Cross Connections

Fire Sprinkler Systems
Single Family Fire Sprinkler Meter Requirements
Single Family Residential 3/4 inch and 1 inch Standard Fire Sprinkler DCVA Connection Detail
Cross Connection Control for Lawn Irrigation Systems
Drinking Water Regulations Relating to Cross Connection

The Sammamish Plateau Water and Sewer District has the responsibility to locate and eliminate cross connections between the public water supply and possible sources of contamination. The control of cross connections is accomplished by two basic methods:

The Washington Department of Health regulations require that certain premises install backflow prevention assemblies on the water supply piping as a condition of water service. Backflow prevention assemblies are to be installed within any premises where, in the judgment of the Water District, the nature of the activities on the premises or the materials used or stored on the premises present a hazard should a cross connection occur.

The Sammamish Plateau Water and Sewer District requires proper installation of a State approved backflow prevention assembly (BFP) on water supply piping to fire sprinkler systems with meet the following conditions:

Type of System	Type of BFP	Type of Service
Fire sprinkler systems	DCVA RPBA DCDA	Residential - Low Hazard Residential - High Hazard Commercial - Low Hazard
Sprinkler systems which contain chemicals of any type (i.e., corrosion inhibitors, anti-freeze), or which have an auxiliary supply or storage tank	RPDA RPBA	Commercial Residential

DCVA: Double Check Valve Assembly
DCDA: Double Check Detector Assembly
RPBA: Reduced Pressure Backflow Assembly
RPDA: Reduced Pressure Detector Assembly

Proper installation procedures and clearances required are available upon request. Please ensure that all fire sprinkler systems designed, installed, and/or maintained on your premises that receive water from the Sammamish Water and Sewer District's system are properly equipped with backflow prevention assemblies suitable for the degree of hazard. All backflow prevention assemblies on such systems must be inspected and tested initially by a state certified backflow assembly tester and annually thereafter. The owner of the backflow prevention assembly must provide a test report, signed by the backflow assembly tester, to the Sammamish Plateau Water and Sewer District showing evidence of a satisfactory annual test.

If you have questions regarding backflow prevention or wish to schedule inspection of backflow prevention assemblies on fire sprinkler systems installed or maintained on your premises, please contact crossconnection@sammplat.wa.org.