Morrow, Ga., April 13, 2001 — Whenever a public water system is in operation, there is the need to protect the general distribution system from the backflow of used water. This is an area of great concern for many water utilities across the country, and the Clayton County Water Authority (CCW A)
is no exception.
Backflow problems can be caused by construction damage to existing water mains, sudden interruptions in the operation of water production facilities, natural disasters, or numerous other emergency situations. In doing their part to ensure the quality of water in the distribution system, the Water Authority has recently expanded its efforts to provide backflow protection on all customer connections, including residential lines.
The CCW A began its backflow prevention program June, 1982, when the Authority began installing double check valve assemblies and reduced pressure zone assemblies at new commercial and industrial meters. The Authority focused on those areas of the water system deemed more hazardous and more likely to cause backflow into the water distribution system.
Backflow prevention is usually accomplished with check valves or reduced pressure zone assemblies, which allow water to pass into the water system of a residence or business, but prevent the passage of water back into the distribution system. These valve assemblies are usually placed at or near the water meter .
Over the course of 18 years, the Authority has been able to budget more funds for the training and certification of personnel in testing backflow preventers, as well as the expansion of backflow prevention coverage to new commercial and residential installations. The authority began installing dual check valve assemblies on all new residential meter installations in December, 1999.
"We've distributed door hangers and inserts in billing statements to make sure that people realize the importance of these new meter installations and what steps they might need to take," says Guy Pihera, water production manager for the Clayton County Water Authority .
Since backflow prevention devices create a closed water system, users may experience higher than normal pressures in the plumbing systems. Standard Plumbing Code dictates that an auxiliary pressure relief valve or expansion chamber should be installed on a typical plumbing system. These devices allow excess pressure caused by thermal expansion to be relieved safely within the home.
Pihera notes that most of these devices can be purchased at a local hardware or plumbing store. One such device can be installed in a toilet tank by the homeowner. Other devices can be attached to water heaters or on a cold water line where an occasional drip won't cause a problem. Homeowners are encouraged to thoroughly evaluate their plumbing system to ensure compliance with Standard Plumbing Code requirements.
"This measure is necessary to ensure that residents and business alike have clean, safe and reliable drinking water at their disposal," adds Pihera. "We're confident that this program will continue to protect the general distribution system from potential backflow problems for years to come."
The CCWA board of Directors has allocated funds necessary to expand and improve this program beyond its previous capacity. In 2000 alone, 634 new commercial accounts, 1,450 new residential accounts and 28 metered fire lines were fitted with backflow prevention devices. Check valve assemblies were also retrofitted to 745 residential accounts this past year. Pihera says that the Authority hopes to have all residential accounts retrofitted over the next 5 years.
As of April 1, 2001, the CCW A enacted a policy in which all water use through fire hydrants must be through a portable assembly consisting of a backflow prevention device attached to a meter . Not only does this provide protection from a possible backflow incident, it also allows the CCW A to accurately bill contractors for water use from a hydrant. Additionally, all tank trucks being filled by a hydrant assembly must do so through a special piping arrangement called an air gap. The air gap physically separates the water in the tank from the supply water flowing from the hydrant.
