About 9,000 gallons of effluent leaked out of a holding area and into a retention basin at a Johnson Utilities facility in Pinal County on Monday.
The incident occurred at the Pecan Water Reclamation Plant, which was in the news last May when 10,000 gallons of sewage spilled due to clogged pumps. However, company officials said the latest incident was not sewage, but treated wastewater commonly used for irrigating golf courses and open spaces.
The company has the holding area to store effluent before it's pumped for irrigation but it hadn't been used it in awhile, said vice president Brian Tompsett.
Part of the dirt berm, a packed earthen wall to hold the water in, failed and caused the leak, Tompsett said. The water spilled into a retention basin south of the plant.
"That's where it was contained," Tompsett said. "We fixed the breach and refirmed up the berm."
Crews were cleaning up the water Monday and were going to chlorinate the area as a precaution, according to an e-mail the company sent to the Arizona Department of Environmental Quality.
On Tuesday morning, a little water remained to be evaporated, Tompsett said. ADEQ had also scheduled a site visit.
Last year's incident involved 10,000 gallons of sewage leaking out of the plant after pumps were clogged.
ADEQ cited the company after finding elevated levels of E. coli several months later in the Queen Creek Wash where it had leaked.
Johnson Utilities disputed the sewage caused the high bacteria levels but it has since disinfected the wash to fulfill an agreement with ADEQ. The company saidit was doing the disinfection as a "public service." Tompsett said there haven't been any recent problems with the pumps.
Johnson Utilities also dealt with a spill in a Pinal County's Cambrilla Ocotillo neighborhood on Feb. 22, when clogged sewer lines caused 9,000 gallons of sewage to leak out into two retention basins.
ADEQ closed an investigation into that incident without citing the company, but the Arizona Corporation Commission has decided to rehear a case to add 1.2 square miles to its service area because Johnson Utilities didn't notify it about the spill at a hearing on the expansion a week later. While the company isn't required to notify the Corporation Commission about spills, it did acknowledge the timing made the issue relevant and apologized for the oversight.