Water and Wastewater Rates
What Makes Up Your Water and Wastewater Bill
Water and Wastewater Utility customers pay various charges that cover the cost of providing water and wastewater services and maintaining the utility's equipment and buildings.
A fixed user charge provides a stable revenue source to cover the utility's fixed costs, while volumetric charges are based on how much water is used. The following water/wastewater user and volumetric charges for incorporated Naperville customers are in effect for 2025:
Water/Wastewater Rates for 2023-2025
Additional charges you will see include:
- Water Capital Charge - This provides a stable revenue source for the utility to consistently maintain and improve the equipment and facilities that deliver water regardless of how much more or less water is used year-over-year.
- Phosphorous Charge - This is used to fund half of the Illinois Environmental Protection Agency-mandated Springbrook water treatment plant improvements to reduce the amount of phosphorous discharged from the facility.
- 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 DWC determines the wholesale water rate each year in April to go into effect on May 1.
- Unincorporated Customer Charge - Unincorporated Naperville water customers pay a 30% surcharge on water rates. These customers' bills will have wholesale, retail, and monthly customer service charge rates 30% higher than the rates noted in the PDF above.
2025 Residential Rates
The Naperville Water Utilities' last rate study took place in 2021 to address financial needs through 2024. Carollo FMG, a third-party consultant, conducted a rate study in the summer of 2024 to determine the appropriate rates to charge in 2025 to support Water's service and improvement plans in 2027.
The Water Utilities are in the middle of several significant infrastructure projects that influenced the most recent rate study. Over the next several years, the improvement program for water and wastewater assets will grow signficantly due to regulatory requirements and the age of the utility's system. The information supporting these needs was gathered through a 2020 asset evaluation of the water distribution system, which found that the City is more than 50 miles behind on water main replacements. While replacement work has increased from one mile to three miles of pipe annually, it remains well behind recommendations. Continued efforts will replace more water mains to minimize breaks and service disruptions.
In addition, a 2021 asset evaluation of the Springbrook water treatment identified several now-underway improvements necessary to meet new mandated environmental standards and capacity expansion. This is the largest capital improvement project in the City's history and will continue until 2030.
With these factors in mind, starting in January 2025, the average residential combined water/wastewater bill, defined as a customer who uses 800 cubic feet of water per month, will be $110 per month. For communities in DuPage County that provide water and wastewater service, the average bill is $120, keeping Naperville customers below the regional average.