Fleck 1,2,3-TCP Filter

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Understanding the Origin of 1,2,3-TCP in Groundwater Decades After Soil Fumigation

A frequent misunderstanding when encountering 1,2,3-trichloropropane (TCP) is to equate any detection to immediate household risk or contamination. For Cary's groundwater sources, the presence of this chlorinated solvent traces back to the historic use of soil fumigants from the 1950s through the 1980s. Over time, residues from those applications migrated into deep aquifers. This slow movement explains why traces might appear long after the original use ceased, yet at concentrations typical of a regional legacy rather than localized contamination.

Why Air Stripping Falls Short for Treating 1,2,3-Trichloropropane in Home Water

TCP is chemically resistant to removal by air stripping due to its low volatility. This means common aeration-based water treatments that rely on volatile contaminant release into air are ineffective. Instead, treatment approaches must focus on adsorption or advanced filtration technologies designed for chlorinated solvents. Recognizing this resistance helps in selecting the proper household water treatment method, preventing wasted effort on unsuitable solutions.

How Certified Laboratory Tests Report 1,2,3-Trichloropropane Results

Testing for TCP is conducted by certified labs using federal procedures, reporting concentrations in micrograms per liter (µg/L), equivalent to parts per billion (ppb). For the Cary public water system, EPA's 2013-2015 Unregulated Contaminant Monitoring Rule (UCMR3) data showed zero detections above the 0.03 µg/L reporting level across 16 samples. It's important to understand that "no detection above the reporting level" is not a declaration of absolute absence, but indicates levels were below the threshold the lab reports. Homeowners seeking definitive information on their own water should have individual well or tap water tested by a qualified laboratory.

Which Household Water Uses Are Most Sensitive to 1,2,3-TCP Presence

While no federal maximum contaminant level (MCL) exists for 1,2,3-trichloropropane, its chlorinated solvent nature means it could impact tastes or odors if present at higher concentrations. Appliances and fixtures involving water heating or consumption, such as drinking water taps, coffee machines, and cooking appliances, would be the first to reveal any aesthetic effects, if any were present. Because Cary's system samples show no reported detection above EPA reporting levels, such impacts are unlikely for most homes served by the municipal supply. However, private wells could have different profiles, reinforcing the value of independent testing.

How California's 5 ng/L State Limit Relates to the Federal Regulatory Framework

California has set a public health goal for 1,2,3-trichloropropane of 0.005 µg/L (5 nanograms per liter), one of the most stringent in the country. This does not represent a federal maximum contaminant level but rather a state advisory level aimed at public health protection. By contrast, EPA has not established an MCL for 1,2,3-TCP nationally. Knowing this distinction assists homeowners in contextualizing any detected measurements, especially those close to or below the California threshold but still undetected in Cary's EPA data.

Influence of Sampling and Well Characteristics on Detecting 1,2,3-Trichloropropane

Sample depth, well construction, and source type strongly affect whether and in what amount 1,2,3-TCP may be detected. Deeper wells often tap water less influenced by surface or shallow soil contaminants, potentially reducing TCP concentrations. As Cary's water system relies on groundwater, typical monitoring includes these variables but reflects system-wide averages rather than individual wells. Residents with private wells should consider these factors when interpreting their own water testing results.

In summary, this briefing clarified that regional historical use of soil fumigants is the source of 1,2,3-trichloropropane findings in Cary's groundwater. The chemical's low volatility excludes air stripping as an effective household treatment method. Certified lab tests measure TCP at micrograms per liter, and Cary's municipal system shows no detections above reporting thresholds. Appliances handling drinking water would be the first to show signs if TCP were at a notable level. Lastly, California's strict 5 ng/L guideline provides a contrasting reference point to federal absence of an MCL, underscoring the importance of individual water testing to confirm household conditions. For those considering treatment, the Fleck 1,2,3-TCP Filter ships ready to configure as a solution designed for chlorinated solvent reduction.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2013-11-22. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR3 monitoring (2013-2015) for Cary (IL1110100), IL: 16 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level