The Thornton reservoir has been in operation for 11 years, but residents say a persistent smell of raw sewage continues to spread through the village when heavy rain combines with heat, sometimes lingering for days. As of Thursday afternoon, the reservoir was 89% full, down from a record 94% level reached several days ago, following last weekend's storms. While the lower level eased flooding concerns, residents said the heavy rains brought another familiar problem. On Friday, the MWRD said says it expects to have two projects done by the end of the year to address the odor, totaling about $5 million.

The Metropolitan Water Reclamation District of Greater Chicago (MWRD) expects to have two projects totaling $5 million to address odor mitigation near its Thornton Reservoir completed by the end of December 2026, bringing total mitigation efforts over the past decade to $8.6 million, according to officials.

Video: Inside the command center of the MWRD, it has been all hands on deck. Between July 2 and July 4, about 8-10 inches of rain fell over 48 hours, creating a precarious situation at two of the district’s large deep tunnel reservoirs.

MWRD Executive Director John Murray joins WTTW to discuss how 13 billion gallons of combined storm and waste water flowed into two Cook County reservoirs this past weekend as part of the region’s network of stormwater management infrastructure.

Public comment period is open for MWRD’s draft 2026–2030 Strategic Plan; deadline is July 24

The Thornton Reservoir is nearly full.