HOT SPRINGS -- The city's regional water system avoided boil orders other utilities resorted to after last month's cold snap burst service lines and hemorrhaged water from distribution systems.
City officials said the system's telemetry kept it viable amid temperatures that were stuck at or below freezing for six straight days, according to weather statistics recorded at Hot Springs Memorial Field. The ability to monitor meters and storage tanks remotely informed which accounts to turn off and where to send water to maintain pressure across the 145-square-mile service area's seven elevation zones.
The city asked utility customers to conserve water, a request the city said many took to heart. Some restaurants stopped serving fountain drinks during the shortage.
"All of us were in the same boat, but we recovered faster because we did have (advanced metering infrastructure) that we used to our advantage," said Monty Ledbetter, utilities director, referring to municipal and investor-owned utilities in Saline and Jefferson counties, where boil orders proceeded from a lack of pressure in the distribution system.
Shutting off more than 3,000 meters with usage rates averaging more than 50 gallons per hour stemmed water loss, giving the two treatment plants time to refill the distribution system. Ledbetter said it dropped to 20% of its more than 16 million capacity, forcing the city to take storage tanks offline and pump water directly to the service area's more than 35,000 meters.
"If we lost another couple million gallons, we would've been at a point where we'd have to go under a boil order," he said.
More than 90 city employees, including firefighters and wastewater crews, worked around the clock to shut off meters with high use rates. Ledbetter said it was a considerable feat of logistics given the size of the sprawling service area and the number of meters crews had to visit.
Crews were organized according to billing cycles that correspond to geographical areas. Assigning crews to specific areas allowed problem meters to be valved off more expeditiously, Ledbetter said, stanching the tens of thousands of gallons the system was losing by the hour on the customer's side of the meter.
"We deployed everybody we could to shut water off," he said. "We divided it up into routes. That saved a lot of time, because people weren't having to run all over the place."
Operators at the Ouachita Plant that treats water from upper Lake Hamilton and the Lakeside Plant that treats water from the city reservoir at Lake Ricks ran the more than 50- and 70-year-old facilities at their cold weather capacities for a week, producing more than 20 million gallons a day.
Making surplus water in advance of the winter storms wasn't an option, as the system's 11 active storage tanks combined capacity can't hold volumes the two plants treat during high-demand days.
"You can only produce what you can hold," Ledbetter said. "We only have so many tanks. If we had bigger tanks or more tanks, we would've eventually been in the same situation."
The Arkansas Department of Health requires storage equal to average-day demand, which, according to the sanitary survey of Hot Springs' regional system the Health Department released in December, required more than 13 million gallons of daily production from 2017 to 2019.
The $5.2 million Cornerstone tank project added 3 million gallons of usable storage in August.
"That bumped us up to 18 million gallons," Ledbetter said of total storage capacity. "We're looking at adding more storage in our system. The next place we're looking at is the Highway 70 west area."
Operators and technicians maximized what water was in the distribution system, using the supervisory control and data acquisition system to monitor where it was most needed. City Manager Bill Burrough said the institutional knowledge brought to bear by employees who have worked for the utilities department for more than 20 years also helped.
"With our SCADA system, with a touch of an iPad or computer screen we can see every tank in the system and how much volume is in each one of the tanks," he said. "We were able to respond to that by shutting off a pump at one tank or manipulating a valve to push water to another tank that may be losing pressure."
Burrough said overtime hours needed to keep the system viable exceeded what was built into the 2021 budget the Hot Springs Board of Directors adopted last year.
"We do budget some overtime for inclement weather, but it won't be on a scale of what we saw," he said, noting the extent of overtime won't be known until the next pay period. "We'll certainly be over what we would normally budget for inclement weather overtime."
City offices were closed for a full week while utility, public safety and public works employees worked during the winter storm. Burrough said employees whose offices were closed will be paid for the week.
"Those are decisions I make each day, and they're not going to be penalized by that decision" Burrough, referring to his decision to close city offices from Feb. 15-19, said. "We have a lot of employees who are considered inclement-weather essential. They work, but some of those worked quite a bit of overtime during the snowstorm. They'll be paid overtime. As far as office staff and those that may be at City Hall, they'll be paid even though they weren't able to come in with me closing the offices."