What are some examples of hazards at my home that could contaminate the drinking water system?

Irrigation systems, hose bibs, boilers, radiant heat systems, wells, docks, ponds, fountains, pressure boosting systems, pools, spas, graywater systems, rain water collection systems, reclaimed water, and solar heating systems are just a few examples of hazards that could contaminate the drinking water system.

A cross connection is a connection between a potable drinking water pipe and a non-potable source. For example, say that you are planning to spray weed killer on your lawn. You hook up your hose to the faucet on your house and to the sprayer containing the weed killer. If the water pressure drops at the same time you turn on the hose, the pressure change may cause the chemical in the sprayer to be drawn back into your home’s plumbing system through the hose. This is called backflow and could contaminate the water in your home plumbing or the public water supply.