Pollution Has Fouled Rialto Well. New tests show that an underground plume of pollution that has fouled drinking water supplies in the San Bernardino Valley is moving toward another well used by Rialto.
“It’s getting too close for comfort,” Bradley Baxter, the city’s director of public works, said Friday by telephone. “It’s one of our top producers.”
Rialto already has shut down five of its 13 drinking wells tainted by perchlorate, an explosive salt used in making rocket fuel, ammunition, fireworks and other products. With one-third of its supply contaminated, Rialto declared a water emergency in July. The city’s 100,000 residents have voluntarily reduced use by 12 percent, Baxter said.
The city will serve as a backdrop for an announcement by Sen. Nell Soto, D-Pomona, and other state officials touting Gov. Davis’ intention to sign a package of bills designed to protect the state’s water supply from perchlorate, said Russ Lopez, a Davis spokesman.
In all, 20 wells that serve more than 250,000 people in Rialto, Colton and Fontana have been shut down or restricted because of the perchlorate. The chemical can impair thyroid function and stunt development of fetuses and newborns.
The perchlorate is believed to have seeped into the ground over the past 60 years at an industrial site in north Rialto used by defense contractors, fireworks manufacturers and San Bernardino County, which operates the Mid-Valley Sanitary Landfill.
Tests Show Presence Of Perchlorate
Groundwater tests conducted recently by the county show that perchlorate as high as 310 parts per billion, nearly 80 times the state’s advisory level, is present southeast of the landfill, according to a report submitted to the Santa Ana Regional Water Quality Board.
The perchlorate, which is moving an average 2 feet per day, is about three-quarters of a mile from Rialto’s drinking well, according to the tests. More investigation could find that it’s even closer, said Kurt Berchtold, assistant executive officer of the regional water board.
San Bernardino County officials say the contamination appears to be coming from a bunker area the county bought in 1993 to expand its landfill. The county demolished the bunkers that stored munitions and fireworks, and used the area to store dirt dug from other parts of the landfill.
The county will look at ways to prevent the perchlorate from reaching the Rialto well, said Peter Wulfman, the county’s solid-waste management manager.
“Our goal,” he said, “will be to limit the situation as soon as possible.”
Several other companies are in various stages of soil and water investigations to determine if they contributed to the pollution, Berchtold said. The board, along with the U.S. Environmental Protection Agency, has been working to define the boundaries of the contamination and find those responsible.
Perchlorate has contaminated water sources nationwide, including the Colorado River, a major Inland source, and sites in Redlands, Corona and the Jurupa Valley.
State and federal officials are developing drinking water standards for perchlorate. California has an “action level” of 4 parts per billion, at which point water agencies are encouraged to notify consumers.