What is back-siphonage?

Back-siphonage is backflow caused by negative pressure (i.e. vacuum or partial vacuum) in a public water system or customer’s potable water system. The effect is similar to drinking water through a straw. Back-siphonage can occur when there is a stoppage of water supply due to nearby firefighting, a break in a water main, etc.

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1. Why does the City of Forest Lake need a Cross-Connection and Backflow Testing Program?
2. What is backflow?
3. What is a backflow prevention assembly or device?
4. What is the process for installing/replacing a backflow prevention assembly?
5. Why do backflow prevention assemblies need to be tested?
6. How often does the backflow prevention assembly need to be tested?
7. How can I contact a licensed backflow assembly tester/rebuilder?
8. When requesting a test for my backflow prevention assembly, how much should I expect to pay for this service?
9. What type of document needs to be returned to the city as proof that testing of the backflow prevention assembly was completed?
10. How can I verify that testing of my backflow prevention assembly has/has not been completed?
11. Does a lawn irrigation system require a backflow prevention assembly?
12. How long does a backflow prevention assembly last?
13. What is considered a “potential hazard” to the potable water supply?
14. Has the City of Forest Lake process for permitting or overseeing the inspection of new, relocated or repaired backflow prevention changed?
15. What is backpressure backflow?
16. What is back-siphonage?
17. What is a cross-connection?