< RETURN TO Watershed Improvement & Protection
Watershed Improvement and Protection Unit

Nonpoint Source Pollution Mitigation

Revised On: Oct. 1st, 2026 - 03:53 pm

Program Overview 

Nonpoint source (NPS) pollution occurs when rainfall or snowmelt, moving over and through the ground, picks up and carries natural and human-caused pollutants, depositing them into lakes, rivers, and streams. Unlike point sources, nonpoint sources come from numerous indirect sources, rather than a single source. 

Some examples of nonpoint sources of surface water pollution include:

  • Recreation
  • Domesticated animals 
  • Wildlife
  • Agriculture
  • Irrigation
  • Septic systems
  • Abandoned/inactive mines

NPS Pollution in Arizona

Arizona’s implementation of the federal NPS Program is vital to safeguarding the chemical, biological, and physical integrity of its surface waters. This mission is particularly critical in Arizona’s arid climate, where surface water resources are limited. The ubiquitous nature of NPS pollution presents significant challenges that require substantial time, effort, and funds to remediate. 

According to the U.S. Environmental Protection Agency (EPA), states continue to report that NPS pollution is the leading remaining cause of water quality problems in the United States. An internal analysis of existing total maximum daily load (TMDL) reports found that approximately 96% of Arizona’s surface water impairments are attributable to NPS pollution, further supporting EPA’s claim. 

Every two years, the Clean Water Act (CWA) Sections 305(b) and 303(d) require ADEQ to assess the health of Arizona’s surface waters against established standards. Following EPA guidance, ADEQ combines these requirements into an Integrated Report. The Impaired Waters are shown on the CWA Section 303(d) list in the Integrated Report | Learn More >

How is NPS Pollution Being Addressed?

Diverse partnerships and watershed improvement projects are integral in mitigating the diffuse nature of NPS pollution. Arizona’s watersheds depend on landowners, local watershed groups,various industries, and other state, local, and federal government agencies to voluntarily reduce NPS pollution.

Each year, ADEQ allocates federal funding from EPA to implement on-the-ground projects across the state to improve and protect surface water quality from nonpoint sources of pollution. Projects are generally identified in watershed plans | Learn More >

ADEQ works closely with partners to implement watershed projects to protect nearby streams and lakes. Completed projects include:

  • Social trail restoration and unpermitted parking closures to mitigate Escherichia coliform (E. coli) and sediment loadings 
  • Creek-side restroom installations to prevent E. coli pollution 
  • Grassland restoration to stabilize soils and reduce the transport of sediment and bacteria
  • Bank stabilization, sediment retention, and erosion-prevention to restore natural conditions
  • Mine tailings and waste rock stabilization and capping to prevent metal contamination

Each year, ADEQ allocates approximately $1.3 million of federal grant dollars to implement on-the-ground projects across the state to improve and protect surface water quality from NPS of pollution. Each grant’s performance period is five years.

  • Funding Sources: EPA Section 319(h) of the Federal CWA
  • Total Annual Funding: Approximately $1.3 million

Since 2002, ADEQ has spent over $43 million to control NPS pollution and improve Arizona’s surface waters. 

Match Requirements 

A 40% non-federal match (cost share) is highly encouraged for each Section 319 grant. The match must come from non-federal sources, such as state, local, and private entities, and includes in-kind donations such as donated personnel time, supplies and equipment.

The example below shows how non-federal match can be calculated:
  • $75,000 (federal share) ÷ 60% (federal percentage) = $125,000 (total project cost)
  • $125,000 (total project cost) - $75,000 (federal share) = $50,000 (recipient share/non-federal match)

 

CWA Section 319 funding can be used to reduce contamination in impaired waterbodies or prevent degradation in non-impaired waterbodies. Per EPA guidelines, the funding must be used to implement an existing TMDL or other watershed plan. All projects, budget, and pollutant load reductions are reported to EPA via the Grants and Reporting Tracking System (GRTS).

ADEQ implements targeted projects in priority watersheds by two means: 1) Procuring private entities and/or services through the state procurement process, and 2) subawarding to non-private entities through the grant award process. Through the years, ADEQ has learned that targeted groups of projects in a watershed enable greater pollution reductions and more efficient spending. 

  • Awarded project partners include:
  • Environmental consultancies
  • Non-profit watershed groups
  • Arizona universities
  • Federal land managers
  • State agencies
  • Tribal Nations
  •  

A project proposal must accomplish all of the following to be considered eligible for evaluation:
  • Improve, protect, or maintain a water body in the state of Arizona by addressing a source of NPS pollution
  • Demonstrate acceptable water quality management principles, sound design and appropriate procedures
  • Yield benefits at a level commensurate with project costs for the benefit of the State
  • Have an on-the-ground implementation component within the state of Arizona
  • Provide for at least 40% of the total project costs as non-federal match (Highly encouraged)
  • Be eligible under applicable state and federal regulations, and comply with the application process described in the Arizona Nonpoint Source Grant Program Manual
  • Be completed within five years or less
Activities which are ineligible for funding include:
  • Projects designed to comply with required permits. Funds may not be used to implement specific requirements of draft or final Arizona Pollutant Discharge Elimination System (AZPDES) permits, or to implement permit application requirements of EPA’s stormwater regulations. Funds may not be used to pay for “end of pipe” treatments that are required as part of draft or final AZPDES permits.
  • Projects that are considered day-to-day operations or maintenance and lack a focus on improving water quality.
  • Studies, assessment or education projects that are not part of an implementation plan. An eligible application must have an on-the-ground implementation component and a component of public outreach or education.

ADEQ prioritizes projects by their expected outcomes and ability to reduce contamination in streams impaired for the most common parameters identified in the Integrated Report - metals (collectively) and E. coli. In its 2026-2030 Arizona Nonpoint Source Management Plan (also known as the NPS Five Year Plan), ADEQ committed to implementing targeted NPS mitigation projects in metals-impacted watersheds, E. coli-impacted watersheds, and other watersheds identified by ADEQ as high-priority.

When selecting a priority watershed, ADEQ considers the following at a minimum:

  • Parameter concentrations in relation to surface water quality standards;
  • Partnerships and ability to collaborate with local entities and citizens;
  • Whether or not a TMDL or watershed plan currently exists or is in development;
  • Existence of sufficient data to examine trends and make informed decisions.
ADEQ has identified the following as priority watersheds:
  • Verde River:
    • E. coli
    • Metals
  • Middle Gila River:
    • Metals
  • Bill Williams River:
    • Metals
  • Santa Cruz River:
    • E. coli
    • Metals
  • San Pedro River:
    • E. coli
    • Metals

 

 

  • Nonpoint Source Grant Scope of Work (SOW0 Template | View SOW >
  • Load Reduction Estimation Tool | View Tool >
  • Budget Template | View Template >
  • Request for Reimbursement Form | View Form >

NPS Five-Year Plan and Annual Reports:
  • NPS Management Plan (NPS Five-Year Plan)
  • 2026-2030 | Learn More >
  • 2020-2025 (amended 2024) | Learn More >
Annual Reports:
  • 2025 | Learn More >
  • 2024 | Learn More >
  • 2023 | Learn More >
  • 2022 | Learn More >
Other reports and Data: 
  • Past plans and reports are accessible by making a public records request | Learn How >
  • Additional project data and water quality load reductions are viewable through EPA’s GRTS | Learn More >

Watershed Improvement Unit Manager
602-663-4519
Email>