Odor Control Improvements

  • Client

    City of Newburyport

  • EP’s Role


  • Awards

    Engineering Excellence Silver Award, American Council of Engineering Companies of Massachusetts (ACEC/MA), 2020

Complaints of wastewater odor in the City of Newburyport, MA had been a longstanding problem near the City’s wastewater treatment facility. The facility is located near the commercial hub, Newburyport Center, and within a densely developed residential area. A recent multi-million dollar upgrade at the facility was unable to alleviate the odor problems, leaving residents and business owners with unresolved issues. Environmental Partners (EP) was hired to identify the location and cause of the odors, and design the needed upgrades. EP found that the odors originated from several specific process locations at varying intensities, but the greatest contributor was the discharge of a three-mile long force main at the head of the facility.

To quickly resolve the odor issues while the municipal budgeting process could be completed, the project was completed in three phases. The first phase consisted of chemical dosing equipment throughout the facility to reduce odors from anaerobic wastewater, funded by available budget allocated to the treatment facility. As part of the second phase, Environmental Partners structured the overall construction contract so the City could pre-purchase important equipment that had long delivery times. This would enable the City to begin construction prior to the next summer season. A third phase, concurrent with the second phase, involved improvements to the daily operations of the facility, with equipment upgrades completed by the operations staff. Several suggestions by the operators were incorporated into the design to improve odor capture and operator comfort and safety.

The project improved ventilation in the headworks and sludge processing rooms to reduce the risk of excess hydrogen sulfide and to capture a larger volume of air for treatment by an engineered media biofilter. The two primary clarifiers received flat aluminum covers, the headworks and grit wash room were fitted with booster fans and new ductwork, new make-up air units were installed in various work spaces, the gravity thickener ventilation was upgraded, a new septage receiving system was provided, and a 20,000 cfm biofilter system with dual blowers was constructed. A new chemical dosing facility was also added at a remote pump station to inject magnesium oxide for odor control at the force main discharge.

Environmental Partners engaged in an extensive public outreach with the Mayor’s office and City Council throughout this project, including public presentations, site tours, status meetings, website updates, and an odor complaint hotline. To date, over one year from project completion, not a single complaint of odors has been lodged.  Properties adjacent to the treatment facility are being marketed at premium prices without the liability of noxious odors, and attendance at the annual festivals in Newburyport Center continues to grow.