How Can Green Infrastructure for CSOs and SSOs Help S.O.S?
Green infrastructure is now a proven method to help reduce combined sewer overflows (CSO) and sanitary sewer overflows (SSO) and should be part of any utilities long-term control plan. EPA’s new guidance promotes integrated planning for wastewater and stormwater programs to offer more sustainable solutions. Perhaps the benefits of this program are best summarized by the EPA itself in a recent National League of Cities article:
“EPA is firmly committed to helping local governments identify opportunities to achieve clean water using a comprehensive integrated planning approach,” EPA Deputy Administrator Bob Perciasepe said. “An integrated approach allows communities to prioritize their investments to address the most serious water issues first and provides flexibility to use innovative, cost-effective storm- and wastewater management solutions — including green infrastructure.”
EPA’s integrated permitting initiative includes multiple approaches. The permitting process is one option; however, administrative orders and consent decrees are other avenues that EPA can consider. The challenge facing most managers is how to maximize this as a cost-effective strategy. It has to make sense from a utility management perspective and be affordable to the customers. Green infrastructure citing and design must consider a complex set of variables including soils, slopes, available space and the condition of the existing structural infrastructure in place.
Our role as consultants is to help clients make informed decisions on structural solutions versus green infrastructure solutions using a comprehensive analysis that combines sanitary and stormwater inventories, sanitary sewer evaluation studies (SSES), watershed and sewer modeling, GIS analysis, risk assessment and prioritization, and cost-benefit analyses. The utility manager is then left with a cost-effective solution that is based on sound science using EPA-approved methods.