Missouri backflow testing rules
Missouri 10 CSR 60-11.010 (Safe Drinking Water Commission, Dept of Natural Resources) sets backflow prevention requirements for all community water systems; suppliers run the local program.
Who sets the rules in Missouri
Under 10 CSR 60-11.010(8)(D), the water supplier sets an annual anniversary date and requires an annual inspection or test report from a certified tester.
Suppliers may write local procedures but these must be no less stringent than the state rule.
Source: State backflow rule applies to all community water systems
Is an annual test required?
State rule requires annual testing of reduced pressure principle (RPZ) assemblies by a certified tester, by a date no later than 30 days past the supplier's anniversary date.
State rule requires annual testing of double check valve assemblies by a certified tester, by a date no later than 30 days past the supplier's anniversary date.
Air gaps must be inspected each year, no later than 30 days past the anniversary date set by the supplier.
DNR FAQ answer to whether a device must be tested: yes, annually by a certified tester, and also on installation for new facilities.
Sources: Reduced pressure principle assemblies tested yearly; Missouri DNR FAQ: annual testing for all assemblies
Which properties need a backflow preventer
Class I (RPZ or air gap) examples in 10 CSR 60-11.010(3)(A)2 include hospitals and clinics, car washes, commercial facilities using pesticides or fertilizers, fire sprinkler systems using chemical additives, and irrigation systems with chemical injection.
Class II (minimum double check valve assembly) examples include irrigation systems without chemical injection and new or modified fire sprinkler systems not using additives.
A supplier or the department can designate a facility a Class I or Class II hazard by written notice to the customer.
State rule exempts solely residential facilities unless a cross-connection is specifically identified or the rule indicates otherwise.
DNR FAQ: residential lawn sprinkler systems, personal swimming pools and fire sprinkler systems need a backflow assembly.
DNR guide notes that many public water systems classify all in-ground lawn irrigation systems as a Class I hazard.
Sources: Class I hazards list names commercial, medical, irrigation with chemical injection, fire sprinklers with additives; DNR names lawn sprinklers and fire sprinklers as residential cross-connections needing assemblies; Many Missouri water systems treat in-ground irrigation as Class I
Who may do the test
All assemblies must be inspected and tested by testers certified under 10 CSR 60-11.030 (Missouri certification is state-level, not utility-approved).
Missouri DNR recognizes certification by passing written and hands-on exams from ABPA or ASSE.
Sources: Only certified backflow prevention assembly testers may test; Tester certification is through ABPA or ASSE exams, with the department certifying
How the test report is filed
Certified testers must send results to the appropriate governmental authority (if one exists), the supplier of water and the customer, and to the department if requested. Routine reports are due within 30 days of the test.
If a report is not received within 60 days after the anniversary date the supplier must notify the customer, local agency and the department.
Suppliers retain reports of inspections, tests and repairs for five years.
Source: Testers report to supplier, local authority, customer within 30 days
If a test is missed
Water supplier shall remove the meter or sever the service line when it knows a customer is causing an unprotected cross-connection or refuses to correct a violation after notice.
DNR FAQ says the supplier shall disconnect when a customer is failing or refusing to correct violations after being notified.
False test reports are grounds for removing the tester from the list of authorized testers.
Sources: Supplier must remove the meter or sever service for violations; DNR FAQ: shutoff for not annually testing
Finding a tester
Missouri DNR maintains a roster of certified testers at the Certified Assembly Testers page (roster not scraped). The DNR backflow page links it as List of Backflow Prevention Assembly Testers.
FAQ: to find a certified tester check the list, or call the local water supplier or Missouri DNR.
Sources: DNR page with state list of certified backflow prevention assembly testers; DNR FAQ points to the state tester list or the local water supplier
Common questions
Is backflow testing required every year in Missouri?
State rule requires annual testing of reduced pressure principle (RPZ) assemblies by a certified tester, by a date no later than 30 days past the supplier's anniversary date.