The main reason for back flow preventers is to protect the publicís drinking water from potentially dangerous chemicals, pathogens, and bacteria. There are many real life examples of contaminants getting into municipal water supplies and causing illness requiring hospitalization. The legal ramifications for those cities can run into millions of dollars.
Illinois is one of the strictest states when it comes to back flow prevention. The only legal back flow prevention system in Illinois is a R P Z. These devices are basically a double check valve system that operates on pressure differences. If there is more pressure on the outlet side of the back flow preventer than on the inlet side of the preventer, the backflow preventer will eject the back pressured water out the ejection port on the bottom of the device. And to make sure that this happens they have a secondary valve in case the first valve fails.
Illinois law goes on to require that all back flow preventers be tested once a year by a Cross connection device inspector otherwise called a (C C D I) licensed plumber. After inspection the inspector is required to send copies of the back flow inspection paper work to the city and the state. Home owners with a lawn sprinkler system that do not have their device inspected are subject to fines and discontinued water service.
The main concerns in regards to lawn sprinkler systems are that submerged heads can syphon water into sprinkler lines possibly picking up contamination from fertilizers pesticides and animal residue. Then in a case where the city water pressure becomes less than the pressure that is in the sprinkler system the water will flow backwards to equalize pressure. Without a back flow preventer that contaminated water can travel all the way into the city drinking water or in the case of a well can contaminate the entire water table.
At first a lot of lawn sprinkle contractors thought that the plumbers union made all of this up to extract money from the lawn sprinkler industry and the home owners, but after studying the information and actual back flow cases that have happened. It is clear that these devices are very necessary. No one can blame the plumbers or the city for requiring testing as there is so much at stake. Public lawsuits are one reason but the public health is a far more important reason to follow all the rules that have been set.
One more important point about these devices is that in Illinois they should be removed for the winter, stored inside and reinstalled in the spring. Although the manufactures of R P Z devices only warranty them for 1 year from the date of first install. They void freeze damage warranty and recommend that they be stored inside for the winter. Another good reason to do this is that if your sprinkler shut off malfunctions there is no way that it can fill up the sprinkler system which would result in expensive freeze damage.
If your lawn sprinkler company is not following these procedures and providing R P Z certification for 60.00 or less contact Nick Boyle at Allscape inc 847-769-9529.