Q: What is a cross connection?
A: A cross connection is; Any Direct or indirect connection between a non-potable source of water and a potable source of water.
Example: Hot sunny day, Mom/Dad decides to fill the baby pool up in the back yard. Mom/Dad Leaves the hose in the pool while the child plays. The Pool becomes contaminated due to fecal mater from the child, birds, pets etc.. The hose is still inside the pool while filling. For some unknown reason a "high" demand situation occurs street side or inside the home. When this happens a "Back Siphon" occurs VIA the hose in the pool. Sucking pool water in to the home. After a few days the contaminated water grows inside the homes pipes and the family gets sick. Worse still the water gets back in to the City main and causes sickness in the whole area.
This is just one example of a possible 50,000 Cross connections that happen each day according to the AWWA "American water works association
Q: How Can i prevent a Cross Connection?
A: [part A] Being aware is the best way to stop possible cross connections. Knowing your City/Township's Bylaws are your best bet against these connections from happening. If your City or town does not have a cross connection bylaw in place. I would advise you contact your local officials to start up a preventative water contamination program.
Example: Here is a link to the city of Calgary's water utility bylaw. To which every land/building owner/operator in the city of Calgary must know.
http://www.calgary.ca/DocGallery/BU/cityclerks/40m2006.pdf
A: [part B] There are Many Devices and ways to stop possible Cross connections.
1. Using proper national plumbing code practices will stop 95% of cross connections. If you purchased a home or building, Have licensed Cross connection control specialist inspect your property. (I'll go further in to this topic on another post)
2. Choosing the correct device.
[list of devices]
- Air Gap eg present in a Toilet with ball-cock Assembly, Flushometer valve, Janitor sink.
- AVB Eg. Home outside hose bib faucet
-PVB Eg. Home/business irrigation with no chemicals present
-LFVB Eg. Hospital lab bench faucet
-DuCap Eg. home boiler heating system with no chemicals present
-DCVA Eg. Fire suppression system or townhouse complex meter-tree no chemicals present
-RP Eg. For use when sever hazard present. heating boiler with chemicals, fire suppression with chemicals, irrigation with chemicals.
3. Testable Devices require Testing and maintenance on an annual basis. these devices are:
PVB,DCVA and RP. Or any other CSA,UL Approved back flow prevention device with test ports.
4. Annual Inspection of property or after Construction/Renovation. Including Changes in type of business. Eg; Retail clothing store now changed to a Hair salon. Or produce market adding a bakery.
Adding new services to your business may also warrant a cross control consultation. Keep in mind your insurance company may want to know of such changes. (More on insurance in another topic.)
