About this Project:
The Nut Island Headworks Odor Control and HVAC Systems Improvements project involves an extensive rehabilitation of the facility that will ensure that Nut Island continues to work as designed. Odor Control facility access, fuel tank replacement and other appurtenances will be rehabilitated. This project will take approximately 36 months to complete. Walsh Construction will be performing this work in phases Monday through Friday between the hours of 7AM-3PM.
The first phase of work will begin on Tuesday, April 21, 2020. The work involves the installation of erosion controls (silt fencing and straw waddles), catch basin inlet protection, tree protection, temporary chain link fence and concrete barriers delineating work zones. The initial work will be followed by establishing a temporary construction laydown area. Once these activities are complete, the next phase of work will begin in May at the Nut Island facility.
Public Access Plan
Public Access paths will remain open during construction. Please obey all posted signage on site.

Exterior sluice gate area
MWRA Contact:
If you have any questions please contact MWRA Public Affairs.
To receive electronic project updates, please register your email address with the MWRA Alerts Service, provided through Everbridge.
Updates
June 29, 2022
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Constructing stair 12 Masonry and tie into existing bench structure
April 28, 2022
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Odor Control Stainless FRP Duct
Odor Control FRP Duct Installation
Wet Scrubber Rehab and Chemical Pumps
Odor Control Fan #2 (fan and damper controls)
AHU-3 & 4 rigging (Truck Bay hatch hoist)
March 31, 2022
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Odor Control Stainless Steel Duct Installation
Odor Control FRP Duct Installation
Wet Scrubber Rehab (Chevron Mist Eliminators, spray nozzles and media)
Stair 12 at ground level. Masons will begin building a stair tower.
Air Handler Replacement (AHU- 1 & 2) will serve pump and blower room
March 3, 2022
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Odor Control Duct Installation at Wet Scrubbers
Air Handler Replacement (Pump & Blower Room)
February 3, 2022
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Odor control fan #1 and 2 pads
Wet scrubber & 90-inch Duct Demo
Elevated walkway platform (access to dampers and controls)
8-inch Sanitary Ejector Piping
January 5, 2022
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New fuel oil tanks in service
Odor Control Fan Headers (new fan on left, old fan on right)
Caustic storage tanks and pumps
November 3, 2021
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Utility relocation at Stair 12 (Building code requires new egress path)
HVAC duct replacement in Grit Area
Underground fuel oil tank piping and wiring
Breeching for new boilers
September 28, 2021
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Setting one of the 20,000 Fuel Oil Storage Tanks
20,000 Gallon Underground Fuel Oil Storage Tanks in place
Odor control duct being rigged into the odor control room
Wet Scrubber #3 Inlet Duct fitup
Carbon absorber #1 demolition
September 7, 2021
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Temporary OC Duct (preliminary testing to test flow for changes)
Temporary Supply Air Fans
Excavation for new underground storage tanks
August 6, 2021
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Portable CAD Unit (ductwork outside)
April 27, 2021
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Fan 4 intake (suction) prior to installation of additional Odor Control Duct
Exhaust from fan 4 as it enters the header
Odor control room (future hypochlorite location)
Sub-contractor prep work to get fan up and running
New stainless steel ducts in grit level
March 31, 2021
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Odor Control Fan #4 set in place & grouting base frame
New Odor Control SCADA cabinet set in pump and blower room
New caustic tanks set in place
Chemical fill piping for sodium hypochlorite and sodium hydroxide
Temporary carbon absorber unit
HVAC duct work in screen room
Work at spillway, finishing grouting rails and planning stop logs
March 2, 2021
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Stop log frames being ins stalled in the emergency spillway
Stop log frames being ins stalled in the emergency spillway
90-inch odor control fan header installed
Forms for new odor control dan foundation
Caustic storage tanks delivered and stored on site
February 3, 2021
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Temporary Ductwork at grit level
Temporary duct system to provide ventilation while existing ductwork gets replaced
Temporary fans to provide ventilation while air handlers get replaced
Outdoor roof and removable covers and ductwork being delivered to site
New 90-inch Odor Control Header being rigged into place
New odor control fans being shop tested to confirm operation
December 14, 2020
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90-inch duct and dampers removed from odor control room
Sawcutting walls in Grit Room for temporary duct work
Temporary ductwork in Grit Room prior to replacing new ductwork
Sluice gates at emergency spillway that will be replaced
Portable operator to close spillway gates if power is lost.
October 29, 2020
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Demolition of sodium hypochlorite containment wall
Site of future sodium hydroxide (caustic) storage tanks and pumps
Ductwork from grit area to feed odor control room
Next month's work at emergency spillway stop logs and sluice gates
October 2, 2020
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Odor Control Roof with removable covers for equipment access to wet scrubbers and CAD-1
Temporary waterproofing at removable concrete planks on Odor Control Roof
Ductwork and heat exchanger below removable roof planks that will be demolished in Odor Control Room
Demolition of existing wet scrubber recirculation pumps

Electrical conduits installed in the Odor Control Room to power new equipment
June 16, 2020
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Contractor establishing work zone with concrete barriers, fences and screens at the Odor Control Roof
Contractor removing soil from Odor Control Roof
Location of new odor control fan that will replace the fan that was damaged in the 2016 fire
April 22, 2020
Project updates will be posted throughout the period of construction.