Cross-Connection Frequently Asked Questions (FAQs)


What backflow prevention related items can I do on my own? What backflow prevention related items do I need a plumbing services provider (licensed plumber) for?

In general, homeowners can and should become more knowledgeable in the subject of backflow prevention. So if you are reading this, Thank You! More specifically, a homeowner can install or replace “non-testable” backflow devices. See specific “hands-on” related information for the various fixtures, appliances, and/or water end-uses described below. Installation, repair, replacement and/or testing of “testable” backflow assemblies shall be performed by a licensed Plumbing Services firm.


Who is licensed to test my backflow prevention assembly?

Plumbing Services Firms

Under Maryland Law, only firms registered under a licensed Master Plumber can perform Plumbing Services which includes the installation, repair and testing of backflow prevention assemblies. Therefore, cross connection technicians have to be performing their duties under the direction of a registered plumbing services firm.

Courtesy List of Service Providers

The following link is a list of licensed plumbing firms who have declared they provide this specialty line of services. WSSC Water has validated their licensing credentials, but does not endorse these firms; you are free to choose any licensed firm.


Are my old fixtures and/or unprotected outlets grandfathered-in because protection was not required when my home was constructed?

No, there is no supporting rationale for ignoring a hazard based on how old it is; it will be the current negative event/usage that may harm or sicken you or others around you. The current Plumbing Code requires everyone to follow modern backflow protection requirements.


Does my WSSC Water submeter have “built-in” backflow protection?

No, water meters are generally on metering devices. Auxiliary backflow protections are needed based on the downstream usage.

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