If water is drawn from the irrigation or pool into the potable water system of the home, then water at the tap can be contaminated. Sprinkler lines lay in gardens and lawns that often contain weed killer, pesticides and other poisons. Auto fills may empty into pools below the water line. If the home’s or the city’s water pressure drops, then contaminants from these locations may be drawn into the home’s or the city’s potable water supply.
International Plumbing Code (IPC) & International Residential Code (IRC) requires protection of potable water systems from sources of contamination. “A potable water supply system shall be designed and installed in such a manner as to prevent contamination from non-potable liquids, solids or gasses being introduced into the potable water supply. Connections shall not be made to a potable water supply in a manner that could contaminate the water supply or provide a cross-connection between the supply and source of contamination unless an approved backflow prevention device is provided.”
Older homes do not likely have backflow prevention devices installed, as these older homes are grandfathered and are not required to meet the new code requirement. However, backflow devices are a sensible installation and you should consult with a plumbing contractor to determine what type of backflow device is appropriate for your home.
If you have one, it is common to find backflow devices leaking, even when they are only a couple of years old. The cost of replacement ranges from $200-$300. However, generally they just have a slow drip and should simply be monitored until water is actually pooling near the foundation. A slow leak will not significantly add to your water bill and as long as water is not pooling, it will not cause any significant settling of the ground around the foundation.
Backflow preventers are one sensible upgrade to your plumbing system that you may wish to seriously consider.
For more on this or other home care subjects, contact Scott at www.scottsauer.com.