If your household water treatment device has ceased to manage 1,2,3-trichloropropane (1,2,3-TCP) effectively, you might notice differences at your faucet despite government water supply data. Fairfax County's water authority serves over one million residents using surface water, and records indicate no detection of 1,2,3-TCP above the reporting level in their 2013-2015 federal monitoring results.

How California's 5 ng/L State Limit Compares With the Absence of a Federal MCL

Unlike many regulated contaminants, 1,2,3-TCP currently lacks a federal maximum contaminant level (MCL). The Environmental Protection Agency (EPA) tracks its occurrence but sets no enforceable limit, reflecting ongoing evaluation. California has adopted a stringent notification level of 5 nanograms per liter (ng/L), or 0.005 micrograms per liter (µg/L), far below the EPA's reporting threshold of 0.03 µg/L. This difference means federal monitoring will only note 1,2,3-TCP presence when it reaches levels six times higher than California's notification level, underscoring varying approaches to this chlorinated solvent.

What Distinguishes 1,2,3-TCP From Similar Common Water Concerns

1,2,3-TCP, also known as chloropropane, differs fundamentally from more frequently discussed water components such as chlorinated disinfection byproducts or industrial solvents. It is neither a metal nor a routine disinfectant residue. This distinction matters because treatment methods effective for one category may not address 1,2,3-trichloropropane. Understanding these differences helps households target the specific contaminant they face, especially after home equipment failure.

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

1,2,3-TCP was a trace impurity in soil fumigants widely used between the 1950s and 1980s. Over time, this compound leached through soil layers and migrated to groundwater, where it may persist. This historical use explains why 1,2,3-TCP can appear in water supplies long after direct application ceased. The lag in detection highlights the importance of ongoing water quality monitoring, especially for regions like Fairfax County relying on surface water sources.

How the Documented Treatment Technology Addresses the Constituent

After household equipment failure, restoring water treatment targeting 1,2,3-trichloropropane involves technology documented to reduce this chlorinated solvent effectively. The C-Series 1,2,3-TCP Filter ships ready to configure for residential use and is designed specifically for this compound. It operates by adsorbing and neutralizing 1,2,3-TCP from water, providing a tailored solution distinct from general water softening or filtration systems.

What 'Detected', 'Median' and 'Range' Mean in the Sampling Record on This Page

The EPA monitoring reference for Fairfax County Water Authority recorded 20 samples for 1,2,3-TCP, with zero detections above the 0.03 µg/L reporting level. 'Detected' indicates a measurement above this threshold; 'median' would be the middle value of reported concentrations, but since no samples exceeded detection limits, it’s effectively zero. The 'range' would normally express the lowest to highest readings, but here it confirms no values above the limit during the 2013-2015 monitoring period.

How Seasonal or Multi-Year Variation Shows in the Record

The referenced sampling occurred between July 2013 and April 2014, covering different seasons. Despite potential for variation in source water, no 1,2,3-TCP was detected over this period. This consistency suggests that within the timeframe and methodology of this federal occurrence survey, 1,2,3-TCP levels remained below the reporting level for Fairfax County’s water system. However, such data does not guarantee absence at an individual home’s tap, where point-of-use factors and older equipment may influence actual water quality.

What Fairfax County Residents Should NOT Conclude From Area Data

The absence of detected 1,2,3-trichloropropane in system-wide records is not a substitute for testing your own household water. Your well or home connection could differ due to plumbing materials, local conditions, or equipment status. A failure of home water treatment equipment targeting this compound means that your water might contain concentrations not reflected in the public water system record. Therefore, personal water testing remains necessary to establish your specific situation.

For households in Fairfax County seeking to address 1,2,3-TCP after equipment failure, the C-Series 1,2,3-TCP Filter offers a documented, specialized approach ready to configure for residential concerns, focusing on this compound’s specific removal.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2014-04-14. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR3 monitoring (2013-2015) for Fairfax County Water Authority (VA6059501), VA: 20 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level