Like a hand in a glove, wastewater treatment has matched the rapid growth of housing in Huntley, Ill. Developments like Sun City, Talamore, Heritage, and Covington Lakes have boosted the population of this suburban Chicago village from 5,000 to 23,000 in 10 years.

Rather than become outdated or overwhelmed, the public infrastructure has kept pace through forward-looking planning and partnership between village officials and developers. As part of the planning, Huntley’s West Wastewater Treatment Plant, built in 1999 and managed by chief operator Adrian Pino, has grown from a capacity of 650,000 gpd to 2.6 mgd through a series of regular expansions, funded by the development companies.

In return, the plant pumps purified effluent back to the community’s developments as irrigation water for a new championship golf course and other common areas. It’s a classic case of residential development and infrastructure working together to deal with growth and progress.

Utilities superintendent Steve Zonta says the development proceeded neighborhood by neighborhood. Residential areas were built out in succession and the infrastructure was put in place. “Meetings were held weekly with the public works director, street superintendent and village manager,” he recalls. “We worked on all the infrastructure issues at once — sewers, meters, force mains.”

“It’s been a great marriage,” says the public works director Jim Schwartz.

Brand-new plant

The West treatment plant was a greenfield project, the first phase consisting of a headworks containing three 1,700 gpm Weir Specialty Pumps / WEMCO Pump raw sewage pumps and a RAPTOR fine screen (Lakeside Equipment). An Orbal oxidation ditch (Siemens) matched with a pair of 50-foot-diameter Tow-Bro clarifiers (Siemens) provided secondary treatment. Two Siemens traveling bridge sand filters and a vertical UV disinfection system from Ozonia (Degremont Technologies) polished and disinfected the effluent.

Biosolids were aerobically digested in the converted outer ring of the oxidation ditch, a temporary cost-saving solution as further expansions were planned. A Komline-Sanderson Kompress belt filter press with the company’s Roto Kone design dewatered the biosolids cake, which was stored on concrete pads and trucked by a private hauler four times a year to farm fields for application.

Pino, who joined the Huntley water and wastewater staff in 1999, explains that Phase 2 of plant improvements occurred in 2002, as capacity increased to 1.6 mgd through the addition of a second Orbal oxidation ditch and another clarifier. In 2008, Phase 3 expanded the plant to its present capacity. “We added quite a bit of new equipment, including another oxidation ditch (for a total of three), two new 85-foot clarifiers, and a single 50-foot clarifier (for a total of six), and an additional traveling bridge filter,” says Pino.

Three Pulsafeeder pumps and a 6,500-gallon alum storage tank supply aluminum sulfate to remove phosphorus. The UV system was replaced with a new system of the same design from Ozonia. “The system consists of two channels, with two modules each, and a total of 160 bulbs,” says Pino. “It’s really easy to clean the bulbs and it only takes one person to do it.” The system is also flow-paced, providing only as much UV light as needed.

The biosolids side also saw improvements in Phase 3. The material goes through a pair of Ashbrook gravity belt thickeners and then it is stabilized in a new four-celled aerobic digester supplied with air from two 150 hp Kaeser blowers. Two Moyno progressive cavity pumps move the digested solids to the existing filter press. A new 80- by 100-foot storage pad more than doubled biosolids cake storage.

The upgraded plant contains new power and control systems. A 1,250 kW Cummins diesel generator supplies emergency power for the entire plant. SCADA software (Invensys Operations Management — Wonderware) and Allen-Bradley (Rockwell Automation) PLCs were integrated by Baxter & Woodman Control Systems Integration (BWCSI), of nearby Ridgefield, Ill. The system controls water and wastewater treatment as well as sanitary lift stations. All information is communicated to the control panel at the West plant.

Pino says the control system is “an outstanding addition. We can monitor the process and make changes in operational values from virtually any place there is a computer with Internet. It’s saving us a lot of time and money.”

Recycle, reuse

The West plant’s permit calls for recycling 34 percent of its effluent as irrigation water for the community from April through October. The plant is actually recycling and reusing 100 percent of the effluent during those months. “We use a flow baffle to divert all of our effluent for recycle and reuse from spring through fall, and discharge treated water to the Kishwaukee River during the winter,” Pino says.

Two WEMCO pumps move the recycled water to the recycle pond through a 7,000-foot pipeline. Pino explains that Huntley was the first recycle-reuse project in a four-season climate for housing developer Del Webb, who had previously been active in Arizona and California. “They were really interested in reuse when they came here,” he says.

Zonta notes that the recycle-reuse system takes considerable strain off the community’s potable source — a deepwater aquifer. “This year, we supplied 243 million gallons of water,” he says. “That is about 25 to 30 percent of the total potable water used by the village in a typical year, so the savings in cost and source water usage is significant.”

Plans are in place to start supplying recycled water to another development, and the reuse piping is already in place.

Work-arounds

Expanding and upgrading treatment while continuing to treat flow and meet permit is always a challenge. Like other treatment plant staffs, the Huntley team has learned some lessons from these on-the-fly situations.

“It really helped that we had a phased long-term plan and permit in place,” says Schwartz. “And it was also helpful that we used one contractor (J.J. Henderson of Gurnee, Ill.) throughout the initial construction and the expansions.”

Pino says extra tank capacity came in handy as new lines and processes were tied into the system. “We were able to divert flow or stop flow as necessary,” he says. However, no matter how well one prepares, there are bound to be incidents.

“Something always gets hit during excavation when existing pipe and conduit are in place,” says Pino. “It’s inevitable.” He says good communication is the key. He acted as the single point of contact between the plant staff and the contractor: all communications about requests, issues and projects channeled through him.

The expansion presented opportunities to improve treatment, as well. “We used the project as a chance to start the biomass over again from scratch,” Pino says. “Due to long conveyance time in our sewers, we were getting significant filamentous growth. We pressed and dewatered all our old solids, then started new by filling a tank with effluent, mixed liquor and raw wastewater. With new biomass, we saw improved settling and ammonia numbers, and we solved the filamentous issues.”

The new developments in Huntley are nearly completed. Original plans called for more than 11,000 new homes and a population of about 25,000. Today, the last of the developments is awaiting the end of the recession before construction is complete, and the village population is nearly 24,000.

“Fifteen years ago, this was the wild west out here,” says Schwartz. Now, Huntley is one of the more substantial communities in the northwest suburban areas of Chicago. In addition, while the current growth spurt is just about over, village officials are already prepared for future needs. Phase 4 of the West treatment plant expansion is already on the books and would take the capacity to 4.8 mgd with a maximum build-out to nearly 8 mgd.