El Centro, a city 100 miles east of San Diego, was experiencing significant issues with odour control in its sewer system, despite many different attempts from different chemical dosing suppliers to resolve the issue.
One particular sewer line, designed to serve the projected population growth around a shopping mall which has not yet eventuated, was too big for the relatively small volume sewer flow. Rotten egg gas (H2S) measurements at some man-holes in the system were exceeding 4000ppm, which is both highly dangerous as well as highly corrosive to the system.
Calix committed to fixing the problem. The solution was to methodically dose Calix ACTI-Mag, its concentrated, stabilised suspension of magnesium hydroxide made from its proprietary technology at its Bacchus Marsh facility in Victoria. Despite shipping the product to the US, the product remained stable and ready-to-use.
The City of El Centro said
“ACTI-Mag technology has been applied successfully in our Sewer Line 3. The dangerous levels of H2S have been greatly reduced and we now have a safer sewer system. The success of this project lies of course in the product, but also equally in the high level of customer service, sincerity and professionalism practiced by all Calix personnel”
After six weeks of dosing, there was a reduction in H2S levels to around 1,500 ppm, and after twelve weeks a significant flushing of fatty acids was noted, representing the break-up of “fat-bergs” in the system. Odour measurements after this event rapidly decreased to below 100ppm average, with instantaneous readings down to 3ppm.
ACTI-Mag has a higher neutralising value per kilo when compared with caustic while being significantly safer to handle than other traditional alkalis, making it a very safe
and cost competitive option for hydrogen sulphide gas (H2S) control in sewers.