Combined Sewer Overflow Management and Planning

Managing combined sewer overflows (CSOs) can present a serious challenge to utility managers in urban areas. These wet weather discharges can cause or contribute to water quality impairments, beach closures, contamination of drinking water supplies, and other environmental and human health problems. Municipal utility managers are increasingly faced with creating plans and finding technologies to control CSOs’ frequency and severity.

LimnoTech has been a leader in developing national guidance for CSO management. This includes working for scores of municipalities coast to coast as well as establishing national performance measures on CSO abatement and conducting research for WERF on wet weather TMDLs, adaptive management, and UAAs. We have assisted EPA in developing technical guidance and evaluating wet weather management programs, including CSO, sanitary sewer overflow (SSO), stormwater, peak flows at wastewater treatment plants, and disinfection effectiveness. LimnoTech is also at the forefront of review and revision of water quality standards and using a holistic, adaptive watershed management approach to control CSOs.

LimnoTech has specific national and municipal experience that benefits our municipal clients and assists them in producing cost-effective, sound CSO Long Term Control Plans (LTCPs). We offer our clients experience in a wide range of technical support areas including:

  • Model simulations of collection systems, watersheds, and receiving water quality.
  • Development and review of Long-Term Control Plans.
  • Setting appropriate water quality targets for CSO LTCPs, TMDLs, and watershed plans.
  • Development of an integrated approach to controlling sources of wet weather pollution, including innovative, holistic watershed management.
  • Managing urban stormwater, including developing conceptual Best Management Plan (BMP) designs and low-impact, cost-effective green infrastructure solutions.