Thursday, October 10, 2013
Open House at Alexandria ReNew
Alexandria Renew will show visitors how it cleans dirty water to its highest standards, turning it into clean, renewable and sustainable natural resources that can be used for a variety of safe and accepted purposes. AlexRenew removes over 90% of the nitrogen and close to 100% of the phosphorus from the sewage water coming into the plant. Those nutrients are what fuel the growth of algae blooms in the waterways and are the two of the three pollution targets of the Chesapeake Bay pollution diet mandated by the U.S. Environmental Protection Agency. Instead, AlexRenew nutrients in the removed solids and converts them into pathogen-free renewable material called Class A Exceptional Quality Biosolids.
The solids removed from the sewage liquid are thickened and dewater using centrifuges and then pasteurized at 158 degrees Fahrenheit for an extended period of time to kill all the pathogens. AlexRenew treats their sludge to remove not only pathogens, but also heavy metals and other contaminants to produce Class A Exceptional Quality bio-solids. This environmentally-friendly product is provided to farmers in Virginia as a nutrient-rich fertilizer. Some of the Class A Exceptional Quality Biosolids gets sent to a mulch facility where they get combined with wood fines, creating a soil amendment product that they are calling “George’s Old Town Blend” and is typically given away free at their open house to consumers, though there are plans to sell the product at some time in the future. At the open house you can see the garden where they planted with and without George’s Old Town Blend.
Annually AlexRenew reuses over 1.3 billion gallons of their own treated effluent for plant maintenance and cleaning – this saves AlexRenew almost $3 million in purchased water expenses and reduces using finished drinking water for grounds watering and cleaning. AlexRenew also uses their on-site generated methane gas that is created by the bacteria in the digesters. AlexRenew generated and captured close to 130 million cubic feet of renewable methane gas last year enough methane to heat 793 homes for a year. Their neighbors are aware that AlexRenew is undergoing an expansion, installing a new 18-million gallon wastewater storage tank that when completed with be underground and topped by a soccer field. This storage tank is part of AlexRenew’s major upgrade, which is needed to meet even more stringent environmental regulations and the Chesapeake Bay TMDL. Stop by, I plan to.