Understanding 1,2,3-TCP in Kitsap: Choosing Treatment for Residential Water Concerns

Residents in Kitsap County, Washington, using water served by Silverdale Water District #16 may notice differences in water taste or worry about contaminants like 1,2,3-trichloropropane, commonly called 1,2,3-TCP or simply TCP. Even without direct evidence of elevated levels at individual homes, awareness of this chlorinated solvent's properties can help guide choices about household water treatment options.

Why 1,2,3-Trichloropropane Resists Air Stripping and What That Means for Treatment Choice

1,2,3-TCP is a chlorinated solvent that does not easily release into the air from water through typical aeration or air stripping methods due to its chemical stability and low volatility. This characteristic means treatments relying on aeration technologies are less effective in addressing this compound. Instead, approaches that adsorb or chemically capture 1,2,3-TCP are preferred for residential water treatment to reduce its presence if detected at concerning levels.

Why the Reporting Level for This Solvent Is Thousands of Times Lower Than for Common Metals

Government monitoring for 1,2,3-TCP in the Silverdale Water District used a reporting level of 0.03 micrograms per liter (µg/L), equivalent to 0.03 parts per billion (ppb). This extremely low reporting limit contrasts with the often higher thresholds set for detecting common metals. The low level reflects the compound’s potential persistence in groundwater and the precautionary principles guiding federal monitoring programs, not a violation or direct health risk by itself.

The Role of Plumbing Material and Age, Separate From the Source Water

1,2,3-TCP originates primarily from historic industrial and agricultural soil fumigant use and is not produced or generated by household plumbing materials. Therefore, the age or type of pipes inside a home does not contribute to the concentration of this solvent in tap water. Understanding this distinction helps homeowners realize that testing the source water directly is necessary for accurate information about 1,2,3-TCP presence.

Granular Activated Carbon Contact Time: Why Bed Depth Matters More for TCP Than Taste

Granular activated carbon (GAC) filters are documented to adsorb chlorinated solvents like 1,2,3-TCP effectively. The key factor influencing TCP reduction through GAC is contact time within the filter bed, which depends on bed depth and flow rate. Longer contact time allows more TCP molecules to bind with carbon surfaces, improving treatment performance. This differs from filters designed primarily to improve taste or odor, where contact time requirements can be less stringent.

Why Aesthetic Secondary Standards Differ From Health-Based Limits, Applied to This Constituent

In water quality evaluations, aesthetic secondary standards address issues like taste, staining, or corrosivity rather than health risks. The Silverdale Water District’s record shows no EPA health-based violations related to 1,2,3-TCP, with all monitored concentrations below the reporting level. This means that while 1,2,3-TCP is monitored for presence, it does not exceed any enforceable health standard at the system scale. Understanding the difference helps households make informed decisions about water treatment priorities.

What Questions a Commercial or Industrial Operator Adds That a Household Does Not

While this page addresses residential water concerns, commercial and industrial users often consider additional factors such as volume-specific treatment capacity, regulatory compliance at larger scales, and potential impacts on equipment or processes. These concerns require different assessment approaches and equipment sizing compared to household needs, reinforcing the importance of selecting treatment designed for home water use.

Government monitoring from 2014 to 2015 for the Silverdale Water District #16 in Kitsap County did not detect 1,2,3-trichloropropane above 0.03 µg/L in any samples, serving over 35,000 people. This data is from federal unregulated contaminant monitoring and does not reflect specific conditions at individual homes. Testing your own water source is the only way to characterize the exact 1,2,3-TCP concentration. For households exploring treatment options tailored to this chlorinated solvent, the Pentair 1,2,3-TCP Filter offers an approach designed to address the compound’s unique properties and treatment challenges.

For more detailed information about the monitoring data and regulatory scope, the EPA's Safe Drinking Water Information System (SDWIS) resources provide official records and technical explanations.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2015-06-17. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR3 monitoring (2013-2015) for Silverdale Water District #16 (WA5379300), WA: 22 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level