Understanding 1,2,3-TCP Presence in Arapahoe County Water: What Public Records Reveal

When deciding what type of water treatment is appropriate for your household, it is important to understand what publicly available water quality data can and cannot tell you about your specific water supply. This is especially true for less common contaminants like 1,2,3-trichloropropane (TCP), a chlorinated solvent of increasing interest that has been monitored in parts of Colorado.

Granular Activated Carbon Contact Time: Why Bed Depth Matters More for TCP Than for Taste

Effectively addressing 1,2,3-TCP in water requires more than a simple filter focused on taste or odor. TCP is a synthetic chemical requiring sufficient contact time in a specialized filter that uses granular activated carbon (GAC) media. The depth of the carbon bed affects how long water remains in contact with the media, which is critical for breaking down or adsorbing TCP molecules. Short contact times that may suffice for chlorine taste or odors are generally inadequate for this chlorinated solvent.

Why the Reporting Level for This Solvent Is Thousands of Times Lower Than for Common Metals

Monitoring data from the East Cherry Creek Valley Water and Sanitation District in Arapahoe County show that testing for 1,2,3-TCP has a reporting level of 0.03 micrograms per liter (µg/L), equivalent to 0.03 parts per billion (ppb). This is far lower than typical reporting levels for metals like lead or copper, which are monitored at much higher concentrations. This low threshold reflects the strong regulatory caution exercised for this compound due to its historical use and potential health concerns, even though federal regulations have not established a maximum contaminant level for TCP.

What Distinguishes This Problem From the Two Problems Most Often Confused With It

1,2,3-trichloropropane is sometimes confused with contaminants like trihalomethanes or other chlorinated solvents. Unlike trihalomethanes, which are byproducts of disinfectant reactions, TCP was primarily used as a soil fumigant and industrial solvent. Its chemical behavior and treatment approaches differ. Additionally, TCP is not related to nitrate or general hardness problems that affect water aesthetics or plumbing but require different treatment strategies.

How a Soil Fumigant Impurity from the 1950s-1980s Reached Deep Groundwater Decades Later

The presence of 1,2,3-TCP in water sources can often be traced back to its unintentional formation as an impurity in soil fumigants widely applied in agriculture and land management from the 1950s through the 1980s. Over time, residual TCP from these applications infiltrated deep groundwater aquifers. This legacy contamination can persist for decades, as TCP is relatively stable and moves slowly through subsurface environments.

How the Constituent Enters Groundwater or the Distribution System in This Region

In Arapahoe County, the East Cherry Creek Valley Water and Sanitation District uses surface water as its supply source, not groundwater. While 1,2,3-trichloropropane can be present in groundwater impacted by legacy agricultural chemicals, public system records show zero detections above the reporting level in this surface water system. Contaminants like TCP can also enter distribution systems through cross-connections or backflow if present, but such occurrences are not reported in this system’s monitoring data.

It is important to emphasize that the publicly reported data for this water system includes 22 sampling results conducted during 2013 to 2015 with no detected 1,2,3-TCP above the 0.03 µg/L reporting level. This absence of detection is not a guarantee that no TCP exists in your household water, but it does establish that the public supply is not known to have measurable levels based on federal monitoring.

If your household relies on a private well or a different supply source, testing your specific water is essential because regional data cannot confirm your water quality. To address potential 1,2,3-TCP, a treatment solution based on a Fleck System is available. The Fleck 1,2,3-TCP Filter ships ready to configure and uses granular activated carbon media designed for appropriate contact time with water, making it suitable for reducing this chlorinated solvent if confirmed present.

In conclusion, the East Cherry Creek Valley system’s federal monitoring record is clear: no 1,2,3-trichloropropane was detected above the reporting threshold during monitoring periods between 2013 and 2015. This federal record covers over 19,000 connections serving more than 66,000 people in Arapahoe County. For more detailed federal data, consult the EPA’s Safe Drinking Water Information System (SDWIS) public water system record for East Cherry Creek Valley Water and Sanitation District.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2014-11-10. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR3 monitoring (2013-2015) for East Cherry Creek Valley WSD (CO0103035), CO: 22 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level