The eastern Kentucky city of Prestonsburg sits in a valley of the Appalachian foothills, and from there, the water utility’s pipes stretch out to surrounding areas and across county lines.

“We’re one of the biggest small-town utilities that I know of,” says Donald Compton, water and wastewater treatment manager. That, along with highly variable-quality source water, means daily challenges for the plant operations team.

The plant has seen three substantial upgrades since it opened in 1957. That includes the most recent plant expansion in 2005 to the current 5 mgd design capacity (average production is 2.5 mgd).

Far and wide

The Prestonsburg plant serves most of the northern end of Floyd County (population 37,000), but there’s much more to the utility distribution system. Just over the border in Martin County lies the largest customer: a maximum-security federal prison with a minimum-security work camp.

Area communities attracted the prison for the jobs it created in the prisons and at businesses that the inmates’ visitors use. Martin County couldn’t provide enough water for the prison, so Prestonsburg stepped in and now usually fulfills 100 percent of the prison’s demand of 250,000 to 270,000 gpd.

The federal government and Prestonsburg utility shared the cost of laying about 20 miles of pipe from the Prestonsburg plant, and the city added a few residential customers along the route. Martin County built a 1-million-gallon storage tank above the prison; Prestonsburg built a smaller tank below the prison to feed the pump station that pushes water up to the larger tank.

Recently, the city acquired about 1,200 water customers from another utility that was already buying Prestonsburg water for them. So the city now has a 15-mile run of pipe to the southeast and up to the border of Pike County.

No more chlorine

Being in a developed area of the community, the plant faced issues with its original chlorine disinfection. In 2005, the utility stepped away from using chlorine gas to reduce risk to its neighbors, which include a school with 750 students, a nursing home, and a large residential area. Only half a dozen of the 1-ton chlorine cylinders were kept on site at any time. Because of the handling risk, Compton wouldn’t let any team member change a cylinder alone, and that sometimes meant calls at 2 a.m. when a cylinder was empty.

“We would limit chlorine deliveries to before 7:30 a.m. or after 3:30 p.m. so that just in case something did happen, students wouldn’t be in the school,” Compton says. The Fire Department provided hazmat protection, but the utility paid for the firefighters’ protective suits and for drills.

In place of chlorine, the city installed a MIOX system, which uses electricity to convert a brine solution to chlorine and other byproducts. A 45-ton salt silo holds the base material. “With MIOX, the dangers are greatly reduced,” Compton says. “The product tank smells like an overchlorinated swimming pool.”

River challenge

Also in 2005, the utility installed a new raw water intake. Prestonsburg draws its entire supply from the Levisa Fork of the Big Sandy River. At the new intake, a pair of 100 hp pumps (KSB) pulls water into a 20-inch manifold to one 20-inch line that feeds a single 16-inch pipe entering a building equipped with a Grit King grit separator (Hydro International). The older intake has a pair of 75-inch Pentair Water - Hydromatic pumps.

“We have used that older intake quite a bit when conditions in the river plugged the new intake, even though we have an airburst on the screen,” Compton says. “The river is aptly named Big Sandy.”

No one knows the exact cause of the plugging because there is no way to see into the river, he says. The new intake is about 6 inches lower than the old one, so possibly river bottom sediment enters the intake during times of high turbidity. Another possible cause is leaves in the water after storms. Between 30 and 40 miles upstream is a flood-control lake and dam, and water it releases may still be roiling when it reaches Prestonsburg. It’s not uncommon to see 1,500 NTU or higher in raw water during heavy flows. The highest recorded turbidity at the plant is 11,500 NTU.

The intake screens have openings of about one-eighth inch, and to improve the flow, the city hired divers to blow some 1- and 2-inch holes into the screens. “It doesn’t stop up as much, but the holes mean we have larger debris coming in,” Compton says. That can be handled by the Grit King grit separator, along with good maintenance of the flocculation basins.

From the separator, the water goes into a Chemineer flash mixer from NOV and then into the floc basins, equipped with single-speed drives. There are three settling basins — two conventional and one with a lamella plate system. Four mixed-media filters come next — two using gravel, sand, and anthracite, and two updated in 2011 to use sand and anthracite with a Leopold - a Xylem Brand IMS cap support. Then comes post-treatment with MIOX and fluoride. A 750,000-gallon clearwell split into four sections feeds two 300 hp distribution pumps (Aurora Layne/Verti-Line). A U.S. MOTORS 75 hp pump (Nidec Motor) handles backwashing.

The Stonecrest baseball complex stands on a hill above the city; pipes run to the top of the 2,000-foot hill where there are three storage tanks, one for reuse water from the wastewater plant, used to irrigate a nearby golf course. One tank is elevated to provide pressure to buildings on the hilltop.

Reaping recognition

The city’s accomplishments haven’t escaped notice. In 2016, Prestonsburg won the Drinking Water Plant Award from the Kentucky Water and Wastewater Operators Association. The Prestonsburg team also won the Kentucky Water and Wastewater Operators Association Water Treatment Plant of the Year award in 2009.

From the Kentucky/Tennessee Section American Water Works Association, Prestonsburg won the Small Plant Award in 1997 and the Medium Plant Award in 2011. In addition, the team has five top 10 finishes for the Kentucky Rural Water Association’s Wooden Bucket Award for customer relations and high-quality services.

It takes a skilled team to make it all happen. Plant team members are Tim Goble, water treatment plant manager, and operators Woody Jarrell, Larry Josh Slone, Darrell Crider, and Charlie Rice. “I have an outstanding staff,” Compton says. “They take a lot of pride in their jobs. All the awards are a tribute not just to our staff, but to the entire utility.”

The utility is led by Turner E. Campbell, the new superintendent and CEO, who was chief financial officer for more than 15 years. Brian Music, distribution manager, works with the treatment plant to keep water flowing, and distribution crews lend a hand at the plant for maintenance. William Campbell, administration manager, oversees the warehouse and purchasing. All three are also certified operators and can assist at the plant if there is an issue.

Looking ahead, a multimillion-dollar plant upgrade is in the works for 2018. Final plans are still taking shape, but the project will add two filters and retrofit the floc basins with variable-speed drives. The two settling basins without lamella plates will be retrofitted with them to improve efficiency.

If demand increases, that will require more extensive changes, such as additional pumps and the clearwell capacity. “The question is whether another utility needs help,” Compton says. If the city were to become the sole supplier to the prison, that would be a factor. Prestonsburg also sells water to the city of Martin and to the Southern Water District, which covers the southern part of Floyd County.

Staying proactive

While operations proceed day to day, the utility has dealt successfully with residents’ concerns about water quality. The utility’s website includes a page about chromium 6 (hexavalent chromium), even though it’s not an issue for Prestonsburg’s water quality.

“We were just taking an aggressive approach to a social media frenzy,” Compton says. In fall 2016, news stories reported sampling results from the EPA Unregulated Contaminant Monitoring Rule and California’s independently set low chromium limit. Customers then began asking whether chromium 6 and other substances were in the city’s water.

The webpage leads readers through a Q&A discussion of chromium, including the results of Prestonsburg’s testing and the specifics of the EPA chromium rule. “Once we put the post out there, I believe we didn’t hear anything after that,” Compton says.  

Meanwhile, last year, the utility took third place in a Kentucky water tasting contest, the first one the utility entered in Compton’s time with the city, going back to 1985. “I looked at the agenda for a conference, saw they had a best-tasting water contest and thought we should see where we stand,” Compton recalls.

It was another small triumph for a big small-town utility.

Helping students to new careers

In summer, Prestonsburg, Kentucky, runs a help program to hire young people for seasonal jobs: college students and a few new college-bound high school graduates. The program does more than provide summer income; it can spark students’ interest in engineering and water technology.

“If we get an application from someone who’s interested in water or wants to work at the water plant, that person will be steered toward me,” says Donald Compton, water and wastewater treatment manager. Those interested in wastewater are steered to that department.

Students rehired after their first summer have the chance to go out with workers and learn the operation in more depth. “Our current water treatment plant manager, Tim Goble, was in our summer help program for two or three years,” Compton says. The college where he studied accounting had a small water plant, and he helped run that as part of his tuition payment.

The program isn’t intended to attract only future plant operators. Usually six to eight students are hired and are spread across the utility: water plant, natural gas service, construction and other areas. Students pick up garbage, do painting and maintenance, and generally keep busy.