WASHINGTON D.C.'S CSO CONTROL PLAN - EARLY ACTIONS YIELD BIG BENEFITS

In 2002, the District of Columbia Water and Sewer Authority (WASA) proposed a 1.9 billion plan (actual dollars) to control combined sewer overflows (CSOs) in our nation's capital. From 2002 to 2005, WASA negotiated an implementation schedule and water quality standard compliance determinations with regulatory agencies. While negotiations were underway, WASA has not been standing still. Early action projects have resulted in a 23% reduction in CSO overflow volume, while other projects that are scheduled to be completed by 2008 will result in a net 40% reduction in CSO overflow volume. This paper will show that improvements with relatively moderate costs can result in significant CSO reduction. However, achieving the high degree of control contemplated in the CSO Policy is extremely costly and involves the difficult issues of affordability and water quality standards