BIOSOLIDS

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Yuma County Addresses Biosolids Operations Concerns

Summary

Yuma County has been actively engaged for years regarding biosolids operations in southern Yuma County, including concerns related to odors, flies, dust, debris, quality-of-life impacts, enforcement standards, and long-term community effects.

The County has pursued legislative advocacy, coordinated with state agencies, conducted inspections within its authority, supported monitoring efforts and formally requested additional oversight and enforcement.

Under Arizona law, primary regulatory authority over biosolids permitting, State Trust Land leasing and environmental enforcement rests with state agencies. While Yuma County cannot independently terminate or relocate the operation, the County continues to advocate for stronger oversight, document resident concerns and pursue every available avenue within its legal authority.

This page explains what biosolids are, which agencies have authority, what actions Yuma County has taken, and how residents can direct concerns to the agencies responsible for regulation, leasing and state law.

What are biosolids and why are they a matter of concern?

According to the U.S. Environmental Protection Agency, biosolids are nutrient-rich organic materials derived from treated sewage sludge generated during municipal wastewater treatment.

A biosolids operation in southern Yuma County has generated ongoing complaints related to persistent odors, flies, dust, debris and other quality-of-life concerns. Residents and County officials have also raised concerns regarding pathogen standards, enforcement and potential long-term impacts on nearby communities.

The local operation reportedly accepts material originating in California and cities within Yuma County. Residents have questioned differences between Arizona and California treatment standards and regulatory requirements.

While transportation and land application activities may fall within existing legal frameworks, Yuma County has continued to raise concerns with responsible agencies and lawmakers regarding oversight, enforcement, and community impacts.

Overview and Key Takeaways

Concerns regarding biosolids operations in southern Yuma County are not new: Biosolids activities in the region predate the current Board of Supervisors by more than 40 years and involve longstanding regulatory and contractual frameworks administered at the state level.
The County and Board of Supervisors have been activley engaged on this issue for several years.
The Board of Supervisors has maintained a consistent position opposing the continued importation of California biosolids into Yuma County.
Authority over biosolids regulation, permitting and State Trust Land leasing is shared among multiple state agencies and excludes Yuma County.
Yuma County has consistently advocated for stronger oversight, enforcement and local involvement.
County actions have included permissible inspections, public meetings, legislative advocacy, coordination with state agencies and formal requests for additional action and termination.
The County continues to evaluate additional enforcement, legislative and policy options within its legal authority.

Who has authority to act?

Arizona Department of Environmental Quality (ADEQ)

Responsible for enforcing biosolids regulations, environmental standards and pathogen requirements.

Arizona State Land Department

Responsible for State Trust Land leasing decisions and land-use approvals involving State Trust Land.

Arizona Legislature

Responsible for establishing and revising Arizona laws governing biosolids regulation and environmental policy.

Yuma County

Coordinates local response efforts, investigates issues within County jurisdiction, conducts vector-control inspections, documents resident concerns, and advocates for stronger oversight and state action.

What Yuma County has done

Formally Pressed for greater oversight and enforcement.
The Board of Supervisors formally opposed expansion of biosolids and septage application activities and requested increased oversight, enforcement and local involvement in the review process.
Participated in monitoring and investigative efforts.
The County participated in inspections, monitoring efforts, meetings and study activities to better understand impacts, evaluate enforcement options and document concerns raised by residents.
Advocated for stronger state law.
County concerns contributed to broader statewide discussions regarding biosolids regulation, including legislation adopted through HB 2669 requiring Arizona’s sewage sludge program rules to remain consistent with the federal Clean Water Act.
Evaluated additional local options.
The Board discussed potential local responses including zoning approaches, fee structures, public education efforts and additional policy tools when state-level actions did not fully resolve concerns.
Requested State Land Department action.
In 2025, the Board formally requested that the Arizona State Land Department terminate AgTech’s lease and pursue a new lessee in response to ongoing complaints related to odors, flies, dust and debris.

Current status

County engagement with responsible agencies remains active.

The Board of Supervisors continues to maintain a unified position opposing the continued importation of California biosolids into Yuma County.

The County continues to communicate with ADEQ, the State Land Department and state lawmakers.

Vector Control conducts inspections related to fly activity concerns.

Recent inspections reported no fly larvae at six inspected AgTech biosolids facility sites.

The County continues documenting concerns, evaluating available options and advocating for additional oversight and enforcement.

The AgTech lease currently remains in holdover status and has not been renewed by the Arizona State Land Department.

Decisions regarding the State Trust Land leases, biosolids permitting and potential termination of operations remains under state authority.

Timeline of County action

2016

The Board begins formal public discussion regarding nuisance and public health concerns related to biosolids operations. County efforts focus on investigation, monitoring and coordination with outside agencies.

2018

Monitoring and study efforts provide additional information regarding fly populations and caution against attributing all fly activity to a single source.

2020

The Board formally opposes a proposed 6,000-acre biosolids site and communicates concerns to ADEQ regarding expansion of biosolids and septage activities.

2021

The Board continues to advocate for stronger oversight, enforcement and additional local involvement while acknowledging limits established under Arizona law.

2023

HB 2669 is adopted, requiring sewage sludge program rules to remain consistent with the federal Clean Water Act.

2025

The Board requests that the Arizona State Land Department terminate AgTech’s lease in response to ongoing complaints regarding odors, flies, dust, and debris.

2026

County inspections, documentation efforts and public communication continue while broader policy discussions remain active.

Supervisors meet directly with leadership from the Arizona State Land Department, ADEQ and representatives of the Governor’s Office. ADEQ commits to increasing inspections and enforcement. The Board reiterates its request that the State pursue every available avenue to end the biosolids contract.

Frequently asked questions

What has Yuma County done so far?

Yuma County has been actively engaged on this issue for several years through legislative advocacy, coordination with state agencies and public outreach.

County officials supported efforts that contributed to passage of HB 2669 in 2023, which strengthened requirements that Arizona’s sewage sludge program remain consistent with the federal Clean Water Act.

The Board has also formally opposed expansion efforts, requested increased oversight and enforcement, and requested State Land Department action regarding the AgTech lease.

Why can’t the County simply shut the operation down?

Arizona law places primary regulatory authority over biosolids permits and leases of State Trust Land with state agencies, not Yuma County.

Because the operation is located on Arizona State Trust Land and operates within a state regulatory framework, Yuma County does not have unilateral authority to terminate the lease or independently shut down the operation.

The County’s role includes inspections within its jurisdiction, documentation of concerns, coordination with responsible agencies and continued advocacy for stronger oversight and enforcement.

Are the biosolids operations the primary source of flies in the area?

Research commissioned by ADEQ and conducted by the University of Arizona in 2016 found that less than 1% of fly larvae sampled throughout Yuma County originated from septage or biosolid application sites. The study identified the composting and decomposition of agricultural produce at recycling facilities and within agricultural fields as major contributors to fly populations within the county.

What about PFAS and groundwater?

Yuma County has coordinated with ADEQ on private well concerns on the Mesa and with the Arizona Corporation Commission regarding remediation where appropriate. Naval Facilities recently provided Yuma County with results from well testing conducted outside Marine Corps Air Station Yuma. PFAS compounds were detected at concentrations below current regulatory thresholds. The County has requested additional inspections and testing on the Yuma Mesa and continues coordinating with state agencies regarding groundwater concerns.

Certain treatment systems, including reverse osmosis and activated carbon filtration, may reduce PFAS compounds in drinking water when properly installed and maintained.

Why doesn’t the State Land Department terminate the lease?

Lease termination may involve legal and financial obligations, including potential reimbursement for leaseholder investments and costs related to site remediation. Those decisions fall under the Arizona State Land Department’s authority. Yuma County has formally requested state action, but lease decisions remain under state control.

Can we stop the delivery of waste materials from California?

Arizona has established a statewide regulatory framework governing biosolids activities. Because these activities involve interstate commerce and state-regulated environmental permitting, Yuma County does not have independent authority to prohibit the transport or land application of those materials.

What residents can do

Residents can support stronger oversight and accountability by:

Reporting odors, flies or nuisance concerns with specific dates and locations.
Contacting ADEQ regarding inspections and enforcement.
Contacting the Arizona State Land Department regarding State Trust Land leasing decisions.
Communicating with state legislators regarding Arizona biosolids laws and standards.
Participating in public meetings and agency comment opportunities.

Yuma County encourages residents to document concerns clearly and respectfully so responsible agencies can evaluate complaints effectively.