[Water_news] 4. DWR'S CALIFORNIA WATER NEWS -WATERQUALITY-3/4/09

Department of Water Resources

California Water News

A daily compilation of significant news articles and comment

 

March 4, 2009

 

4. Water Quality –

 

Source of downtown Visalia well contamination sought

The Visalia Times-Delta – 3/4/09

By David Castellon

 

Workers began drilling a series of six wells in downtown Visalia Tuesday, seeking the source of a cancer-causing chemical found in the city's water supply.

 

The wells will be in an area where California Department of Toxic Substances Control researchers found high levels of perchloroethylene (PCE) in water wells.

 

Two dry-cleaning businesses are in the area, as well as the locations of two former dry-cleaning businesses.

PCE is a solvent widely used by dry cleaners.

 

In the early 1990s, California Water Service Co. found high levels of PCE in some of its wells in and around Visalia that supply drinking water and water for firefighting.

 

Those levels were above 5 parts per billion, the maximum limit allowed for PCE in drinking water, said Phil Mirwald, the company's district manager for Visalia.

 

Four of the wells had carbon filters installed in their extraction pumps to remove the PCE and make the water safe for drinking.

 

Currently, CWS has 73 active wells in and around Visalia, Mirwald said.

 

PCE contamination has prompted the destruction of three downtown wells, all in the vicinity of the four current and former dry cleaners.

 

It's around those businesses that the new wells were being drilled Tuesday, said Mike Vivas, a mechanical engineer and site contamination cleanup manager for DTSC. His organization obtained a U.S. Environmental Protection Agency grant to begin looking at PCE levels in Visalia's groundwater in 2007.

 

Vivas said his organization has tested all 73 CWS wells and several of the 272 other private and public wells under Visalia, though he didn't know the exact number Tuesday.

 

He said CWS' water is safe for drinking, including the water coming from wells with filters.

 

Downtown

 

The downtown drilling project is intended to tap into groundwater about 90 feet below to determine the levels of PCE there, as well as in portions of soil collected during the drilling, Vivas said.

 

One of the drill sites is directly across the street from Paragon Dry Cleaners, 119 S. Willis St. A couple of blocks to the east, more drilling was being done near One Hour Martinizing, 717 W. Main St.

 

Employees at both businesses said the owners were not there and couldn't be reached for comment. Drilling also is being done near two former dry-cleaning businesses: One, at 110 N. Willis St., now is a parking lot, while the other, at 220 N. Encina St., is a law office.

 

And there are indications of at least six other dry cleaners having operated over the years in that vicinity, Vivas said.

So, how did the PCE get into the ground?

 

Up until the early 1990s, PCE could be discharged into sewers with wastewater, but concerns over it showing in groundwater and wells, along with the health risks, resulted in laws that forced dry cleaners to install washing devices that separate PCE vapors in tanks and reuse it.

 

Unfortunately, leaks, pipe breaks and spills of PCE in its liquid form result in it getting into the ground. Once there, it can eventually migrate down to the water table, Vivas said.

 

In fact, he said, soil contamination here could have occurred years ago, and only now is slowly seeping into the groundwater. The current owners of those properties — even if they aren't dry cleaners now — could be liable for at least part of the cleanup costs if the DTSC research shows their properties as the sources.

 

Karen Jurist, a site assessment manager for the EPA, said the testing and a final report on the downtown sites could be completed in a couple of months.#

 

http://www.visaliatimesdelta.com/article/20090304/NEWS01/903040317/1002

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