Problem: It is well established that green infrastructure or non-structural programs can be effective in reducing stormwater runoff volume and pollution from urban areas. One Tennessee utility put their GI investment to the test by developing a bioretention basin to decrease the volume of stormwater runoff. The utility was concerned with the effects of runoff from a park going into an adjacent stream. 

Solution: Both the runoff volume and potential pollutant loads from pet feces led them to design a system which reduced the runoff volume through measures such as infiltration and evapotranspiration. To measure performance, a stormwater vault upstream from the GI area captured park runoff, which then distributed into an area with selected, high uptake, native plants. Residual runoff from the GI area was captured at a second vault located downstream. ADS ECHO level monitors were installed in both the up and downstream vaults. Data was captured in 15-minute intervals (5-minute intervals during storm events), stored in memory and transmitted daily to cloud-based software. The time series data from the inlet was compared to the outlet to show a reduction in flow, hence lowering the amount of E. Coli going into the receiving stream.

Result: The utility found that they had a substantial capture rate, confirming the success of the GI implementation. With this type of validation, the utility now has data and corresponding proof to tackle additional areas knowing that they can justify investment. 877-237-9585; www.adsenv.com