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City of San Luis Obispo looking to purify contaminated well water

Posted at 10:47 PM, Nov 07, 2022
and last updated 2022-11-08 02:47:04-05

From chemicals to seawater intrusion, agencies across the Central Coast are dealing with a variety of groundwater issues.

City of San Luis Obispo water resource officials are taking steps to flush out groundwater that has been contaminated with dry cleaning chemicals.

Recent studies have narrowed down that problem area.

A plume of contamination in San Luis Obispo is the focus of new efforts to clean up dirty well water.

PCE is an industrial chemical used for dry cleaning that has been found in wells along San Luis Obispo Creek between Los Osos Valley Road and downtown.

“If it’s above the maximum contamination level and you drink it for a prolonged period of time, it could cause some types of cancers or kidney damage,” said Nick Teague, water resources manager for the City of SLO.

Recent testing showed that four wells have higher levels of PCE than the state allows. One of the wells showed levels four times higher than the acceptable threshold.

“I wouldn’t say it’s a health threat to those who live in San Luis Obispo,” said Teague.

That’s because city officials stopped using well water in 2015 and that well water was pulled from unaffected areas.

“The sources have been cut off and we’re getting clean water coming in that’s diluting that contaminated groundwater,” added Teague.

In a statement, the Central Coast Regional Water Quality Control Board said”

“There are known current and former dry cleaner and industrial facilities in the Downtown San Luis Obispo area that are potential sources of the PCE. The Central Coast Water Board has two active dry cleaner cases in the area. Both are in investigative phases.”

City leaders are looking to clean the area and resume groundwater use as soon as possible.

There are plans in the works to pump clean water in to flush the chemicals out.

Nearby Los Osos, meanwhile, continues to deal with the threat of saltwater intrusion.

Officials say they have kept the ocean at bay-- however, more saltwater has been seeping in during this most recent drought.

“During the wet years we experienced in 2017 and 2019, we saw that chloride metric decline. Then, in the more recent drought years we’re experiencing, we’re seeing it come back up,” said Dan Heimel, executive director for the Los Osos Basin Management Committee.

Officials with the City of San Luis Obispo say they hope to use groundwater again in 2024.

The city will hold a public meeting on groundwater contamination on Nov. 16.

Study findings on PCE in groundwater will be presented at the meeting, which takes place from 5:30 to 8 p.m. at the Ludwick Assembly Room—located at 864 Santa Rosa St.