1. Understanding California’s 5 Nanograms per Liter Standard Compared to No Federal MCL
In California, 1,2,3-trichloropropane (TCP), a chlorinated solvent, is regulated with a strict public health goal of 0.005 micrograms per liter (µg/L), equivalent to 5 parts per trillion (ppt). This is a far more stringent guideline than any federal regulation, as no maximum contaminant level (MCL) currently exists at the federal level for TCP. South Bend's public water system, South Bend Waterworks, has federal occurrence monitoring data showing no detections above the reporting level of 0.03 µg/L (30 parts per trillion), which is higher than the California standard but below any federal action threshold. Thus, when comparing these benchmarks, residents must consider that while federal rules do not limit TCP, California’s limit reflects a cautious approach to protect sensitive populations.
2. How Sample Depth, Well Depth, and Source Type Influence Expected 1,2,3-TCP Levels
South Bend’s water supply comes from groundwater, drawing from wells of various depths that can affect the presence of TCP. Different aquifer layers may experience varying contamination based on historical land use and chemical migration. Shallow groundwater near old agricultural sites or industrial zones, for example, could have different concentrations of chlorinated solvents compared to deeper wells. However, the EPA sample data for South Bend Waterworks represent a composite understanding from multiple wells and time periods, rather than any single testing point. This means a homeowner’s individual well or tap water may differ, emphasizing the importance of site-specific testing if TCP presence or levels are a concern.
3. Essential Details to Document Before Seeking Treatment Guidance
Before consulting any treatment option, homeowners should gather key information about their water system. Important data includes the source of water (municipal or private well), recent laboratory test results specifying TCP concentration if available, and any history of water quality issues. Knowing the exact measurements, units reported (usually micrograms per liter or parts per billion), and dates of tests provides context and aids in selecting an appropriate technical solution. Without these details, it is difficult to assess which approach—such as targeted filtration or other technologies—will be effective or necessary.
4. Interpreting the Number of Samples and Wells Behind Regional Figures and What Small Sample Sizes Mean
The EPA’s unregulated contaminant monitoring rule (UCMR3) for South Bend Waterworks included 18 samples taken between June 2013 and April 2014 with zero detections of TCP above 0.03 µg/L. While this dataset covers multiple wells serving about 115,000 people through 46,000 connections, the sample number is relatively modest. A limited sample size reduces statistical certainty and means that sporadic or localized TCP presence might not be reflected. Homeowners should understand that regional monitoring offers an overview, not a guarantee of individual water quality, which can vary due to plumbing, well condition, or site-specific factors.
5. Sources and Pathways of 1,2,3-Trichloropropane Entering Groundwater and Distribution in South Bend
1,2,3-TCP is a legacy contaminant primarily originating from soil fumigants used in agriculture decades ago. Its chlorinated structure allows it to persist in soils and leach slowly into groundwater over time. In St. Joseph County, historical fumigation and industrial activities have contributed to its occasional detection in groundwater supplies. Because South Bend Waterworks sources groundwater, TCP can enter the distribution system indirectly through these aquifers. However, the public system’s monitoring record shows no measurable concentrations above the detection method’s reporting level during 2013-2015, indicating minimal presence in the supplied water.
In summary, the government records provide a regional snapshot of 1,2,3-TCP levels for South Bend’s municipal water supply but do not describe any individual household's actual water quality. This distinction is important for homeowners weighing technical solutions. Only specific laboratory analysis of the household water can determine existing TCP concentrations. For those looking to address 1,2,3-TCP concerns with effective technology, the Autotrol 1,2,3-TCP Filter ships ready to configure as a direct-purchase solution designed to reduce this chlorinated solvent in residential water. For further official data, residents can consult the EPA’s public water system records at the source website.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2014-04-02. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for South Bend Waterworks (IN5271014), IN: 18 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level