Municipal water systems around the United States often encounter difficulty maintaining the same chlorine residual level to rural areas as they do for the closer-grouped, more densely populated areas of their communities.
That was certainly the challenge facing Campbellsville, Ky., even though the community had long used chlorine gas at its primary treatment plant. Unfortunately, according to Steve Skaggs, water plant superintendent, the chlorination system had not always maintained the desired residual at outer limits of the service area. With todays technologies, the challenge has been met
Previously, the chlorine level leaving the plant was 2 ppm, but by the time the water reached rural areas, the level had dropped by more than half. Yet while that problem was the primary factor initiating the search for a new chlorination system, Skaggs says that city officials also were looking for a safer and easier method to maintain than gas.
Tablet Chlorination
To help maintain remote chlorine residuals, Campbellsville selected PPG Industries Accu-Tab(tm) tablet chlorination system. The system uses granular chlorine in three-inch tablet form which, when used with a specially engineered chlorinating system, accurately and dependably chlorinates the water stream. Cal hypo is much more concentrated than liquid chlorine - it contains a minimum of 65 percent available chlorine.
Tablet Chlorination
Once in the water, it sanitizes with the same active ingredient (hypochlorous acid) as gas and liquid chlorine.
Tablet Chlorination
Stored in its original sealed container in a cool dry place, cal hypo remains chemically stable and retains high available chlorine content for up to one year. Since the tablets dont lose strength as rapidly as bleach does, more consistent chlorine addition is provided with fewer adjustments, and drum or cylinder depositories are not needed.
Tablet Chlorination
Cal hypo has long been recognized as an effective chlorinating agent, but was not widely used for larger applications due to the predissolving step that was required.
Tablet Chlorination
The Accu-Tab system resolves this difficulty with an erosion feeder that treats only a side stream of the main water flow, returning that chlorinated water to the main system. Adjusting water flow through the chlorinator rotameter can control the chlorine delivery rate. This is much like adjusting a gas cylinder rotameter.
Tablet Chlorination
With vinyl construction and no small openings or moving parts in the chlorinator, the system is low in maintenance and is simple to clean. For Campbellsville, the Accu-Tab system solved numerous problems. Not only was the Accu-Tab system easier to maintain and safer than gas, its design helped plant operators reliably provide the desired boost in chlorine residuals to service area outer limits.
Tablet Chlorination
The Accu-Tab system meets many federal requirements, including the National Safety Foundation (NSF) Standards 60 and 61 for drinking water; American Water Works Association (AWWA) Standard B-300, and several United States Department of Agriculture (USDA) standards.
