What Happened?
The city Tacoma determined storm water is the source of water pollution threatening the safety of Puget Sound. As a result, the city is using extensive data points to map out the natural flow of water and trace back pollutants to their specific source.
Goal
The Tacoma approach to eliminating rain and storm water pollution is highly scientific and detail-oriented. The city collects data from the seven outlets that flow into the Foss Waterway and Puget Sound, as well as the numerous sediment traps holding storm water across the city, The New York Times reported.
When the water in these locations shows signs of chemical changes due to water pollution, the development is detected in the data and highlighted on the map, which illustrates the flow of water so officials can see what flowed into the data point and where that contaminated water is headed.
This data-driven tactic accurately pinpointed deposits of PCBs that were flowing into Puget Sound from a residential storm water drain where pollutants had built up overtime and created a black goo.
The Storm Water Problem
An EPA Administrator told The New York Times that 85 percent of water pollution was attributed to industrial pipes 40 years ago. Presently, however, 85 percent of water pollution is sourced to storm water and the runoff from farmers’ fields or urban waste.
When Tacoma officials statistically tracked down where the pollutants from Puget Sound originated, they found large concentrations of PCBs that are carcinogenic and outlawed in many areas. Other common pollutants found in storm water and runoff include:
- Industrial byproducts
- Airborne toxins
- Automotive oil and grease
- Pesticides
- Pharmaceuticals from leaking septic tanks
To proactively address the persistent storm water pollution problem, Tacoma and other cities are implementing a variety of strategies:
- Fining polluters
- Continual pipeline scrubbing
- Rain gardens
Rain gardens are designed to absorb the storm water and toxins from the runoff into the soil and away from storm drains. The rain gardens are typically depressed in the land to funnel the polluted storm water, and full of plants with root systems to absorb the water.
Tacoma and other cities are leveraging available technology and forensics practices to trace back to the exact source of water pollution and enforce environmental protection laws, while avoiding costly cleanups from contamination.
Hawaii’s Prediction Model
The Pacific Islands Ocean Observing System and the University of Hawai’i created the PacIOOS Ala Wai Turbidity Plume Model to measure water clarity and better predict instances of brown water runoff after storms. When tiny solids are added to the water column, turbidity levels increase. In the aftermath of a serious storm, brown runoff from the island – which contains pollutants and contaminants - is likely to raise the turbidity level.
The Turbidity Plume Model makes water quality data available to the public while tracking the flow of water to aid in preventing contamination and protecting residents. With the prediction model, oceanographers hope to device a comprehensive system to guide residents to make better choices for when and where they enter the water.
Clean Water
Gov1 has reported on several storm water strategies that are experimenting with green technologies to clean up water sources.