JACQUE PLESE, SUPERINTENDENT of the water department, answers a few questions regarding cross connection controls at his home during a demonstration of an online survey city water users are being asked to complete. Bill Doody, project manager for CCRA Professional Services, the company managing the city survey process, stands by to offer assistance.
An important message from the city's water department will be included on the next water bill.
Wilmington is asking recipients to complete a short survey. Those who don't can expect the city to come calling.
The survey is about cross-connection contamination, which might seem like something only the city's public works department needs to worry about, but that's not quite so. The water department staff can't do its job fully without residents' cooperation in completing the survey in the next few months.
"It's very important and it's the law," notes water department superintendent Jacque Plese.
Cross-connection control programs are based on preventing contamination in a water system like Wilmington's.
"Cross connection is when any potentially contaminating equipment is hooked up to a domestic water system. That equipment can be used to do various things - in manufacturing they mix various chemicals, including coolants such as antifreeze," said Tom Mach, president of CCRA Professional Services, the firm contracted by the city of Wilmington to oversee the city's state mandated cross-connection contamination control program. Other potential sources of contamination are boiler heating systems, sprinklers and hot tubs.
"Without a device to prevent it, you can get chemicals in the domestic water system through a back siphon, caused by what is called negative pressure in the water main," he explained. "The negative pressure can easily happen due to use of fire protection equipment or during a water main break."
As long as a positive pressure is maintained in the system (which is normal) contaminants are not likely to be siphoned into the main, Plese added. But if a serious loss in pressure should occur, contaminants could be drawn in.
According to the Environmental Protection Agency (EPA), website , "Between 1981 to 1998, the Center for Disease Control documented 57 waterborne disease outbreaks related to cross connections, resulting in 9,734 cases of illness. They included 29 outbreaks (6,333 cases of illness) caused by chemical contamination, and 22 outbreaks (2,722 cases of illness) where contaminant was not reported.
For example, consider a California man who, in 1983, died after drinking from a garden hose at his home. Not long before taking that fatal drink, the man used a common aspirator-type spray attachment on his garden hose to put weed killer on his lawn. Once he finished the spraying, he turned off the water and removed the attachment.
It turned out that while he was spraying, a brief back-flow condition (also called cross-connection) occurred, and the weed killer chemical was carried back into the hose. One drink and he was poisoned to death.
That and many other dangerous situations can be prevented by installation and maintenance of backflow prevention devices at both residential and commercial properties where necessary. The survey is the first step in helping to make sure the city's residents and commercial customers are using safe practices and helping to keep the city's supply safe.
"There are devices that will prevent this and this is the intent of the upcoming survey. To determine at what customer connections backflow prevention devices are necessary," Mach explained.
Every year owners/occupants are required to have these devices tested and certified by a licensed and approved plumbing contractor to make sure they are working properly. Every two years municipalities are required to do a survey of the community, to determine where backflow prevention devices are necessary. The survey will ask questions such as what kind of heating system a resident or commercial user has etc. The biggest residential threats come from hot water or boiler heating systems and in-ground yard sprinkler systems.
All water customers are required by the state Safe Water Act to participate in an online survey. The survey is comprised of simple questions seeking yes or no answers.
Any water users who are unable to complete the survey online can call city hall to receive a copy in the mail or arrange for Mike Stroud from the water department to bring a computer to their home to help them complete the survey online. Residents will also be able to go to City Hall, where the staff will assist them in completing the survey. It will take less than 10 minutes.
Once the surveys are completed, the software system reviews the responses and information, then rates customers by risk level. It is anticipated that less than 10 percent of residential customers will need further contact concerning backflow prevention equipment and/or any remediation. Remediation is typically something as minor as a part added to the outside hose bib by the home owner.
Residents and commercial water customers in Wilmington will receive step by step instructions on how to find the survey using the link on the city website in the water bills that will be mailed on May 1.
Posted: Sunday, May 4, 2014
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