Backflow Prevention Program

backflow hazards

For Questions or Assistance

Jason Laskowski
225 N. Memorial Drive
Lancaster, OH 43130
(740) 687-6630 ext 2617
jlaskowski@lancasterohio.gov

What is backflow?

Distribution systems depend on pressure to keep water flowing in the proper direction through the pipes. However, a sudden or unexpected change in pressure can cause an undesirable reversal in the normal flow of water. This is called backflow. During a backflow event, water runs backwards from the consumer's water system and returns to the public water distribution system. The reversal of flow can allow potentially contaminated water to flow back into the public water supply, creating a possible health risk. For example, soapy water or other cleaning compounds can backflow through a hose submerged in a laundry basin or lawn chemicals can backflow through submerged irrigation nozzles.

Backflow is caused by two hydraulic principals: back siphonage and back pressure. Both occur when a pressure differential exists causing lower pressure in the public water distribution side and a higher pressure in the consumer's internal plumbing. Back siphonage can occur in cases of extreme water demand such as a water main break, hydrant flushing or fighting a fire. Back pressure occurs when there is an increase in pressure within the consumer's water system due to elevation or mechanical pumping above the pressure of the public water distribution system. In both cases, water will flow from the high-pressure system to the low-pressure system; potentially allowing drinking water to become contaminated and unusable within the public water distribution system.

back siphonage

While backflow and cross connections (an arrangement whereby backflow can occur) are not new, they are more strictly regulated by the Ohio Environmental Protection Agency (EPA) under the Ohio Administrative Code section 3745–95. The City of Lancaster backflow program is under ordinance number 911.02 DEVICE TO PROTECT SYSTEM FROM CONTAMINANTS DUE TO BACKFLOW.

Approved Backflow Devices

Under this ordinance, the City of Lancaster Division of Water will conduct a site survey for all existing commercial and industrial facilities and high-risk residential locations to determine the appropriate backflow device, if any. Devices that may be required by this survey are as follows:


  • Air-Gap Separation - A complete physical separation of piping (water free falls from incoming line to user's needs). Considered the best form of protection and not usually needed.
  • Double Check Valve Assembly - Two single independently acting check valves used where incoming pressure is a concern and the degree of hazard is deemed by survey to be low.
  • Double Check Detector Check – The same as double check but designed to be line size for fire protection only with a small bypass line and meter to detect fire flow, line leakage or unauthorized use.
  • Reduced Pressure Backflow Prevention Assembly - Two independently acting check valves operating in a series and automatic relief valve. Second only to air-gap in protection and used wherever there is another water source on site, or the ability for your site to generate greater pressure than city supply water pressure.
  • Reduced Pressure Detector Assembly - Same as above but used on dedicated fire protection system that uses additives in the system or the site has an auxiliary water source.
  • Pressure Vacuum Breaker - Utilizes spring loading to actuate the valve when a problem is detected, used in all irrigation systems using “pop up” heads.
  • Low Suction Cut off Controller - Senses low incoming pressure and shuts off any and all booster pumps on your site. Used where you have demonstrated a need to have constant pressure greater than is provided to your site and approved by the water division.

 

All backflow devices that are deemed necessary must be tested at time of installation and annually thereafter by a Department of Commerce (DOC) certified tester. All new construction must include backflow prevention devices as outlined in the City of Lancaster Water Specifications, which can be found here. A dual check type backflow device must be installed on all new residential water services and during water line replacements. As a courtesy, we have posted a list of DOC certified testers that have submitted reports through our Compliance Engine program.