Drinking water meets standards as 400-acre PCE plume remains in South Lake Tahoe

Tetrachloroethylene (PCE) was found in drinking water wells in South Lake Tahoe near the "Y" in 1989, and it remains in the groundwater today, forming a containment plume from the intersection of Highway 50 and State Route 89 and heading toward Lake Tahoe through the Tahoe Keys.

During a recent public informational meeting, representatives from South Tahoe Public Utility District (STPUD), Lukins Brothers Water, Tahoe Keys Property Owners Association (TKPOA) and the Lahontan Water Quality Control Board spoke about the current status of the plume and what they are doing to remediate the situation. 30 people were in attendance with others able to watch on a live-streamed telecast.

The first message given was to let residents know that drinking water in South Lake Tahoe meets all standards and there is no PCE in it.

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 in the Lukins and Tahoe Keys areas have been impacted by the South “Y” PCE Plume which starts at the site of the old Lake Tahoe Laundry Works (which was around the corner from what now is Raley's).

Lahontan has conducted numerous investigations and testing done to determine the source of PCE and is working with the responsible parties to determine the total extent of the contamination.

99 percent of the drinking water in South Lake Tahoe comes from groundwater. The aquifer holding that water is below sedimentary soil that is great for groundwater, but susceptible to contamination. When the PCE hit the soil, it moved into five wells, three operated by Lukins Brothers and two by TKPOA.

The plume is deep, from 26 feet to 52 feet deep, 140-180 feet below the surface.

Jennifer Lukins from Lukins Brothers Water said she is now authorized to start seeking funding on treatment for their Well #5 and she is working with the Division of Drinking Water.

"It is a slow process but we're navigating through it," said Lukins.

She also said they are waiting for direction from Lahontan to determine what legal action Lukins Brothers has in getting the situation fixed. To date, they have spent about $237,000 on the situation, with about $100,000 coming back in the way of grants. Lukins also has to buy water from STPUD for their customers to fill the void of the missing three wells. That has cost about $200,000 so far.

In 2019 they will have a granulated active carbon (GAC) filtration system in place.

Rick Robillard, the TKPOA water company manager, said they have spent approximately $400,000 on filtration and $600,000 on sampling. Their Well #2 currently has a GAC system and they are monitoring their Well #1 and looking to replace their Well #4.

STPUD has been working with TKPOA and Lukins on the PCE situation. The District received Proposition 1 grant funds in the amount of %504,295 for PCE testing and remediation.

Lahontan representative Scott Ferguson said he and his team are responsible for protecting and restoring groundwater and surface water quality. They also are the enforcement and investigative arm of the PCE investigation and have issued clean-up and abatement orders for the Laundry Works site. They have been in talks with the surviving family members of the site's owners and have received several versions of a work plan on cleanup of the chemical. So far, 900 pounds of PCE have been removed from near the Laundry Works, but more is needed.

Ferguson said they expect a final approval letter for the clean-up plan this week or next week.

There may be additional sources of the PCE plume and other responsible parties.

Ferguson said they are moving forward and working with STPUD on funding, planning, public coordination and preparation for cleanup. He also said factual information is critical in this situation.

PCE has not been detected in wells west of the original contamination site, just north of the site. PCE is descending as it moves north towards Lake Tahoe, according to Ivo Bergshon, STPUD hydrologist. The chemical is driving deeper into the aquifer with the highest concentrations 26-52 feet down in the aquifer though some is found 94-100 feet into it. These levels are 140-180 feet below the surface.

At this point there are three options concerning the PCE plume: Do nothing; Work on the mid-plume contamination with cut-off wells and remediation; Well-head treatment.

There will be evaluations of what would happen should the plume ever hit Lake Tahoe. Those at the presentation feel the vast amount of water in the lake would dilute the PCE to quantities undetected.

During a question and answer period, one of the audience members asked why the process is taking so long, 30 years after the chemical entered the ground.

Ferguson said they have worked with the information they had and had to investigate the rest. The PCE plume cannot be seen from above ground, thus creating lots of testing and drilling. Clean-up and abatement orders must meet the requirements of the law, and proving the plume was started by Laundry Works was once of them. There are possible other contamination sites, possibly from automobile repair shops in the days before environmental requirements.

There has been active remediation at the site since 2010.

Another public update meeting will be held in Fall, 2018.