123 TCP (1,2,3-trichloropropane) is an extremely toxic chemical contaminating the groundwater that is used as drinking water in cities and small communities across California. It is disproportionately found in drinking water supplies for the San Joaquin Valley. 123 TCP was added to the list of chemicals known to the State of California to cause cancer in 1999; however, to this day, it remains unregulated and therefore untreated in hundreds of water systems across the state. Setting a legal limit for 123 TCP has lagged for over a decade, so CWC is advocating with our partners to ensure that the State Water Board remains focused on setting the most health-protective drinking water standard for 123 TCP this year.
To ensure access to safe drinking water, we need the timely adoption of a strong legal limit, or Maximum Contaminant Level (MCL), for 123 TCP in groundwater. Establishing the MCL requires board meetings, public comment, and extensive environmental, health, and cost studies. This process could take over a year. CWC staff and partners have been meeting with State Water Board members and Drinking Water Program Staff to ensure our concerns over public health and treatment costs are being addressed and make sure that setting the MCL this year remains a priority for the Board.
Most 123 TCP contamination stems from the extensive application of soil fumigants manufactured by Shell Oil and Dow Chemical Company containing the unnecessary impurity 123 TCP prior to the 1980s. Despite the companies’ knowledge of the health risks, they failed to remove the ingredient from their products or notify farmers of the risk. As a result, farmers unnecessarily and unknowingly injected millions of pounds of 123 TCP into the ground, causing widespread contamination of our shared groundwater resources by an extremely potent carcinogen. 123 TCP has been detected in over 350 active and standby sources, belonging to 92 water systems in 17 counties located all over California, but detections are highly concentrated in the San Joaquin Valley.
California Health and Safe Code requires the State Water Board to prioritize public health when establishing a contaminant's MCL and to establish the MCL at a level as close as is technically and economically feasible to its public health goal (PHG). Unlike other water contaminants such as nitrate and arsenic, the origins of 123 TCP are clear, the responsible parties are known, and these parties have the ability to pay for treatment. Thus, cost of treatment should not detract from the State Water Board’s power to make the MCL as low as possible (ie - equal to the public health goal).
Stay updated on CWC’s campaign to help ensure the State Water Board adopts a health-protective MCL for 123 TCP in 2016 -- and to ensure that the polluters pay for the clean-up up this contaminant. If you are interested in joining CWC in advocating for the most health-protective legal limit for 123 TCP, sign up here.