WEFTEC.08 Tours

For the Biggest in Size and Load

• By L. K. Williams
• Oct 14, 2008

The Stickney Water Reclamation Plant and Abbott Laboratory Wastewater Pretreatment Plant tours are all about extremes.

These facilities are hosting two of the seven facility tours at the 81st annual Water Environment Federation Technical Exhibition and Conference on  Oct. 18-22 in Chicago, Ill.

Identified as one of the largest, if not the largest, wastewater treatment facilities in the world, the Stickney plant covers a lot of ground and treats a lot of wastewater. On about 570 acres, the activated sludge, secondary treatment facility has a design maximum flow of 1,440 million gallons per day. The average flow is about 1,200 mgd, but Metropolitan Water Reclamation District of Greater Chicago staff said the facility treated flow in the maximum range during the latest September rain event.

Neil Dorigan, assistant engineer of treatment plant operations of the Stickney plant, said that the facility originally was constructed as two separate plants. Operators at the facility use all-electric vehicles to reach more remote areas, such as the West Side Plant.

Stickney Water Reclamation Plant Facts

• Serves 2.38 million people

• Geographical service area includes the central part of Chicago and 43 suburban communities

• West side portion of the plant went online in 1930

• Southwest portion of the plant went online in 1939

• State-of-the-art biosolids heat drying palletizing facility built in 2007

For the size of the facility and its capacity, you would expect it to have some good neighbor issues. But Dorigan says that just isn't the case. "I have an aunt who grew up in Chicago. She never takes the highways and knows all the back roads. She had no idea -- although she drives by it every day -- that the plant was there," he said.

The plant is surrounded by berms that have trees planted on them. The trees were grown on a farm at Hanover Park Plant using treated biosolids from the same facility. (The plant is growing and selling corn for ethanol use now.)

Solids, which often create odor problems at wastewater treatment facilities, are digested and centrifuged for thickening. The facility offers treated biosolids for Class B agricultural land application or dries the material to 65 percent solids for use as landfill land cover, top dressing at golf courses, or other beneficial reuses.

The Post-Digestion Centrifuge Dewatering Facility uses 21 high-solids centrifuges to dewater 1,600 tons (400 dry tons) of solids processed per day. The odor control system treats hydrogen sulfide, ammonia, and volatile organic compounds.

Dorigan said that his team of 540 operators, engineers, tradespeople, and laborers makes a strong effort to be a good neighbor.

At Abbott Laboratories' North Chicago facility, the plant manufactures pharmaceuticals and some agricultural products, such as gibberellic acid, a plant growth hormone. As you might imagine, this type of work will produce a challenging mix of constituents.

Bill Dickman, manager of waste treatment operations, explained, "All of the wastes are biologically degradable. They're just a lot stronger than you would see in a municipal plant."

Abbott Laboratories has come a long way since 1888, when Dr. Wallace C. Abbott, a practicing physician and drug store proprietor, founded the Abbott Alkaloidal Co. It now is a global, broad-based health care company.

Process water generated from bulk pharmaceutical manufacturing and research and development work is managed at the on-site, 2-million-gallons-per-day (design average flow) wastewater pretreatment plant. The plant uses anaerobic digestion of high-strength waste, activated sludge to reduce carbonaceous waste, and nitrification/denitrification to manage ammonia. Dickman noted that Abbott has recently fine-tuned its instrumentation and pumps, but the last expansion of the plant was 10 years ago for the nitrification/denitrification process.

The influent has an average biochemical oxygen demand (BOD) concentration of 2,000 mg/L and chemical oxygen demand (COD) of 6,000 mg/L. The average BOD level in the effluent is less than 10 mg/L, and the COD is less than 200 mg/L. Dickman, who manages 11 operators, one maintenance coordinator, and three laboratory employees, said he was most proud of his facility's "excellent removal rate."

The effluent is discharged to North Shore Sanitary District’s publicly owned treatment works. Dickman noted that wastewater from the North Chicago facility makes up 8 percent of the district's flow.

The district is the second largest sanitary district in Illinois, encompassing an area from the Wisconsin border (north) to Lake-Cook Road (south) and from Lake Michigan (east) to I-94 Tollway (west).

FYI: These and all other WEFTEC.08 tours are sold out.