The Laboratory Section collects and analyzes a wide variety of samples, including water, wastewater, industrial wastewater, and biosolids.

Sampling and analysis are performed to support the City’s water and wastewater facilities and ensure compliance with environmental regulations such as the Clean Water Act, the Safe Drinking Water Act (SDWA), the Arizona Pollution Discharge Elimination System (AZPDES), the 40 CFR Part 503 Biosolids Rule, the City’s Publicly Owned Treatment Works (POTW) Pretreatment Program, and other Federal and State programs.

As part of the AZPDES permit for the Figueroa Avenue Water Pollution Control Facility, staff conduct routine sampling of the Colorado River. Microbiological testing for the City’s drinking water treatment plants and distribution system is also carried out, with results reported to the Arizona Department of Environmental Quality (ADEQ) and the U.S. Environmental Protection Agency (USEPA).

This section also serves as the primary point of contact for customer concerns related to water safety and quality. Most inquiries or complaints are addressed within the same business day.

Water Quality Information

The City of Yuma’s potable water system, Public Water System No. 14024, is regulated under the the Safe Drinking Water Act and is overseen by the U.S. Environmental Protection Agency and the Arizona Department of Environmental Quality.

Water Quality Report

The Consumer Confidence Report (CCR) or Water Quality Report is mandated by USEPA to be published and available to the public by July 1st each year. The data reported is for the previous calendar year. For example, the CCR published for July 1, 2025 contains data for January through December 2024.

Total Coliform Bacteria

The City of Yuma conducts monthly monitoring for Total Coliform bacteria, collecting over 100 samples from locations throughout the City's water distribution system. Under the Safe Drinking Water Act (SDWA), a maximum of 5% of these samples may test positive for Total Coliform in any given month. (Note: A sample that is negative for Total Coliform is also considered negative for E. coli.) The City’s drinking water system is operated and monitored in full compliance with SDWA requirements.

For produce and agricultural operations: If your customers or regulatory agencies require verification of water potability for contractual purposes, such as compliance with the Leafy Green Products Handler Marketing Agreement (LGMA), your facility is responsible for any additional sampling and analysis beyond what is routinely conducted by the City of Yuma.

For More Information

If you have any questions or would like more information regarding the quality of your drinking water, contact the Laboratory Section at (928) 373-4597.