Odor Control
Odor Control Systems
Since 1996, the District has been operating wet chemical scrubbers and biological odor control systems to reduce odors at the source. In addition, the District has placed covers over many process tanks to eliminate fugitive odor emissions from escaping into the atmosphere and traveling outside of the facility into residential neighborhoods.
In May 2012, the District embarked on the Nitrogen Upgrade Construction Project that as of July 1, 2015, is 100% complete. As part of the upgrades to the facility new state-of-the-art odor control systems, including carbon canisters and wet chemical scrubbers, are being installed to replace all of the existing aging odor control systems.
The District takes great pride in these new state-of-the art odor control systems, which should greatly improve our ability to ensure that odors are reduced and/or eliminated. In addition, the District will be covering the septage and sludge handling facility to reduce fugitive emissions from these processes.
Recent Odor Issues
The new odor control systems are on-line, and the existing systems have been taken off-line. The District has invested significantly in all fugitive odor emissions since 2014 with new equipment and annual maintenance. The District has the most state-of-the-art Nitrogen removal equipment and as a result we have seen a 94% reduction between 2015 and 2019. Odors have dropped 24% between 2015 and 2023.Odor Monitoring
In addition to the chemical, biological and enclosed process systems, the District will also be installing state-of-the-art, fence-line Jerome odor monitoring meters, designed specifically for fence-line monitoring applications. Real-time H2S readings are displayed at the Operations Control Room to alert an operator. These, in conjunction with weather data, will be assessed to determine fugitive odor emissions from the facility.Reporting Odors
Odors can be reported to the District by downloading and filling in this form, then email it back to us.
See PDF for instructions:
REPORT ODOR FORM (PDF) Once an odor is reported, the District immediately dispatches a field operator to the reported location to investigate. In addition, our treatment process and activities being conducted are reviewed to ensure that these do not generate odors.
If your complaint needs immediate attention, please call (860) 635-5550 ext 240.
The District conducted 60 odor surveys in the period between January 2025 to the end of
November 2025, and has found odors inonly 4 of those surveys. See the table below.
| ODOR MONITORING - ODORS DETECTED ON MAIN ST & SOUTH ST |
||||
| Preemptive Odor Surveys 1/1/25 - 11/30/25 | Preemptive Odor Surveys | |||
| Total | Odor Detected | Total conducted since 1/1/25 thru 11/30/25 | 60 | |
| 60 | 4 | Surveys with Odors | 4 | |
ODOR MONITORING - ODORS DETECTED ON MAIN ST & SOUTH ST |
||||
| Preemptive Odor Surveys 1/1/25 - 11/30/25 | Preemptive Odor Surveys | |||
| Total | No Plant Odors | Total since 1/1/25 thru 11/30/25 | 60 | |
| 60 | 4 | Surveys without Plant Odors | 56 | |
ODOR CONTROL PROJECTS |
START |
BALANCE TO |
Plant Odor Evaluation |
6/28/24 |
COMPLETED |
Centrate Pump Station Design & Middletown PS Bioxide Dosing Eval |
3/10/25 |
ON-GOING |
Centrate Pump Station - Materials |
10/10/25 |
COMPLETED |
Centrate Pump Station - Construction |
10/1/25 |
COMPLETED |
Odor Monitoring for CTREG 22a-174-23 & retest Middletown PS WW |
11/21/24 |
COMPLETED |
Middletown Pump Station Dosing Evaluation- continued |
10/13/25 |
ON-GOING |
Dewatering Bldg Chemical Tower Replacement Evaluation & Recommendation |
7/1/25 |
ON-GOING |
Dewatering Bldg Roll Up Door Replacement - Engineering Services |
6/27/24 |
ON-GOING |
Dewatering Bldg Roll Up Door Replacement - Engineering Services |
6/6/25 |
ON-GOING |
Dewatering Bldg Roll Up Door Replacement - Roll Up Door & Installation |
10/1/25 |
COMPLETED |
Dewatering Bldg Roll Up Door Replacement - Hawkeye |
3/12/25 |
ON-GOING |
Dewatering Bldg Roll Up Door Replacement - NIC |
3/12/25 |
ON-GOING |
TOTAL COST ODOR PROJECTS - $573,000.00 |
|
$128,000.00 |
| 2025-2026 CAPITAL & ODOR CONTROL PROJECTS |
START DATE | EXPECTED COMPLETION & REMAINING BALANCE TO COMPLETE |
| Facility & Equipment Assessment | 4/29/2024 | Evaluation Completed |
| Culverts Assessment in ROW | 4/29/2024 | Evaluation Completed |
| Load assessment for 14 Access Hatches & signs | 12/1/2025 | |
| Mercury Non-Compliance Evaluation | 2/24/2025 | Evaluation Completed |
| Dewatering Stairwell Structural Design | 8/15/2024 | Work Completed |
| Incinerator Regulatory Compliance | 7/8/2025 | Work On-Going |
| Culvert cleaning project - (design & permitting for 6 culverts) | 12/1/2025 | |
| Trunk sewer backflow assessment & modeling | 3/13/2024 | Evaluation Completed |
| Sludge storage blower motor replacement design | 4/15/2024 | Project Cancelled |
| Sludge storage blower motor replacement EVERSOURCE rebate application | 11/21/2024 | Project Cancelled |
| Plant Odor Evaluation | 6/28/2024 | Evaluation Completed |
| Centrate Pump Station Design & Middletown PS Bioxide Dosing Eval | 3/10/2025 | Work On-Going |
| Centrate Pump Station - Materials | 10/10/2025 | materials delivered |
| Centrate Pump Station - Construction | 10/1/2025 | |
| Odor Monitoring for CTREG 22a-174-23 & retest Middletown PS WW | 11/21/2024 | Evaluation Completed |
| DOE grant Assistance | 6/28/2024 | Work On-Going |
| GHG's Inventory & Benchmarking | 12/9/2024 | Work On-Going |
| Flood Vulnerability Study | 7/19/2024 | Work On-Going |
| Middletown Pump Station Dosing Evaluation- continued | 10/13/2025 | Work On-Going |
| Dewatering Bldg Chemical Tower Replacement Evaluation & Recommendation | 7/1/2025 | Work On-Going |
| Dewatering Bldg Roll Up Door Replacement - Engineering Services | 6/27/2024 | Evaluation Completed |
| Dewatering Bldg Roll Up Door Replacement - Engineering Services | 6/6/2025 | Evaluation Completed |
| Dewatering Bldg Roll Up Door Replacement - Roll Up Door & Installation | 10/1/2025 | Evaluation Completed |
| Dewatering Bldg Roll Up Door Replacement - Hawkeye | 3/12/2025 | Work On-Going |
| Dewatering Bldg Roll Up Door Replacement - NIC | 3/12/2025 | Work On-Going |
| Develop SPCC and Stormwater Plans per new requirements | 12/1/2025 | |
| Energy Rebates for Air Comressor System | 4/12/2023 | Evaluation Completed |
| TOTAL COST ODOR CONTROL PROJECTS | ||
| $573,000.00 | $128,000.00 | |
| TOTAL COST ALL PROJECTS | ||
| $950,000.00 | $370,000.00 | |