Nothing Left To Chance

The Beaver Water District safeguards supply volume and quality with a variety of protective measures and a lot of staff initiative.
Nothing Left To Chance
Beaver Water District team members

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The people of northwest Arkansas can have the utmost confidence in their water supply.

That’s because the Beaver Water District (BWD), serving Fayetteville, Bentonville, Springdale and Rogers, goes several extra miles to make sure the water is safe, plentiful and available even after natural disasters.

Redundancy, multiple barriers and a proactive approach are hallmarks of the district. “We’re very proactive on water quality,” says Stacy Cheevers, water treatment plant manager. “Not only quality and quantity, but with a lot of critical industries located here, we maintain the ability to produce water in any conditions.”

The preparedness includes multiple disinfection steps. The process is protected by on-site power generators, and plans are in the works to expand emergency generating capacity.

Meeting A Need

The district’s history goes back more than 50 years. Seeing the need for a long-term supply of affordable water, community leaders worked to establish the Beaver Lake Reservoir. The dam that created the reservoir and the first water treatment plant were completed in the mid-1960s. Since that time, the Beaver Water District has expanded facilities and improved to keep up with increased demand and stricter water standards. Today, the district acts as a wholesaler, providing water to a total population of 320,000.

Raw water is drawn from the reservoir through a pair of intakes (one built in 2006) and is pumped 2 1/2 miles to the treatment facilities: the Joe M. Steele and Hardy Croxton water plants, the latter recently expanded. The two plants have 140 mgd capacity.

The plants use nearly identical treatment processes. The raw water, pretreated with chlorine dioxide, passes through a splitter box and flow metering and is distributed to the various trains within the treatment facilities. A rapid-mix flocculation process is powered by energy efficient four-stage vertical mixers (Philadelphia Mixing Solutions and Lightnin/SPX Corp.). Alum and ferrous sulfate are added as coagulants; polymer can be added in cold weather if necessary. Operators can add chlorine at the rapid mix step as a secondary disinfectant if the pre-oxidation process is turned off.

Lime is used to adjust pH after the single rectangular sedimentation basin. Settled water moves on to tri-media filters. At the Steele plant, the shallow-bed Leopold filters use anthracite and sand over garnet. Croxton uses the same media, but has deep-bed filters (Degremont/Paterson-Candy underdrains). The water is chlorinated, then flows to a 12-million-gallon clearwell before distribution. Fluoride is added at the clearwell entrance, which will be expanded in the future.

At the sedimentation basins, longitudinal collectors capture sludge, which is blown down to the solids handling facility. Solids are gravity thickened, mechanically dewatered on centrifuges (Hiller) and taken to a City of Fayetteville land application site.

Barriers Protect Quality

The district’s water system is big on barriers. Disinfection is of utmost importance as evidenced by the three disinfection points in the process and the chlorine dioxide used to meet and exceed disinfection byproduct requirements. “We have an in-house goal of being better than the standards,” says Cheevers. “We hold ourselves more accountable than the regulations do.” On DPBs, the district’s goal is 80 percent of the maximum contaminant level (MCL).

Taste and odor are watched carefully. “We actually have our own taste and odor panel, involving employees, for early detection purposes,” Cheevers reports. “We don’t want any residual chlorite taste or odor issues. Typically, we have only one event per year, and that is when the lake turns over. The natives are used to that.” The team operates the filters so that the finished water exhibits better than standard turbidity, typically in the range of 0.015 to 0.02 NTU.

The treatment processes are designed with future water-quality issues in mind. The treatment plants have capability to add activated carbon for additional purification, although that process has not been required. The rapid-mix flocculation/settling sequence is housed in a single structure, as is the sedimentation basin. That design saves money, and the close proximity to the floc basins prevents floc damage.

To ensure continuity in case of storms or other disasters, the systems are equipped with standby generators (Kohler). “We’re entering a predesign study for additional generator capacity,” says Cheevers. “We haven’t been hit yet, but ice storms and tornadoes are all around us. We want to be able to survive such an event.” Current generator capacity is 6 MW, and the district is looking to add 4 MW to accommodate expected growth in water demand.

Pure Dedication

Cheevers, named Arkansas Water Operator of the Year in 2013 by the Arkansas Water Works and Water Environment Association, has worked with the district for 22 years, first as an electrician on a construction project, then as head of the instrumentation and electrical department, and for the past 12 years as plant manager. He holds Grade IV (highest) Water Operator Treatment and Distribution licenses and a Master Electrician license in Arkansas. His background in electrical work has come in handy as the district expanded facilities and added treatment capacity.

“The new raw water intakes required multiple underground power feed lines for system redundancy,” he says. The plant’s backup generators are tied to underground feed lines as well, so they can operate in case the commercial power supply should go down.

Cheevers credits his staff for successful completion of numerous projects. The team includes Dean Ward, operations supervisor; and Bob Evans, Rob Turner, Danny Phipps, Brandon Scott, Alan Littrell, Drew Dickey, Roger Huddleston, Dustin Mayhew, Jesse Burch, Mike Smart and Randy Paris, operators.

“I’m proud of what our staff has done,” he says. “We operate as efficiently and independently as we can. We now do a lot of the work in-house that we used to contract out.” For example, with a 12-member maintenance staff and mechanics, the district pulls and services its own pumps, and that includes doing all the electrical work. Maintenance supervisor is Lenny Millar, and the mechanics are Kevin Oxford, Rick Sims, Cary Davis, Frank Blowers and Kelly Payne. The instrumentation and electrical  group includes Jon Rogers, supervisor; Damon Hoops and Rob Bottoms, electricians; and Jim Johnson and Patrick Frizzell, instrument technicians.

“We send our people to pump school, but most of what we learn is by experience,” Cheevers says. “New people coming in start at Mechanic 1, then Mechanic 2, and work their way up.” Within the last couple of years, the district has built a new administrative center that earned LEED Gold certification, largely for energy efficiency, health and wellness of staff and customers, and use of recycled resources. Cheevers and his staff took responsibility for the electrical systems and building inspection and reviewed construction drawings.

Proactive Maintenance

Another example of staff initiative is an oil analysis program conducted with ExxonMobil. The treatment plants include 112 flocculation drives and 21 vertical turbine pump motors. The equipment runs around the clock, and the pump motors operate in extreme temperatures. “We approached ExxonMobil to determine a lubricant solution that could safely extend oil drain intervals, enhance operational efficiency and save on oil change costs,” says Cheevers.

After reviewing the operation, ExxonMobil engineers recommended transitioning the plant’s flocculation drives to a premium-performance synthetic oil designed to provide protection in demanding applications. They also recommended a routine schedule of oil analysis to monitor the condition of the machines’ components and in-service lubricant.

As a result, the district achieved four years of reliable service from the flocculation drives without an oil change after the oil transition. Meanwhile, drain intervals were extended to more than three years on the vertical turbine pump motors. “We reduced annual oil consumption by 81 percent,” says Cheevers. “That, plus reduced labor, has saved us $13,000 to $14,000 a year.”

What’s Next?

Like most water districts, Beaver Water saw development and construction decline during the recession, but the pace is beginning to accelerate again. The area is home to Wal-Mart, the University of Arkansas and the popular Crystal Bridges art museum. Cheevers expects demand for water to continue increasing: “We probably won’t see the levels of development we saw before the recession, but housing is picking up again. We are continuing to grow.”

As in the past, Beaver Water District will be prepared. “Our challenge will be to meet new regulations — probably ones that we don’t even know about yet,” says Cheevers. “The stage two Disinfection Byproducts Rule is just starting to come in, and so is the next round of sampling for the rule on unregulated contaminants. But with all the preliminary actions we’ve taken, I expect we’ll be in good shape. Change is inevitable. We need to be proactive, flexible and adaptable.”

More Information

Fluke Corporation - www.fluke.com

Hiller Separation & Process - 855/556-5707 - www.hiller-us.com

Infilco Degremont Inc. - 800/446-1151 - www.degremont-technologies.com

KOHLER Power Systems - 800/544-2444 - www.kohlerpower.com

Leopold - a Xylem Brand - 704/409-9700 - www.fbleopold.com

Philadelphia Mixing Solutions - 800/956-4937 - www.philamixers.com

SPX - 888/649-2378 - www.spxprocessequipment.com



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