Backyard BNR: Passive Nitrogen Reduction System Research for Onsite Wastewater Treatment


  • Josefin E. Hirst, Damann L. Anderson - Hazen and Sawyer

Approximately 25 percent of the U.S., and 30 percent of Florida’s population relies on onsite wastewater systems (OWS) for wastewater treatment. Nutrient loading from many sources including OWS has received increased attention from water quality regulators and the public in many watersheds. Nitrogen in particular is an important nutrient of concern for water quality, and nitrate-nitrogen represents perhaps the most common groundwater pollutant from OWS. The environmental effects of excess nitrogen on groundwater and surface water can ultimately lead to the degradation of water quality, since excess nitrogen loading can lead to algal blooms and oxygen depletion in surface waters, which can be harmful to natural aquatic life. The protection of watersheds and surface water bodies has from excess nitrogen loading has led to increasing regulatory actions requiring nitrogen reduction from OWS in areas such as the Florida Keys, Chesapeake Bay, and Cape Cod, to name a few.

In Florida, the degradation of water quality in the many freshwater springs and nitrogen limited estuarine surface water bodies has led to legislation requiring protection of these areas, including requirements for nitrogen reducing OWS. The Florida Department of Health (FDOH) initiated the Florida Onsite Sewage Nitrogen Reduction Strategies (FOSNRS) Project to research, develop, construct and test different onsite wastewater treatment systems to address nitrogen reduction from OWS.

This paper provides field testing results from a full-scale two stage passive biofilter system installed at a single family residence in Florida as part of this project.

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Horizons Fall 2017 (pdf)

Horizons showcases significant water, wastewater, reuse, and stormwater projects and innovations that help our clients to achieve their goals, and can help you achieve yours. Articles are written by top engineers and process group leaders, demonstrating and explaining the beneficial application of a variety of technologies and tools.

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