Deciding How to Address 1,2,3-TCP in Matanuska-Susitna Borough Home Water

This week, your decision comes down to selecting the most effective technical approach for addressing 1,2,3-trichloropropane (1,2,3-TCP) in your household water in Wasilla, Matanuska-Susitna Borough.

Why does 1,2,3-trichloropropane resist air stripping and what does that mean for treatment choice?

1,2,3-TCP is a chlorinated solvent known for its resistance to air stripping because it does not easily volatilize from water into air. This property implies that techniques relying on aeration or air stripping will be ineffective for reducing TCP concentrations. Instead, treatment solutions must involve adsorption or advanced filtration methods capable of targeting this compound on a molecular level. Households considering treatment technologies should prioritize systems designed specifically to address chlorinated solvents, rather than generic aeration approaches.

What is the agricultural land-use history of Matanuska-Susitna Borough and how does it map onto 1,2,3-TCP detections?

Matanuska-Susitna Borough, including Wasilla, has a history of intensive agricultural activity, including the use of soil fumigants during the mid-20th century. These fumigants, used between the 1950s and 1980s, contained impurities like 1,2,3-TCP which have migrated deep into groundwater over time. This historical use explains the presence of 1,2,3-TCP detections in the area’s groundwater supply. However, according to the EPA’s Unregulated Contaminant Monitoring Rule data collected from 2013 to 2015 from the Wasilla Water System, six samples were tested and none detected 1,2,3-TCP above the reporting level of 0.03 micrograms per liter (0.03 parts per billion).

Why is the reporting level for 1,2,3-trichloropropane set thousands of times lower than for common metals?

The reporting level for 1,2,3-TCP is set very low due to its chemical characteristics and potential health considerations. Unlike common metals—which have higher thresholds for detection based on taste, staining, or corrosion—TCP is a synthetic organic compound, and it is measured at trace levels to provide early awareness. This low reporting level (0.03 micrograms per liter) reflects sensitivity to even minute concentrations that might warrant closer observation. It is important to understand that a detection above this reporting level is simply a measurement and does not indicate a violation or unsafe condition under current federal standards.

How did a soil fumigant impurity from the 1950s-1980s reach deep groundwater decades later?

The impurity 1,2,3-TCP originated as an unintended component of soil fumigants widely applied in the region’s past agricultural practices. These compounds, designed to control pests, gradually migrated through the soil profile over decades, reaching the groundwater that supplies Wasilla's municipal system. Groundwater movement is slow, so legacy contaminants from many years ago can still be present, albeit at very low concentrations. This explains why a historical agricultural footprint continues to be relevant for water quality considerations today.

What does a certified laboratory test for 1,2,3-trichloropropane report and how should a homeowner read it?

A certified laboratory test for 1,2,3-TCP in household water will report concentrations in micrograms per liter (µg/L), which are equivalent to parts per billion (ppb). The test results should indicate whether TCP was detected above the reporting level, which for Wasilla is 0.03 µg/L. Homeowners should interpret any detection as a factual measurement, not a violation or safety breach. To understand the significance of a result, it is crucial to consult standards, health guidance, and consider the effectiveness of available treatment technologies tailored for chlorinated solvents.

Choosing the right treatment approach involves understanding why TCP resists air stripping, how regional agricultural history contributes to its presence, and the meaning of low reporting levels. Although Wasilla's public water system did not detect 1,2,3-TCP above reporting levels in recent surveys, testing your own water is essential for accurate assessment. The Autotrol 1,2,3-TCP Filter system can provide direct purchase options designed for households seeking effective filtration of this compound.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2013-12-16. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR3 monitoring (2013-2015) for Wasilla Water System (AK2224646), AK: 6 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level