Champaign‑Urbana Sanitary District says wastewater reuse and permit limits can limit aquifer impacts from data centers

The Champaign‑Urbana Sanitary District told the county task force on June 8 that wastewater reuse and clear permit limits can blunt local groundwater impacts if data centers are proposed.

Rick Manor, the district’s executive director, walked attendees through cooling options and local wastewater arrangements. Manor explained that air‑cooled chiller systems (closed‑loop) typically have near‑zero direct water impact, while cooling towers evaporate a large share of their intake water. As an alternative, he described wastewater‑fed cooling — a model the district has used in local industrial agreements — as “the greenest solution for an Illinois climate.”

Using a public example under discussion (Cronis fertilizer), Manor said the district negotiated an arrangement that protects instream flows and ratepayers: the contract would guarantee the first 1.5 million gallons/day to the creek, make up to 6.3 million gallons/day available for sale, and require the purchaser to build and fund pipeline infrastructure beyond the district fence. The district would build and operate pump infrastructure to its fence line and require a purchaser letter‑of‑credit and backup supply for drought conditions.

Manor also outlined monitoring and compliance: the district uses continuous sensors for flow, dissolved oxygen, pH and temperature, conducts frequent biochemical oxygen demand and solids testing, and runs an annual priority‑pollutant sampling program. He said the district duplicates many samples and enforces existing permit limits; any surface discharge would also require IEPA permits. Manor added that if a purchaser failed to pay or went bankrupt, contractual protections would protect ratepayers.

On local water balances, Manor said historical conservation and reduced distributed wastewater flows mean that one to four midsize data centers in the county would likely be manageable; larger or unregulated megasites would require detailed review. He recommended that the task force consider requiring chiller technology or wastewater reuse for large heat loads and that applicants disclose wastewater handling in permit applications.

The task force asked staff to circulate standard permit conditions and examples; Manor said such conditions and contractual protections are feasible and have precedent in the district’s practice.