A dry cleaner near the "Y" in South Lake Tahoe closed decades ago. The chemical it spilled is still underground, and this week a proposed $4.1 million settlement would pay to treat and monitor local drinking water wells for the next 59 years. It is a very local story, but it explains something every well owner and city water customer in the foothills should understand: how a solvent poured out in the 1970s ends up in a kitchen faucet in 2026.
What happened at the Y
The chemical is tetrachloroethylene, better known as PCE or "perc." For most of the 1960s through the 1980s it was the standard dry-cleaning solvent and a popular metal degreaser. According to South Tahoe Now, the former Lake Tahoe Laundry Works sat at the South Y Center, where a Raley's stands today, and Active NorCal reports the spills happened between 1972 and 1979.
PCE is heavier than water and does not dissolve easily, so it sinks through soil and spreads slowly through the aquifer. South Tahoe Now describes a plume of roughly 400 acres that has moved from the Highway 50 and Highway 89 junction toward the Tahoe Keys. About eleven years ago the chemical turned up in two municipal wells and three private domestic wells on the west side of town, and five supply wells belonging to Lukins Brothers Water Company and the Tahoe Keys were eventually shut down.
The Lahontan Regional Water Quality Control Board first ordered the property owners to investigate in 2006, and the legal back-and-forth has run for two decades. The proposed settlement with Seven Springs Limited Partnership and Fox Capital Management Corporation, the former and current owners, would fund treatment for the affected water companies, compensate them for past impacts, pay for a 59-year network of monitoring wells to catch PCE before it reaches a municipal well, and continue cleaning up the source with soil vapor extraction. Lahontan executive officer Ben Letton said the deal should give residents "confidence that their drinking water is safe today." The board can accept or reject the settlement but not change it, and public comments are due November 20.
Why a 59-year plan
Fifty-nine years sounds like a long time for a cleanup. It reflects how PCE behaves underground. The State Water Resources Control Board's groundwater fact sheet on PCE estimates a half-life of one to two years in groundwater under ideal conditions, but notes it may be considerably longer in practice. When PCE does break down, it can turn into trichloroethylene (TCE) and then vinyl chloride, which are themselves contaminants that utilities have to watch for.
PCE is not rare, either. The same fact sheet counts 173 of 8,994 California public wells tested between 2007 and 2017 with at least one result above the drinking water standard of 5 micrograms per liter. Most of those were in Los Angeles County, but the Water Board notes that dry-cleaner plumes are common across the Central Valley and Bay Area too. Long-term exposure above the standard is linked to effects on the liver, kidneys and nervous system, and the EPA classifies PCE as a probable human carcinogen.
How utilities, and homes, remove it
Water systems that find PCE have two reliable tools, and both are familiar to anyone who has looked into home filtration. The first is air stripping, which pushes water through a tower of air so the volatile solvent evaporates out. The second is activated carbon, which traps PCE and other volatile organic compounds (VOCs) as water passes through. Those are the technologies the Water Board lists as the traditional fix for PCE, and they are why treated city water in South Lake Tahoe tests clean even with a plume nearby.
At home, the same chemistry applies at a smaller scale. A whole-home carbon filter is designed to catch VOCs along with chlorine, chloramine and the taste and odor they leave behind. Reverse osmosis at the kitchen sink is designed to address dissolved contaminants such as nitrates, PFAS and lead. For a solvent like PCE, carbon does the heavy lifting.
How to check your own water
If you are on a city or district system, your utility publishes a Consumer Confidence Report every year that lists PCE and other VOCs it tested for; the report is usually on the utility's website. The Environmental Working Group's Tap Water Database lets you search by zip code and see what has been detected in your system.
Private wells are a different story. The Water Board's figures only cover public systems, so if your home in El Dorado, Placer or Sonoma County runs on its own well, nobody is testing it for you. The State Water Board's GAMA groundwater map shows what has been detected in nearby monitoring and supply wells, which is a useful first look at what might be in your area. The most direct answer, though, is a test at your own tap. Old gas stations, dry cleaners and machine shops are the usual sources of solvent plumes, and many of them closed long before the current homeowners moved in.
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Sources
- South Tahoe Now, "Remember PCE? Proposed settlement to fund treatment of groundwater contamination caused by former dry cleaner in South Lake Tahoe," October 31, 2026 — https://southtahoenow.com/10/31/2026/remember-pce-proposed-settlement-to-fund-treatment-of-groundwater-contamination-caused-by-former-dry-cleaner-in-south-lake-tahoe
- Active NorCal, "The Groundwater Under South Lake Tahoe Has Been Contaminated Since the 1970's. Now Someone Has to Pay." November 2, 2026 — https://www.activenorcal.com/the-groundwater-under-south-lake-tahoe-has-been-contaminated-since-the-1970s-now-someone-has-to-pay/
- Lahontan Regional Water Quality Control Board, "Cleanup and Abatement Order R6-2026 (Proposed) for Lake Tahoe Laundry Works, South Lake Tahoe, El Dorado County," updated August 17, 2026 — https://www.waterboards.ca.gov/lahontan/water_issues/programs/enforcement/lake_tahoe_laundry_works_2022_cao.html
- State Water Resources Control Board (GAMA Program), "Groundwater Fact Sheet: Tetrachloroethylene (PCE)," revised October 2017 — https://www.waterboards.ca.gov/gama/docs/coc_pce.pdf
- EWG Tap Water Database — https://www.ewg.org/tapwater/