South Carolina backflow testing rules
Under South Carolina's State Primary Drinking Water Regulation R.61-58.7(F), set by the Department of Environmental Services (SCDES, formerly DHEC), every public water system must start and maintain a cross connection control program.
Who sets the rules in South Carolina
R.61-58.7(F) requires each water system's program to keep records of where existing backflow prevention assemblies are, their type and size, and their test results.
SCDES describes the Cross Connection Control/Backflow Prevention program as a state-mandated program to protect public drinking water by finding and eliminating cross connections.
Sources: Every public water system must run a cross connection control program; SCDES calls the program state mandated
Is an annual test required?
Under R.61-58.7(F)(7), each assembly must be tested by a certified tester at least once a year, as well as after installation and before the customer uses it.
R.61-58.7(F)(7) requires every backflow prevention assembly to be tested immediately after repairs of any kind.
Greenville Water's Cross Connection Control Manual requires every existing backflow prevention assembly to be tested at least once a year.
City of Columbia Water says backflow systems must be inspected annually by an approved tester.
Spartanburg Water says certain commercial and industrial backflow assemblies must be tested annually by an SCDES certified tester.
Sources: Assemblies tested at installation and at least once a year; Greenville Water: annual test of every existing assembly; Columbia: annual inspection by an approved tester; Spartanburg Water: annual test by an SCDES certified tester
Which properties need a backflow preventer
Under R.61-58.7(F)(4), a high hazard cross connection must be protected by an air gap or an approved reduced pressure principle backflow prevention assembly.
R.61-58.7(F)(2) sets an approved double check valve assembly or pressure vacuum breaker as the minimum on a low hazard cross connection, with a separate rule for residential lawn irrigation.
R.61-58.7(F)(5) requires fire sprinkler lines to be protected by an approved double check valve assembly, except high hazard systems (such as antifreeze or foam systems), which follow the high hazard rule.
Under R.61-58.7(F)(3), each water system needs a written lawn irrigation policy; the state minimum device for low hazard residential lawn sprinkler systems is a residential dual check, though a utility may require a testable assembly.
R.61-58.7(F)(3) treats a residential lawn irrigation system with chemical addition, or one also connected to a non-public water source, as a high hazard cross connection.
The City of Florence allows single family homes to have a non-testable residential dual check on the domestic water line.
Sources: High hazard connections need an air gap or RP assembly; Florence: dual check allowed on single family homes
Who may do the test
SCDES states that all backflow testing in South Carolina must be done by a state certified backflow prevention tester.
Charleston Water System asks customers to have assemblies tested annually by a third-party tester from its own Approved Tester List.
Sources: Only state certified testers may test; Charleston Water: only its Approved Tester List
How the test report is filed
R.61-58.7(F)(7) requires the certified tester who did the test to submit the written test report to the public water system.
Greenville Water requires certified testers to upload test results through its online portal.
Charleston Water System's manual asks for test reports within seven calendar days after the assembly is tested.
Sources: Tester sends the written report to the water system; Greenville Water: testers upload results to its portal; Charleston Water: report within seven days
If a test is missed
Greenville Water's manual lists a $500 charge when a test is 15 days late.
Spartanburg Water's Cross Connection Control Manual says water service will be terminated within ten days if its policy requirements are not met.
Beaufort-Jasper Water and Sewer Authority's policy says it will disconnect water service the first business day after the annual due date if no passing test is received.
Sources: Greenville Water: $500 charge at 15 days late; Spartanburg Water: service terminated within 10 days; BJWSA: disconnect the first business day after the due date
Finding a tester
SCDES links a listing of certified backflow testers from its cross connection program page.
The SCDES list of Certified Testers, General (dated 01/20/26) names the testers who serve the public, grouped by county.
Sources: SCDES publishes the certified tester lists; SCDES General Tester list, by county
Common questions
Is backflow testing required every year in South Carolina?
Yes. South Carolina regulation R.61-58.7(F)(7) requires each backflow assembly to be tested by a certified tester at installation and at least once a year.