Backflow Prevention/Cross Connection Program

Property owners that install systems which could potentially drain non-City or used water back into the City’s system should install backflow preventers. These systems might include irrigation systems connected to the City’s system that are also serviced by a well, cooling systems with secondary storage containers, or other types of systems.

These systems must be inspected annually by an approved tester. In addition, they must also be tested by an approved tester immediately after installation or repairs of any kind. The inspector should submit a Field Test Report.

What is backflow?

Click to see a video from Charleston Water System.

Program Contact Info

Roderick Herring, Cross Connections Supervisor
Pamela Steele, Cross Connections Inspector
4013 W Beltline Blvd.
Columbia, SC 29201
Phone: (803) 545-3876
Fax: (803) 779-5846

Customer Care Contact Info

1136 Washington St.
Columbia, SC 29201
(803) 545-3300
24 hours a day
7 days a week

Frequently Asked Questions

What is a cross-connection?

A cross-connection is any temporary or permanent connection between a public water system or consumer’s potable (drinking) water system and any source or system containing non-potable water or other substances. An example is the piping between a public water system or consumer’s potable water system and an auxiliary water system, cooling system, or irrigation system.

What is a backflow preventer?

Backflow Preventers are mechanical plumbing devices installed in a plumbing system to prevent water from flowing backward in the system. A properly installed, tested and maintained backflow preventer at the service entrance to a building or property can reliably prevent the backflow of water of an unknown quality from flowing back into the community water system.

What can cause backflow?

Backflow can be caused by a sudden drop in the water pressure in a public water main, which can create a sub-atmospheric condition. For example, if a drop in pressure occurs while a hose is in a bucket of dirty water, that water could be sucked back into the public water system, potentially contaminating the water for other users. A drop in pressure could be caused by a variety of things, including a water main break, loss of power at a pump station, etc. Backflow preventers keep this from happening.

Whose responsibility is it to install a backflow preventer?

It is the customer’s responsibility to purchase and install the backflow preventer. The backflow preventer is installed to protect the public water supply against possible hazards in the customer’s plumbing system. The actual or potential cross connection belongs to the property owner and not to regulatory officials or the water utility. Once the water goes beyond the meter, water quality could be altered. The water utility does not want the water back, nor do the water customers want to purchase used water. If a backflow preventer is required to keep the water safe, then the person who created the cross connection (actual or potential) should purchase, install and maintain the backflow preventer.

Water Quality Regulations

The United States Environmental Protection Agency (EPA) and the South Carolina Department of Health and Environmental Control (SCDHEC) have established strict quality standards for drinking water. These standards are designed to protect consumers against disease-causing bacteria and other harmful substances. EPA requires public water systems to send their customers an annual report containing information about their drinking water quality and compliance with the standards.

The City of Columbia is pleased to present the information contained in the Latest Consumer Confidence Report to you and hope that it will be both informative and helpful in making personal health-based decisions regarding your drinking water consumption.

We welcome your comments and questions. We may be reached during normal business hours by calling (803) 545-3300 or email us at