If You Consider Agricultural History and Its Effect on Local Water
Thurston County, Washington, where the Lacey Water Department supplies water to over 100,000 residents using groundwater sources, has a history of agricultural activities. This history matters because 1,2,3-trichloropropane (1,2,3-TCP), also called TCP, is a chlorinated solvent that was once an impurity in soil fumigants widely used mid-20th century. Its presence in groundwater is linked to past applications of these fumigants. While no recent agricultural use directly causes current water quality issues reported, the legacy of these chemicals in soil can map onto detections found in regional water supplies.
If You Wonder Why Measurement Levels for 1,2,3-TCP Are So Low Compared to Metals
The federal reporting level for 1,2,3-trichloropropane in water is 0.03 micrograms per liter (µg/L), equal to 0.03 parts per billion (ppb), which is thousands of times lower than typical thresholds for common metal contaminants. This reflects the chemical’s status as a volatile organic compound and the sensitivity of current detection technology, rather than indicating that higher levels of metals or other substances are more problematic. The low reporting level helps identify even trace concentrations relevant for monitoring but is not itself a health-based enforceable limit.
If You Observe Sampling Dates and Results Over Time
The EPA’s Unregulated Contaminant Monitoring Rule (UCMR3) included 26 samples taken by the Lacey Water Department from December 2014 to June 2015. During this period, none of these samples showed 1,2,3-TCP above the reporting level of 0.03 µg/L. This snapshot over roughly six months illustrates no federal-detected presence of the solvent at or above the chosen threshold during monitoring, yet it is a single survey period and does not capture all possible seasonal or year-to-year variation.
If You Compare These Measurements to Federal Standards and What They Mean
There is currently no federal maximum contaminant level (MCL) established for 1,2,3-trichloropropane, so detections or results below the reporting level do not constitute a violation or confirmed health risk. The monitoring by Lacey Water Department shows zero detections above the reporting threshold, and together with a record of zero EPA health-based violations, this indicates that the water system meets federal health standards related to this constituent. The measurements provide information, not a determination of safety or risk for any individual household’s water without further specific sampling.
If You Consider Having Your Household Water Tested by a Certified Laboratory
To understand the specific level of 1,2,3-TCP in your home water, a test from a certified laboratory is necessary. These tests will report concentrations in micrograms per liter or parts per billion, with detection limits comparable to or lower than the federal reporting level. Interpreting these results involves comparing them with public system data as well as any applicable state advisories or federal guidelines. Without a sample, no assumptions can be made about your home’s water quality based solely on regional data.
If You Distinguish Public Water System Sampling from Private Well Testing
The Lacey Water Department’s monitoring data represents the water quality of groundwater sources it serves to a large population. This data does not reflect individual private wells in Thurston County, which may vary based on location, depth, and well construction. Private well owners concerned about 1,2,3-TCP should consider direct testing to understand their water’s characteristics, since public water system records do not set conditions for private wells.
Summary: This page clarified what the agricultural legacy means for potential 1,2,3-TCP presence in Thurston County groundwater, why detection levels are set very low compared to common metals, and how no detections were found during EPA monitoring from 2014 to 2015 for the public water system. It also outlined what sampling and testing mean for households seeking precise data on their own tap water.
For households wishing to manage or reduce detectable 1,2,3-trichloropropane, the Autotrol 1,2,3-TCP Filter ships ready to configure as a documented solution for residential water treatment addressing this chlorinated solvent.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2015-06-30. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for Lacey Water Department (WA5343500), WA: 26 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level