Updates to PCE contamination in South Lake Tahoe to be discussed at public meeting

A 400-acre plume of tetrachloroethylene (PCE) has been found in some of the South Lake Tahoe groundwater and the agencies tasked with protecting the local drinking supply will be updating the community on cleanup efforts and the status of the plume on Wednesday, June 26 from 6:00 p.m. to 7:30 p.m. in the South Lake Tahoe City Council Chambers at the airport.

The South Tahoe Public Utility District, Lukins Brothers Water Company, and Tahoe Keys Property Owners Association (Water Suppliers) are hosting the public meeting which will review recent actions they've taken with the Lahontan Regional Water Quality Control Board (Lahontan) to protect the public water supply.

It is a deep plume, from 26 feet to 52 feet deep, 140-180 feet below the surface. One of the sources has been identified as the old Lake Tahoe Laundry Works, which was located at the South Y Center. At their March community meeting, Lahontan revealed some other points of entry for the chemical are around Tucker and Glorene avenues, near where the former Big O Tire store and the current Napa Auto Parts store are located, as well as the current site of TJ Maxx where another old dry cleaners was located.

The Water Suppliers are working to identify the most cost-effective means for managing the groundwater contamination problem while providing a sustainable drinking water supply for South Lake Tahoe. Over the last year and a half, they have hosted quarterly public meetings to provide the community with an update on
contending with the groundwater contamination. At their March meeting, six different scenarios were presented that address the groundwater problem. These ranged from installing clean-up wells within the contaminated area, drilling new wells outside of the contaminated area and increasing treatment at the current
drinking water well sites within the contaminated area, to name a few. At the upcoming meeting on June 26, alternatives developed from evaluating the scenarios will be presented, with the goal of identifying the best scenario to move forward.

In South Lake Tahoe, the primary source of drinking water is groundwater. In 1989, PCE was discovered in drinking water wells. Although the PCE first contaminated groundwater in the 1970s, it still remains in groundwater and is now believed to cover more than 400 acres (see map).

PCE is a manmade chemical that was used from the early 1960s through the mid-1980s as a solvent for dry cleaning clothes and degreasing metal. During the late 1980s, concerns about the toxicity of PCE led Federal and State environmental agencies to list PCE as a probable carcinogen and as a toxic pollutant. Presently, five public
drinking water wells have been impacted by the South “Y” PCE contamination.

When PCE is detected in a well, the well is either shut down, treatment is added to remove the PCE contaminant, and/or an un-impacted alternative source of drinking water supply is found. The Water Suppliers are working together to protect and sustain our communities groundwater supplies. All of the water they provide meets drinking water standards and is safe to drink.

To watch previous meetings, or to live stream this meeting, visit www.stpud.us/groundwater.