1. Understanding How the Legacy of a Soil Fumigant from Decades Ago Affects Today's Groundwater
1,2,3-Trichloropropane (referred to as TCP) is a chlorinated solvent historically used as a soil fumigant from the 1950s through the 1980s. Over time, residues of this chemical have migrated downward, reaching deep groundwater sources. This legacy contamination is notable in areas relying on groundwater, such as Washington, Franklin County, Missouri, where public water systems source their supply exclusively from these subterranean water bodies.
2. Comparing California's Stringent 5 ng/L Reference with the Absence of a Federal Maximum Contaminant Level
Although there is no federally enforceable maximum contaminant level (MCL) for TCP in drinking water, California has established a state guideline of 5 nanograms per liter (ng/L), equivalent to 0.005 micrograms per liter (µg/L). This benchmark is approximately six times lower than the reporting level used in the Environmental Protection Agency’s (EPA) Unregulated Contaminant Monitoring Rule (UCMR3), which identified no detections above 0.03 µg/L in the public water system serving Washington. No federal MCL means water utilities are not legally required to adhere to a specific limit for TCP, but the state-level standard demonstrates a more precautionary approach.
3. What Information Homeowners Should Document Before Seeking Treatment Options
Before considering treatment options, households should gather key information, including:
- Results from a certified laboratory test analyzing their own water supply for TCP concentration.
- Daily water usage approximations to determine treatment capacity needs.
- Details of existing water equipment and its known performance limitations, especially if current devices struggle to keep up with TCP concerns.
Compiling this data allows for informed decisions about selecting equipment designed to address TCP effectively.
4. Interpreting Certified Laboratory Test Reports for 1,2,3-Trichloropropane
A certified laboratory analysis of water for TCP reports results in micrograms per liter (µg/L), which corresponds directly to parts per billion (ppb). Reports specify the lowest concentration levels that can be reliably detected, known as the reporting level. For Washington’s public system, the reporting level was 0.03 µg/L, and all sampled points registered below that detection threshold. It is important to understand that not detecting or detecting below the reporting level is not an indication of violation or safety risk but shows the concentration is very low or not measurable with the method used.
5. Assessing Treatment Capacity Relative to Household Water Demand
TCP treatment technologies, such as the Fleck 1,2,3-TCP Filter, are designed to handle specific flow rates and contaminant loads. Homeowners should match daily water demand — often measured in gallons per day — with the capacity ratings of such equipment to ensure effective management without overtaxing the system. This involves calculating typical daily usage for drinking, cooking, and other uses, and comparing it with the filter’s capacity to maintain desired water quality consistently.
6. Distinguishing Between Public Water System Records and Private Well Testing
Washington’s public water system record covers 7,361 connections and serves over 14,000 people using groundwater sources. The EPA UCMR3 results provide a snapshot of TCP occurrence for the entire system. However, individual private wells may differ substantially, and their water should be tested independently to determine specific 1,2,3-TCP levels. Public system data cannot substitute for a private well’s analysis, which must be obtained through laboratory testing tailored to the household’s source.
In summary, the public water system serving Washington, Franklin County, relies on groundwater with no EPA-identified health-based violations for TCP and no detections above 0.03 micrograms per liter in federal monitoring. Understanding this context equips residents to interpret their own water test results accurately and evaluate options like the Fleck 1,2,3-TCP Filter, which ships ready to configure for residential use. For authoritative data, see the EPA’s Safe Drinking Water Information System and UCMR3 monitoring records specific to Washington, MO water system number MO6010838.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2013-10-01. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for Washington (MO6010838), MO: 18 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level