The Goleta Water District (GWD) is evaluating JC 9465, a water treatment chemical manufactured by Jenfitch, Inc., as a means of reducing trihalomethane (THM) formation while maintaining compliance with drinking water standards.
Background
Water quality in Lake Cachuma, GWD's surface water source, has degraded as a result of drought and the watershed impacts of wildfire. These conditions have increased the level of organic matter entering the treatment process, creating the need for enhanced organic matter removal to control disinfection byproduct formation.
The same mineral oxychloride chemistry is certified to NSF/ANSI/CAN Standard 60 for drinking-water treatment under the product code JC 9450, at a maximum dose of 84 mg/L, which is what makes full-scale application at a public water treatment facility possible.
What did jar testing show?
Bench-scale jar testing demonstrated the chemical's potential to significantly reduce trihalomethane formation while keeping the district in compliance with the 80 μg/L total trihalomethane (TTHM) standard.
Jar testing showed a 95% reduction of TTHM and a 21% reduction in the seven-day TTHM formation level.
These results indicate that JC 9465 can reduce both immediate TTHM concentrations and the continued formation of TTHM over the seven-day period that reflects distribution-system residence time.
What is the full-scale testing plan?
Based on the jar testing outcomes, GWD planned full-scale plant testing at the Corona Del Mar Water Treatment Plant (CDMWTP):
- An initial two-week pilot scheduled for January 2018.
- A proposed throughput of approximately three million gallons per day.
- Potential follow-up testing extending up to three months in duration.
Previous implementation
JC 9465 has been successfully deployed at the Stenner Surface Water Treatment Plant in San Luis Obispo and at the Martinez Water Treatment Plant. One documented issue, filter turbidity, was resolved through standard maintenance procedures, providing operational confidence for the Goleta Water District trial.
Why can't a district dose away TTHM?
Total trihalomethanes are not a contaminant that enters the source water; they are created by the treatment process itself. When free chlorine meets natural organic matter — humic and fulvic material washed off a watershed — the reaction produces chloroform and its brominated relatives. The regulatory limit is 80 µg/L as a locational running annual average, measured in the distribution system rather than at the plant, which is the detail that makes this hard.
Because the average is locational and annual, a district cannot manage the problem by sampling at the clearwell. Formation continues for days as chlorinated water sits in storage and travels through the mains, so the number that determines compliance depends on the residence time of the furthest point in the system. Cutting the chlorine dose to reduce formation risks losing the residual required to hold the system microbiologically safe. That is the squeeze every utility on a high-organic surface water lives in.
The only durable escape is to remove the precursor before chlorination rather than manage the by-product afterwards. That is what the jar testing was designed to evaluate.
What did drought and fire do to source water?
Lake Cachuma's problem is a compound one. Drought concentrates dissolved organic carbon as reservoir volume falls, and prolonged low water encourages algal productivity that adds a second, internally generated organic load. Wildfire in the watershed then removes the vegetation and soil structure that would normally intercept runoff, so the first significant rain events mobilise ash, char, and dissolved organic carbon straight into the reservoir.
The combination raises both the concentration and the reactivity of the organic matter reaching the plant. From the operator's point of view, coagulant demand rises, filter run times shorten, and TTHM formation potential increases at the same time — all of which push the plant toward its regulatory margin from several directions at once.
Reading the jar-test result
Two numbers were reported, and they measure different things. The 95% reduction in TTHM is the immediate formation at the point of testing. The 21% reduction in seven-day TTHM formation is the more operationally meaningful figure, because seven days approximates the residence time in the distribution system — it estimates what a sample at the far end of the network would actually show.
The mechanism is precursor destruction. JC 9465 is a mineral oxychloride that generates a family of reactive oxygen species — superoxide, hydroxyl radical, singlet oxygen, hydroperoxyl, and peroxide — at an oxidation potential of 2.8–2.9 V, second only to fluorine at 3.06 V and above ozone at 2.07 V, chlorine dioxide at 1.57 V, chlorine gas at 1.36 V, and sodium hypochlorite at 0.94 V. Applied ahead of chlorination, it oxidises the organic matter that would otherwise become a trihalomethane, so the precursor is gone before the chlorine ever meets it.
| Process | Target ORP |
|---|---|
| RO pre- and post-treatment | 500–650 mV |
| Drinking-water disinfection | 650–750 mV |
| Biofilm / EPS destruction | 600–800 mV |
Feed is controlled to an ORP setpoint rather than a fixed ppm, with the standard recommendation of +650 to +750 mV for iron, manganese, and biofilm removal, dosing in front of the filter for optimum removal. The working pH range is 4–9. The ORP reference chart gives the complete set of targets.
Operational precedent and what a district should expect
Two California plants provide operating history: the Stenner Surface Water Treatment Plant in San Luis Obispo and the Martinez Water Treatment Plant. The single documented issue — filter turbidity — was resolved through standard maintenance procedures. That kind of finding is worth more to an evaluating utility than a clean report, because it identifies where to watch during commissioning.
At Martinez, the same chemistry allowed ozone generator capacity to drop from above 110% to 40% while holding a 0.20–0.30 mg/L ozone residual, a 50–60% energy reduction — described in full in enhancing ozone systems with ROS. A separate Northern California trial dosing 8–10 mg/L over 90 days improved settled-water turbidity by 70.0%, filtered-water NOM by 61.4%, filtered-water TOC by 50.0%, bromate by 79.8%, and TTHMs by 56.5%.
The Goleta programme was structured the way a utility evaluation should be: bench-scale jar testing first, then a two-week pilot at the Corona Del Mar Water Treatment Plant at roughly three million gallons per day, with provision for follow-up testing up to three months. Installation is minimal — a metering pump, a storage tank, and an optional ORP controller, typically under 30 minutes.
Further reading: Municipal & Utilities, the municipal and industrial research library, JC 9465 compared with chlorine, and the document library.
Frequently asked questions
What is the TTHM limit for drinking water?
80 micrograms per litre, measured as a locational running annual average in the distribution system rather than at the plant. Because formation continues as water travels through the mains, compliance depends on residence time at the furthest point in the network.
What did the Goleta jar testing show?
A 95% reduction in TTHM at the point of testing and a 21% reduction in seven-day TTHM formation. The seven-day figure is the more operationally meaningful one because it approximates distribution-system residence time. The bench-scale jar testing showed the chemical could reduce trihalomethane formation while keeping Goleta Water District in compliance with the 80 microgram per liter total trihalomethane standard. Those results supported a planned full-scale test.
How does JC 9465 reduce trihalomethanes?
By precursor destruction. Applied ahead of chlorination, its reactive oxygen species oxidise the natural organic matter that would otherwise react with free chlorine to form trihalomethanes, so the precursor is removed before the chlorine meets it. This matters where organic loading has risen, as at Lake Cachuma, whose water quality degraded from drought and wildfire impacts on the watershed, increasing the organic matter entering the treatment process and the need for enhanced removal.
Why has Lake Cachuma water quality degraded?
Drought concentrates dissolved organic carbon as reservoir volume falls and encourages algal productivity, while wildfire in the watershed removes the vegetation and soil structure that would intercept runoff, so rain events mobilise ash, char, and dissolved organic carbon into the reservoir.
Is the chemistry approved for potable water?
Under the product code JC 9450, the same mineral oxychloride chemistry is certified to NSF/ANSI/CAN Standard 60 for drinking-water treatment at a maximum dose of 84 mg/L. JC 9450 and JC 9465 are the same chemistry on two registration paths, and that Standard 60 certification is what makes full-scale application at a public water treatment facility possible, including the planned testing at the Corona Del Mar Water Treatment Plant.
Have a water challenge like this?
Talk to Jenfitch about JC 9465, safety data sheets, or scoping a treatment program for your facility.
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