Water and Wastewater Rates

Components of Your Water and Wastewater Bill

Fixed User Charges

As of January 1, 2020, the following fixed water/wastewater user charges are in effect for Naperville Water Utility customers:

For more information on Naperville's water and wastewater rates, please read the 2017 Water Rate Study section of this webpage.

Phosphorus Surcharge

A graduated phosphorus surcharge was introduced in 2017 for wastewater customers. These phosphorus surcharge funds will be utilized to fund 50% of the Illinois Environmental Protection Agency-mandated Springbrook Water Reclamation Center improvements to reduce the amount of phosphorus discharged from the facility. Work on the improvements is anticipated to begin around 2025. The phosphorus surcharge will expire once funds collected are equal to 50% of the cost of improvements.

 Jan. 1, 2020Jan. 1, 2021
Monthly Surcharge $1.80 $1.80

DuPage Water Commission/City of Chicago Costs

The wholesale water rate on customer bills is a direct pass-through of the water rate charged by the DuPage Water Commission (DWC), the City of Naperville’s water supplier. The wholesale water rate component is determined by the DWC based on the City of Chicago’s water rates.

In May 2019, the DWC wholesale water rate increased from $3.70 to $3.72. To accommodate this increase, the average residential water customer (using 5,610 gallons or 750 cubic feet) saw their monthly bill increase by $0.15 per month starting June 1, 2019.

Unincorporated Customer Surcharge

Unincorporated Naperville water customers pay a 10% surcharge on water rates. These customers' bills will have wholesale, retail and monthly customer service charge rates 10% higher than the rates in the above PDFs, which apply to incorporated Naperville customers.

2017 Water Rate Study 

Planning for the Future

In 2017, the Water Utility conducted a rate study to help plan for its financial needs through 2021. Throughout the study, the utility considered the costs of day-to-day operations, critical infrastructure improvements needed to ensure continued reliability and upcoming Illinois Environmental Protection Agency regulations that would require phosphorus removal improvements to the Springbrook Water Reclamation Center.

A new rate structure was put into place in May 2017 to meet these needs. However, during the 2018 budget process, discrepancies were noted in the Water Utility’s year-to-date financial performance that ultimately led to the discovery of three errors in the 2017 rate study. These errors resulted in the utility’s actual revenues and expenses differing significantly from what the rate study projected. Without intervention to fix the errors, the utility would be underfunded for the foreseeable future. 

The rate increase that went into effect on January 1, 2018, provides the utility with a structurally balanced budget where revenues fully cover operating expenses and capital improvement costs beginning in 2018. In addition, the new rates begin the process of rebuilding the utility’s required cash reserves within the coming years. 

2020-2021 Rates

An average residential water/wastewater customer will see the following average monthly utility bills in 2020 and 2021 under the rate structure approved in January 2019. 

YearAverage monthly bill 
2020 $81.73
2021 $83.19