Tacoma, WA waterfront. IMG: via Shutterstock.
Keeping the Puget Sound clean and in healthy condition is a high priority for the environmental engineers in Tacoma, WA. However, environmental engineers were shocked last year when they found the water was being polluted by polychlorinated biphenyls, or PCBs. The engineers worked their way upstream where they discovered the source of the problem: a storm drain in a residential neighborhood. The storm drain had black goo stuck to its sides, old grout that contained large concentrations of PCBs.
PCB, anodorless and carcinogenic toxin, was used in local road building in 1975 and was outlawed soon after due to its toxic qualities. The biggest problem the Tacoma environmental engineers are facing seems to be the rain that washes these toxins and other pollutants down storm drains, through drain pipes, and out into the Puget Sound. As Seth P. Brown, an engineer with the Water Environment Federation, said, normal storm water runoff “is the only source of water pollution in the country that’s getting worse.”
However, Tacoma is working hard to monitor the pollution going into storm drains by having a continually monitored chemical map of the storm drain pipes, which alerts them if there is a change in the chemicals. Tacoma’s detection system also allows for the ability to pinpoint where the chemical change is coming from. This system is what allowed the environmental engineers to detect and locate the PBC contamination.
Due to how effective this system has shown to be, officials from other countries have started studying it in the hopes of gaining some control over their own storm water pollution problems. Tacoma is serious about keeping their water clean and this motivation has also led to the city holding polluters responsible via fines.
Another possible way Tacoma is considering to handle the toxins in the storm water is rain gardens, which reabsorb the toxins keeping them out of the drainpipes. As the PCBs case shows, storm water pollution is a continuing problem in Tacoma and around the world, but one that is slowly starting to become better contained.