Whole House 1,2,3-TCP Reduction Water Filter System - Trichloropropane Removal
The Westerly Water Department, serving nearly 35,300 people through 14,800 connections in Washington County, Rhode Island, draws from groundwater sources. According to the U.S. Environmental Protection Agency’s Unregulated Contaminant Monitoring Rule (UCMR3) data gathered between 2013 and 2015, 1,2,3-trichloropropane (TCP) was not detected above the reporting level of 0.03 micrograms per liter (µg/L), or 0.03 parts per billion (ppb), in any sampled locations. Although 1,2,3-TCP currently has no federal maximum contaminant level (MCL), water system records show no health-based violations.
If You Want to Understand Why Granular Activated Carbon Bed Depth Is Key for TCP Treatment
Granular activated carbon (GAC) technology is often employed to address chlorinated solvents like 1,2,3-TCP in water. Unlike compounds causing taste or odor issues, 1,2,3-TCP molecules require more thorough contact with the carbon media to be effectively processed. Greater bed depth in the carbon contactor allows a longer contact time, enhancing the potential for interaction that reduces TCP presence. This is distinct from taste-related contaminants, where shorter contact may suffice. The increased bed depth compensates for the chemical’s low reactivity and high persistence, factors important to households weighing treatment options.
If You Wonder How a Soil Fumigant Impurity from Decades Ago Reached Deep Groundwater
1,2,3-trichloropropane is a byproduct impurity once found in soil fumigants commonly used between the 1950s and 1980s. Over many years, this chlorinated solvent migrated downward through soil layers, eventually reaching aquifers tapped for groundwater supply. Its chemical stability and slow degradation in subsurface environments mean that TCP can persist in groundwater decades after fumigant use ceased. This history explains why even areas without recent use of such chemicals might detect trace amounts of 1,2,3-TCP in water.
If You Consider What Happens When This Problem Is Not Addressed Over Time
Leaving 1,2,3-trichloropropane untreated in a household water supply does not cause immediate taste or odor changes but can lead to gradual aesthetic concerns and potential long-term chemical exposure. Because no federal MCL exists, regulatory guidance is limited; however, some states and agencies encourage reducing TCP due to its classification as a likely human carcinogen. Over time, TCP accumulation in plumbing or water fixtures is unlikely, but continuous ingestion without treatment may not align with desired household water quality goals.
If You Want to Know How Many Samples and Wells Back These Government Figures
The EPA’s data for the Westerly Water Department includes 14 sample results collected from public groundwater sources between March and September of 2015. None of these samples detected 1,2,3-TCP above the 0.03 µg/L reporting level. While this sample size provides a snapshot reflecting system-wide water quality, it is not a substitute for testing individual household water, as local variations can occur. Homeowners concerned about their specific water should consider laboratory testing to identify actual TCP levels at their tap.
If You Are Considering Changes for a Large Household, Second Home, or Seasonal Property
Household size and usage patterns influence treatment needs for 1,2,3-trichloropropane. Larger households demand greater water volumes, which can affect contact times in filtration media if equipment is sized inadequately. For second homes or seasonal properties, periods of water stagnation may impact water quality and the effectiveness of treatment media. Selecting treatment equipment such as the C-Series 1,2,3-TCP Filter, which ships ready to configure, allows greater flexibility and can be matched to household water demand and usage cycles.
In summary, government sampling data for the Westerly Water Department shows no detections of 1,2,3-trichloropropane above the reporting threshold, and no health-based violations exist. When evaluating treatment options for TCP in residential water, consider the importance of granular activated carbon bed depth, the compound’s historic environmental pathways, the implications of long-term exposure, and the scale of your household’s water use to make an informed technical choice.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2015-09-16. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for Westerly Water Department (RI1559512), RI: 14 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level