Bio Gro Systems, Inc.
Black & Veatch
CH2M Hill
Cincinnati (Ohio) Metropolitan Sewer District
City of Manassas
City of Virginia Beach
Coastal Environmental Services
Colorado Professionals of Onsite Wastewater
Frederic R. Harris, Inc.
Hampton Roads Sanitation District
Hayes, Seay, Mattern & Mattern
Malcolm Pirnie, Inc.
Maryland Onsite Wastewater Professionals Association
Metcalf & Eddy, Inc.
Mitchell & Best Homes, Inc.
Montgomery Watson
National Onsite Wastewater Recycling Association
National Association of Wastewater Transporters
Northeast Ohio Regional Sewer District
O'Brien & Gere Engineers, Inc.
Parsons Brinckerhoff
Parsons Engineering Science
Piedmont, Olsen, Hensley
Prince George's County, Department of Environmental Resources
Tetra Tech, Inc.
The U.S. Environmental Protection Agency
    * Office of Water
    * Office of Wetlands, Oceans, and Watersheds
    * Office of Science and Technology
    The Washington Suburban Sanitary Commission
Virginia Department of Transportation
Virginia Onsite Wastewater Recycling Association
Upper Occoquan Sewage Authority
Water Environment Federation
Whitman, Requardt and Associates