PCE FAQTetrachloroethylene (PCE) in South Lake Tahoe
Frequently Asked Questions
[SI1]Ref - https://www.tceq.texas.gov/assets/public/remediation/superfund/jonesroad/ppb_chart.pdf
What is Tetrachloroethylene (PCE)?
PCE is a colorless liquid with a mild, chloroform-like odor. It is mostly used in the textile industry and as
a component of aerosol dry-cleaning products. PCE is also commonly used in wood processing, metal
degreasing, paint remover, glues and silicone lubricants.
When PCE is improperly disposed of or spilled into the environment (improper disposal of materials in
storm drains, spilling onto soil) the potential for water supply contamination is present. PCE will seep
through the soil and eventually reach groundwater supplies.
Where is PCE in South Lake Tahoe?
In 1989, PCE was first found in drinking water wells near the intersection of Highways 50 and 89,
referred to as the South “Y”. Today, the PCE remains in groundwater and forms a contaminant plume
believed to cover more than 400 acres. Groundwater used by wells operated by the Lukins Brothers
Water Company and Tahoe Keys Property Owners Association are currently impacted by the plume.
During the 1990s, the South Tahoe Public Utility District (STPUD) installed a treatment facility to remove
PCE from four drinking water wells. Today, three of the wells have been destroyed and the remaining
well is currently not used. In 2009, TKPOA installed a treatment system to remove PCE from
groundwater at one of its wells. In 2014, Lukins discovered PCE in two wells and immediately stopped
using them. All three drinking water systems are interconnected and the water providers have the
ability to share water and are working together to ensure our entire community has access to reliable
and safe drinking water.
How much PCE is allowed in drinking water?
In order to ensure that tap water is safe to drink, the U.S. Environmental Protection Agency (USEPA) and
the State Water Resources Control Board (State Board) prescribe regulations that limit the amount of
certain contaminants in water provided by public water systems. California established a regulatory
limit for PCE of 5 parts per billion in drinking water which is like 5 drops of water in an Olympic
swimming pool [SI1]. Use of drinking water standards and regular water quality testing by water
suppliers is used to ensure our water is safe to drink.
How are people exposed to PCE?
PCE exposure can occur through breathing air containing PCE vapor, skin contact by using products
containing PCE’s, and through drinking water from a ground water source contaminated with PCE.
What are potential health impacts due to prolonged exposure to high levels of PCE?
People with long term exposure to PCE in drinking water above the maximum contaminant level can
experience adverse effects to the liver, kidneys and central nervous system.
How is PCE treated in drinking water?
Best available technology for treatment of groundwater containing PCE can be done by using an air
stripping tower or activated carbon filtration. Both technologies are currently being used by water
suppliers in the Lake Tahoe Basin.
An important part of PCE treatment is removing the source of the contaminant. After determining the
source of contamination, agencies can begin removing the contamination by pumping and treating, soil
vapor extraction, and/or surface or thermal treatment.
Do I need to filter my water at home?
No. Lake Tahoe Water suppliers test water regularly to ensure that our drinking water meets state
standards. The water we provide is safe to drink. It is not necessary to filter your water at home. You
can drink, prepare food, and cook with water as you normally would.
Is it ok for my kids to drink water at Tahoe Valley Elementary School?
Yes. The water delivered to Tahoe Valley Elementary School meets all drinking water standards.
What is being done about PCE?
The Lahontan Regional Water Quality Control Board is the state regulatory agency which oversees the
cleanup of contaminated groundwater. Lahontan has conducted numerous investigations to determine
the source of PCE and is working with the responsible parties to determine the total extent of their
contamination. The South Tahoe water providers are working together to develop and implement short-
term fixes and long-term solutions to provide clean drinking water to our community. To date, the water
providers have secured a $500,000 grant from the State Water Resources Control Board to complete a
feasibility study that will help to identify potential alternatives for addressing contamination from the
South “Y” Plume.
Is there a cost being passed onto the customer to deal with PCE?
Costs passed onto customers are dependent on who supplies your water. Please contact your individual
water supplier for further information on costs associated with PCE contamination.
Are there any preventative measures we can take at home or at school to prevent PCE from getting in
our water?
Do not pour any chemicals onto the ground or into storm drains.
Food for thought
In Tahoe, historically, we have had some of the most pristine drinking water in the world. Water
suppliers in South Lake are working together to ensure every drop of water that flows from your tap is
safe.
For more information go to www.stpud.us/groundwater