In response to petitioner GM Loupassi’s request that the State Board of Health amend the Virginia Waterworks regulations governing backflow prevention and cross connection control, I offer the following comments.
As the water purveyor for the City of Virginia Beach, citizens’ safety and confidence in the public water supply system are Public Utilities’ biggest concerns. First, I would like to address the petitioner’s reference to irrigation systems being at a “low risk of contamination” to the water system. There are two key possibilities that would induce contamination from an irrigation system; at the time the system is shut off and/or if there is a reduction in pressure in the public waterline. When irrigation systems are turned off, a vacuum is created thereby pulling whatever elements and contaminates are present into the irrigation piping. This introduces the possibility of not only chemical fertilizers and pesticides but also parasites, animal feces, and water borne virus invading the citizen’s home or drinking water system. When a water main break or fire hydrant is in use, a drop in main line pressure occurs creating a backsiphonage throughout the water system. If a backflow device is not installed or if it is not working properly, these contaminants can enter the public drinking water system. A properly working backflow device can protect the citizen and the system from contamination. Due to these possibilities, irrigation systems are considered high risk hazards and require a testable backflow prevention device, a reduced pressure device, or a pressure vacuum breaker to be installed.
The following is a list of contamination incidences due to improperly working irrigation backflow prevention devices1: (1www.nobackflow.com/pnw-awwa.htm)
· 1991 Michigan - Two homeowners found parasitic worms, or nematodes, in their water. One homeowner found the worms swimming around in his bathtub when he started filling the tub for his child. He also found rust and other debris in his water. The Wayne County Health Department determined that water had backflowed through a residential irrigation system into the public water system.
· 1969 Connecticut - University football team members stricken with infectious hepatitis through irrigation water backsiphonage.
· 1976 Texas - A faulty DCVA permitted lake water to be pumped through an irrigation system into the public water supply.
· 1979 Arizona - An outbreak of diarrheal illness in campground residents resulted from a cross connection with an irrigation system containing sewage effluent.
· 1982 Oregon - Backflow though an irrigation hose resulted in insect larvae entering a food processing vat.
· 1985 Washington - A cross connection with an irrigation system resulted in the pesticide contamination of a well supplying four residences.
· 1988 Arizona - An interconnection between an irrigation system and a decorative pond may have resulted in non-potable water being pumped into the public water system.
· 1995 Washington – A cross connection permitted untreated irrigation water to flow into domestic water lines causing 11 cases of giardiasis
Backflow devices are mechanical devices and can fail for many reasons. The majority of the residential irrigation devices in our jurisdiction are located outside and are exposed not only to all the natural elements and weather occurrences but also physical damage from lawn maintenance equipment and other machinery. As such, these devices are the most common to fail or need repair.
The City of Virginia Beach has a vigorous backflow and cross control prevention program and tracks the testing of all recorded backflow devices. Notification letters are mailed in advance of the testing due date and followed through with each device to ensure they are in compliance with ASSE Guidelines, AWWA, USC Cross Connection Control Foundation, Virginia Waterworks Regulations and the Virginia Maintenance Code Section 505. There are several reasons behind the need for annual testing and include:
· Assurance that the device is working properly
· Assurance that the device has not been by-passed
· Assurance that the device has not been removed
· Assure that the internal checks have not been removed to increase line pressure
We are privileged to have one of the safest drinking water systems in the world and people take for granted that they can drink straight from the faucet in the United States; people in other countries including Europe are not so lucky. This is due in large part to the water regulations that are in place and should remain in place. Waterworks regulations are used to provide for the health, safety and welfare for all citizens and should not be tailored to meet the desires of one specific group.
For the above reasons, the City of Virginia Beach does not support changing the annual testing requirement for backflow devices associated with irrigation systems. If you have any questions or would like to discuss further, please do not hesitate to contact me at (757) 385-8654 or via email at tleahy@vbgov.com.
Thomas M. Leahy, III, P.E.
Director of Public Utilities
