Course Correction

Marked improvements in wastewater treatment performance help a small city in Kansas meet permit requirements and prepare for suburban growth

The motto of the City of Sedgwick, Kan., is “Tradition with a Vision.” That is reflected in the city’s award-winning wastewater treatment plant and the forward-thinking attitude of city administrator Jaci Reimer and plant operator Richard Ludowese.

A suburb of Wichita, this city of 1,700 offers a small-town environment close to big-city job opportunities. Its goal is to grow slowly and keep its hometown feel.

While the city’s 0.3-mgd activated sludge treatment plant is also small, Ludowese and Reimer are always thinking on a larger scale. “We are constantly looking for better ways to control our process and improve plant performance,” says Reimer. “With recent upgrades, regular maintenance and a quest for continual learning, today our plant looks like a state-of-the-art facility, not a ‘sewer plant.’”

An operating challenge

It wasn’t always this way. Before 2006, a combination of antiquated equipment, a history of part-time operators, and high influent TSS and BOD was causing the 27-year-old plant to exceed discharge standards occasionally.

In fact, during a five-year period, it failed to meet the standards 21 times. The trouble was eventually traced to a nearby industry that was discharging vegetable oil into the sewer, leading to influent TSS over 500 ppm and BOD from 2,000 to 20,000 ppm. In 2006, the city wrote a new ordinance for industries discharging to the sewer, but the offending company could not meet the new standards and was disconnected.

Even with the high-strength influent, the Sedgwick plant met its permit requirements most of the time, and in the past three years, it has consistently met or exceeded them. Reimer and Ludowese attribute that to equipment upgrades, along with Ludowese’s status as a full-time operator and his willingness to go the extra mile.

“When I took over as plant operator in 2004, we realized we needed to make some improvements to the plant,” says Ludowese. “We replaced the automatic rotor blades, which were 25 years old. Some of them were falling out due to wear, and some had even broken.”

The plant also replaced the weir and installed automatic DO meters in the ditch, both on the south and north sides, about 30 feet behind the rotors. The old weir was made of wood and had to be manually lifted up and down to control the level of the ditch. The new fixed aluminum weir is at a set height determined by the plant engineers.

For the future

The plant also upgraded to variable-speed automatic drives controlled by feedback from the DO meters in the ditch. Before this improvement, plant personnel had only two rotor speeds — fast or slow. Now, each rotor independently speeds up or slows down to maintain a more favorable DO level and deliver more control over algae.

The plant also installed a SCADA system to make critical process readings available in real time around the clock and to automatically log data into the computer.

“These changes were mostly to control our process due to the issues we had been having with the industrial discharges, and to improve the plant for the future,” Reimer says.

While upgrading the equipment, Ludowese and his team also decided to install railings, paint the steps and make sure everything was properly marked for safety. Those improvements were made “just because it was a good idea and the right thing to do,” Reimer observes.

Besides Ludowese’s 40 hours per week, the plant benefits from two part-time operators who rotate on weekends. Ludowese is adamant about continuing his education by taking classes and sharing best practices with other operators. He makes sure he keeps his part-time operators up to speed, running through plant operations every six months and pointing out any changes that have been made.

“Richard took a whole different approach than our previous operators,” notes Reimer. “He took the time to find out why things didn’t work. We could have done everything we did with a different operator, and it wouldn’t have had the best results.”

Most improved plant

His efforts paid off. In 2007, the plant was awarded the Kansas Water Environment Association (KWEA) award for the most improved plant in the small plant category. The plant was also nominated for the award in 2008.

“Since we won that award, the city council members come out every year to tour the plant,” Reimer says. Adds Ludowese, “The technical school where I studied to become a Class IV operator brings students by to see the plant, and city engineers bring operators from other treatment plants that have had similar problems to ours so we can share information.”

In spring of 2006, the plant received a Kansas Department of Health & Environment (KDHE) grant to participate in a biological nutrient removal program. By then, the plant had been making progress and has started passing state exams regularly. KDHE determined that Sedgwick was ideal for the program.

“Our almost 30-year-old plant wasn’t designed to do micronutrient removal,” says Ludowese. “But with this program, we will be able to reduce phosphorus and ammonia, and will be able to reduce nitrogen in the future to meet increasingly stringent permit specifications.”

KDHE developed the Nutrient Reduction Plan to reduce nutrients, mitigate eutrophication, and allow long-term improvements in water quality. The Sedgwick plant can now do micronutrient testing in-house as part of its monitoring for chlorides, dissolved oxygen, total phosphorus, Kjeldahl nitrogen, nitrate, nitrite and total nitrogen.

Reimer and Ludowese are quick to acknowledge help from others along the way, from the city’s $900,000 investment in the plant over the years, to the city’s engineers, and to Jerry Grant, a retired KDHE employee who monitors the grant funds that help treatment plants experiment with biological nutrient removal.

When the Sedgwick plant received the grant, Reimer and Ludowese decided they needed some better testing equipment to perform daily and sometimes twice-daily tests for ammonia and pH so that they could better maintain an anoxic zone for nutrient removal. They purchased a pH meter and ammonia tester, and also a TSS meter so they could monitor mixed liquor solids.

They began testing the three lift stations daily to determine the TSS, ammonia and pH levels before the influent reached the plant. This helped plant operators figure out where the treatment load was coming from and at what times spikes were occurring. It also allowed them to handle the situation without having to wait for lab results. The plant also replaced its antiquated DO meter with an LDO meter, which allows plant personnel to double-check the automatic system’s operation.

Looking to the future

Ludowese looks forward to taking plant operations to the next step, meeting future challenges like micronutrient removal. “The state rewrites the specs every three years, so we don’t know how much tighter they will be next time around or whether we will be required to remove nitrate or phosphate,” he says.

The city is developing another industrial park, and Ludowese is looking at the ramifications for the treatment plant. Sedgwick’s population is growing at about 3 percent per year. And, while Reimer would like to attract more industry to the area, she plans to be more careful this time.

“Back when we started to promote the city to industries, we weren’t quite prepared for the resulting waste, and we forgot about what it would do to the sewer,” she says. “We need to be more diligent, and ideally we would like to attract smaller-volume businesses.” Today, there are 12 industries in the city, but its closeness to Wichita and its location on a major highway and near a railway line make it ripe for industrial growth.

The plant is in a good position to deal with population increases, since it operates at only 50 percent of capacity and can be easily upgraded by adding another oxidation ditch and UV disinfection bays, as well as pretreatment for nutrient removal.

Always learning

Other challenges remain, such as preparing to rebuild the main lift station and perhaps adding another sludge storage tank. To Ludowese, the biggest challenge for the future is simply learning. “After five years I’m still an amateur,” he says. “My success will depend on better process control. It’s a big job for one person, and some days I wonder if I can get it all done. But I set a schedule and keep picking away at it.”

Besides a Class IV certification in plant operations, Ludowese has a Class IV in water treatment and is working toward his Class IV in distribution. He takes advantage of other resources to continue his education, including conferences sponsored by KWEA and the Kansas Rural Water Association.

Reimer, who went to school to become a Class II wastewater treatment plant operator so she could understand the process better, agrees with his approach, although she thinks Ludowese is being too humble about his success. “Without an operator like Richard who went the extra mile and maintained everything so we could get full life from our equipment, we would have had to rebuild the plant,” she says. “As it stands now, it’s good for another 20 years.”



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