Oct 06, 2009

Budget-Friendly Bacteria Removal

Incidences of waterborne illnesses are on the rise in coastal communities. In turn, many localities are seeking out solutions to mitigate the levels of bacteria from storm water runoff and protect the economic viability of their natural resources.

As many entities face uncertain economic futures, it is paramount that solutions be not only be cost-effective but also easily implemented through retrofit scenarios with low long-term maintenance costs and no proprietary products required for long-term viability.

In determining how to meet these requirements and balance a budget, many have turned to Bacterra bioretention filtration systems. The Bacterra advanced bioretention system allows for comfort and peace of mind because independent testing and research data on the media blend is available to provide for easy specification.

Mount Trashmore Park

Mount Trashmore Park in Virginia Beach, Va., is a popular tourist area and local attraction suffering from a variety of high-pollutant discharges, including bacteria contributed from wild bird and pet waste. Bacteria and other pathogen discharges have significantly impaired the health of the Lynnhaven River watershed’s aquatic environment, as well as shellfish health and population. Shellfishing in the Lynnhaven River has been prohibited for several years, primarily due to excessive bacteria levels in this estuary.

Partly funded by the Virginia Department of Conservation and Recreation through a Water Quality Improvement Grant, the city of Virginia Beach installed the Filterra system with Bacterra media blend as part of a multifaceted solution to significantly reduce the amount of bacteria and pollutants discharging into Thalia Creek and the Lynnhaven River watershed. The treated water discharging into local waterways will meet local and state requirements and improve shellfish standards to promote the growth and health of the shellfish population.

Marina Del Rey

The Marina Del Rey harbor area in Los Angeles County, Calif., is a popular tourist area and local attraction suffering from a variety of high-pollutant discharges from retail, commercial and residential activities. Bacteria and other pathogen discharges had significantly impaired the health of the aquatic environment and impacted the local economy. Marina Del Rey is densely populated, offering limited space for large treatment and collection systems for runoff.

After reviewing several storm water treatment options, Los Angeles County Department of Public Works staff chose Filterra for five separate locations along Marina Del Rey streets. Sites were selected where the highest potential concentrations of bacteria and pathogens could be captured and treated. Filterra was chosen due to its compact design and aesthetic features. County staff is currently reviewing Filterra performance monitoring results for bacteria reduction and maintenance cost benefits.

The first two years of results from this full-scale field evaluation of the Bacterra advanced bioretention technology delivered greater than 95% removal of all key bacterial pathogen indicators analyzed, including fecal coliforms, E. coli and Enterococcus spp., following the filter maturation period. This performance is similar to or better than other storm water maintenance systems, yet with the critical advantage of continued performance at very high flow rates; this allows larger drainage areas to be treated within a compact installed footprint, increasing the cost-effectiveness of the solution.

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