If your water test report lists 1,2,3-trichloropropane levels
A certified laboratory test report for 1,2,3-TCP, also known as TCP or 1,2,3-trichloropropane, typically specifies the concentration in micrograms per liter (µg/L) or equivalently parts per billion (ppb). Understanding these values is crucial because the report clarifies your actual water condition rather than regional averages or system-wide samples.
The local public water system in VI, served by the Water & Power Authority (St. Thomas), recorded no instances of 1,2,3-trichloropropane above the reporting level of 0.03 µg/L during federal monitoring from 2013 to 2015. This monitoring was part of a federal occurrence survey, meant to detect the presence but not to enforce standards, as no federal maximum contaminant level (MCL) currently exists for TCP.
If your household's test results show detectable amounts, it's important to note that detection alone is not a safety violation or cause for alarm. Instead, it provides a basis for assessing what kind of treatment might be appropriate.
If you consider granular activated carbon contact time for TCP concerns
Granular activated carbon (GAC) filtration is a key technology for addressing chlorinated solvents such as 1,2,3-trichloropropane. The effectiveness of GAC in treating TCP depends heavily on the contact time between water and the carbon bed. Deeper carbon beds generally provide longer contact time, which is more important for treating TCP than for addressing taste or simple odor issues because TCP molecules require sufficient exposure to the carbon to adsorb effectively.
Therefore, when selecting treatment equipment for TCP, pay close attention to systems that prioritize bed depth and contact time over just superficial filtration capacity. This distinction shapes the class of treatment you need.
If you know about the agricultural land-use history of the region
The presence of 1,2,3-trichloropropane in groundwater often links back to its historical use as a soil fumigant and industrial chemical impurity primarily during the 1950s to the 1980s. Areas with intensive agricultural activity in those decades, including parts of VI, have shown detections in the federal monitoring records.
This agricultural land-use history helps explain why TCP ended up in deeper groundwater over time. Understanding this legacy assists in evaluating the risk and potential fluctuations in TCP levels related to past land treatments rather than current surface contamination.
If you observe seasonal or multi-year variations in 1,2,3-TCP levels
The federal monitoring data for the Water & Power Authority (St. Thomas) system between February and November 2014 showed no detections above 0.03 µg/L, but seasonal or multi-year variations can occur due to groundwater flow, changes in water source blending, or environmental factors.
Long-term monitoring is important to detect any emerging trends. Since no federal MCL exists, the focus is on consistent water quality reporting and careful evaluation of any changes over time.
If you want to understand how to read a certified laboratory test report for 1,2,3-TCP
A certified test report will list the concentration of 1,2,3-trichloropropane detected, the laboratory's reporting limit, and possibly the method used. The reporting limit is the smallest concentration reliably detected—in this system's monitoring, it was 0.03 µg/L. Values below this are reported as nondetect.
Knowing this helps you interpret whether your household water tests indicate presence within measurement limits or actual concentrations that might warrant treatment consideration.
If you plan to gather information before seeking treatment advice
Before consulting with water treatment experts or requesting treatment options, you should record and keep handy your laboratory test results showing 1,2,3-TCP levels in µg/L or ppb, the test method, and the date of testing. Also note your water source type (public system, well, etc.) and any history of taste or odor issues or staining, as these details aid in selecting the right treatment approach.
Since the regional public water system has no health-based violations for TCP, your individual water test is key to making informed decisions.
For households in VI exploring treatment for chlorinated solvents like 1,2,3-trichloropropane, the C-Series 1,2,3-TCP Filter ships ready to configure and is engineered for the appropriate carbon bed depth and contact time this constituent requires. This equipment targets TCP specifically but is best considered after confirming your water test results.
In summary, the Water & Power Authority (St. Thomas) system’s publicly available monitoring data from 2013-2015 found no 1,2,3-trichloropropane above 0.03 µg/L. This record characterizes the regional system but not individual household water. For detailed guidance and verification, refer to the EPA's public water system records at https://www.epa.gov/dwucmr/occurrence-data-unregulated-contaminant-monitoring-rule.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2014-11-05. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for Water & Power Auth. (St. Thomas) (VI0000443), VI: 4 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level