City’s water-quality labs serve vital role

Last Updated: 2/2/2015

Most of us never think about what happens after we flush, but there are seven City of Roseville employees who think about it every workday. They work at the city’s water-quality labs, located at the Dry Creek and Pleasant Grove Wastewater Treatment Plants, and it might surprise you to learn that it’s an interesting job.

Lab technicians collect samples from several sites throughout the treatment process and perform a host of tests to monitor the treatment process and make sure treated wastewater meets state requirements and is suitable for discharge into our local creeks. Their work helps the city avoid fines and penalties by verifying compliance with state and federal laws that regulate the quality of treated wastewater. Tests performed check temperature, pH, ammonia, electrical conductivity, and bacteria content, as well as the organic strength of the wastewater. The bacteriological tests analyze for total coliform as well as E. coli. The lab also sends treated wastewater samples and the sludge to outside contract labs where technicians analyze for various organic materials and metals, including mercury.

Outside the lab, an industrial waste specialist collects samples from industrial customers for lab testing. And because fats, oils, and greases (FOG) can clog sewer pipes and lead to sewer blockages and spills, a specialist visits more than 300 city restaurants at least once a year to make sure they’re complying with the laws that prohibit FOG from entering city sewers.

The city treats wastewater to comply with state-issued discharge permits. This compliance ensures the treated wastewater is safe to release into local creeks and reused for landscape irrigation. The rigorous testing the labs perform is one of the keys to making that happen.