Pentair 1,2,3-TCP Filter

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Understanding the Limits of Regional 1,2,3-Trichloropropane Data for Your Household

The EPA's monitoring in Seward, Kenai Peninsula Borough, focuses on the public water system serving over 3,300 people through groundwater sources. Between 2013 and 2015, federal surveys recorded six samples tested for 1,2,3-trichloropropane (TCP), a chlorinated solvent noticed in some agricultural and industrial applications decades ago. None of these samples detected TCP above the laboratory reporting level of 0.03 micrograms per liter (ppb). However, these results reflect the water system as a whole and do not specify conditions at any individual household or well.

Why 1,2,3-Trichloropropane’s Chemical Properties Affect Treatment Choices

Because TCP resists removal by common air stripping methods—where volatile compounds are stripped from water by air bubbles—household solutions often require different technologies. Unlike some volatile organic compounds, TCP’s chemical stability means air stripping is ineffective and would not address household water concerns when existing equipment fails.

Significance of Reporting Levels for 1,2,3-Trichloropropane Compared to Metals

The laboratory reporting level for TCP, at 0.03 micrograms per liter (ppb), is set thousands of times lower than typical reporting levels for metals due to different regulatory focuses and detection capabilities. This ultra-low level helps identify the presence of TCP even in trace amounts but does not indicate a violation or health risk by itself.

Interpreting ‘Detected,’ ‘Median,’ and ‘Range’ in the Seward Sampling Record

The EPA’s term "detected" means the chemical was measured above the reporting level in at least one sample. For Seward’s water system, TCP was not detected in any of six samples, so the median and range reflect non-detectable levels throughout the sampling period. This does not guarantee individual household water is free of TCP, but it supports a generally low presence in the public supply.

The Legacy of Soil Fumigants and Their Journey to Groundwater

1,2,3-Trichloropropane was historically an impurity in soil fumigants used primarily during the 1950s to the 1980s. Though these fumigants have been banned or restricted for decades, TCP’s chemical stability allows it to persist and slowly migrate into groundwater, sometimes reaching deep aquifers. Such legacy contamination explains why TCP can appear in groundwater long after agricultural use has ceased.

How Source Characteristics Influence Expected 1,2,3-TCP Levels

Sampling depth, well construction, and type of water source all affect TCP presence. Seward’s system uses groundwater where deep wells may draw from aquifers less exposed to surface contamination, which often contributes to the non-detection of TCP. Nevertheless, conditions can vary significantly between private wells and the public system, making specific testing necessary to determine a household’s water quality.

Consideration of Household Plumbing Materials and Age

While plumbing materials and age impact water aesthetics and corrosivity, they do not affect the concentration of TCP, which is introduced from the water source. Therefore, adjusting or replacing plumbing does not address TCP presence. Treatment equipment designed for TCP targets the contaminant at the water source entry point for the home.

Summary and Recommended Action for Seward Residents

The EPA public water system record for Seward shows no detection of 1,2,3-trichloropropane above the reporting level in six samples taken from the public supply groundwater source. This data applies to the municipal system and not to individual households or private wells, which may have different conditions. Households with failed water treatment equipment concerned about TCP should consider specific water testing to know their home's concentration.

For addressing TCP when detected or suspected, the Pentair 1,2,3-TCP Filter ships ready to configure and is documented to reduce TCP concentrations effectively through advanced filtration technology tailored to this chlorinated solvent.

For more details, the EPA’s Safe Drinking Water Information System (SDWIS) public water system records provide comprehensive data on water quality in Seward and other Kenai Peninsula Borough areas.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2013-11-05. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR3 monitoring (2013-2015) for Seward (AK2240757), AK: 6 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level