Partnership for Safe Water standards drive everything from operating procedures to equipment specifications at a Phase IV-recognized water treatment plant.
Achieving Phase IV in the AWWA’s Partnership for Safe Water is a big deal. But at Carlisle Borough, operating the water treatment plant according to Partnership goals and standards is even bigger.
“We were the first water treatment plant in Pennsylvania to reach Phase IV,” recalls Peter Selan, director of the water plant, who retired in late February. “But we did something that nobody has ever done when we built the Partnership standards into our equipment specs, and used the standards — which were more stringent than our permit — as the target for our operational performance.”
The key was getting everyone from the operations team to the members of the Water Authority to the Borough Council to buy into the standards: “We take the standards very seriously.”
Public water treatment in Carlisle Borough can be traced back to 1853, when a dam was constructed on Conodoguinet Creek and the first waterworks plant was built. On the same site, more modern facilities were constructed in 1932, then expanded in 1946 and 1975. The current treatment train dates to a major upgrade in 1993-96. Improvements to the Long’s Gap Road Dam were finished in 2002.
The borough draws water from the creek through a headrace — an open channel intake structure. Excess water taken in is recycled to the creek. Pumps transport the water to the plant where potassium permanganate and powdered carbon are added for taste and odor control. Coagulating chemicals are then added, and the water passes through flocculation, settling basins and inclined plate separators.
Two-stage sand and anthracite filters (Leopold) remove turbidity before the finished water is disinfected with gaseous chlorine and fluoridated in a basement clearwell. Ortho-polymer is added for corrosion control in the distribution system. Pumps then move the water to a pair of 1.3-million-gallon reservoirs.
New SCADA and monitoring systems control and analyze plant operations, enabling operators to ensure the production of the highest-quality water. Continuous monitoring and laboratory testing is performed to control taste and color and to ensure that water quality requirements are met. Operation and maintenance of all water treatment, pumping and storage facilities is performed continuously.
Average daily output is 2.5 to 3 million gallons, and the water is distributed through 77.2 miles of mains to about 18,000 users in Carlisle Borough, plus another 4,000 customers in the townships of North and South Middleton, Middlesex and West Pennsboro. The distribution system includes a 2.3-million-gallon standpipe and two smaller storage tanks.
The borough maintains emergency interconnects with South and North Middleton townships, which can supply up to 2 mgd in case of an emergency. A contractor hauls waste solids from the treatment process to farms. “We try to keep the solids levels down,” says Selan. “We haul about once a week and try to stay ahead of the game.”
The capacity of the Carlisle Borough plant was doubled in 1965 with the addition of four filters, bringing the total to eight, and two new sedimentation basins, for a total of four. Filter media was replaced, new pumps were added, and a new SCADA system with PLCs was installed to give operators better control.
“The new SCADA works very well for us,” says Selan. “We brought in a professional consultant (Carlisle Consulting) to help us with it. They’ve been great to work with and have provided advice on better operational control. It was all manual before.”
Even though the plant staff is not responsible for distribution, the borough has made improvements to the standpipe. Pumping and mixing equipment was added to improve water turnover. The improvements were primarily driven by Pennsylvania Department of Environmental Protection regulations. More recent upgrades have been aimed at meeting the higher standards of the Partnership for Safe Drinking Water.
The borough started the Partnership process in 2002. “We met people, started gathering data, and submitted our application,” Selan says. Since then, in addition to building the standards into equipment specifications, borough officials have made numerous improvements and upgrades to the process train, some of them solely to meet the Partnership standards.
“You have these standards, which review and treat each process individually,” Selan says. “It’s great to look at the plant that way. It’s easier to make improvements.” The plate settlers received major attention: “They were old, with plastic plates. They were hard to clean. Pieces of plastic kept flaking off.”
The Partnership standards also led to more precision in the plant’s various chemical feed stations. “We had to optimize our chemical feed and be more precise,” Selan says. “We can’t overdose and waste money, or under-dose and not meet the standards.”
That has led to the installation of new chemical feed and monitoring equipment, including the carbon feed process where a new Stranco unit (Evoqua) has improved operations. The staff closely monitors its filtration system, too, and has changed backwashing methods to help meet turbidity standards. The plant has new Hach turbidimeters and particle counters.
“Turbidity drives everything with us,” Selan says. “All our controls and chemical feed processes are tied into turbidity. Our operators read values on the screen and make changes automatically.” The plant achieves 0.01 NTU out of the filters. While the permit calls for 0.1 NTU out of the pump house, the plant averages 0.04 to 0.05 NTU. “With the Partnership program, you have to be at those types of levels,” Selan says.
The need for such high-quality water drove the borough to tie Partnership standards into the construction and performance specifications for new equipment. Selan recalls one case where the equipment was slightly off on the turbidity requirements, and the borough withheld a portion of the final retainage.
Everyone on board
The most critical factor in adopting the Partnership for Safe Water performance standards — and building them into plant operating procedures — was getting buy-in that extends through all levels of the operation.
First, says Selan, there must be buy-in from the governing body that provides the funds.
“Our Water Authority gives recommendations to the Borough Council, which controls the funds and approves construction,” Selan says. “As long as everybody’s on board and you give them regular updates, you’ll get their buy-in.”
Operators are just as important. “At first, the extra work may seem frustrating and unnecessary,” says Selan. “We had to carefully monitor the filters, and we add more media when needed. But once our operators started seeing that we were very serious about this, they understood what we were doing and they bought in.”
Today, the Carlisle staff members — mechanic Rick Horn and operators Scott Hart, Randy Bender, Jamy Handshew, Haroon Pakhtiawal, Eugene Zeiders and Travis Kauffman — fully embrace the standards. Selan says training is mostly face-to-face and stresses the Partnership goals. “It’s noticeable,” he says. “When a new operator comes on, the person he’s replacing talks about the standards and the differences between them and the DEP regulations.
“In the long run, we have a sort of cushion to work with. There’s a difference between what the DEP requests and what the Partnership program requires. We realize we’re doing better than the DEP regulations and it gives us a sense of pride.”
The Carlisle Borough Water Treatment Plant is the first in Pennsylvania to reach Phase IV of the Partnership for Safe Water program, the highest achievable and a recognition of optimized performance. The goal of the Partnership is excellent drinking water quality. Water experts provide utilities with guidance, advice and technical assistance for fine-tuning water treatment.
Partnership members must commit to continuous water treatment improvements, meet state and U.S. EPA water-quality standards and comply with the surface water treatment rule. They are also subject to assessment by outside water professionals and must make improvements identified in the assessments.
The program consists of four phases of achievement. In Phase I, plants agree to participate and to at least complete Phases II and III, and notify their customers of progress. Phase II involves data collection, and Phase III is a comprehensive self-assessment of operations that leads to improvements.
Phase IV recognizes a fully optimized treatment plant, eligible for Presidents and Excellence awards.