Finding a 21st century solution to a 20th century problem: New Jersey’s combined sewer overflow story

In 2007, the State of New Jersey faced unique challenges associated with controlling CSOs and addressing a national CSO policy that included the elimination or reduction of CSOs to achieve appropriate water quality objectives of the Clean Water Act. The primary goal of any CSO control program is to implement the most cost-effective controls to reduce water quality effects from CSOs. During that time, New Jersey’s CSO permittees were developing feasibility studies to evaluate the cost-effectiveness of different alternatives. These alternatives included sewer separation as well as constructing storage and conveyance facilities. But, in the end, New Jersey in most cases found that end-of-pipe treatment technologies for wet weather flows provides the most cost-effective answer.