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Bernardin Lochmueller & Associates (BLA), a leader in sustainable infrastructure design, recently received a method patent for its Eco-Treatment constructed wetland system to treat wastewater from animal confinement operations
Manure management processes by Confined Animal Feeding Operations (CAFOs) have come under increasing scrutiny. Some CAFOs store manure in lagoons, until they can dispose of it, most often by applying it to fields. Environmentalists and some regulators are concerned about the release of raw wastes into watersheds, especially when rain causes lagoons to overflow or manure runs off of fields into nearby bodies of water.
In 2008 the EPA established zero discharge requirements but did not require facility-specific reporting. A proposed EPA rule would require CAFOs to provide information on waste discharges starting this July in an effort to protect water quality. The public comment period for this new rule closes January 19.
Constructed wetlands, whether used as a stand-alone system or in combination with land application or other treatment alternatives, offer a cost-effective solution to assist CAFOs in meeting the zero discharge requirement. Using plants and a variety of filter media, the system provides a natural approach to reducing or eliminating nutrients and other chemicals from manure and wastes. The system can even be fine-tuned to provide effluent with nutrient loads that match the needs of specific crops.
To date, BLA’s Water Resources Team, led by Mark Harrison, PE, LEED AP, has designed more than 80 constructed wetland systems for the treatment of animal waste, site and municipal sewage, and Combined Sewer Overflows (CSOs). A number of these have won state and national awards for innovative engineering.
One recent project is saving the City of Washington, Indiana, a city of 12,000, more than $40 million on its plan to meet federal mandates for CSO water quality. The wetland system will also save the city $1.6 million in annual operations and maintenance. It was recently named one of the Top Projects for 2011 by Water & Wastes Digest.
“Constructed wetlands offer a variety of benefits,” says Harrison. “Because nature does the work, it reduces the energy used, be that energy needed to transport manure or run a mechanical treatment system, not to mention cutting the cost of additional chemicals to treat waste. In some instances, we’ve even designed wetlands to provide habitat for wildlife or walking trails. It’s just an all-around great solution!”