The Carlsbad Municipal Water District is a subsidiary of the City of Carlsbad, located in San Diego County, California. The district’s service area covers approximately 85% of the city, an area of about 32 square miles. The District provides wastewater collection services through 145 miles of collection pipelines, 40 miles of sewer laterals and 16 pump stations.
The Batiquitos Pump Station is located adjacent to the Batiquitos Lagoon Tidal Wetlands Area. The lagoon itself consists of 610 acres with a drainage basin of about 55,000 acres and is bordered on its north side by a popular walking/hiking trail. The pump station is located within a few yards of the walking trail.
Wastewater from the local residential area and an upscale golf resort is collected at the Batiquitos Pump Station. The city was using other hydrogen sulfide control products at other stations, but agreed to a pilot program at Batiquitos with BioMagic to test the product’s performance on a station with high sulfide levels. The challenge was to reduce the liquid sulfides in the force main discharge to less than 0.5 milligrams/liter (mg/L) consistently and cost-effectively. Initial readings taken from the force main discharge ranged from 1.5 to 3.4 mg/L depending on the time of day and where in the pump cycle the sample was taken. Initial hydrogen sulfide gas readings taken by an OdaLog hydrogen sulfide datalogger at the force main discharge averaged 19 parts per million (ppm) with daily concentration peaks of 150-250 ppm.