Maricopa council hears Global Water briefing after single E. coli detection; company and regulator say water safe

Global Water representatives told the City of Maricopa City Council on Sept. 16 that the utility found one positive E. coli bacteria test in August, followed by multiple confirmation tests that returned non‑detect results, and that Arizona Department of Environmental Quality (ADEQ) had determined the incident was resolved.

Why it matters: Residents raised concerns that Global Water did not notify all customers about the initial positive detection, leaving some households unaware for several days. Council members pressed the company on its communication practices and what changes it will make to notify vulnerable customers more quickly.

John Corwin, vice president and general manager for Global Water: "The water is safe. We are in compliance with the drinking water rules," and he said the utility had pulled multiple additional samples that returned negative results. Corwin said ADEQ "has said the issue is resolved." Chris Krieger, Global Water chief operating officer, said the company is reviewing internal processes and will look at ways to improve customer outreach.

Global Water said it pulled three confirmation samples at the original location that were non‑detect for E. coli, and that, through September, it had taken 39 additional samples related to the event that all returned non‑detect results. The company also said it typically collects about 90 bacterial samples per month in the distribution system.

ADEQ and regulation: Council members were briefed that drinking water regulation is administered in Arizona by ADEQ (the state’s primacy agency for Pinal County), under federal rules from the Environmental Protection Agency. Council member Smith (Mayor Smith) cited ADEQ guidance in saying the agency did not treat the event as a medical‑health crisis; if it had, the state Department of Health Services and county health authorities would have become involved.

Communication and lessons learned: Global Water emailed customers Aug. 30 and later sent a broader follow‑up; the company reported roughly 73 percent email open rates on the messages it sent. Some long‑time customers told the council they did not receive any notice because their contact information on file was outdated. Resident Dan Wilson said he learned about the detection only when a neighbor told him and urged the council to press the company to notify customers immediately in future incidents.

Global Water described operational actions it took after the initial positive result: flushing lines, hyperchlorination, and increased sampling. Company staff said their chlorination residuals generally run above the regulatory minimum (the company cited 0.8 parts per million as the regulatory minimum and typical operating residuals around 1.5–1.7 ppm).

Council and resident concerns centered on notification timing, outreach to immunocompromised residents and those who lack up‑to‑date electronic contact information, and whether ADEQ’s advisory templates (a precautionary notice) should be issued earlier in similar future events. Global Water said it would analyze possible changes, including wider immediate notification and ways to shorten sample transit and lab turnaround times.

No formal council action was taken; the item was a presentation and public comment session. Council members said they would follow up with ADEQ and with Global Water on procedural changes and improved lines of communication.

The council encouraged residents with questions to use the telephone numbers and resources Global Water and ADEQ made available and suggested the city would repost official water notices on the city public‑notice page and on social media to broaden reach.

Ending: Global Water and the council said they will pursue follow‑up improvements to communication and sampling processes; the company reiterated its conclusion that the water system is operating within regulatory limits and ADEQ had judged the incident resolved.