What Government Measurements Can—and Cannot—Show for Your Home’s Water
The federal EPA’s monitoring of the City of Idaho Falls public water system, serving Bonneville County, shows no detection of 1,2,3-trichloropropane (1,2,3-TCP) above the reporting level from 2013 to 2015. This data represents the public system serving about 69,450 people through groundwater sources. However, it does not provide information about any individual household’s tap water quality or plumbing. To determine 1,2,3-TCP levels in your own water, testing of your specific water supply is necessary.
Why the Reporting Level for This Solvent Is Thousands of Times Lower Than for Common Metals
The Reporting Level Sets a Very Low Measurement Threshold
For 1,2,3-TCP, the federal reporting level is 0.03 micrograms per liter (µg/L), or parts per billion (ppb). This is much lower than reporting levels for common metals, reflecting the solvent’s potential health concerns even at very low concentrations. A "not detected" result means the chemical was below this low threshold, not that it is completely absent.
Low Levels Reflect Sensitive Analytical Methods
Detecting 1,2,3-TCP requires advanced laboratory techniques capable of measuring extremely small amounts, unlike metals with higher thresholds. This sensitivity helps characterize trace presence in groundwater.
How California's 5 ng/L State Limit Compares with the Absence of a Federal MCL
California Uses a Stringent Public Health Goal for 1,2,3-TCP
California has set a 5 nanograms per liter (ng/L, equivalent to 0.005 µg/L) level as a public health goal, reflecting precautionary guidance for this chlorinated solvent. This is more stringent than the federal reporting level or any enforceable federal standard.
Federal Regulations Have No Maximum Contaminant Level (MCL) for 1,2,3-TCP
The EPA does not currently have a maximum contaminant level for 1,2,3-TCP, meaning monitored detections do not imply violations or unsafe conditions by federal standards. Public records for Bonneville County show zero health-based violations related to this compound.
Which Fixtures, Appliances, or Processes Are Affected First and Why
Water Used for Drinking and Cooking Is a Primary Concern
Because 1,2,3-TCP is a volatile chlorinated solvent, it can pose the greatest concern where water is consumed or ingested directly—such as from kitchen taps or drinking water dispensers.
Appliances That Heat Water May Promote Off-Gassing
Devices like coffee makers or kettles that heat water might increase the release of volatile compounds like TCP into the air, though national data shows no detections above reporting level in this area.
The Household or Facility Symptoms That Do and Do Not Point to This Problem
No Odor or Taste Specifically Indicates 1,2,3-TCP Presence
Household water symptoms such as unusual taste or smell are not reliable indicators of 1,2,3-TCP, since it is typically odorless and tasteless at low levels common in groundwater.
Staining or Corrosion Is Not Linked to 1,2,3-TCP
Stains or discoloration from water, or damage to plumbing, do not arise from this chlorinated solvent. These symptoms usually relate to other water quality factors.
How the Chlorinated Solvent Enters Groundwater or the Distribution System in This Region
Historical Use of Soil Fumigants Is a Known Source
1,2,3-TCP originated as an impurity in soil fumigants used from the mid-20th century onwards. Residual contamination can migrate into deep groundwater over decades.
Groundwater Source May Have Trace Levels Even Without Detected Presence
While Bonneville County’s public water system monitoring found no detections above the reporting level, groundwater in agricultural areas can hold trace amounts due to legacy practices. Ongoing monitoring helps assess any changes.
Government water-quality data for the City of Idaho Falls system in Bonneville County covers the overall public supply serving tens of thousands but not individual household water. This information originates from the EPA’s Safe Drinking Water Information System and Unregulated Contaminant Monitoring Rule surveys conducted 2013–2015.
For households seeking to address potential 1,2,3-TCP concerns in their water, the Fleck 1,2,3-TCP Filter ships ready to configure as a targeted treatment option specifically designed to reduce this chlorinated solvent from well or municipal water supplies.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2014-04-07. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for City of Idaho Falls (ID7100039), ID: 28 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level