Written by Lucy Allen (Kasco Municipal Business Development Manager) & Scotty Boggs (Assistant General Manager at Searcy Water Utilities)
When supplying water to a community, delivering fresh and clean water is of utmost importance. The city of Searcy, Arkansas is no different than any other city in America with plans and procedures in place to make sure citizens receive safe water. Searcy’s water system dates back to 1896.
The original system included a well located in the southeast section of town and a pipe that was laid to reach the center of town. In 1899, the size of the system was increased when several citizens called for the establishment of an improvement district known as the Searcy Electric Light, Sewer, and Waterworks Improvement District No. 1. This district was formed to facilitate and increase the utility services in Searcy. At this time pumps, pipes, a standpipe, and well hydrants were added.
Modern Times for Searcy Water Utilities
Fast-forwarding to today, in the city and areas surrounding the town, Searcy Water Utilities now serves approximately 60,000 people. As a surface water treatment system, water is pulled from the Little Red River.
“Our water source is very dynamic,” says Scotty Boggs, assistant general manager at Searcy Water Utilities. Boggs highlighted that the water in Searcy is naturally considered aggressive. “There’s not a lot of minerals or buffering and it’s on the corrosive side.”
Searcy Water Utilities sells about 54 percent of their water to wholesale customers and surrounding communities. The remainder of the water is used for residential and industrial use. Currently, Searcy Water Utilities has a total of four tanks in the distribution system with mixers.
“As a water operator in any type of ground storage reservoir or standpipe, mixing is imperative,” said Boggs.
Issues with the Wrong Active Mixer in a Water Tank
Although mixers were in place in all four storage tanks, Searcy’s naturally corrosive water began to cause problems for certain mixers.
“Our first mixer was in our 4-million-gallon water ground storage tank. Being a shorter tank at 32-feet tall, it was an easy install, but the main issue was that we experienced a motor failure,” said Boggs.
He mentioned that there were high amps which kept tripping the breaker. After receiving a replacement mixer, no more than three short years later, the mixer had the same motor failure.
“We took apart the bad mixer. It has a very complex system. Evidently over a 3-year span, the seals begin to fail.” Boggs included that once the water gets past the seals it causes a catastrophic failure to the mixer. “The entire time, the bearings are exposed to the water and cause a motor failure. This has happened to us twice now,” said Boggs. Scotty also highlighted that the seals with their other mixers were not designed to handle the chlorinated water that runs through Searcy. From this moment, Boggs and the Searcy Water Utilities crew decided enough was enough. “It’s a big deal to pull a mixer out of a tank; it’s a big inconvenience. Even if somebody was giving us a free mixer, the physical requirements of pulling the unit out and putting a new unit in are such an impedance. The taller the tank, the more drastic the situation becomes,” said Boggs.
New Active Mixers Installation
Searcy Water Utilities has a close relationship with Instrument Supply Incorporated (ISI) located in Hot Springs, Arkansas. ISI gave an initial push to implement two CertiSafe by Kasco standard mixers in two of the four tanks. One of the tanks is a 300,000-standpipe standing 125-feet tall. The mixer is powered by a solar grid which converts to AC (alternating current) power and operates the mixer. Boggs included that the other is a standard 110-volt Certisafe unit in a million-gallon storage tank which stands about 72 feet tall.
“Both CertiSafe by Kasco mixing units are mounted halfway down the tank rather than thrown to the bottom of the tank,” Boggs said. “It can be mounted on the bottom, but we didn’t need to. Engineers looked at the install and decided there would be better mixing for the standpipe ground storage reservoirs at this location in the tank.”
The Searcy Water team worked with Certisafe by Kasco on the engineering plan for the installation. This included submitting plans to the health department in order to do the install.
To make sure mixer installation is done in a sanitary fashion, the State of Arkansas has protocols in place for disinfecting the equipment, completing sampling and testing. “We didn’t have to drain the tank or anything close to that,” said Boggs. We developed an engineering and testing plan to get it done. We didn’t waste a teacup of water which was very nice.”
Performance of the CertiSafe by Kasco Mixers
Since installing the new CertiSafe by Kasco mixers, Boggs said has noticed an improvement. “I liked the fact that it has an oil-cooled motor in it,” said Boggs. He also mentioned that with the mineral oil lubricating the motor, it is much more difficult and unlikely that the water would encroach and push itself into the cavity filled with air within the mixer.
CertiSafe by Kasco mixers are NSF certified with food grade mineral oil in their mixers. The oil in the active mixer circulates the water faster and more efficiently than tanks that do not include food grade mineral oil. The oil in the active mixer provides better cooling to the motor, allowing it to operate more efficiently and extend service life. This allows our mixers to provide more mixing with less maintenance.
With the disinfection by-products rule and the requirements of good chlorine residuals through the distribution system, tank mixing has become a paramount issue. Boggs said the design of the Certisafe by Kasco unit also made more sense to him compared to other competitors’ units. “It looked like it was built with longevity in mind. The competitor’s unit was designed mainly for water that did not have chlorine in it,” said Boggs.
Searcy Water Utilities learned that in other parts of Northwest Arkansas, they had also been using Certisafe by Kasco mixers with similar success, which gave Scotty Boggs and his crew some reassurance.
Better For Business
Scotty Boggs said that he expects the new Certisafe by Kasco mixers to last at least twice as long as the previous mixers. “It’s been out of sight, out of mind. Our only requirement is to go by and make sure it’s still working properly. It’s not a maintenance consideration at all. We just verify that it’s still operational,” said Boggs.
During the installation, there can be situations where a complete draining of the tank is required, but this was not the case for Searcy Water Utilities. Boggs added. “Sometimes they require people to physically get in the tank, but this install involved disinfecting the equipment and lowered it in on a chain and fixed a bracket on the chain to hold the unit up. We were able to get it back online right away.”
Experts on the Job
With the responsibility of delivering water to the community of Searcy and beyond, Boggs mentioned how thankful he was to work alongside Certisafe by Kasco. “It was nice to have their expertise. It’s a relief to not have to worry about our new mixers. I would rather have mixers that are going to last. It’s one less thing to worry about,” said Boggs.
When it comes to mixing, Boggs and his team know the importance of having an efficient tank mixer. “I really think you are doing yourself a disservice if you don’t have some sort of blending or mixing in a tank. As far as the Certisafe by Kasco unit goes, the simplicity and the robust design of it, having a motor cavity filled with oil where water can’t get into it and the simple propeller type system makes the most sense to me. Simplicity is a good thing,” concluded Boggs.