts of coastal, fluvial and groundwater flooding on the City’s wastewater system and inform the development of adaptation alternatives, a vulnerability and risk assessment was completed. The assessment was conducted utilizing hydrodynamic modeling of current and future tidal water levels, precipitation events and groundwater levels to identify flood pathways, extent, depth and duration for a range of flooding scenarios.

The vulnerability assessment addresses the questions: What wastewater assets may be adversely affected by flooding, at what water level, and when? The risk assessment accounts for the likelihood that an asset will be impacted, the types of impacts, and the consequence of those impacts. The risk assessment is used to inform the temporal and spatial prioritization of adapting assets for future conditions.

The vulnerability assessment was completed as follows:
• Collect and model relevant hydroclimatic data.
• Inventory of critical assets. This information was provided by the City of Arcata and is comprised of wastewater infrastructure. Additional information was obtained from previous studies; it was the starting point for this assessment.
• Consideration of design criteria. Information was collected from City of Arcata policies and standards, and other organizations that provide guidance on the development and evaluation of engineering projects. • Conduct a sensitivity analysis. Site visits, observations from previous flood events, and engineering judgement were used to determine critical thresholds for the various asset types (or individually, as applicable). Critical thresholds represent the point at which there is a high potential for damage or reduced function of a wastewater asset.
• Conduct an exposure analysis. Utilize the results of a range of hydrodynamic modeling and available groundwater information to identify the extent, depth and duration of flooding to which wastewater and related assets are exposed.
• Determine adaptive capacity. Identify actions to moderate potential damages or cope with the consequences associated, and critical thresholds that limit these actions. • Determine vulnerability. Identify the projected timing and frequency that impacts to assets may occur based on state SLR and precipitation guidance.

The project study area for the Arcata SLR Assessment and Adaptation Plan included a range of City assets. For analysis of the wastewater system assets within the Coastal Zone that are potentially vulnerable to coastal and fluvial flooding, the results of the Arcata SLR Assessment and Adaptation are used in the following sections.

For the Arcata SLR Assessment and Adaptation Plan, previous modeling of Humboldt Bay developed by Northern Hydrology and Engineering (NHE) was expanded and water level datums and annual exceedance probabilities of extreme events along the study area shoreline were developed. Modeling conducted by NHE provided tidal water level

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time series in Humboldt Bay influenced by astronomical tides and storm surge events with additional modeling providing wind setup and wave runup effects on water levels along the shoreline.

Tidal time series from the NHE model and stream flow hydrographs developed from the USGS StreamStats were used to develop model scenarios representing a range of existing and future conditions. A hydrodynamic model of the shoreline and landward areas was developed to evaluate flooding pathways, extent, depth and duration of each model scenario. The United States Geological Survey (USGS) Coastal Storm Modeling System (CoSMoS) Our Coast Our Future web tool was utilized to estimate existing and future groundwater conditions.

These SLR scenarios were used to describe changes to water level datums and annual exceedance probabilities over the course of the planning horizon. Risk and vulnerability of assets are presented for 2025, 2055, 2075 and 2105.

3.1 Tidal Water Levels
As with any dynamic system, water levels along the City of Arcata shoreline differ from those along other shoreline segments of Humboldt Bay due to varying hydrodynamic factors. To forecast shoreline tidal water levels, a hydrodynamic model was developed by Northern Hydrology and Engineering (NHE) and the results were summarized in the report Humboldt Bay: Sea Level Rise, Hydrodynamic Modeling, and Inundation Vulnerability Mapping, 2015. In 2024, NHE built upon previous modeling, and expanded inputs and developed water levels and annual exceedance probabilities of extreme high-water levels for the Study Area (NHE, 2024). The resulting water levels and estimated annual exceedances are shown in Table 12. Further discussion of factors considered in the model are presented below.

Table 12 2023 Tidal water levels and still water return periods for the study area (NHE, 2024).

Tidal Datum and Annual Exceedance
Probability (%)
Annual Expected Number
of Occurrences (#/yr)
Annual Average
Recurrence Interval (yr)
Year 2023 Value (ft,
NAVD 88)
Mean High Water (MHW) - - 6.4
Mean Higher High Water (MHHW) - - 7.1
Mean Monthly Maximum Water (MMMW) - - 8.5
Mean Annual Maximum Water (MAMW) - - 9.5

99.0 0.99 1.01 9.3

95.0 0.95 1.05 9.3

90.9 0.91 1.10 9.3

80.0 0.80 1.25 9.4

66.7 0.67 1.5 9.5

50.0 0.50 2 9.6

20.0 0.20 5 9.9

10.0 0.10 10 10.1

5.0 0.05 20 10.3

4.0 0.04 25 10.4

2.0 0.02 50 10.5

1.0 0.01 100 10.7

0.5 0.005 200 10.8

0.2 0.002 500 11.1

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3.2 Wind Effects on Tidal Water Levels
Water levels in Humboldt Bay are based on tidal elevations which can be significantly influenced by local wind effects.

Water levels are influenced by both wind setup and wave runup which result in total water level (TWL). Wind setup is the increase in still water level of the Bay caused by wind generally pushing the water from one end of the Bay to the other. Wave Runup is the result of the interaction between wind waves and the shoreline, resulting in temporary spray or surge of water up the shoreline slope or feature. Total water levels (TWL) at a given shoreline location are estimated by combining still water levels (tide levels plus storm surge), wind setup, and wave runup from locally generated waves (Figure 5). NHE analyzed local wind characteristics and performed a wind wave analysis using data from local NOAA weather stations (Appendix A). A summary of these effects is provided below.

Figure 5 Conceptual representation of wind, wind waves and wave runup resulting in total water level (TWL).

3.2.1 Wind Setup
The tidal water levels in Humboldt Bay are influenced by wind setup that is dictated by local wind characteristics. As wind blows over the surface of the Bay a shear stress is applied to the water surface which pushes water in the direction of the wind. The wind stress effects can magnify or suppress tidal water levels along the Bay shoreline depending on the location and the prevailing wind direction and magnitude. At the study area, wind blowing from south to north (south winds) tend to increase water levels in the northern part of the Bay and tend to decrease water levels in the south part of the Bay. Conversely north winds tend to increase water levels in the southern part of the Bay and tend to decrease water levels in the northern part of the Bay.

NHE (2024) utilized a hydrodynamic model of Humboldt Bay to estimate wind setup including the study area for various wind speeds and directions. The modelling results indicated that the largest wind wave setup occurred at a wind direction aligned to the longest wind fetch (the longest unobstructed wind path across the Bay’s water surface, which is 240.3 degrees relative to the project shoreline, Figure 6). The resulting wind setup in feet at the study area shoreline is presented below in Table 13.

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Figure 6 Fetch directions relative to the Project shoreline adjacent to Klopp Lake in North Bay (NHE, 2024).

Table 13 Estimated wind setup at project shoreline (NHE, 2024) Annual Exceedance Probability (%) Wind Setup (ft)
95 0.59

66.7 0.64
50 0.68
20 0.79
10 0.86
4 0.95
2 1.00
1 1.04
The wind setup elevations presented in Table 13 are the increase in still water level in the Study Area caused by south wind events (typically winter storms). The 95% or approximately yearly wind event increases still water levels by 0.59 feet, while the 1% or 100-year wind event increases still water levels by 1.04 feet. In addition to wind setup, wind wave conditions and wave runup can result in temporary increases in water levels along the shoreline as waves interact with the Bay shoreline.

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3.2.2 Wind Wave Conditions and Runup
Despite being largely sheltered from the open coast, the north bay in the vicinity of the Study Area has sufficient fetch (wind exposure) such that locally generated wind waves have the potential to contribute to flood hazards along the shoreline of the Study Area. Depending on specific shoreline feature height and shape as well as the still water level, the addition of wind waves and the magnitude of wave runup can result in temporary overtopping of the shoreline feature.

The relationship between wind speed and the creation of wind wave heights and periods were estimated along the longest fetch direction for eight extreme wind speeds (95, 66.7, 50, 20, 10, 4, 2 and 1% exceedance probability). The corresponding peak wave heights and periods were calculated using procedures outlined in the US Army Corps of Engineers 2015 Coastal Engineering Manual and used to then calculate the wave runup as the wind waves interact with an armored shoreline as shown in Table 14, using the Technical Advisory Committee for Water Retaining Structures (TAW). Wave runup may be added to the stillwater level at a given location to estimate the peak of the temporary spray or surge of water in the immediate vicinity of the shoreline.

Table 14 Peak wave heights/period and wave runup at project location (NHE, 2024).

Annual Exceedance
Probability (%)
Adjusted Wind Speed
(mph)
Peak Wave Height (ft) Peak Wave Period (s) Wave Runup R2% (ft) 95 37.6 2.35 2.66 4.14

66.7 38.9 2.45 2.70 4.29
50 39.9 2.53 2.73 4.40
20 42.6 2.74 2.80 4.70
10 44.2 2.87 2.85 4.89
4 45.9 3.01 2.90 5.09
2 47.0 3.09 2.92 5.21
1 47.9 3.17 2.95 5.32

3.3 Sea Level Rise and Climate Change
SLR is an issue of concern when considering how a changing climate could affect infrastructure and lands within the Humboldt Bay region. SLR, like many other natural processes, is continually evolving over time. In the short term, SLR may be appear to be minimal in comparison to other factors that affect water levels of Humboldt Bay. However, even a small amount of SLR may increase the risk of coastal flooding during extreme events, posing an increased threat to a variety of coastal resources.

The potential rate of SLR is forecasted by considering scenarios based on various sets of assumptions. SLR scenarios along the west coast of California are provided in the latest 2024 State of California Sea Level Rise Guidance document (OPC, 2024). The California Coastal Commission (CCC) Sea Level Rise Policy Guidance refers to these as the “best available science.” These scenarios, as described in OPC’s guidance are as follows:

Low: the scenario is on the lower bounding edge of plausibility given current warming and sea level trajectories, and current societal and policy momentum.

Intermediate-low: a reasonable estimate of the lower bound of most likely SLR in 2100 Intermediate: Based on sea level observations and current estimates of future warming, a reasonable estimate of the upper bound of most likely SLR in 2100.

Intermediate-high: Intermediate-to-high future emissions and high warming; this scenario is heavily reflective of a world where rapid ice sheet loss processes are contributing to SLR.

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High: high future emissions and high warming with large potential contributions from rapid ice-sheet loss processes; given the reliance on sea level contributions for processes in which there is currently low confidence in their understanding, a statement on the likelihood of reaching this scenario is not possible.

How SLR affects actual water elevations is influenced by a variety of factors. For the Humboldt Bay region, one of the most significant factors is vertical land motion. Vertical land motion results from movement of the earth’s crustal plates, as well as other local factors. Humboldt Bay is subject to a multitude of factors causing the ground surface to slowly subside. The rate of vertical motion is not uniform around the bay and hence varies by location.

OPC provides adjusted scenarios for 13 NOAA tide gauge locations that include local vertical land motion. The closest gauge location to the Study Area, for which SLR scenarios are provided is Humboldt Bay North Spit (Station ID:
9418767), approximately nine miles south of the Arcata shoreline. Greater amounts of vertical land motion occur at the North Spit tide gauge (-3.21 mm/yr) compared to the Mad River Slough (-0.54 mm/yr) along the northern extent of the bay, approximately 3 miles west of the AWTF, at a similar latitude (Patton, et al., 2023).

For assessing future risks to the Arcata WTF, rates of SLR were determined using the Humboldt Bay North Spit projections and adjusted with the anticipated vertical land motion for Mad River Slough. These are shown in Table 15 below.

Table 15 SLR scenarios for Humboldt Bay North Spit (OPC, 2024) with vertical land motion for Mad River Slough in feet.

Year Low Int-Low Intermediate Int-High High
2000 0.0 0.0 0.0 0.0 0.0
2020 0.2 0.2 0.2 0.2 0.3
2030 0.4 0.5 0.5 0.5 0.5
2040 0.5 0.6 0.7 0.8 0.9
2050 0.6 0.7 0.9 1.1 1.3
2060 0.7 0.9 1.2 1.6 2.1
2070 0.8 1.1 1.5 2.3 3.1
2080 0.9 1.3 1.9 3.1 4.2
2090 1.1 1.6 2.6 4.1 5.6
2100 1.2 1.8 3.3 5.1 6.8
2110 1.3 2.0 4.0 5.9 8.2
As surface temperature rise, the probability of reaching and exceeding each SLR scenario also increases as shown in Table 16. If Global surface temperatures reach 3.0°C above pre-industrial levels by 2100, there is near certainty that the Low SLR Scenario will be exceeded, and 5% chance that the intermediate Scenario will be exceeded. The High SLR Scenario is a highly improbable scenario for all presented warming levels, having 0.1% chance of occurring for the maximum 5.0°C of warming scenario. As SLR progresses over time, projections may be modified based on the best available climate science on how water levels are estimated to change over time.

Table 16 Exceedance probabilities for the SLR Scenarios based on IPCC warming level – based GMSL projections (OPC, 2024).

Global Mean Surface Air
Temperature 2081-2100

1.5° C 2.0° C 3° C 4.0° C 5.0° C
Low Scenario 92% 98% 99.50% 99.90% >99.9%
Intermediate-Low Scenario 97% 50% 82% 97% 99.50%
Intermediate Scenario 0.50% 2% 5% 10% 23%
Intermediate-High Scenario 0.10% 0.10% 0.10% 1% 2%
High Scenario <0.1% <0.1% <0.1% <0.1% 0.1%

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3.4 Reference Flood Design Criteria
Engineering design criteria serve as guidelines and benchmarks for developing and evaluating engineering projects.

Typically, flood design criteria for critical assets are based on the 100-year, or 1-in-100 chance flood event with a specified freeboard (protection above the design flood elevation) to provide a factor of safety for the design. The 1-in100 chance water level increases with SLR over time, thus planning for future projects are based on the current specified flood event plus the SLR presented in the OPC scenarios above. Some key purposes of design criteria include:

Promote Safety: Help identify and mitigate potential hazards, protecting users and the environment.

Meet Regulatory Standards: Design criteria align projects with local, national, and international regulations and standards.

Achieve Functionality: Define the necessary functions and performance requirements Facilitate Communication: Clear criteria help communicate expectations and requirements.

Guiding Decision-Making: Provide a framework for making informed decisions throughout the design process.

Optimize Resources: Criteria help in the efficient use of materials, time, and budget, leading to cost-effective solutions.

Quality: Help meet the desired quality and reliability standards.

The City of Arcata Title VIII Building Regulations Chapter 4, Flood Hazard Mitigation Standards guide development in flood prone areas of the City jurisdiction. City guidance requires any development to be designed around a Base Flood Elevation (BFE), a Federal Emergency Management Agency (FEMA) term referencing the elevation of surface water resulting from a flood that has a 1% chance of equaling or exceeding that level in any given year (FEMA, 2024). For example, all new construction of residential and commercial buildings in the City must be elevated a minimum of 1-foot above the FEMA BFE (City of Arcata, 2016). The reference design criteria for each asset type considered in this study are summarized in Table 17. It should be noted that there is no design criteria for the collection system for flooding.

The collection system piping is underground and designed to not allow water into the collections system. While the system may be exposed to rising groundwater levels, a maintained collection system should not experience issues.

Table 17 Reference Design Standards for Wastewater Asset Flood Protection Asset Reference Flood Design Criteria
Wastewater Collection Piping
No references for flood design of pressure mains.

No references for flood design of gravity pipes and manholes.

Wastewater Lift Stations
Minimum Lowest Floor Elevation (ASCE, 2015):
<1% Annual Chance + 1 ft Freeboard
Minimum Elevation of Utilities and Equipment (ASCE, 2015)::
<1% Annual Chance + 1ft Freeboard
Wastewater Treatment Facilities
Minimum Lowest Floor Elevation (ASCE, 2015):
<1% Annual Chance + 1 ft Freeboard
Minimum Elevation of Utilities and Equipment (ASCE, 2015)::
<1% Annual Chance + 1ft Freeboard
Minimum Elevation of Shoreline Protection
< 1% Annual Chance of Overtopping + Minimum Freeboard
2 feet (Levee or Dike height 6-12 feet) (USDA, 2022)

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3.5 Vulnerability Assessment of the Arcata Wastewater
System
The focus of the vulnerability assessment was to characterize potential adverse effects to wastewater infrastructure, resulting from a range of existing and future tidal and groundwater levels and stream flows. The vulnerability of assets was assessed based on the framework described in the 2024 State of California Sea Level Rise Guidance document that includes an evaluation of the impacts to infrastructure due to exposure and sensitivity of an asset to flooding and erosion, and the ability to moderate damage due to future conditions (adaptive capacity).

The vulnerability assessment focused on the following factors:
• Asset sensitivity: characterized how service may or may not be affected if exposed to flood waters • Exposure: identified if flooding associated with a given water level or storm event would interact with the asset • Impacts: were described based on the asset sensitivities and flood exposure to identify thresholds, characterized by marked changes to operations (i.e. typical wet conditions, maintenance, and damage following an event).

Reference design criteria was identified, intended to inform typical avoidance or mitigation measures. • Adaptive Capacity: characterized the asset and City staff’s ability to moderate potential damages. • Vulnerability: utilized the results of the steps above and projected changes to the recurrence and magnitude of hazards to characterize the likelihood of impacts over the course of the planning horizon. The exposure and likelihood of an event was compared to reference design criteria to understand if and when an asset meets or will no longer meet typical design criteria.

Vulnerability as a function of impacts and changing likelihoods affecting each asset was evaluated for 2024 (current), 2055, 2075, and 2105 to capture the existing conditions and changes of the project planning horizon. An overview of the vulnerability of the AWTF and Collection System are presented in the following sections.

3.5.1 Collection System Vulnerability
The collection system includes gravity pipes, pressure pipelines, manholes and lift stations. The vulnerability of lift stations are discussed in Section 3.5.2 below. Gravity wastewater mains are located subsurface throughout the City with manhole vaults providing access along pipe alignments. Many of these facilities are also located in areas of high seasonal groundwater. Cracks and loose joints in pipes, damaged service connections and other deficiencies can allow infiltration of groundwater into the collection system. As groundwater levels increase near the Bay with increases in SLR, infiltration could increase if pipeline deficiencies are not addressed. The collection system can also experience conveyance capacity reduction through inflow from unsealed manholes, that when flooded allow stormwater into the sewer system, taking up a portion of the available conveyance capacity.

Infiltration from groundwater and inflow from flooded manholes reduces available conveyance capacity in the system and can result in Sanitary Sewer Overflows (SSOs) and discharge of untreated wastewater to the surrounding environment and regulatory fines. Inflow and infiltration can also affect the AWTF capacity and treatment effectiveness. It is assumed that occasional flooding would be similar to existing larger storm events for which the City does not regularly experience SSOs. However, more frequent (more than once per month) or the continuous inundation of manholes would likely impact operations due to inflow into the system.

The number of wastewater manholes becoming regularly flooded (six or more times per year corresponding to MMMW) under the OPC Intermediate Scenario, Intermediate-High Scenario, and High Scenario are presented in Table 18. Under the Intermediate Scenario, by 2055, nine wastewater manholes, located in low elevation areas, will likely experience flooding multiple times per year. By 2075, this increases to 14 or more, and by 2105, this increases to 40 or more for the Intermediate Scenario. Submerging of manholes could result in sanitary wastewater overflows in addition to treatment capacity and quality challenges.

Pressure sewer mains are also located subsurface. Many of these pipes exist in areas of high seasonal groundwater and flooding would not significantly affect the operation of these facilities. Increases in salinity may result in increased

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 26
corrosion of ductile iron and other metal components resulting in reduced service life and increased frequency of maintenance and replacement. These facilities are not considered to be sensitive to flooding.

Figure 7 Example of Inundated Manhole Flooding Collection System

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 27
Table 18 Number of Wastewater Manholes Experiencing Flooding Greater Than 6 Times Per Year (MMMW) That Will Need to be Relocated or Replaced.

Sewer Manhole Flooding
Number of Manholes Affected by MMMW
2025 2055 2075 2105
OPC Intermediate Scenario - (8.5 ft) (9.4 ft) (10.1 ft) (12.0 ft) Estimated SLR from 2000 1.0 ft 1.7ft 3.6ft
Outside of Roadway
(Janes Creek Drainage, Agricultural Fields, Enhancement Marshes) -
6 6 27
S G St 3 5 9
S I St
-
1 5
H St 2 4
F St 2
2nd St 2
OPC Intermediate-High Scenario (8.5 ft) (9.7 ft) (11.1 ft) (13.8 ft) Estimated SLR from 2000 1.3 ft 2.7 ft 5.5ft
Outside of Roadway
(Janes Creek Drainage, Agricultural Fields, Enhancement Marshes) -
6 23 40
S G St 5 9 9
S I St 1 4 5
H St 2 4 6
F St
-
2 2
2nd St 2 2
Samoa Blvd
-
4 3rd St 5
5th St 2
4th St 3
Community Park Way 3
Union St 1
OPC High Scenario (8.5 ft) (10.0 ft) (12.0 ft) (15.8 ft) Estimated SLR from 2000 1.7ft 3.7ft 7.5ft
Outside of Roadway
(Janes Creek Drainage, Agricultural Fields, Enhancement Marshes) -
6 23 48
S G St 5 9 9
S I St 1 4 6
H St 2 4 6
F St
-
2 3
2nd St 2 2
Samoa Blvd
-
10 3rd St 5
5th St 4
4th St 3
Community Park Way 3
Union St 3
6th St 1

3.5.2 Lift Station Vulnerability
GHD conducted field inspections of wastewater lift stations to evaluate the sensitivity of these facilities to flooding. Lift stations may have a structure/building to house components or be a locking cabinet. An example of a lift station exterior is shown in Figure 8, image A. Lift station exteriors are located on concrete slabs. Flooding in and around these structures poses the potential for impacts to the function of the facility if floodwaters come in contact with electrical panels or flood into conduits (Figure 8, images B and C). Flooding below these components would result in cleanup and pose challenges to access during the flood event but would not be expected to result in damage or significant disruptions to service.

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 28
A) B)
C)
Figure 8 Typical Lift Station Components Consisting Of A) Lift Station Building on Concrete Slab B) Electrical Panels and C) Electrical Panels and Backup Generators
The likelihood of lift station flooding under the OPC Intermediate Scenario is outlined in Table 19. Multiple flood conditions were considered that include when flooding will enter or interact with the building or foundation, the backup power supply (if present), and the electrical equipment. Reference design criteria uses the 1-in-100 annual chance water level and one foot of freeboard for the building or foundation and two feet for the backup power and electrical equipment. The generator and electrical facilities in the First Street Lift Station exhibit clearance above the foundation while the other pump stations exhibit electrical facilities at foundation elevation. All lift station components, with the exception of the First Street Lift Station building floor elevation, currently meet reference design criteria. By 2075, the First Street Lift Station building is expected to be exposed to flooding multiple times per year and the backup power supply and electrical equipment will no longer meet reference freeboard criteria. The Meadowbrook and Samoa Lift

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 29
Stations all exhibit elevations above the 1-in-100 annual chance water level through 2105, but do not meet freeboard criteria at the end of the century.

Table 19 Likelihood of flooding resulting in damage / failure of lift station facilities (OPC Intermediate Scenario).

Lift Station Flooding
Flooding
Water
Level
Chance of Occurrence per Year
2024 2055 2075 2105
OPC Intermediate Scenario
Estimated SLR from 2000 1.0ft 1.7ft 3.6ft
First St Lift Station
Building Floor Flooding 10.7 ft Tide 1-in-100 1-in-3 1-6/year Daily Generator (Backup Power) 11.7 ft Tide <1-in-500 1-in-100* 1-in-10 >1/Month Electrical Equipment 13.3 ft Tide <1-in-500 <1-in-500 <1-in-500* 1-in-3 Meadowbrook Lift Station
Foundation and Electrical Equipment 100-yr Fluvial <1-in-500 <1-in-500 1-in-500* <1-in-500* Wetlands Lift Station
Foundation and Electrical Equipment 14.9 ft Tide <1-in-500 <1-in-500 <1-in-500 <1-in-500* Samoa Lift Station
Foundation and Electrical Equipment 15.3 ft Tide <1-in-500 <1-in-500 <1-in-500 <1-in-500* Meets Reference Design Criteria of <1-in-100 annual likelihood of flooding and freeboard Does Not Meet Reference Design. >=1-in-100 annual likelihood of flooding and freeboard * = asset not flooded, but does not meet freeboard requirements Under the OPC Intermediate-High and High Scenarios, the likelihood of First Street Lift Station flooding becomes more regular between 2055 to 2075 (Table 20). The other three lift stations no longer meet reference freeboard criteria in 2075 and are exposed to regular flooding at the end of the century.

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 30
Table 20 Likelihood of Flooding Resulting in Damage / Failure Of Lift Station Facilities (OPC Intermediate-High and High Scenario) Asset Flooding
Elevation Chance of Occurrence per Year
2024 2055 2075 2105
OPC SLR Scenario Int-High High Int-High High Int-High High Estimated SLR from 2000 1.3ft 1.7ft 2.7ft 3.7ft 5.5ft 7.5ft First St Lift Station
Building Flooding 10.7 ft Tide 1-in-100 2-in-3 1-6/year >1/Month Daily Daily Daily Generator (Backup Power) 11.7 ft Tide <1-in-500 1-in-33 1-in-10 1-6/year >1/Month Daily Daily Electrical Equipment 13.3 ft Tide <1-in-500 <1-in-500 <1-in-500 1-in-100 3-in-7 >1/Month Daily Meadowbrook Lift Station
Foundation and Electrical Equipment 14.9 ft Tide <1-in-500 <1-in-500 <1-in-500 <1-in-500* <1-in-500* 2-in-3 >1/Month Samoa Lift Station
Foundation and Electrical Equipment 15.3 ft Tide <1-in-500 <1-in-500 <1-in-500 <1-in-500 <1-in-500* 1-in-5 >1/Month Meets Reference Design Criteria of <1-in-100 annual likelihood of flooding and freeboard Does Not Meet Reference Design. >=1-in-100 annual likelihood of flooding and freeboard * = asset not flooded, but does not meet freeboard requirements

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3.5.3 Wastewater Treatment Facility Vulnerability
The AWTF is comprised of multiple components at varying elevations and likelihood of exposure to flooding impacts (Table 21). All vulnerabilities are presented without the Levee Augmentation project the City currently has in the design phase. The City’s Phase I project locates most essential facilities at an elevation that meets or exceeds reference design criteria of the 1-in-100 annual chance water and freeboard through 2055. The Headworks Lower Grit Pump Area and Generator building are projected to be exposed to flooding multiple times per year by 2055 without the upgraded levee. The backup power supply (Generator Building Electrical Equipment) will begin to see flooding multiple times per year at the end of the century. The enhancement marshes will likely see multiple tidal flooding events per year in the latter part of the century. Office facilities will see a similar number of flooding events.

Table 21 Likelihood of Flooding Resulting in Damage / Failure at AWTF Facilities (OPC Intermediate Scenario).

AWTF Asset and Access Flooding
Elevation
Annual Probability of Flooding Exceeding
Design Criteria
2024 2055 2075 2105
OPC Intermediate Scenario
Estimated SLR from 2000 1.0ft 1.7ft 3.6ft
Essential Facilities
Headworks Lower Grit Pump Area

10.7 ft Tide 1-in-100 1-in-3 1-6/year Daily Generator Building Oxidation Ponds 11.1 ft Tide 1-in-500* 1-in-10 2-in-3 >1/Month Treatment Wetlands Pond Pump Station and Pump Station No. 1 11.4 ft Tide <1-in-500* 1-in-33 1-in-3 >1/Month Emergency Pond Pump Station 11.9 ft Tide <1-in-500 1-in-500* 1-in-20 >1/Month Generator Building Electrical Equipment 12.4 ft Tide <1-in-500* <1-in-500* 1-in-100 1-6/year Electrical Building 13.3 ft Tide <1-in-500 <1-in-500* <1-in-500* 1-in-3 Electrical Equipment for Essential Facilities1 14.0 ft Tide <1-in-500 <1-in-500 <1-in-500* 1-in-33 Enhancement Wetlands Pump Station 14.9 ft Tide <1-in-500 <1-in-500 <1-in-500 <1-in-500* UV & Chlorine Contact Basins 15.7 ft Tide <1-in-500 <1-in-500 <1-in-500 <1-in-500* Primary Clarifier No. 2 16.7 ft Tide <1-in-500 <1-in-500 <1-in-500 <1-in-500 Headworks Top Deck 22.4 ft Tide <1-in-500 <1-in-500 <1-in-500 <1-in-500 Headworks Electrical Equipment 24.0 ft Tide <1-in-500 <1-in-500 <1-in-500 <1-in-500 Other AWTF Facilities
Office Facilities 10.7 ft Tide 1-in-100 1-in-3 1-6/year Daily Sludge Drying Beds
Site and Facility Access 11.1 ft Tide 1-in-500* 1-in-10 2-in-3 >1/Month Meets Reference Design Criteria of asset above 1-in-100 flood elevation plus freeboard Does Not Meet Reference Design. >=1-in-100 annual likelihood of flooding and freeboard * = asset not flooded, but does not meet freeboard requirements 1Electrical Equipment for Grit Pump, Primary Clarifier No. 2, Pond Pump Station, Pump Station No. 1, Emergency Pond Pump Station, UV & Chlorine Contact Basins, Enhancement Wetland Pump Station, Electrical Building) Under the OPC Intermediate-High and High Scenarios, multiple flooding events per year affecting the lower-elevation facilities will occur more frequently in 2055 to 2075 (Table 22). Additionally, the duration for which facilities can meet reference design criteria is reduced by up to 20 to 30 years for the High scenario.

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Table 22 Likelihood of Flooding Resulting in Damage / Failure at AWTF Facilities (OPC Intermediate-High And High Scenarios).

AWTF Asset and Access Flooding Threshold Chance of Occurrence per Year 2024 2055 2075 2105
OPC SLR Scenario Int-High High Int-High High Int-High High Estimated SLR from 2000 1.3ft 1.7ft 2.7ft 3.7ft 5.5ft 7.5ft Essential Facilities
Headworks Lower Grit Pump Area 10.7 ft Tide 1-in-100 2-in-3 1-6/year >1/Month Daily Daily Daily Generator Building 10.7 ft Tide Oxidation Ponds
Treatment Wetlands 11.1 ft Tide 1-in-500* 1-in-4 2-in-3 6/year >1/Month Daily Daily Pond Pump Station and Pump Station No. 1 11.4 ft Tide <1-in-500* 1-in-10 1-in-3 1-6/year >1/Month Daily Daily Emergency Pond Pump Station 11.9 ft Tide <1-in-500 1-in-100 1-in-20 Yearly >1/Month Daily Daily Generator Building Electrical Equipment 12.4 ft Tide <1-in-500* <1-in-500* 1-in-100 1-in-3 1-6/year Daily Daily Electrical Building 13.3 ft Tide <1-in-500 <1-in-500* <1-in-500* 1-in-100 3-in-7 >1/Month Daily Electrical Equipment for Essential Facilities1 14 ft Tide <1-in-500 <1-in-500 <1-in-500* <1-in-500* 1-in-25 1-6/year Daily Enhancement Wetlands Pump Station 14.9 ft Tide <1-in-500 <1-in-500 <1-in-500 <1-in-500* <1-in-500* 2-in-3 >1/Month UV & Chlorine Contact Basins 15.7 ft Tide <1-in-500 <1-in-500 <1-in-500 <1-in-500 <1-in-500* 1-in-20 >1/Month Primary Clarifier No. 2 16.7 ft Tide <1-in-500 <1-in-500 <1-in-500 <1-in-500 <1-in-500 <1-in-500* 1-6/year Headworks Top Deck 22.4 ft Tide <1-in-500 <1-in-500 <1-in-500 <1-in-500 <1-in-500 <1-in-500* <1-in-500* Headworks Electrical Equipment 24 ft Tide <1-in-500 <1-in-500 <1-in-500 <1-in-500 <1-in-500 <1-in-500* <1-in-500* Other AWTF Facilities
Office Facilities 10.7 ft Tide 1-in-100 2-in-3 1-6/year >1/Month Daily Daily Daily Sludge Drying Beds
Site and Facility Access 11.1 ft Tide 1-in-500* 1-in-4 2-in-3 6/year >1/Month Daily Daily Meets Reference Design Criteria of <1-in-100 annual likelihood of flooding and freeboard Does Not Meet Reference Design. >=1-in-100 annual likelihood of flooding and freeboard * = asset not flooded, but does not meet freeboard requirements 1Electrical Equipment for Grit Pump, Primary Clarifier No. 2, Pond Pump Station, Pump Station No. 1, Emergency Pond Pump Station, UV & Chlorine Contact Basins, Enhancement Wetland Pump Station, Electrical Building)

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3.5.4 Enhancement Marsh System and Site Access Vulnerability In addition to the infrastructure described above, the City’s wastewater system includes the Enhancement Marshes, which provide enhanced treatment required under the City’s discharge permit and conformance with the EBEP. The wastewater system also relies on local roads for access to the AWTF. Both the Enhancement Marshes and access roadways are currently protected from tidal inundation and flooding by linear landforms created for and/or providing an elevation barrier between water bodies and low-lying areas.

The linear landforms protecting the Enhancement Marshes and access roads are subject to erosion from short, shallow overtopping and potential failure under longer durations. The threshold and likelihood for the initiation of shoreline structure overtopping that would result in erosion and flooding and threshold for potential failure for the Marsh protection structures and access roads are shown in Table 23. Thresholds are associated with the lowest point along these linear features. Many of the linear landforms were not constructed for the purposes of flood control or were constructed prior to modern design standards.

Shoreline protection along South G Street exhibits the lowest elevation structures and currently exhibits a 2-in-3 likelihood (1.5-yr return interval) of overtopping, with less than 1-in-500 likelihood of failure.

In 2055, areas along South G Street are projected to overtop up to six times per year and have a 1-in-10 annual chance of potential failure at discrete lower elevation locations along the levee. Overtopping and flooding of the AWTF perimeter levee without temporary sandbag placement has an existing chance of occurrence of 1-in-10 and is expected to occur multiple times in a given year by the end of the century. With anticipated 3.3 feet of SLR (OPC Intermediate Scenario), the repeated overtopping of the levee by the end of the century could potentially lead to failure of lower elevation stretches of the levee.

Table 23 Likelihood of Shoreline Protection Overtopping Resulting in Erosion and Maintenance (OPC Intermediate Scenario) Shoreline Protection Overtopping
Threshold
Chance of Occurrence per Year
(Erosion and Maintenance) 2024 ~2055 ~2075 ~2105
OPC Intermediate Scenario
Estimated SLR from 2000 1.0ft 1.7ft 3.6ft
(Erosion and Maintenance)
South G Street 9.5 ft Tide 2-in-3 1-6/year >1/Month Daily Enhancement Marshes/ South I Street 10.7 ft Tide 1-in-100 1-in-3 1-6/year Daily (Potential Failure)
South G Street
Enhancement Marshes/ South I Street 11.1 ft Tide 1-in-500 1-in-10 2-in-3 >1/Month Meets Reference Design Criteria <1-in-100 annual likelihood of overtopping and freeboard Does Not Meet Reference Design Criteria. >1-in-100 annual likelihood of overtopping and freeboard Under the OPC Intermediate-High and High Scenarios, in 2055 overtopping results in flooding of South G Street and the Enhancement Marshes and would likely occur multiple times per year (Table 23). Conditions indicate potential failure of these linear landforms are projected to occur in 2075.

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 34
Table 24 Likelihood of Shoreline Protection Overtopping Resulting in Erosion and Maintenance (OPC Intermediate-High and High Scenario).

Shoreline Protection Overtopping Threshold Chance of Occurrence per Year 2024 ~2055 ~2075 ~2105
OPC SLR Scenario Int-High High Int-High High Int-High High Estimated SLR from 2000 1.3ft 1.7ft 2.7ft 3.7ft 5.5ft 7.5ft (Erosion and Maintenance)
South G Street 9.5 ft Tide 2-in-3 >1/Month >1/Month Daily Daily Daily Daily Enhancement Marshes/ South I Street 10.7 ft Tide 1-in-100 2-in-3 1-6/year >1/Month Daily Daily Daily (Potential Failure)
South G Street
South I Street
Enhancement Marshes 11.1 ft Tide <1-in-500 1-in-4 2-in-3 6/year >1/Month Daily Daily Meets Reference Design Criteria <1-in-100 annual likelihood of overtopping and freeboard Does Not Meet Reference Design Criteria. >1-in-100 annual likelihood of overtopping and freeboard

3.5.5 Current Vulnerabilities Identified
In the previous sections, vulnerabilities for the Collection System, Lift Stations, AWTF, and Enhancement Marshes were identified for current conditions through 2105 for multiple OPC emission scenarios. The following vulnerabilities were identified for assets that would be impacted by the current 100-yr (10.7 ft tide) or less flood events. As water levels increase with SLR, impacts at these vulnerable locations are expected to become more frequent and severe:
– In low lying areas of the collection system, there are 44 manholes that are vulnerable to overtopping at a 10.7-foot tide. This would increase flows to the AWTF, increasing the volume of wastewater treated during the winter months, further exacerbating the I&I issues that the City already faces.
– The floor of the First Street Lift Station is at an elevation of approximately 10.5 feet. The lift station is expected to experience nuisance flooding (less than 1 foot of flooding for 2 hours or less) at a 10.7-foot tide. This is not expected to disrupt the operation of the lift station. – Access to the AWTF along South G Street is anticipated to experience nuisance flooding at a 9.5-foot tide. – The Enhancement Marshes levees have a minimum crest elevation of approximately 9.5 feet along South I Street and are currently vulnerable to overtopping during a 10.1-foot tide. This may disrupt treatment effectiveness of the Enhancement Marshes and limit access to essential treatment facilities at the end of South I Street.
– The AWTF levees have a minimum crest elevation of less than 10.0 feet and are vulnerable to minor overtopping during a 10.1-foot tide. This would impact the headworks grit pump area and generator building with nuisance flooding which is not expected to disrupt treatment operations.

This overtopping is expected to become disruptive by 2055.

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 35

3.6 Coastal Hazards Risk Assessment
While the vulnerability assessment identified what and how assets will be impacted, the risk assessment was used to determine the scale and severity of impacts. Characterizing risk allows the City to make informed decisions regarding the allocation of resources and development of adaptation strategies for AWTF infrastructure, based on the temporal and spatial distribution of risk. The Risk Assessment includes consideration of the likelihood and consequence of an event. Event likelihood is based on existing recurrence intervals and future projections using OPC and Cal Adapt Intermediate Emissions and Sea Level Rise Scenarios as described in the scale below (Table 25).

Table 25 Likelihood Scale providing qualitative terms for numerical likelihoods for use in Risk Analysis Likelihood Scale Description
Almost Certain Multiple times per year
Very Likely 1-in-2 to yearly Annual Chance (2- to 1-yr recurrence) Likely 1-in-25 to 1-in-2 Annual Chance (25- to 2-yr recurrence) Unlikely 1-in-50 to 1-in-25 Annual Chance (50- to 25-yr recurrence) Very Unlikely 1-in-500 to 1-in-50 Annual Chance (500- to 50-yr recurrence) Almost Unprecedented 1-in-500 or Less Annual Chance (greater than 500-yr recurrence) Consequences utilize the components of the vulnerability assessment to qualitatively or quantitatively describe how impacts affect the City’s ability to manage and maintain wastewater operations. Consequences are described on a relative scale of severity. A consequence scale is a tool used to evaluate and categorize the potential outcomes or impacts of an event. The proposed risk scale for this study is provided in Table 26.

Table 26 Consequence Scale providing qualitative consequence terms, definitions and examples for use in Risk Analysis Consequence Scale Description Examples
Insignificant Easily manageable within typical
operations and maintenance
No change to typical operations and maintenance
Within typical budgeted costs
Minor
Minimal impact, easily manageable with
some additional maintenance/staff time
required
Small additional operations and maintenance
Additional costs within typical annual contingency
Moderate Manageable impact, some effort required
to address.

Short (hours) delays in service
Increased costs not typically budgeted
Limited additional resources required
Major Noticeable impact, requires significant
effort to manage
Temporary (1+ days) delays to service
Requires repair of facilities or parts
Additional resource required
Severe Significant impact, challenging to
manage, requiring additional resources
Extended (multiple days to one week) service
disruption.

Significant financial cost not typically budgeted
Requires replacement of limited facilities or parts
Substantial outside resources required to address
Catastrophic Severe impact, potentially unmanageable
even with additional resources
Long term (multiple weeks) service disruption
Massive financial loss, failure and replacement of
assets required
Requires extensive replacement, repair, and or
reconstruction of facilities

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The combination of the likelihood (almost certain to almost unprecedented) and consequence of a given event (insignificant to catastrophic) can then be used to apply a qualitative risk rating using a risk matrix evaluation (Table 27).

Table 27 Risk Matrix Evaluation combining Consequence Scale and Likelihood Scale to assign a qualitative risk rating.

Risk Matrix Evaluation
Consequence
Insignificant Minor Moderate Major Severe Catastrophic
Likelihood
Almost Certain
Very Likely Very High
Likely High
Unlikely Medium
Very Unlikely Low
Almost Unprecedented Very Low

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 37

3.6.1 Qualitative Risk Analysis
For this study, the qualitative risk analysis focus is on flooding and impacts to operations, maintenance and continual service of City wastewater infrastructure. A similar process could be applied to evaluate effects on public health, habitats, or other assets of interest. A qualitative evaluation of consequences of impacts to wastewater assets is presented in Table 28. The consequences are then combined with the likelihood of the event causing the impact, as presented previously, for each asset and type of impact to inform an overall risk rating for wastewater assets over time. Risk ratings associated with the OPC Intermediate Scenario are reported in the following sections as a baseline for evaluating risk. Review of the previously discussed increases in likelihood associated with the Intermediate-High and High Scenarios may be reviewed to inform the potential for earlier onset of increased risk ratings.

Table 28 Assignment of Risk Consequence Scale to asset exposure based on anticipated impacts.

Asset Exposure
Asset Impact Consequence
Insignificant Minor Moderate Major Severe Catastrophic
Shoreline
Protection Overtopping No Overtopping
Erosion And
Maintenance
Potential Failure
Protecting
Agricultural
Areas
Potential
Failure
Protecting
Developed
Areas
Lift Stations Surface Flooding
Flooding Near
Lift Station
(Roadways)
Flooding
Enters
Structure
-
Flooding At
Elevation of
Generators
Flooding at
Elevation of
Electrical
Panel
-
AWTF Surface Flooding
Disruption of
Access,
Flooding Enters
Structure,
Potential
Overflows to
Sensitive Areas
Flooding
Disrupting
Operations /
Treatment
Effectiveness
Flooding
Damaging
Backup Power
and Treatment
Flooding
Damaging
Electrical
Infrastructure
Wastewater
Gravity Main
and
Manholes
Monthly
Submergence
1-5 Manholes
Submerged
6-10 Manholes
Submerged
11-15 Manholes
Submerged
> 15 Manholes
Submerged
Asset impact consequences are specific to the Study Area, asset consequences descriptions are provided for threshold values of consequences to assets. Description left blank if no further damage or change in damage due to increased flood depth is expected.

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 38

3.6.2 Wastewater Collection Piping
Consequences associated with the flooding of wastewater manholes vary depending on the number of manholes submerged and anticipated impacts to treatment effectiveness and the ability of the City to respond to overflows. The threshold of flooding that results in impacts is when flooding becomes regular, roughly exceeding 6 times per year.

The threshold for this is associated with water levels corresponding to MMMW. Flooding of less than ten manholes results in insignificant to minor consequences as overflows may be limited to isolated areas and the treatment plant can likely accommodate this amount of additional inflow into the system. As regular flooding begins to affect 11 or more manholes, consequences progress to moderate and major as the City’s ability to respond to all locations to contain overflows requires additional resources and impacts to the ability to effectively treat sewer flows with higher saltwater concentration decrease.

The risk rating associated with these consequences and the likelihood of the threshold water level occurring are presented in Table 29. Currently, a low-risk rating is achieved, but when considered in aggregate at all impacted locations, the risk rating increased to medium late century and high at the end of the century due to challenges responding to the extent of potential overflows and impacts to treatment capabilities.

Table 29 Risk Rating for Flooding of Sewer Manholes Resulting in Sanitary Sewer Overflows and Reduced Treatment Capabilities Sewer Manhole Flooding
(OPC Intermediate SLR Scenario)
Impact: Sewer Overflows,
Reduced Treatment Consequence Year | Risk Rating
2055 2075 2105
Outside of Roadway
Minor to Major:

Sanitary sewer overflows, reduced
treatment effectiveness with
saltwater entering system.

S G St
S I St
H St
F St
2nd St
Overall Risk
Risk Rating
Very High
High
Medium
Low
Very Low

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 39

3.6.3 Wastewater Lift Stations
Flooding of wastewater lift stations result in escalating consequences as flooding first affects access and foundationlevel equipment and components, then may progress to impact the backup power supply and electrical equipment that would result in failure of lift station’s ability to maintain service. Minor consequences result from flooding entering the building, affecting access and requires cleanup. Depending on the configuration of the wet well, flood waters could enter the wet well chamber, requiring more extensive clean up of sediments and other debris that could affect pump operation. Major consequences are associated with flooding and failure of the backup power system and requires replacement of the backup system but does not disrupt longer-term service. Consequences are severe when the electrical panel is exposed to flooding and failure of the lift station occurs that requires replacement and or reconstruction of facilities.

The risk rating associated with these consequences and the likelihood of the threshold water level occurring are presented in Table 30. The First Street Lift Station is located at the lowest elevation and backup power and electrical facilities are located 1.0 to 2.5 feet above the floor elevation. While this lift station currently achieves a low-risk rating, the low ground and floor elevation results in a risk rating that progresses to medium and then high late century. All other lift stations are located at higher elevations and achieve a low-risk rating throughout.

Table 30 Risk Rating for Flooding of Lift Stations That Affect the Building Access, Backup Power and Electrical Equipment Lift Station Flooding
(OPC Intermediate SLR Scenario)
Impact: Operations,
Service Threshold Consequence Year | Risk Rating
2024 2055 2075 2105
First St Lift Station
Building Flooding 10.7 ft Tide
Minor:

Flooding enters structure, cleanup
required
Generator (Backup
Power) 11.7 ft Tide
Major:

Flooding at elevation of generators,
failure of backup power, replacement
of generator required
Electrical Equipment 13.3 ft Tide
Severe:

Flooding at elevation of electrical
panel, failure of Lift Station,
replacement / reconstruction
Meadowbrook Lift Station
Foundation and Electrical
Equipment 100-yr Fluvial
Severe:

Flooding at elevation of electrical
panel, failure of Lift Station,
replacement / reconstruction
Samoa Lift Station
Foundation and Electrical
Equipment 15.3 ft Tide
Severe:

Flooding at elevation of electrical
panel, failure of Lift Station,
replacement / reconstruction
Risk Rating
Very High
High
Medium
Low
Very Low

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 40

3.6.4 Wastewater Treatment Facilities
The AWTF is comprised of multiple components that exhibit a range of consequences due to the impacts on treatment, operations and the ability to maintain wastewater services, in addition to potential overflow to sensitive areas. Moderate consequences result from impacts to buildings, pump station and storage facilities that disrupt access or have potential to result in overflows. Major consequences are associated with a disruption of operations and reduced treatment effectiveness due to saltwater entering treatment facilities. Consequences are severe when flooding damages backup power, and repair and replacement of equipment is needed. Catastrophic consequences are a result of damage to the electrical infrastructure that results in a failure of treatment capabilities and requires reconstruction and replacement of facilities and equipment.

The risk rating associated with these consequences and the likelihood of the threshold water level occurring are presented in Table 31 for essential facilities and Table 32 for other facilities. Currently, AWTF facilities exhibit a very low to low-risk rating. Although the consequence of impacts can be severe to catastrophic, the likelihood of those impacts is very low (below 1-in-500 annual chance) as a result of the City’s Phase I project that elevates several essential facilities. Risk ratings for building facilities and some treatment facilities (ponds and marshes) escalate to medium mid-century. High to very high-risk ratings are associated with late century impacts to the headworks and lower grit pump area, backup power supply, and pond and marsh treatment facilities.

Table 31 Risk Rating for AWTF Facilities Affecting Treatment, Operations and Service AWTF Flooding
(OPC Intermediate SLR Scenario)
Impact: Treatment, Operations,
Service, Overflows Threshold Consequence Year | Risk Rating 2024 2055 2075 2105
Essential Facilities
Generator Building 10.7 ft Tide
Moderate:

Disruption of access,
flooding enters structure,
potential overflows to
sensitive areas
Pond Pump Station and Pump Station
No.1 11.4 ft Tide
Emergency Pond Pump Station 11.9 ft Tide
Electrical Building 13.3 ft Tide
Enhancement Marsh Pump Station 14.9 ft Tide
Headworks Lower Grit Pump Area 10.7 ft Tide
Major:

Flooding disrupting
operations, reduced
treatment effectiveness
Enhancement Marshes 10.7 ft Tide
Oxidation Ponds 11.1 ft Tide
Treatment Wetlands 11.1 ft Tide
UV & Chlorine Contact Basins 15.7 ft Tide
Primary Clarifier No.2 16.7 ft Tide
Headworks Top Deck 22.4 ft Tide
Generator Building Electrical
Equipment 12.4 ft Tide
Severe:

Flooding damaging backup
power, replacement required
Electrical Equipment for Essential
Facilities1 14 ft Tide Catastrophic:Flooding damaging electrical Infrastructure, failure of
treatment capabilities
reconstruction required
Headworks Electrical Equipment 24 ft Tide
1Electrical Equipment for Grit Pump, Primary Clarifier No. 2, Pond Pump Station, Pump Station No. 1, Emergency Pond Pump Station, UV & Chlorine Contact Basins, Enhancement Wetland Pump Station, Electrical Building) Risk Rating
Very High
High
Medium
Low
Very Low

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 41
Table 32 Risk Rating for AWTF Facilities Affecting Treatment and Access AWTF Flooding
(OPC Intermediate SLR Scenario)
Impact: Treatment, Access Threshold Consequence Year | Risk Rating 2024 2055 2075 2105
Other AWTF Facilities
Office Facilities 10.7 ft Tide Moderate:

Disruption of access and
operations,
flooding enters structure,
potential overflows to
sensitive areas
Sludge Drying Beds 11.1 ft Tide
Site and Facility Access 11.1 ft Tide
Risk Rating
Very High
High
Medium
Low
Very Low

GHD | Rural Community Assistance Corp. & City of Arcata | 12616645 | Arcata Wastewater Treatment Facility Sea Level Rise Adaptation Feasibility Study 42

3.6.5 Coastal Hazards Risk Assessment Summary
Figure 9 below presents risks to assets in the AWTF and surrounding area for 2024, 2055, 2075 and 2105 under the OPC Intermediate Sea Level Rise Scenario. Under existing conditions, access to the AWTF along South G Street exhibits medium risk due to likely flooding resulting in moderate to major consequences associated with the road becoming inaccessible. All AWTF assets exhibit a low to very low risk rating due to likelihood ranging from unlikely to almost unprecedented. By 2055, access along South G progresses to high risk. AWTF facilities risk increases to medium risk due to the increased likelihood of flooding, erosion and associated disruption to services and the City’s ability to manage impacts. By 2075 and beyond, the increased likelihood of major consequences occurring, such as damage to assets and increased duration of disruption to services results in the majority of assets evaluated exhibiting high risk. Figure 9 is based on the OPC Intermediate Sea Level Rise Scenario. If sea level rise faster, based on the intermediate-high or high scenarios, impacts from flooding would occur sooner.

Figure 9 Risk Ratings of City Assets Based Likelihood and Consequence During the Planning Horizon (OPC Intermediate Scenario)