Lawn irrigation systems or lawn sprinklers are a common in maintaining beautiful lawns and landscapes. In the case of irrigation systems, protection against a potential health hazard from contamination of the public water supply is the both the consumer and the water purveyor’s responsibility as well as an EPA requirement.
Irrigation systems can potentially contaminate the supply of water through the reversal of water flow. This process is referred to as backflow. Backflow can occur in two instances: back siphonage and back pressure. You have, I’m sure, toyed with back siphonage at one time or another, drawing liquid through a hose and allowing it to flow out the lowered downstream side of the tube. Back pressure is similar but it is done by a mechanical means. Pumps, boosters, and injection equipment all can apply additional pressure into an irrigation system that can cause the direction of water flow to reverse.
What contamination, you ask? The recessed sprinkler heads of the irrigation system in your lawn can receive ground water that with fertilizers, herbicides pesticides and animal feces among other harmful products. All these items are considered a high degree of hazard to humans if consumed. This is where backflow devices come into use.
The EPA and the State of Ohio requires a backflow device to meet an American Society of Sanitary Engineers (A.S.S.E.) standard. These devices are required to be certified (tested) by a “State of Ohio certified backflow tester” a minimum of every twelve months. The device may also need to be tested if it is repaired, moved or tampered with to ensure reliability to protect the consumer and the water purveyor from a possible cross connection.
Documented cases of backflow have occurred throughout the country and here locally. Backflow devices protect the public water supply and the consumer from backflow if applied correctly and tested as required. It is the water supplier, the water consumer and the regulatory agency’s responsibility to protect the public water supply against cross connections.