Why the Reporting Level for 1,2,3-Trichloropropane Is Set Much Lower Than for Common Metals
1,2,3-trichloropropane, or 1,2,3-TCP, is a chlorinated solvent found at very low concentrations in groundwater. The EPA’s Unregulated Contaminant Monitoring Rule (UCMR3) requires detection limits in the parts per trillion range (0.03 micrograms per liter or µg/L) because the compound is considered a possible health concern even at very low doses. This reporting level is thousands of times lower than measurement thresholds for common metals like lead or iron, reflecting the need for highly sensitive equipment to capture any presence of 1,2,3-TCP in water supplies.
How a Soil Fumigant Impurity Used Decades Ago Reached Groundwater in the Brunswick/Topsham Area
1,2,3-TCP was historically an impurity in soil fumigants applied extensively from the 1950s through the 1980s. Due to its persistence and mobility, it has migrated downward through soil layers into the groundwater over decades. The Brunswick/Topsham Water District, drawing from groundwater sources, has monitored for this compound to assess its legacy impact. While no detections above 0.03 µg/L were recorded in six samples between 2013 and 2015, the historical use of fumigants in the broader Cumberland region explains why 1,2,3-TCP remains a substance of interest in water quality evaluations.
What Detected, Median, and Range Mean in the Sampling Record for This Region
In the EPA’s monitoring data for this community water system, "detected" means the compound’s concentration was measured above the reporting threshold of 0.03 micrograms per liter (or parts per billion). "Median" refers to the middle value of all measurements taken, and "range" shows the lowest to highest concentrations found. For 1,2,3-TCP in Brunswick/Topsham, no detections were reported above the reporting level in six samples from 2013 to 2015, so the median and range effectively indicate non-detect over that period. These are system-wide results and do not indicate any individual home’s water quality without separate testing.
How 1,2,3-TCP Differs From the Two Problems Often Confused With It
1,2,3-TCP should not be confused with solvents or contaminants that have higher detection thresholds or different chemical properties. Unlike common metals or aesthetic issues like iron or manganese that affect taste and staining, TCP belongs to a class of chlorinated solvents with distinct health considerations measured at very low levels. Also, unlike widespread pathogens or lead, TCP is a legacy industrial chemical not naturally occurring and was never a water disinfectant byproduct. Understanding these distinctions helps determine the specific kind of treatment needed for 1,2,3-TCP as opposed to general water quality concerns.
Additional Questions Commercial or Industrial Operators Consider Compared to Households
Commercial or industrial water users often need to consider additional factors beyond household concerns. These include larger volume flow rates, varying water uses with different purity requirements, regulatory scrutiny, and potential impacts on equipment and processes. Unlike residential users, they may require ongoing compliance monitoring, detailed contaminant profiling, and system scalability. Households typically focus on safe drinking water and appliance protection, while commercial operators add operational and regulatory layers, which could affect the choice of treatment technology and system size.
For households in Brunswick, Topsham, and Cumberland County weighing the need for treatment against 1,2,3-TCP concerns, the Pentair 1,2,3-TCP Filter offers a documented approach. It ships ready to configure and is designed specifically to address the chlorinated solvent at concentrations relevant to this region’s groundwater profile. Testing your home's water for actual 1,2,3-TCP concentration can help confirm the level needed, guiding whether this focused technology is an appropriate response to your water quality context.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2015-08-04. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for Brunswick/Topsham Water District (ME0090260), ME: 6 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level
- ✓ 90-Day Money-BackNo restocking fees — return within 90 days.
- ✓ Manufacturer WarrantyGenuine Fleck · Pentair · VIQUA equipment.
- ✓ Free Expert SizingTalk to a specialist and buy the right system the first time.