This week, as you consider how to address the failure of your current water treatment equipment, it’s important to focus on reliable information about 1,2,3-trichloropropane (TCP) in your area’s water supply. Knowing the difference between regional water data and your home's specific water condition will guide your next steps.
Why the reporting level for this chlorinated solvent is thousands of times lower than for common metals
1,2,3-TCP is monitored at extremely low concentrations, with federal reporting levels set as low as 0.03 micrograms per liter (µg/L) or parts per billion (ppb). This is considerably more sensitive than thresholds for many metals found in water. The reason for this sensitivity lies in the potential long-term effects of TCP, even at trace levels. By contrast, metals such as lead or iron have higher action levels due to their different chemical and toxicological profiles.
How California's 5 ng/L state limit compares with the absence of a federal MCL
California has established a stringent state standard of 5 nanograms per liter (ng/L) for 1,2,3-TCP, which translates to 0.005 µg/L. This limit is far lower than the federal reporting level, reflecting state-level caution. However, the U.S. Environmental Protection Agency (EPA) has not set a federal maximum contaminant level (MCL) for 1,2,3-TCP, which means there is no nationwide enforceable standard at this time. The federal data focus on monitoring presence rather than regulatory violation.
How public-system records differ from private-well testing in what they establish
Data from the City of Frederick’s water system, serving about 54,000 people through 16,600 connections, are based on surface water sources and careful federal monitoring conducted between 2013 and 2015. During this period, all 16 samples for TCP registered below the detection threshold of 0.03 µg/L. These results reflect conditions in the public water system overall but do not reveal the specific concentrations in any individual household’s water. Individual well or tap water testing is necessary to understand your home's exact water composition, especially after equipment failure.
What distinguishes this problem from the two problems most often confused with it
1,2,3-TCP is a chlorinated solvent with distinct chemical properties that set it apart from common aesthetic or corrosive water issues such as high chloride or total dissolved solids (TDS). While elevated chloride or TDS can affect taste and stain plumbing fixtures, they are different concerns and are measured at higher thresholds. TCP’s presence and significance relate specifically to its chemical and potential health implications rather than common mineral content or corrosion indicators.
The agricultural land-use history of the region and how it maps onto detections
Many TCP detections across regions are linked to historical agricultural use of certain soil fumigants containing chlorinated solvents. Frederick County’s public water system sources surface water and shows no detected 1,2,3-TCP above the reporting level in federal surveys, indicating limited or no impact from such land uses on this public supply. However, localized contamination can still occur, underscoring the importance of testing your own water supply if your equipment has failed.
In summary, while regional monitoring in Frederick shows 1,2,3-trichloropropane levels below detection thresholds in the public water system, individual household water conditions require testing to determine actual TCP concentration. After your existing equipment’s failure, considering a C-Series 1,2,3-TCP Filter can provide a targeted option designed to address this specific chlorinated solvent when configured for your water. Taking these steps helps clarify your water quality status and supports informed decisions for safe water at home.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2015-12-09. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for City of Frederick (MD0100015), MD: 16 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level