A Change in Combined Sewer Overflow Strategy Is Precipitated by Stormwater Policies and Watershed-Based Modeling

Abstract

For over 24 years the City of Lynchburg, Virginia has been pursuing a combined sewer overflow strategy of collection system separation along with upgrades to interceptor capacity and a rainleader disconnect program. Studies conducted in 1979Studies conducted in , 1989Studies conducted in , and 2000 set and then affirmed the strategy of complete separation. However, the 2013 Long Term Control Plan Update (LTCP) has indicated that the time for a major change in strategy with significant cost savings has now arrived.Reasons for the change include:1. New stormwater management mandates 2. Previously implementation of effective 'most efficient project first' strategies 3. Historic interceptor improvements 4. Better modeling technologies By combining the previously completed projects with the evolving stormwater regulations and modern computer modeling capabilities, a tipping point was reached where the benefits of all the previous improvements are now bringing a different strategy to the forefront. Thus, Lynchburg is proposing a 180 degree turn around in combined sewer overflow management strategy.