The U.S. Environmental Protection Agency (EPA) has identified 1, 2, 3 – Trichloropropane (TCP), which does not occur naturally in the environment, as an emerging chemical of concern that can threaten drinking water supplies. It states that TCP is a persistent pollutant in groundwater and has classified it as “likely to be carcinogenic to humans.” California State Water Board member Steven Moore called TCP an “insidious chemical” because it persists in the environment, sinks in water and is harmful in even tiny doses. Currently, there is no federal maximum contamination level (MCL) for TCP; however, there is a federal non-enforceable health-based screening level of 0.00075 ug/L.
Since 2012, TCP has been on the emerging Contaminant Candidate List (CCL), which is a watch list of unregulated contaminants that are known to, or anticipated to, occur in public water systems and may require regulation under the Safe Drinking Water Act (SDWA). The EPA has required, under the Unregulated Contaminant Monitoring Rule (UCMR), that large water systems test for TCP every five years with a minimum reporting level of 0.03 μg/L. This rule allows for the EPA to monitor contaminants suspected to be in drinking water that are unregulated under the SDWA. As a result of the testing, TCP has been identified across the US in drinking water sources. Currently, there is no federal maximum contamination level (MCL) for TCP; there is a federal non-enforceable health-based screening level of 0.00075 ug/L.
The author continues the paper with an examination of what TCP is and how it impacts our environment and our health. She then discusses regulatory policies and how California’s mandatory TCP standard could be a blueprint for other state water agencies currently investigating how to enhance their own drinking water protections from emerging contaminants.
Lyn covers some of the legal aspects, risks to businesses, detection, and treatment options to conclude her white paper. She also provides plenty of resources to start the journey toward sustainable treatment solutions that communities can afford.
About the Author: Lynleigh Love is a Senior Project Geologist with SCS Engineers. She has been a professional geologist for more than 22 years with extensive technical expertise in environmental assessment, remediation, and regulatory compliance. Her experience includes groundwater/soil vapor monitoring, excavation work plans, and remedial action plans.