Understanding California's 5 ng/L Limit Versus the Absence of a Federal MCL
California's 5 ng/L (0.005 µg/L) level for 1,2,3-trichloropropane is a state guideline, not a federal rule
This state limit is more stringent than any federal standards because the EPA has not set a maximum contaminant level (MCL) for 1,2,3-TCP. The EPA considers federal MCLs only for contaminants with established health-based goals.
The EPA records for the CT Water Co. - Shoreline R., Guilford S. system include no health-based violations
Serving Clinton, Guilford, Madison, Old Saybrook, Westbrook, and New Haven County, this public water system has recorded no health-based violations. Sampling from 2013 to 2015 showed zero detections of 1,2,3-TCP above a reporting level of 0.03 µg/L (30 ng/L), which is well above California's 5 ng/L limit but still below any federal MCL.
The Legacy of a Soil Fumigant Impurity from the Mid-20th Century
1,2,3-trichloropropane originated as an impurity in soil fumigants used in the 1950s to 1980s
This chlorinated solvent is a byproduct of historical agricultural practices. It can persist for decades in the environment, slowly reaching groundwater sources. While the public system in your area sources surface water, underground contamination concerns have led to monitoring nationwide.
Its presence in groundwater highlights the importance of monitoring but does not imply your home's water contains TCP
The EPA’s monitoring program detects 1,2,3-TCP in water supplies but does not confirm levels in any single home’s water. Only a lab test of your household water can determine if 1,2,3-trichloropropane is present in your specific supply.
What You Should Note Before Seeking Treatment Advice
Obtain a laboratory analysis specifying TCP concentration in micrograms per liter (µg/L) or parts per billion (ppb)
This data will clarify whether 1,2,3-trichloropropane is present and at what level. Without this, advice or solutions cannot be tailored to your situation.
Know your water source type and history of any previous treatment equipment failures
This helps in selecting technology that addresses your needs, especially after equipment has ceased to function effectively.
Review official sampling data from the public water system serving your area for context
Government records, such as the EPA’s SDWIS database, provide background on typical occurrences but do not replace individual testing.
Why 1,2,3-Trichloropropane Resists Air Stripping and Treatment Implications
1,2,3-TCP’s chemical properties make it resistant to air stripping methods
Unlike some volatile organic compounds, this chlorinated solvent does not readily transfer from water to air, limiting the effectiveness of aeration or air stripping treatments commonly used for other pollutants.
This resistance guides the choice toward filtration technologies designed specifically for TCP
Effective residential treatment requires equipment that can capture or chemically bind 1,2,3-trichloropropane rather than relying on volatilization.
Understanding Detection Terms in the EPA Sampling Record
'Detected' means the compound was measured above the instrument's reporting level, not that it violates health standards
For the Guilford Shoreline system, no 1,2,3-TCP was detected above 0.03 µg/L during the sampling period, indicating levels were below this detection threshold.
'Median' and 'Range' describe the central tendency and spread of measurements across samples
These statistics help interpret variability in water quality but do not apply when no detectable concentrations are reported.
EPA monitoring results serve as a reference and are not substitutes for personalized water testing
They offer general insight into potential occurrences but cannot confirm conditions in your home’s water supply.
Final Checklist: The Test You Need to Settle the Question
Order a comprehensive laboratory analysis for 1,2,3-trichloropropane in your household water sample. A result below your test lab’s reporting level — often around 0.03 µg/L — will provide clarity on whether TCP warrants treatment consideration.
If concentrations approach or exceed your comfort threshold, the Fleck 1,2,3-TCP Filter ships ready to configure for residential use and is documented to address this particular chlorinated solvent effectively.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2014-11-18. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for CT Water Co. - Shoreline R., Guilford S. (CT0608011), CT: 20 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level
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