When the City of North Chicago consolidated the water, street and engineering divisions into a single public works department in 2011, the goal was to cut costs, create efficiencies and increase communication.

The distribution crew merged with the street crew to form the street and utility division. That has been good for the staff at the North Chicago (Ill.) Water Treatment Plant. “Now the water plant team only has to focus on plant operations and not distribution,” says Josh Wheeler, city engineer and public works director. “Not only can they spend all their time producing quality water, but the allocation of resources is much more efficient.”

Since 2011, the 16.4 mgd conventional treatment plant has completed an impressive number of improvements, including energy efficient lighting and variable-frequency drives (VFDs), that have saved $200,000 a year on electricity. In 2012 and 2013, the plant upgraded the SCADA system, cleaned the intake, switched from chlorine gas to liquid chlorine, refurbished the sludge tanks and replenished (topped off) the media in the facility’s 11 filters.

In spite of all these changes, the transition has been smooth. “There has been no negative impact,” says David Soto, water plant foreman. “It’s really wondrous how it all works. Before, we operated the plant as needed, but in a 20th century rather than a 21st century manner. We were being reactive, and now we’re proactive.”

The finished water quality has improved too. “Our sedimentation tanks are completely clean, so by the time the water gets to the filters, it’s pretty good quality with low turbidity,” says Soto. Average finished water turbidity is 0.04 NTU, well below the 0.15 NTU limit.

Highly experienced

A team of 10 handles the North Chicago plant, which serves about 20,000 people (4,100 metered customers). Treatment consists of chlorination at the intake on Lake Michigan, screening, chemical addition, rapid mixing, flocculation, coagulation, sedimentation, filtration, fluoridation and chlorine disinfection.

The team’s experience and training contribute to the plant’s success. “Almost all our employees started their careers here or arrived early in their careers, and when they came, they stayed,” says Wheeler, who has been with the city for two years. As city engineer, he is the sole employee in the engineering division and oversees the newly consolidated Public Works Department.

Soto started in the street department in 1979 and became an operator a year later. He was promoted to assistant superintendent and then distribution foreman; he moved to his current position in 2011. He holds a Class A license. Reporting to him are:

• Jerry Gray Sr., senior operator, Class A license, 25 years with the plant
• Operators Emmanuel Henry, Class A, 23 years; Kenneth Edmonds, Class C, 12 years; Dewayne Roberson, Class A, 12 years; Tim Coleman, Class A, 14 years; and Clifford Young, Class A, 17 years
• Quintin Hampton Sr., head mechanic, 27 years
• Fred Taylor, electrician, nine years
• Michael Clayborne, maintenance II, nine years

The plant’s six operators work eight-hour shifts, Tuesday through Saturday or Sunday through Thursday. They add chemicals, check rotating equipment, run hourly tests, backwash filters and maintain tank levels and pressures. They also perform minor repairs on valves, pumps and other equipment.

Operators can take continuing education classes from the AWWA and seminars from the Illinois Potable Water Supply Operators Association and the North Suburban Water Works Association. The plant offers on-the-job training when needed for certification or to learn new equipment. OSHA training is provided by Safety and Training Consulting.

Steady improvements

Built in 1936, the North Chicago plant was upgraded in the 1950s, 1970s and 1990s. In 1991, the plant added a centrifuge (Centrisys Corp.) to dewater the alum sludge. “We have an auger [also Centrisys] that transfers the dried product to a 10-cubic-yard box, which a waste company picks up and takes to the landfill,” says Soto. “By centrifuging rather than pumping to the wastewater treatment plant, we’ve been able to reduce our sludge handling cost from $300,000 to $30,000 a year.”

An unusual addition was a surge tank in 2006. The plant partnered with Abbott Laboratories (now AbbVie) in North Chicago to add a 30,000-gallon surge tank that would prevent water surges to AbbVie facilities and the entire distribution system.

The North Chicago plant supplies AbbVie with raw water directly from Lake Michigan. A sudden pressure change can affect AbbVie’s pharmaceutical manufacturing.

Explains Wheeler, “Sudden changes in pressure in distribution cause sudden water main breaks. The surge tank reverses the flow of water, which causes the level in the tank to drop. The change in water flow reduces pressure based on the effects of friction within the pipe. Since we installed the surge tank, concerns at AbbVie have been reduced, and breaks in the system now mostly occur due to age rather than pressure surges.”

In 2011-12, new traveling water screens (FMC Corp.), high-service pumps (Peerless Pumps and Goulds Pumps) with VFDs, and screw pumps further improved plant operations. In 2013, the plant upgraded the buildings (new roof, repainting), replaced the flocculator motor and sedimentation pumps, cleaned the intake and refurbished the sludge tanks.

“Previously, we had 18 to 19 feet of sludge in the tanks,” says Wheeler. “Our disposal cost was $75,000 a year, and our labor cost, which included overtime, was $25,000. Our new proactive maintenance program cuts that by 75 percent.”

Easier operation

The upgrades have improved operators’ lives. “The new SCADA system has made it easier to run the plant,” says Soto. “We used to have to walk around every hour and check the equipment, but now we have alarms that alert us to any problems.”

Cleaning of the intake solved a zebra mussel problem. Wheeler observes, “We had installed a chlorine line in our intake line, but the chlorine line stopped working about two years after it was installed, and hadn’t functioned for about 10 years. We cleaned the intake line only when absolutely necessary. When the line needed cleaning again in 2012, we had Lindahl Marine clean it and also remove the broken chlorine line.

“Our new policy is to inspect the intake line yearly and clean it if needed. That will improve water quality, extend pump life and reduce overall costs.”

The buildings look better, too. “We’ve improved the plant’s aesthetics, and we have great pride in the way it looks,” says Wheeler. “The city plans to provide tours during Public Works Week in May each year and start an annual tour program with the local schools.”

A few challenges

With the upgrades came a few challenges. Soto states, “Before the SCADA system upgrade, the operators controlled everything manually, so they had to get used to operating and monitoring the equipment through the SCADA.” Hands-on training helped them come up to speed on the system’s Wonderware software (Invensys).

“Our filters are now on auto/remote and controlled through the SCADA, but when they backwash, the operators still open the valves manually,” Soto says. “We’re responsible for a lot of water, so we need careful operator attention to the filters.”

The addition of a 1 MW natural-gas-fueled emergency generator in the next few years will provide peace of mind. “We have two power lines coming into the plant now, so if we have a power failure on one line, the other can run the plant,” says Wheeler. “If we lose both lines, we would have a problem. Con Ed has us on their priority list, and we have a water tower that would keep us going for a day or two.”

Innovative group

The operations team has found ingenious ways to improve plant performance. “We were the first plant in the area to have a centrifuge,” says Wheeler. “We call it the dinosaur because it has a 26-inch bowl, unlike the new ones that have a 19-inch bowl. It was taking a long time to fill up, so Quintin Hampton came up with good ideas to improve operation, which is why we don’t have sludge problems now.”

Hampton moved the polymer feed line from the centrifuge intake and connected it to the head of the sludge pump. The pump now acts as a mixer so that the water begins to separate from the sludge before it enters the machine. That results in a drier product.

Hampton also provided cross-training to operators for sedimentation tank cleaning and centrifuge operation, improving operator versatility. “He continues to impart his knowledge of the plant to others to prepare the next generation for maintaining the plant as he nears retirement,” says Wheeler.

Meanwhile, electrician Taylor kept an old meter reading system operating. “The system started breaking and the parts and batteries for it were no longer available,” says Wheeler. “So Fred called a few of the contractors he used to work for who were doing demolition work at some old factories, and they said he could help himself to any discarded SCADA system parts.” Taylor retrieved four functional Allen-Bradley input cards and three output cards, saving the plant about $10,000.

Taylor was also instrumental in rehabilitating the plant’s lighting system with money from a $20,000 grant, reducing the electric bill by 25 to 30 percent.

Wheeler observes, “Soto, Hampton and Taylor are the innovators. They are the ones who initiated projects like the chlorine gas to liquid change, the lighting efficiency switchover and the SCADA upgrade, as well as submitting ideas for future projects. They continually provide input for upgrades and enhancements, doing what they can to make the plant a top-of-the-line water facility.”

Future plans

The city has a five-year water plant capital improvement plan for future upgrades such as clearwell cleaning, transformer replacement, generator addition, centrifuge maintenance and other items to be budgeted. The team is also looking to add UV disinfection. “That won’t happen for three to five years, but with EPA regulations becoming more stringent, it will give us an extra measure of protection,” says Wheeler. “Why not plan for it now?”

One thing they won’t have to worry about is capacity. “We are running at around 4 to 6 mgd, and we’ve never run at the permitted capacity,” says Wheeler. The city is not growing, and in fact, Wheeler is concerned about future water sales: “We have some smaller industries, but a lot have moved out. AbbVie is our number one water customer, and if they should leave, we would have excess water to sell.

“The city is over 100 years old and has gone through many changes. What was once a major industrial town is now reinventing itself and doing what it can to increase business and create residential areas that are suitable for second-time and not just first-time homeowners.”

Wheeler believes his purpose as public works director is to set an example for everyone else, so people will ask: How do you do what you do, and what can we do better? “This way, neighboring plants that are similar in size and funding can learn from us,” he says. “I believe that the more you work as a team internally, the more you can work externally. It ends up being better for everyone."