VIRTUAL TOUR

North Shore Water Reclamation Facility (WRF) Virtual Tour

North Shore Water Reclamation District (NSWRD) manages 3 WRFs (Gurnee, Waukegan, and Highland Park) and 1 Biosolid Recycling Facility (BRF) in Zion. Each WRF deploys slightly different methods to accomplish all phases of the wastewater treatment process. NSWRD’s wastewater treatment processes are designed to reduce pollutants found within wastewater. The major pollutants that we treat are: Suspended Solids, Biochemical Oxygen Demand (BOD), Phosphorus, Ammonia, and Pathogens (bacteria and viruses). Solids are removed during the liquid treatment process and further treated in a separate process within the facility. Theses recovered solids then dewatered and dried into a Class A Biosolid that local farmers utilize as a fertilizer. The following virtual tour will guide you through each process.

General Information

NSWRD’s 3 WRFs have the capacity to treat 119.2 million gallons of wastewater per day (mgd) with an additional 108 million gallons of storage capacity to handle excess flows. NSWRD averages thousands of lbs of dry suspended solids per day.

Click here to see an overview of the water reclamation cycle.
Click here to see the wastewater treatment process steps.

Preliminary Treatment

Bar Screens

Influent sewage debris is screened through bar screens. In this section, automatic bar screen rakes remove large solids (wipes, plastics, etc.) from the raw sewage. All debris is then collected in dumpsters and periodically taken to landfills.

Grit Removal

After screening, the sewage moves to a process for grit removal. The NSWRD facilities utilize multiple technologies for grit removal. The general premise is to remove abrasive inorganic solids such as rocks, sand, coffee grounds, to protect downstream equipment. The grit (mostly inorganic solids) goes to a dumpster which is periodically disposed of in landfills.

Primary Treatment

Primary Clarifiers (Primary Settling Tanks)

Larger settleable solids and floating materials are removed from the wastewater in the primary clarifiers. This significantly reduces the load on the aerators and increases efficiency. This process can remove the majority of the suspended solids as well as significant amount of the Biochemical Oxygen Demand (BOD) from the wastewater

Secondary Treatment

Activated Sludge

After primary clarification, wastewater moves to secondary treatment. NSWRD utilizes a process called activated sludge, which is one of the most widely used treatment processes to remove organic pollutants Wastewater is sent through a series of tanks where micro-organisms are used to remove biochemical oxygen demand (BOD), ammonia, and phosphorus. These micro-organisms require a balance of food and oxygen, so the activated sludge can convert organic substances into oxidized products and a settleable floc. This floc is settled out in the secondary clarifiers.

Click here for a history of activated sludge.

Secondary Clarifiers (Final Settling Tanks)

After aeration, the treated sewage and bacteria enter the secondary clarifiers. This process removes additional suspended solids.

Tertiary Treatment

Sand Filters

Sand filtration is an effective method for treating wastewater before it is discharged into the environment. Wastewater is pased through layers of sand where contaminants are physically captured or biologically treated.

Disinfection

UltraViolet Disinfection

Prior to return of effluent water to the watershed, the flow is passed through UV lights. This process will damage DNA of any living bacteria, preventing it from replicating. Using UV light to disinfect wastewater has been around since 1903, when Scandinavian scientist Niels Finsen was awarded the Nobel Prize in Physiology in 1903 for his work in this area.

Effluent Discharge

The final step of the Wastewater Reclamation Process is to return the effluent discharge to the watershed.

Gurnee and Waukegan WRF Effluent is discharged to the Des Plaines River. Clavey Road Effluent is to the Skokie River.

Solids Handling

Gravity Belt Thickeners

Settled solids from the facilities are first treated using gravity belt thickeners to reduce the moisture content. The solids are then either sent to storage tanks or anaerobic digesters for further treatment.

Anaerobic Digesters

All bacteria that perform digestion and secondary treatment are naturally occurring in the wastewater.

Our digesters allow us to create and manage the conditions in which these beneficial organisms can grow and thrive. These bacteria do not need oxygen (anaerobic) and will digest and dissolve the solids to their base components, reducing mass by nearly 50% in 30 days. Digesters produce a stable sludge ready for dewatering.

Filter Press/Dewatering

After digestion, the sludge is pumped to the belt filter presses where a chemical flocculent is added to further separate the water from the solids. Additional dewatering occurs when the remaining solids are squeezed between two belts.

Truck Hauling

Sludge from Waste Treatment Facility is loaded and transported to Biosolids Recycling Facility for final reduction and recycling.

Biosolids Recycling Facility (BRF) - Drying

The solids extracted from the WRFs contain a solid content ratio of about 18% – 20% solids. These solids are trucked to our BRF facility where a drying process removes additional water. The resultant granules contain about 95% solid and are shipped to local agriculture for fertilization.

Other

Odor Abatement

Our responsibility to a clean environment doesn’t stop at water. Since our facilities reside near populated areas, we remove malodorous smells from the air through safe chemical abatement methods. As a responsible neighbor, we are quick to respond to odor complaints to ensure not only community harmony but that the release of odor is not a signal of other process failures.

Emergency Generators

In the event of general power outages, NSWRD has emergency generators to enable us to continue to process waste while fuel supplies last. Working with ComEd, we perform periodic tests to insure proper functionality and compliance with statutes.

Technology

We use state of the art Allen Bradley PLCs to run our pumps, meters, valves, and other necessary equipment. Using state-of-the-art Supervisory Control and Data Acquisition (SCADA) tools, our trained operators, technicians, and engineers can constantly monitoring the data (over 4,000 data points) to identify alerts needing corrective action before they can become major issues.