Autotrol 1,2,3-TCP Filter

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

California's 5 ng/L (0.005 µg/L) guideline is more stringent than federal standards

Unlike California's regulatory threshold of 5 nanograms per liter for 1,2,3-trichloropropane, also called TCP, there is no federal maximum contaminant level (MCL) for this chlorinated solvent. Public water system monitoring in the Virgin Islands by the EPA found no detections above 0.03 micrograms per liter (µg/L), equivalent to 30 parts per trillion (ppt), which is well above California's limit but still no federal violation.

Federal monitoring results indicate detections below reporting levels for this area

The Water & Power Authority of St. Croix reported zero detections of 1,2,3-TCP above the reporting limit of 0.03 µg/L during the 2013-2015 monitoring. This means no measurement in the system was above that threshold, but this does not guarantee any individual home’s water concentration is below stricter state guidelines.

State limits provide context but do not replace specific household water testing

Since no federal MCL exists, residents should consider both the regional data and any applicable local standards like California's for guidance. Actual household water quality can only be established by certified laboratory testing of their individual supply.

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

Longer contact with carbon improves TCP reduction effectiveness

The chlorinated solvent 1,2,3-trichloropropane requires deeper granular activated carbon (GAC) beds to achieve meaningful adsorption. Unlike taste or odor issues that respond to shorter contact times, TCP’s small molecular size and chemical stability make longer contact necessary for effective treatment.

Bed depth is a critical parameter in selecting carbon filtration for TCP

When evaluating treatment options, ensure the technology provides sufficient carbon bed depth to maximize TCP contact. This differs from many common water aesthetic treatments that rely on shorter carbon contact.

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

1,2,3-TCP is monitored at very low levels due to its chemical and toxicological profile

The reporting threshold for TCP at 0.03 µg/L is much lower than typical detection limits for metals like lead or iron. This reflects the sensitivity required because chlorinated solvents can have health concerns at much lower concentrations despite their low occurrence.

Low reporting levels enable early detection but do not equate to safety breaches

Detection above the reporting level indicates presence measured by instrument sensitivity, not a violation or unsafe condition. Devices reporting below this threshold signal absence or very low levels.

The Household or Facility Symptoms That Do and Do Not Point to This Problem

1,2,3-trichloropropane is colorless and odorless in water

Because TCP has no taste, odor, or coloration in water, usual sensory symptoms do not indicate its presence. Detection requires laboratory analysis.

Common water quality issues like hard water or chlorine taste are unrelated to TCP

Household problems such as scaling, metallic taste, or chlorine smell do not correspond to 1,2,3-TCP contamination. Separate testing and treatment decisions should be made for those issues.

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

TCP has low volatility making air stripping ineffective

Unlike more volatile organic compounds, 1,2,3-trichloropropane does not readily transfer from water to air. This characteristic makes air stripping an unsuitable treatment for TCP.

Adsorption via granular activated carbon is preferred for TCP control

Because TCP resists volatilization, treatment options focusing on adsorption, like deep-bed carbon filters, are more reliable and effective for reducing this chlorinated solvent in household water.

What a Certified Laboratory Test for This Constituent Reports and How to Read It

Results are given as micrograms per liter (µg/L) or parts per billion (ppb)

Laboratory analysis for 1,2,3-TCP commonly reports concentrations in µg/L, which is equivalent to ppb. A test result below 0.03 µg/L means TCP was not detected above the EPA reporting limit for this system.

Interpret your laboratory report in context of regional data and local guidelines

Since no federal maximum contaminant level exists for TCP, compare your test results against state limits or health advisories if available. Remember that detection at or below reporting limits does not indicate a violation or health threat.

What You Should NOT Conclude from Area Data

• Do not assume your household's water is free of 1,2,3-trichloropropane based solely on public water system results.
• Do not treat any detection as a violation or safety hazard; it means only that the compound was measurable.
• Regional monitoring is a tool to assess potential exposure but cannot replace local, certified testing for your home’s water supply.
• Public water system records with zero health-based violations show compliance but are not a guarantee of specific constituent concentrations at each tap.

For households in the Virgin Islands concerned about 1,2,3-TCP, the Autotrol 1,2,3-TCP Filter provides a direct-purchase, ready-to-configure treatment technology designed to address this chlorinated solvent through effective granular activated carbon adsorption, meeting the unique challenge of TCP’s chemical properties.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2015-08-11. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR3 monitoring (2013-2015) for Water & Power Auth. (St. Croix) (VI0000097), VI: 4 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level