Operators at the Borough of Carlisle Water Treatment Plant believe in raising the bar. That attitude propelled them through the AWWA Partnership for Safe Water program, culminating in the Excellence in Water Treatment Award in October 2010. The plant received the award at the June 2011 AWWA annual conference in Washington, D.C.

Of the 116 Pennsylvania plants taking part in the program, Carlisle was the first to complete all four phases and only the eighth in the nation to do so. “We’ve always met our regulations and in fact were well within allowable limits,” says Mike McFadden, water plant supervisor. “We joined the Partnership to see if we could do even better.

Continuing commitment

The plant team signed on to the program in 2003 and worked diligently to improve every phase of operations. Improvements included better settled-water turbidity testing, jar test trials to investigate alternative polymers and coagulants, and filter backwash modifications to reduce turbidity and reduce backwash water usage.

These improvements led to more representative sedimentation basin turbidity samples, better sedimentation in the winter — well below goal levels — and 20 percent process water savings, ultimately saving money for the plant. The team continues to work on optimizing operations in an ongoing commitment to the Partnership program. “They have a high level of awareness for meeting our goal of less than 0.1 NTU turbidity 100 percent of the time,” says McFadden. “They react to any hint of trouble that would threaten that.”

Their diligence has paid off: The Pennsylvania Department of Environmental Protection recognized the plant with a state-level Excellence in Water Treatment Award for accomplishing Phase IV of the Partnership program. The award was presented at the May 2011 Pennsylvania AWWA annual conference in Hershey.

McFadden received the 2011 Operator’s Meritorious Service Award, for outstanding service in providing a quality water supply, at the 2012 Pennsylvania AWWA annual conference.

Serving the borough

Built in 1949, the Carlisle water treatment plant is owned by the Carlisle Borough Municipal Authority and operated by the Borough of Carlisle. An upgrade in 1965 doubled capacity to 3.5 mgd with four new filters. Major improvements from 1993-96 — filter replacement, upgraded finished water pumping and chemical feed equipment, and the addition of tube settlers and sludge removal equipment — increased capacity to 7 mgd.

The conventional treatment plant serves 6,600 customer connections in the borough and sends bulk water to small parts of North Middleton Township and Middlesex Township. Source water is from Conodoguinet Creek, a tributary of the Susquehanna River.

The process includes Peerless pumps, turbine flocculators, stainless steel lamella plate settlers (Meurer Research), chemical metering pumps (Siemens Water Technologies), potassium permanganate and powdered activated carbon for taste and odor control, aluminum sulfate coagulant (DelPAC polyaluminum chloride from Delta Chemical Corporation in the winter), chlorine disinfection, fluoride addition, and orthopolyphosphate (Shannon Chemicals) for corrosion control.

Online equipment continuously monitors and displays to the SCADA system the turbidity, and chlorine and fluoride residual results for multiple locations. Adjustable alarm setpoints notify operators when results are outside normal range.

Staffed at all hours

Six operators and one mechanic keep the plant running smoothly 24 hours a day. Besides McFadden, who has been with the plant for 12 years, the team includes:

Pete Selan, treatment plant director (27 years), Scott Hart (25 years), Randy Bender (24 years), Jamy Handshew (22 years), Eugene Zeiders (11 years), Don Waselewski (11 years) and Travis Kauffman (four years), water treatment plant operators Rick Horn, water plant mechanic (25 years)

Three operators work the day shift Monday through Friday. One lead operator runs the plant, while two others perform light maintenance and other tasks and to help the lead operator with any issues. One operator is on duty nights and on weekends.

Operators perform quality-control tests in the control room, which also serves as the quality-control laboratory. In the lab, they test for turbidity, pH, hardness, alkalinity, chlorine, fluoride and orthophosphate. When not involved in operations, they perform light maintenance, grounds work, painting and housekeeping.

The operators run jar tests on a programmable jar test unit (Phipps & Bird) on every shift and use a coagulant charge analyzer (Chemtrac) to help determine the optimum coagulant dose. “They have a coagulant history chart that helps them quickly locate the dose range that has worked for a given turbidity and temperature,” says McFadden. “They also rely on visual observations of floc characteristics and their many years of experience.”

Horn, who is cross-trained and licensed as an operator, performs most of the maintenance, except for specialized electrical and instrumentation repairs.

All about improvement

“Before we started the Partnership program, I presented the idea to the operators because I didn’t want to present it to upper management unless my staff was on board with it,” says McFadden. The response was positive. The staff members, all with Class A water licenses, have more than 100 years of collective experience at the plant, and the motivation to go with it.

“Once we committed to the Partnership program, they took control of it,” says McFadden. “They did all the additional studies and data collection. And even now, they never say ‘We’re optimized.’ We’re always looking for ways to improve.

“It took a solid seven years to go through the program. We didn’t have much downtime, but we were pretty much working on it all the time, making steady progress.” Team members were tough on themselves in the beginning, with a lot of action items to complete. When they began Phase IV, they held off registering for it until they were sure the self-assessment phase was complete.

“We discovered that we were already on track with a lot of the things we had to do for the program,” says McFadden. “We were optimized on many of these items. For example, we were already at less than 0.1 NTU turbidity on the filters. So, we took the data we already had and found ways to reduce the number of times the filters exceeded or approached our 0.1 NTU turbidity goal.”

Seeing results

A key result of the Partnership program was optimization of the filter backwash process. “The filters used to take 40 minutes to filter-to-waste before they could go back online,” says McFadden. “With the improvements, it now takes three minutes.”

Operators modified the backwash from a standard sequence of air scour, low-rate wash, high-rate wash, low-rate wash, then filter-to-waste for over 40 minutes to get turbidities of 0.1 NTU. “The operators tried out a new procedure that replaced the filter-to-waste sequence with an ‘extended terminal subfluidization wash,’ ” says McFadden. “I’ve heard it referred to as rinse-to-waste.”

The operators experimented and documented the correct balance of times and flow rates, then made the formal change. This reduced initial filter turbidities to about 0.07 NTU, even without a filter-to-waste step, and significantly reduced backwash water.

Another feather in the operators’ caps was significant improvement in winter sedimentation results. The operators ran numerous jar test trials and plant trials to see which polymers and coagulants would work best for winter water quality.

“The Meurer Research plate settlers installed in 2008 eliminated settled-water spikes that fluctuated with raw water quality, but our cold-weather results were still above our goal of 1.0 NTU,” says McFadden. “As a result of the operators’ studies, we now alternate between aluminum sulfate and polyaluminum chloride, achieving results well below goal levels virtually all the time.

“After showing the operators the data from the Partnership in a new perspective, we could all identify the long periods of excellent filtered turbidity results, but mixed with short time periods where we could improve.”

Short investigations

All operators took part, individually or in pairs, in mini-studies to target areas for improvement. For example, they double-checked the best location to get a representative settled-water sample, to recalibrate the jar test procedure against actual plant conditions, to confirm the flocculator speeds that produce the best results each season, and to document these. “Many times, small improvements were found as a result of these short investigations,” says McFadden.

The staff used the Partnership program to justify replacing the tube settlers with stainless steel plate settlers. This, combined with better coagulant control, resulted in lower settled turbidity levels. “They often had been greater than 2.0 NTU, but after the upgrade, they were more consistently below 1.0 NTU,” says McFadden.

Support from the borough’s management was key: “The reaction from the borough council and municipal authority to the Partnership program has been very positive. Our plant tends to be under the radar a lot of the time, but when we completed the program, they realized even more the importance of what we do.”

Future improvements

The plant’s greater visibility from the Partnership has resulted in a planned upgrade: “We’re going to replace our reservoirs with two new 1.3-million-gallon tanks.”

The operations staff also continues to improve. “We do both in-house and outside training for continuing education credits, and also for treatment strategies we see in professional publications,” says McFadden. “We review these during our monthly staff meetings to see if we should look more closely at these as a group.” Training also covers optimization and treatment strategies and chlorination safety.

McFadden’s management style is to empower employees: “As long as I provide opportunities for them to succeed by giving them training and a treatment goal, they take it from there. I give them every opportunity to obtain quality water,” he says. “The staff does the troubleshooting and calls for assistance when the problem is out of their reach.”

As for the future, the borough doesn’t anticipate the need to expand. At a population of 20,000, the city is pretty well built-out. Says McFadden, “We just want to continue to provide the highest-quality water we can, year in and year out.”