Understanding 1,2,3-TCP in Bexar County Residential Water: Detection Levels and Treatment Choices

Is 1,2,3-TCP present in my household water in Bexar County? According to the San Antonio Water System's federal monitoring, 1,2,3-trichloropropane was not detected above the minimum reporting level. This overview explains what that means for your water choices and how to address demand if you decide to treat TCP.

Why the reporting level for 1,2,3-trichloropropane is much lower than for common metals

1,2,3-TCP, a chlorinated solvent, is measured at levels as low as 0.03 micrograms per liter (µg/L), or parts per billion (ppb), because it is a synthetic compound with potential health concerns noted by agencies under specific conditions. Metals like lead or iron have much higher reporting thresholds due to their different chemical properties and typical occurrence ranges in water. The low reporting level for TCP means detections are precise and indicate the presence of trace amounts, not necessarily a safety issue.

What changes for a large household, a second home, or a seasonal property

Households with higher water use, such as large families or properties used seasonally, may notice a difference in treatment needs if 1,2,3-TCP is confirmed by testing. Demand affects how treatment equipment performs and the frequency of maintenance or media replacement. Seasonal homes may require different configuration or standby management, making it important to choose equipment that ships ready to configure to meet these varying demands.

How seasonal or multi-year variation shows in the federal sampling record

The San Antonio Water System was monitored for 1,2,3-TCP from March 2015 through December 2015, a period reflecting typical seasonal changes. Over 70 samples were analyzed with zero detections above the 0.03 µg/L reporting level. This multi-month survey indicates stability in public water quality with respect to TCP; however, individual home water quality can only be determined by private testing.

How a soil fumigant impurity from 1950s-1980s reached deep groundwater decades later

1,2,3-TCP originally entered the environment as an impurity in soil fumigants used primarily between the 1950s and 1980s. Over time, it migrated through soil into groundwater supplies, raising concern about its presence in water sources today. In areas with surface water sources like Bexar County, this legacy impact is monitored though not detected in the public water system's current samples.

What 'detected', 'median', and 'range' mean in the sampling record on this page

'Detected' means an instrument measured 1,2,3-TCP at or above the minimum reporting level of 0.03 µg/L; San Antonio's records show zero such detections. 'Median' refers to the middle value in the dataset, which here implies nondetects below the level of quantification. 'Range' indicates the minimum and maximum results found, with no results above reporting level in this system's data from 2013-2015.

Matching equipment to your demand for 1,2,3-trichloropropane treatment: If your household testing indicates a measurable concentration of TCP, the C-Series 1,2,3-TCP Filter ships ready to configure and can meet various residential demand levels with appropriate sizing. This documented solution provides a targeted approach for chlorinated solvent challenges such as 1,2,3-trichloropropane in drinking water.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2015-12-04. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR3 monitoring (2013-2015) for San Antonio Water System (TX0150018), TX: 70 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level