Wastewater Treatment Department

The City of Norwalk's Wastewater Treatment Plant, located at 201 Plank Road, is designed to treat an average flow of 3.5 million gallons of wastewater a day, with a peak flow of 8.2 million gallons a day. The plant operates around the clock. 2024 average daily flow was 2.45 mgd.

Wastewater from throughout the city travels through a series of pipes and pumping stations into two 24-inch interceptor sewers that lead to the plant. The wastewater is subjected to a complicated treatment process before being released as clean water into the west branch of Rattlesnake Creek.

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2020 Annual CSO Report

2021 Annual CSO Report

2022 Annual CSO Report

2023 Annual CSO Report

2024 Annual CSO Report

2023 CSO 4 Hour Event Notifications

1-3-23, 1-12-23, 1-16-23, 1-19-23, 2-9-23, 2-22-23, 2-28-23, 3-3-23, 3-22-23, 3-25-23, 4-1-23, 4-28-23, 6-11-23, 6-13-23, 6-15-23, 6-26-23, 7-6-23, 7-12-23, 7-26-23, 8-12-23, 8-23-23, 11-17-23, 11-21-23, 11-26-23, 12-9-23, 12-27-23

2023 CSO 7 Day Event Notifications

1-3-23, 1-12-23, 1-16-23, 1-19-23, 2-9-23, 2-22-23, 2-28-23,3-3-23, 3-22-23, 3-25-23, 4-1-23, 4-28-23, 6-11-23, 6-13-23, 6-15-23, 6-26-23, 7-6-23, 7-12-23, 7-26-23, 8-12-23, 8-23-23, 11-17-23, 11-21-23, 11-26-23, 12-9-23, 12-27-23

2024 CSO 4 Hour Event Notification

1-9-2024, 1-26-2024, 4-1-2024, 4-10-24, 4-29-24, 5-9-24, 5-14-24, 5-17-24, 5-26-24, 5-30-24, 6-5-24, 6-21-24, 6-29-24, 7-4-24, 7-10-24, 7-11-24, 7-23-24 8-2-24, 8-6-24, 9-25-24, 10-15-24, 11-10-24, 11-14-24, 12-9-24, 12-15-24, 12-29-24

2024 CSO 7 Day Event Notification

1-9-2024, 1-26-2024, 4-1-2024, 4-11-24,4-29-24, 5-9-24, 5-14-24, 5-17-24, 5-26-24, 5-30-24, 6-5-24, 6-21-24, 6-29-24, 7-4-24, 7-10-24, 7-11-24, 7-23-24, 8-2-24, 8-6-24, 9-25-24, 10-15-24, 11-10-24, 11-14-24, 12-9-24, 12-15-24, 12-29-24

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