The Utility
The City of Lakewood Water Resources department serves its Southern California community from 11 deep groundwater wells feeding roughly 180 miles of distribution main. Like many California utilities, Lakewood operates under persistent drought pressure, where wasting treated water simply to take a measurement is increasingly difficult to justify — both financially and for compliance.
The Challenge
Lakewood's existing reagent-based analyzers required a continuous side-stream of sample water that was sent to drain. At several well sites there was simply no tolerance for a waste stream — which meant those locations could not be continuously monitored at all. The utility needed an analyzer that could be installed directly in the pipe, produce no waste, and hold its accuracy without the constant calibration and reagent replenishment of a colorimetric system.
The Solution
In 2021 Lakewood ran a side-by-side pilot of the Halogen MP5 against an incumbent Hach CL17. The MP5 is a reagent-free, self-cleaning amperometric sensor that installs directly in-line and is certified to NSF/ANSI 61 and NSF/ANSI 372 for contact with drinking water. After the pilot proved out, the city deployed a wet-tap MP5 directly into a distribution main at a well site that had previously been impossible to monitor.
The Results
- check_circleZero calibrations over the 6-month pilot — and more than two years of operation with minimal service.
- check_circleMeasured deviation of only 0.04 ppm from the reference method; accuracy held within 0.04–0.05 ppm.
- check_circleEliminated approximately 69,000 gallons/year of waste stream per sensor — about $690/year in water cost.
- check_circleThe wet-tap unit caught a real-time chlorine residual dropout at a well site that the prior system would have missed.
- check_circleUnlocked continuous monitoring at well sites that could not previously tolerate a waste stream.
“There are some sites that cannot be monitored due to the need for a waste stream. The Halogen MP5 solves this problem.”