The CSO Program is a comprehensive initiative aimed at upgrading the City of Richmond's combined sewer system. The program focuses on the implementation of 14 projects that will capture and treat combined sewage that currently pollutes the James River during rainfall events.

About one-third of the City of Richmond is served by a combined sewer system that is over 150 years old. Combined sewers collect both wastewater and stormwater in a single pipe. During heavy rainfall, the capacity of the system is exceeded resulting in overflows into the James River and its tributaries. Since these overflows contain untreated wastewater, they pose risks to aquatic ecosystems and human health.

The City of Richmond's Department of Public Utilities is responsible for implementing the CSO Program.

The CSO Program will benefit all Virginians by significantly improving water quality, enhancing environmental health, supporting economic development, reducing flood risks, and protecting public health across the state.

Although the primary objective of the CSO Program is water quality, the proposed upgrades to the combined sewer system are anticipated provide a moderate level of flood mitigation specifically in Shockoe Bottom.

The CSO Program is estimated to cost approximately $626 million.

The CSO Program is funded through various sources, including City of Richmond bonds, grants, ratepayer fees, and potential public-private partnerships. Notably, the program received $150 million in American Rescue Plan grants between 2021-2022.

In 2024, the Virginia General Assembly appropriated $50 million in State grant funds in support of the Final Plan Projects. Over the next four years, an additional $450 million in State grant funding support will be needed to meet the completion deadline of July 1, 2035.

In addition to State grant funds, the City identified and is evaluating the potential use of other State and Federal funding programs including Justice40 Initiative, Build Resilient Infrastructure and Communities Grants (BRIC), Clean Water State Revolving Loan Fund (CWSRLF), and Water Infrastructure Finance and Innovation Act (WIFIA) loans.

The CSO Program is anticipated to be complete by the statutory deadline of July 1, 2035, as required by legislation passed by the Virginia General Assembly.