CSO & Wet Weather

Existing combined sewer infrastructure is aging, systems are failing, and regulatory agencies are increasingly focused on abatement. Even if cities have no combined sewers, infiltration and inflow (I/I) can overwhelm conveyance or treatment capacity and lead to overflows. Eliminating these problems can be complicated, but it is an essential part of maintaining strong, effective sewer systems. We thrive on challenges like this, and have decades of experience helping clients reduce combined sewer overflows, deal with I/I, and develop and maintain effective drainage systems. 

Eliminating Combined sewer overflows and improving draining infrastructure

With increasing regulatory pressure and decreasing budgets, eliminating CSOs to surface water has become an enormous challenge. Woodard & Curran has both the in-depth regulatory knowledge and the technical staff needed to successfully deliver a CSO project, whether it be long-term control planning or targeted upgrades. We help our clients identify the source of CSOs, develop sewer separation projects, and implement interceptor and detention systems to even out wet weather flows. We tailor the solution to our clients’ needs, considering their infrastructure and budget holistically to find affordable strategies.

Addressing Infiltration & Inflow

It may not be feasible to eliminate every source of I/I across an entire collection system due to the time, labor, and cost of the effort. Communities need effective ways to identify and prioritize I/I problems so they can make the most of their limited capital. Our engineers have experience evaluating collection systems of all sizes, planning mitigation programs, and designing and constructing the rehabilitation projects. We work closely with our clients to identify and implement the appropriate study and design approach and communicate the importance and goals of I/I work to key stakeholders.


National Practice Leader
Municipal Wastewater

Client Manager
Municipal Wastewater
Business Unit Leader
Business Development Leader
Government & Institutional