O.C. Agency Works to Keep Sewers (Relatively) Clean


Forget about ISDN lines and fiber optic cables, Kelly Christensen helps manage a network with really huge bandwidth: the Orange County sewer system.

As a source control supervisor with the county Sanitation Districts, Christensen is responsible for catching companies that dump hazardous materials in the sewer. The high-tech industry is one of the worst offenders, he said, but it is also part of the solution.

As part of its detection program, the agency hides electronic devices in manholes at various locations around the county. Each garbage can-size device has a built-in computer that monitors the chemical composition of the waste passing by, as well as 24 bottles for collecting samples.

“Picture R2D2 without the legs,” Christensen said.


The devices help the agency catch companies that try to cut costs by dumping acids, copper, lead and other metals into the county’s sewer system. “More than 99% of the companies are in voluntary compliance” with waste disposal laws, Christensen said. “But the majority of the ones we have problems with are in the metal plating industry and circuit board manufacturing.”

The pollutants produced by these industries cause real problems in the sewer system, Christensen said. The acid eats away the concrete, and the metals tend to contaminate the solid waste separated from water at treatment plants. When that happens, the solid waste can no longer be recycled as bagged fertilizer for spreading on farms. Instead, the county has to pay extra to have the waste shipped to a landfill, or in a worst-case scenario, disposed of as hazardous waste.

The agency can often trace the contaminants back to the source. Usually, the offender pays for the agency’s inspection costs and signs an agreement to comply with dumping laws. If not, the matter is referred to the district attorney for criminal prosecution.

Even though the high-tech industry has grown significantly in Orange County, the number of dumping cases is dwindling, Christensen said. “We used to have to worry about 10% of our industrial community,” he said. “Now we’re down to 1%.”


That is partly due to the deterrence effect of the so-called sample units, which cost more than $2,000 apiece and are becoming increasingly technologically advanced. “The next generation machine coming out will talk to us over a wireless modem,” Christensen said. That way sanitation workers won’t have to climb down manholes to check on the devices.

Greg Miller covers high technology for The Times. He can be reached at (714) 966-7830 and at