A Cross-Connection Found During a Backflow Survey
During a routine distribution survey you find a commercial laundry with a direct connection between the public main and a reclaimed-water line used for wash water, separated only by a single spring-loaded check valve with no test ports. The laundry also has a hose bibb in a janitor closet sitting below the rim of a floor drain, with no vacuum breaker. Downstream of this service, the main serves 40 homes and a daycare. The building owner says the check valve 'has always been fine' and the reclaimed line is 'just gray water.' Your system has a written cross-connection control program requiring containment assemblies at commercial services and annual testing of testable assemblies. You are the operator on duty; the utility manager is out of town.
1. What is the immediate hazard, and what authority and steps do you use to control it today?
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Hazard: This is an actual or potential cross-connection between reclaimed (nonpotable) water and the public main, protected only by a single non-testable check valve - not an approved backflow prevention assembly. A check valve can fail, be held open by debris, or be defeated by backpressure/siphonage. The hose bibb below the floor-drain rim is a separate, classic backsiphonage cross-connection (a hose in the drain can siphon drain water into the potable line). Downstream are 40 homes and a daycare - a high-consequence population.
Authority and immediate steps:
- Treat it as an imminent hazard. Your cross-connection control program and state rules give the utility authority to require correction and, where necessary, to discontinue or restrict service to prevent contamination. You do not need the manager present to act on an imminent hazard; notify the manager and document the notification.
- Isolate: close the service valve to the laundry (or the reclaimed connection) so the unprotected connection cannot backfeed the main. Coordinate with the owner; explain the basis.
- Protect the hose bibb: require an approved vacuum breaker/backflow device, or lock/remove the bibb.
- Notify the utility manager, the state/primacy agency as required, and consider a precautionary notice to the 40 homes and daycare if there is any evidence of contamination (e.g., reclaimed water in the main, loss of pressure, or positive samples).
- Sample the main in the affected area (bacteriological, and as appropriate for the reclaimed source) to establish whether contamination occurred.
Do not accept the owner's assurance; the lack of test ports means the device cannot be verified and is not an approved assembly.
2. What does the utility require of the owner going forward, and how do you close out the case?
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Requirements for the owner (in writing):
- Install an approved, testable reduced-pressure-principle (RP) assembly (or an air gap, which is preferred where feasible) at the reclaimed-water service, sized for the load, installed per the utility's program and state plumbing code.
- Annual testing by a certified tester, with test reports filed with the utility; the assembly must be tagged and accessible.
- Correct the hose bibb with an approved vacuum breaker or remove it.
- Maintain the reclaimed system with identifiable purple pipe/markings and no cross-connections to potable plumbing.
- A compliance deadline (e.g., 30 days for the assembly, immediate for the bibb) and a consequence for noncompliance (service restriction).
Close-out:
- Reinspect and witness/accept the test report before restoring full service.
- Sample the main after correction and confirm results.
- Update the cross-connection inventory and the service record; add the site to the annual testing tracking list.
- Document the hazard, the isolation, the notifications (manager, state, customers if applicable), and the corrective action in the utility's cross-connection file for the next sanitary survey.
- Brief the survey crew so similar single-check-valve connections are caught system-wide.