# Backflow Testing Compliance Checker

> Check when your St. Louis backflow assemblies are due for annual testing and what testing typically costs. See your status and schedule a test today.

Canonical: https://legacyplumbingmo.com/tools/backflow-compliance
Last updated: 2026-11-06

Compliance Tools

Pick your city or county to see the rules, who may test, where reports go, and which assembly each connection needs across the St. Louis metro and Metro East.

City / county Connections at this building Domestic service — high-hazard building (medical, lab, car wash, chemical, mortuary) Domestic service — office, retail, school Fire sprinkler line Lawn irrigation Boiler / chilled water make-up Restaurant equipment (soda, espresso, ice) Reduced pressure (RP) assemblies: 1 Double check (DCVA / DCDA) assemblies: 0 Pressure / spill-resistant vacuum breakers: 0 Month of last test Last test failed or assembly was repaired

## Your Compliance Status

Status

—

Next test due

Enter your last test month

Devices

1

Testing cost

$250–$500

Estimate: typically $250–$500 per assembly per year; final price depends on device size, number of devices and access

### Requirements for St. Louis County

- **Water provider:** Missouri American Water (most of the county)
- **Governing rules:** Missouri DNR 10 CSR 60-11.010 (cross-connection control); St. Louis County Plumbing Code (county permit & inspection)
- **Test frequency:** At installation, after any repair or relocation, and at least once a year.
- **Who can test:** Missouri DNR–certified backflow prevention assembly tester
- **Report filing:** Test results filed with Missouri American Water, usually through its online tracking portal.
- **Local note:** New or replaced assemblies need a St. Louis County plumbing permit and an initial test at install.

### Assembly typically required

- DCVA typical; RP if provider requires containment Domestic service — office, retail, school · Hazard: Low–moderate

Your water provider's notice sets the final device type and due date. Failed devices need repair and a retest before the report is filed. For the test itself, see our [backflow testing in St. Louis](https://legacyplumbingmo.com/commercial/backflow-prevention) page. Want a yearly heads-up? [Sign up for a backflow reminder](https://legacyplumbingmo.com/commercial/backflow-prevention) .

Conceptual estimate only — not a bid or quote. Actual cost depends on site conditions, access, code requirements and material pricing. Legacy Plumbing will confirm scope and pricing in writing.

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