Disinfection Dilemma

As potable water travels through miles of piping on its way to cities and municipalities, there is a risk for contamination. To prevent this from occurring and to maintain water’s potability, disinfectants such as chlorine, fluoride or chloramine are added to the water at safe levels during transport.

While adding disinfectants to water solves one problem, it creates another: over time, the disinfectants cause a buildup of calcium that can partially or completely plug the quill that injects the chlorine into the water, causing the quill to shut off. When this happens, the disinfectant is no longer being added, putting the water system at risk of being in violation of health codes.

In areas with extremely hard water (containing high amounts of calcium and magnesium), there’s the additional problem of scaling, which restricts the flow of water through pipes. According to the U.S. Geological Survey, 85 percent of the water in the United States is considered hard.

Sam Hutton is the chief operator for the City Water Division in Santa Paula, Calif., a city approximately 65 miles northwest of Los Angeles and just 14 miles east of the Pacific Ocean. He knows all too well the problems caused when chemical buildup occurs.

Griffco Valve corporation stop with optional poppet at the tip of the quill, shown with brass ball valve and PVC quill in 3/4” diameter.

“When the injection quills become impacted, they can slow or stop the injection of the disinfectant, which means we have to shut off the well, close the valves, pull out the quill, clean it and set the system back up again,” said Hutton. “This takes about an hour, and while it does not prevent residents from getting their water, it causes extra work and expense.”

The city of Santa Paula receives its water supply from five wells, which typically had to be cleaned monthly by a two-person crew. “That’s a minimum of 120 man hours per year. It’s a chore and an expense we didn’t need, but if we didn’t do this, there was the risk that the quills would plug and the pumps would continue to pump until the tubing burst, which causes entirely different - and more serious - problems,” said Hutton.

Meanwhile, in Monrovia, Calif. - an idyllic city of approximately 40,000 at the base of the San Gabriel Mountains - Water System Manager Paul Zampiello has also dealt with plugged quills in the distribution of the city’s water from its five ground wells. “We were dealing with clogging issues that required regular maintenance,” said Zampiello. “We were looking for a solution that would save on maintenance costs.”

Griffco Valve Inc. has seen this problem before and was able to help both cities. The Buffalo, N.Y.-based manufacturer had come up with a simple mechanism called a poppet, which fits right into the corporation stops the company manufactures. Griffco corporation stops are designed to ensure chemical feed systems inject into the center of a process stream for better mixing and to prevent corrosion along the process pipe.

Griffco Valve corporation stop with optional poppet at the tip of the quill shown with PVC ball valve and PVC quill in 1/2" diameter.

According to Griffco, anytime chlorine or ammonia -- highly alkaline chemical solutions -- are injected in water, there’s a chemical reaction that causes a buildup of calcium. It’s particularly an issue west of the Rockies, where the water is very hard.

The buildup resembles a limestone formation, and it can completely plug a six-inch water main pipe in just a few months, causing all kinds of problems. According to the company, a different chemical, such as polyphosphates, can be injected into the water main to prevent the solids buildup, and the Griffco corporation stop with poppet can help to reduce or eliminate this problem at the quill tip and pipe wall.

Griffco has over 20 years of chemical feed experience with a wide range of applications, markets, and different pumping technologies. In addition to ensuring chemical feed systems inject into the center of a process stream, its corporation stops are designed to allow for quill servicing without having to turn off or shut down the process or main line. The check valve prevents the process fluid from going back up the chemical line. Robust construction ensures reliability in the rigorous service of municipal and industrial applications. Materials of construction include PVC, CPVC, PVDF, 316 SS, Alloy 20 and Hastelloy C. They are available in 1/2-, 3/4- and 1-inch sizes.

The poppet is a simple, optional plastic device constructed of PVC or CPVC, that fits directly into the company's corporation stops. It controls chemical flow similar to that of a hose nozzle: rather than a straight shot of high-pressure chemical, the poppet sends the chemical through the quill in a softer, more fan-like pattern, expanding the area of chemical reaction, thereby optimizing the chemical mixing process while delaying or eliminating the buildup.

Maintenance time and costs are reduced because an optional poppet on the tip of the quill of a Griffco Valve corporation stop reduces build-up of chemicals injected into the disinfection process.

“Griffco asked us to test the poppet in one of our wells, and we were so impressed we purchased six more,” said Hutton. “In the year or so we’ve been using them, we no longer have to go through the monthly maintenance procedure, which is a huge time and money saver for us. The poppets are still doing their job; we haven’t had any issues at all.”

“We were impressed with the way the poppet atomizes rather than shoots the chemicals through the line, allowing for more even distribution and a slowdown in chemical buildup,” said Zampiello. “The poppet has definitely given us the longevity we were looking for.”

A Griffco corporation stop, with poppet, costs less than $500, depending on configuration. According to Hutton, it’s well worth the cost. “Many water companies, including ours, have experienced staff reduction and other cuts, so we have fewer resources with which to do the same amount of work. Ingenuity and a simple adaptation such as this can mean one less thing on your plate to deal with,” he said.

About the Company: For more information on Griffco Valves, its corporation stops, optional poppets, and other accessories for your chemical feed systems, visit www.griffcovalve.com or call 1-800-GRIFFCO (474-3326). All products manufactured by Griffco are proudly made in the USA. Griffco is NSF, CE, and ISO 9001 certified.