If there’s a great before and after story in municipal wastewater treatment, it could be Kankakee, Illinois.

Before 2010, the Kankakee River Metropolitan Agency used aging primary, secondary, and disinfection processes to treat wastewater from the city of Kankakee and the neighboring villages of Bradley, Bourbonnais and Aroma Park. Biosolids were anaerobically digested, and biogas fired an inefficient cogeneration system that could supply only a small portion of the plant’s power and heat.

“The last major improvements occurred in 1988,” says Richard Simms, executive director. “Some equipment dated to 1936, and wet-weather management was an issue.”

Then, facing new requirements for ammonia removal, dissolved oxygen, and wet-weather flows, the Kankakee River Metropolitan Agency management and its engineer, Strand Associates, launched a multiyear plan to upgrade the facility’s treatment, energy, odor control, and automation systems.

The $58 million in improvements included a new cogeneration plant able to provide one-third of the plant’s power and all of its heating needs, a nitrification-denitrification process, and primary treatment and disinfection of wet-weather overflows.

“Capacity was not an issue,” says Art Strother, Kankakee River Metropolitan Agency superintendent. “We completed the upgrades in four stages over six years. Construction was carefully phased in and did not disrupt existing operations. We stayed in compliance throughout.” Ironically, an explosion in one of the old anaerobic digesters during the design phase actually helped the cause: “It moved us to the top of the funding list for the state of Illinois,” he says.

Heavy industry

About 40 percent of the flow to the new-look regional plant is industrial, from paint, chemical, pharmaceutical and agricultural products plants. The Kankakee River Metropolitan Agency permits and monitors 31 industrial users; nine industrial accounts truck wastes to the head of the plant. “We sample the waste and test them before they are blended into the flow,” says Melanie Gossett, assistant superintendent for technical services. Ten approved septage haulers also truck in wastewater. The plant accepts an average of 2.7 million gallons of trucked-in wastewater per month: “They’re glad to have a place to take it.”

Separate influent lines from Kankakee and the other communities feed the wet well at the head of the plant. Screw pumps (Evoqua Water Technologies) lift the influent to the preliminary treatment structure where three mechanically cleaned bar screens (Vulcan Industries) remove solids and two Vortex cyclone-type units (SUEZ) remove grit. After washing, screenings and grit are collected and removed to landfill. “The grit tanks used to be controlled manually, but now they’re controlled automatically according to flow and level setpoints,” says Dustin Scheppler, assistant superintendent for operations and maintenance.

Six rectangular primary clarifiers settle and skim primary solids, which are blended with secondary solids. The blend is thickened by dissolved air flotation thickening (Evoqua Water Technologies), then anaerobically digested. “We don’t have to use polymer for thickening,” Strother says. “We achieve acceptable thickness by using plant data to obtain an air-to-solids ratio that produces 4-6 percent solids.”

Primary effluent flows to a trio of three-pass rectangular aeration basins. Air provided by high-speed turbo blowers is distributed through fine-bubble diffusers (Sanitaire, a Xylem brand). One bay is devoted to anoxic mixing to remove nitrates. The basins are also set up to remove phosphorus biologically, should that be required in the future.

Treated water that settles in four circular secondary clarifiers is disinfected with chlorine gas, dechlorinated with sulfur dioxide, and discharged to the Kankakee River. Chemical feed equipment was supplied by De Nora Water Technologies.

To contain and control wet-weather flows, the plant’s equalization basin volume was expanded from 10 million to 12 million gallons, and a separate chlorination facility was built for settling and disinfection of wet-weather overflows. The Kankakee River Metropolitan Agency is waiting for an Illinois EPA overflow treatment permit, according to Scheppler.

Target net zero

“KRMA is committed to eventual net-zero energy,” Simms says. To help attain that goal, primary and secondary solids thickened by DAF are fed to three primary and two secondary anaerobic digesters. Methane is collected, scrubbed in a bio-tower to remove hydrogen sulfide, sent through a moisture removal system (Unison Solutions), and then burned in a 450 kW cogeneration engine (Caterpillar). A diesel engine supplies backup power.

The generator supplies about 7,000 kWh per day; most of the plant’s electricity comes from hydroelectric power from Kankakee River Dam. Heat from the engine-generator passes through tube-in-shell heat exchangers (Walker Process Equipment, A Div. of McNish Corp.) to provide hot water for the digesters and treatment plant heating. To manage the input and output from the two power sources, the Kankakee River Metropolitan Agency invested in state-of-the-art switchgear.

A gravity belt press dewaters the digested biosolids to 5 percent solids before storage in four large tanks. Ultimately, the material is trucked to area fields for injection by New Era, a private contractor.

Some years ago, the Kankakee River Metropolitan Agency investigated solar panels and wind power in its effort to become more energy efficient. “Wind power didn’t prove feasible, and at the time, the solar panels offered an unacceptable 17-year payback, even with a grant,” Simms says. “We’ll be looking at that again.” The plant has a large open area that could accommodate a solar installation.

Being neighborly

The Kankakee River Metropolitan Agency analytical laboratory is operated by the city of Kankakee in a city-regional agency arrangement. Odor control and SCADA automation are critical plant support systems.

Odor control is important because the river and a public walking path border the plant to the west, and a public park lies to the south. In addition, a residential neighborhood sits right against the plant’s eastern boundary. The plant uses a variety of biofilters and chemical scrubbers to remove odors at process points around the plant that include the headworks, solids handling facilities, and the primary clarifiers.

The first phase of a new PLC-SCADA system was supplied in 2009 by Wunderlich-Malec. It includes distributed control in which the PLCs perform the control logic, along with a PC-based human-machine interface. Later improvements supplied by Frakes Engineering included replacing electrical equipment, field devices, instrumentation, lighting and control panels. The control centers are Allen-Bradley (Rockwell Automation). “The SCADA system has been a big help,” Strother says. “We can see the O&M requirements for each piece of equipment.”

Phased improvements

Improvements to the SCADA system were at the top of the list in the first phase of the plant modernization project. That phase, completed in 2013 at a cost of $12 million, also included replacement of screw pumps, the addition of high-efficiency blowers and controls for the activated sludge system, rehabilitation of the DAF thickener, a new biogas conditioning system, and the biogas engine-generator and diesel backup generator

The phases were laid out in a rehabilitation master plan developed by Strand Associates and modified, approved and implemented by the Kankakee River Metropolitan Agency. The plan saved money because it broke the overall project into chunks and enabled better control over the many contractors involved. “The state’s funding limit was $20 million,” Simms says. “We broke our $58 million project into four separate phases, with separate financing for each.”

And that’s where the digester explosion came in. The incident took place when no one was in the digester building, so there were no injuries. “For 2 1/2 years, we had to manage our biosolids with chemical addition, a portable dewatering system, and hauling to the landfill,” Strother says. The makeshift operation was “costly and cumbersome,” according to Simms, and made it challenging to stay in compliance, but the situation moved the Kankakee River Metropolitan Agency project from 76th to first on the state funding list.

A year later, the $14 million second phase brought a total makeover of the anaerobic digesters, including a sludge mixing system, new digester feed pumps, new spiral-guided gas holder covers for the secondary digesters, rehabilitation of the three floating primary digester covers, and draft tube mixing and foam suppression systems. The new biogas burner, boilers and heat exchangers were installed. The digester building also includes an extensive safety system (Shand & Jurs) with alarms for high methane and low oxygen, along with fire protection.

The last two phases were completed in 2015 and 2016 at a cost of $16 million each. A new, three-pass aeration system with anoxic zone mixers and nitrate recycle pumps, a new post-aeration system (Kaeser Compressors), excess flow basin improvements, and a new chlorine gas disinfection system were highlights of Phase 3. The disinfection system more than doubled capacity from 45 to 100 mgd. “Before, everything was as manual as could be,” Strother says. “It was all blinking lights and horns. We literally ran it by hand. We added the dechlorination facility on the fly.”

Phase 4 included final clarifier improvements, new headworks equipment and electrical service entrance upgrades. An old manual bar screen, an aerated grit removal system and aging switchgear were replaced.

Data compiled by Strand Associates and Kankakee River Metropolitan Agency show that the projects have enabled the authority to begin realizing the intended process efficiencies. “We’re seeing annual savings for electricity, natural gas, as well as building repairs and maintenance,” Simms says.  

The people side

Training of the operational staff was a big part of the upgrades. “We had 16 operators before the upgrade, and we have 16 now,” Strother says. Besides Simms, Strother, Gossett, and Scheppler, the staff includes Jennifer Salan, office manager; operators Shaun Ownbey, Jason Dockemeyer, Jim Churney, Shawn Malone, Jack Renchen, Brian Power, Steve Smith, Dan Combs, Mike Dauphin, Gary Filanowicz, Kurt Mraz, Ron Haney, Mike Gowler, and Bryan Kennedy; and Josh Peters and Nick Scheppler, electrical, instrumentation and control specialists.

Strand Associates set up an extensive training program, working with manufacturers to develop O&M manuals well in advance of the equipment startup. While the size of the staff has stayed the same, its quality keeps improving, partly due to an incentive program that rewards team members for advancing their license classifications.

“It has broadened their perspective,” Simms says. “Working here is not just a job anymore. Now you can move up within the organization, get credentialed, and become aware of other opportunities. We have a lot of talent here, and we’re probably training superintendents for other utilities. It’s been a real change.”

In the last analysis, Strother has the best perspective on the progress at the Kankakee River Metropolitan Agency and the critical role the operators play. He grew up in Kankakee and joined the plant staff as an operator in 1985, driven by his personal goal of helping to keep the river clean. He earned his Class 1 license in 1993 and moved up to chief operator when the plant was privatized for a time in the early 2000s. He became superintendent in 2016.

Now, with retirement less than three years off, he smiles and says the current team at the Kankakee River Metropolitan Agency is the best he’s seen: “Everyone here is licensed. In all my years, this is the strongest group of individuals I’ve ever worked with.”

Digital-age asset management

Last January, the Kankakee River Metropolitan Agency wastewater treatment plant team began implementing a customized, cloud-based asset management system called EcoAppPro. “We will totally replace the old way of doing things with books and manuals,” says Richard Simms, executive director. “Information will be available instantaneously on operators’ iPads or iPhones.”

The system consists of six modules. In the first module, all plant personnel will be assigned an account providing access to the system and will be able to communicate instantly on operations and maintenance issues with others across the operation. The communications module includes general communications with attachments and commenting, emergency communications, and customer calls.

The plant’s asset management system will become available and manageable in a digital format in the second module, which includes linking assets with communications and digitized facility maps. All manuals and standard operating procedures will be digitized in the third module, eliminating dependence on paper copies and drawings.

The fourth module will do away with manual work orders, and the fifth will include all the information pertinent to the plant’s industrial surveillance and pretreatment system. A GIS-collections systems module will be a second-generation, customized piece, Simms says.