Blue Plains Advanced Wastewater Treatment Plant

Blue Plains Advanced Wastewater Treatment Plant is the largest advanced wastewater treatment facility in the world. It is operated by District of Columbia Water and Sewer Authority (DC Water), which provides water and wastewater (sewer) service to the District of Columbia and provides wastewater treatment service to Montgomery and Prince George's counties in Maryland and Fairfax and Loudoun counties in Virginia. The Blue Plains facility is located on 150 acres on the bank of the Potomac River at the southernmost tip of the District of Columbia. It has a capacity of treating 370 million gallons of sewage per day. The plant began operations in 1983. Nearly 100% of the sewage sludge is applied to land used for agriculture, silviculture (tree farming), and mine reclamation.

Sewage Sludge Land Application
Nearly 100% of the sewage sludge is applied to land used for agriculture, silviculture (tree farming), and mine reclamation. For example, in 2009, DC Water sent 419,368 tons of sewage sludge directly from the plant for land application (including 15,647 tons to a facility for processing as Class A Biosolids); put 134,842 tons into storage; removed 97,174 tons from storage for land application; and sent 4,893 tons to a landfill. However, in the future, DC Water plans to process its sludge as Class A Biosolids and sell it as "compost."

Marketing Sludge as Compost
Whereas the majority of DC Water's treated sewage sludge is classified as class B biosolids (which means there are restrictions on where and how it can be used), in July 2008, DC Water began a program to produce small amounts of class A biosolids (which can be sold to home gardeners as "fertilizer" or "compost"). DC Water does not have its own composting facilities for class A biosolids; it transports some of its sewage sludge to the McGill Composting Facility in Waverly, VA. "This state-of-the-art facility in an enclosed building, with process air sent through a large (one-acre) biofilter for odor control. DC Water sends about 50 wet tons per day (two truckloads) for the facility to produce a Class A compost product."

In 2009, DC Water staff planted a demonstration vegetable garden at the Blue Plains plant using the Class A biosolids compost from McGill. "Dr. Sally Brown was hired to help with the DC Water composting program. 100 tons of compost from the McGill Environmental Systems site was used on the DC Water Blue Plains plant to produce several kinds of vegetables in 2009. Next Steps: DC Water is developing a brand, data on content and greenhouse gas reductions, and other materials for a potential compost market."

Farmland Application in Virginia and Maryland
Most of the solids removed from the wastewater treated at Blue Plains (sewage sludge) is currently applied to farmland in the following counties in Virginia and Maryland (all numbers are wet tons applied in 2009):
 * Buckingham: 46,897
 * Cumberland, VA: 34,439
 * Albemarle: 26,910
 * Sussex: 23,579
 * Dinwiddie: 23,575
 * Prince Edward: 21,212
 * Culpepper: 18,518
 * King William: 14,700
 * Charlotte: 13,569
 * Nottoway: 11,464
 * Talbot: 11,171
 * Westmoreland, VA: 8,939
 * Fauquier: 7,722
 * Essex: 7,505
 * Appomattox: 7389
 * Madison: 7,205
 * Orange: 6,988
 * Powhatan: 6,138
 * Brunswick: 6034
 * Queen Anne's: 6,011
 * Clarke: 5,962
 * Prince George's, MD: 5,780
 * Hanover: 5,293
 * Prince George's, VA: 5,290
 * Henrico: 5,278
 * King and Queen: 5,135
 * Lunenburg: 4,636
 * Middlesex: 4,398
 * Caroline, MD: 4004
 * Caroline, VA: 3457
 * Greene: 2,347
 * Charles City: 2012
 * St. Mary's: 1,952
 * Louisa: 1,939
 * Amelia: 1,917
 * Campbell: 1911
 * Fluvanna: 1,214
 * Goochland: 1,185
 * Frederick, VA: 1,062
 * Richmond: 805
 * Charles: 619
 * King George: 550
 * Spotsylvania: 95
 * Total: 376,806

Sewage Sludge Treatment Process
As of 2011, the current treatment process for sewage sludge is as follows:


 * "First, debris and grit are removed from the sewage and trucked to a landfill. The resulting wastewater goes to tanks where solids are separated from the liquid. The liquid is cleaned by beneficial bacteria and is disinfected before it goes to the Potomac River. The residual solids—or sludge—are further dewatered and thickened to reduce volume. Lime is added to remove harmful organisms and reduce odor."

Biosolids Management Plan
DC Water has a long-range biosolids management program (BMP) that involves building new anaerobic digesters with storage facilities, new solids-thickening facilities, and expansion of and improvements to the dewatering systems, as well as "associated projects to improve biosolids and the solids handling processes, and to reduce odors on site and off site."

According to DC Water, the the future biosolids treatment process different from the current one because "the new process will use anaerobic bacteria, rather than the current 100+ tons a day of lime, to treat the sludge and reduce odors." The BMP plan is projected to take nine years to complete.

Related SourceWatch articles

 * Biosolids
 * Sewage Sludge
 * Food Rights Network
 * District of Columbia Water and Sewer Authority

External articles

 * CDM Awarded Joint Contract to Upgrade D.C. Wastewater Treatment Plant Biosolids Management System: Facility will introduce Cambi Thermal Hydrolysis Process to U.S., CDM.com, June 20, 2011.
 * Darryl Fears Blue Plains upgrade could produce valuable farm fertilizer, but critics are wary, Washington Post, April 23, 2011.