Background on Water Supply in Fairfield County, CT
The Aquarion Water Co. of Connecticut provides surface water to over 350,000 people across Fairfield County, including areas like Stamford, Norwalk, and Westport. This public water system draws from surface water sources, treating and distributing water to more than 100,000 connections. Water reaching homes reflects this system's quality, though individual household plumbing and private wells may have different characteristics.
Why 1,2,3-Trichloropropane’s Reporting Level Is Extremely Low Compared to Metals
Federal Monitoring Uses a Very Sensitive Reporting Level for TCP
The EPA's unregulated contaminant monitoring for 1,2,3-TCP uses a reporting level of 0.03 micrograms per liter (µg/L), or parts per billion (ppb). This is much lower than levels set for common metals. This sensitivity arises from TCP’s chemical properties and the difficulty of removing it once present in water, necessitating detection at very low concentrations to support public health research.
Low Reporting Level Does Not Signal a Violation
A detection above this reporting level indicates measurement by specialized instruments, not a health-based violation or contamination. For this public water system, no measurements of 1,2,3-TCP were reported above the 0.03 µg/L level during EPA’s 2013-2015 monitoring period.
Granular Activated Carbon (GAC) Contact Time: The Importance of Bed Depth for TCP Treatment
Contact Time Is Critical for Effectively Addressing 1,2,3-TCP
Removing 1,2,3-trichloropropane from water typically relies on technologies that adsorb contaminants, such as granular activated carbon. TCP molecules require adequate contact time with the carbon media, which depends on the depth of the carbon bed and the flow rate through it. Faster flow or shallower beds reduce the effectiveness of TCP capture compared to taste and odor compounds, which are generally easier to remove.
Choosing Treatment Needs Based on TCP’s Unique Behavior
Households considering treatment for 1,2,3-TCP should recognize that systems optimized solely for taste or chlorine reduction may not provide adequate contact time or bed depth to address this solvent. Systems designed specifically for TCP consider these factors to ensure proper performance.
Reading and Interpreting Certified Laboratory Results for 1,2,3-TCP
Understand What a Lab Test Reports
A certified laboratory test for 1,2,3-trichloropropane will report concentrations in micrograms per liter (µg/L) or parts per billion (ppb), typically with reporting limits around 0.02 to 0.03 µg/L. If no TCP is detected above this limit, the result will state not detected. A detected value below federal or state health-based limits merely indicates the presence of trace amounts measured by sensitive instruments.
Why Home Testing Is Important for Treatment Decisions
Because government data reflect the water system as a whole, individual home tests are essential to understand a household’s specific water quality and to decide the appropriate class of treatment. This is the only way to know if 1,2,3-TCP is present at levels warranting action.
Historical Context: How a Soil Fumigant from Mid-20th Century Can Appear Today
Legacy Use of TCP as a Soil Fumigant Explains Some Detections
1,2,3-TCP was historically present as an impurity in soil fumigants used in agriculture from the 1950s through the 1980s. Over decades, these chemicals traveled through soil and groundwater pathways, sometimes reaching deep aquifers and surface water supplies. This slow migration explains why trace detections may still occur in certain water sources today despite discontinued usage.
Relevance to Surface Water Supply in Fairfield County
Because the Aquarion Water Co. of CT primarily uses surface water, historical groundwater migration is less directly relevant but still important for ongoing monitoring and understanding possible contaminant sources.
Distinguishing 1,2,3-TCP from Other Common Water Concerns
1,2,3-TCP Is a Specific Chlorinated Solvent, Not a General Industrial Chemical
This solvent differs chemically and behaviorally from other chlorinated solvents and common industrial chemicals that may appear in water. Treatment and monitoring approaches are tailored accordingly, and assumptions about it based on general solvent knowledge can be misleading.
1,2,3-TCP's Unique Treatment Requirements
Unlike some taste or aesthetic water issues, TCP requires focused treatment considerations to ensure contact time and filter media are adequate to reduce its concentration effectively.
A Worked Example: Understanding the Public Record's Median and Range
Public Water System Data Shows No Detects Above Reporting Threshold
For the Aquarion Water Co. of CT public water system serving Fairfield County, federal monitoring from 2013 to 2015 reported 16 samples with zero detections above the 0.03 µg/L reporting level. This means all measurements were below this sensitive threshold, indicating very low or no measurable TCP in the system's source water during that period.
How Homeowners Should Use This Information
This record provides a general baseline for the public system but cannot predict levels in any particular home. Home testing for 1,2,3-TCP is necessary to make informed treatment decisions based on specific water conditions.
Important Points to Avoid Misinterpretation
Residents should not conclude from these area data that their water is free from 1,2,3-TCP or that treatment is unnecessary without a specific home water test. The absence of detection above the reporting level in public system monitoring data is not a guarantee of zero TCP. Likewise, the federal data do not represent any health violation or unsafe condition in municipal water.
For those evaluating which treatment solutions suit their household, the C-Series 1,2,3-TCP Filter ships ready to configure and is designed addressing the unique properties of TCP, including the need for sufficient granular activated carbon contact time to capture this chlorinated solvent effectively.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2014-06-18. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for Aquarion Water Co. of CT - Main System (CT0150011), CT: 16 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level