1. The 72" outfall pipe for the new storm drain has been installed and awaits the final backflow prevention and connection to the box culvert.
2. Preble Street has been paved and crews will continue to put the curbing and sidewalk back together.
3. Tank 1 and 4 continue to go vertical with the rebar.
4. Crews are working on a schedule that provides weekly concrete pours. This is the corner of Tank 4.
Week Ending 4/30/2020 Update
1. The rebar within Tank #4 has gone vertical with crews working on the wall sections.
2. Riprap installation along Back Cove to accommodate the new pedestrian and traffic pattern at the intersection of Preble Street and Baxter Boulevard.
3. The new CSO 16 diversion structure has been installed at the intersection of Preble Street and Baxter Boulevard.
4. Preparing the final grades for Preble Street to be paved.
5. Box culvert at Exit 7 has almost reached Marginal Way.
6. Exit 7 coffer dam and storm drain installation ongoing.
**MAJOR TRAFFIC ALERT** Preble Street at Baxter Boulevard Traffic Impacts Begin April 13 Construction work is part of Back Cove sewer separation project
PORTLAND, Maine -- The ongoing work on Preble Street will move into the intersection of Baxter Boulevard beginning April 13th. Access to northbound Baxter Boulevard will be restricted. A detour will be established sending traffic to Forest Avenue. Baxter Boulevard southbound will be detoured at Darmouth Street sending traffic up to Forest Avenue. Barricades and detour signs will be set up directing traffic. These closures are part of the City’s Back Cove South Storage Facility Project, and are necessary in order to connect the existing utilities within the intersection of Marginal Way and Franklin Street to the new storage tanks under the Preble Street playing fields. The project is one of the City’s latest sewer separation projects to prevent combined sewer overflows into Back Cove. The work to reduce overflows is part of the City’s agreement with the U.S. EPA to reduce and eliminate the flow of combined waste being discharged. A combined sewer system transports wastewater from home, industries, and businesses, as well as storm water collected from streets, parking lots, roofs, and yards to the East End Wastewater Treatment Plant. A combined sewer overflow occurs when the combined sewer capacity is overwhelmed during heavy rain events and a mix of sewer and storm water is discharged into Back Cove.
For the week ending 3/21/2021
Despite a bitter cold start to the week Sargent crews continue to make progress with the installation of sewer on Preble Street at a depth of 23 feet.
The dewatering system on Preble Street continues to keep the trench dry.
Sewer manhole #4 was placed by the end of the week.
Meanwhile at Exit 7 the dewatering system was installed.
The Exit 7 storm drain transition pieces have started to arrive.
And were subsequently installed.
For the Week ending March 12, 2021
As a reminder for the travelling public - Exit 7 Southbound on the I-295 will be closed starting Monday morning. Please see Alternate Routes.
NS Giles and Bill Dixon Rebar completed the assembly of the deep sump for Tank #1 to allow for the concrete to be poured Friday morning.
Work began in Preble Street with the installation of the dewatering wellpoint systems.
Followed by the installation of sewer manhole #3 in Preble Street.
And the installation of new sewer pipe.
Sargent Corp has additional aerial pictures taken of the site which can be found on their Facebook page.
Project Milestones as of March 5th, 2021.
As of this morning, the first of four CSO tanks has had the complete concrete base slab placed. Approximately 1,900 cy of concrete have been placed for it. Also as of this morning, the first sewer manhole structure of the Preble Street CSO pipe has been set. The base elevation is approximately 22 feet below the pavement on Preble Street.
For the week ending February 26th, 2021
It has been 2 weeks of very active work on the site as N.S. Giles completed the third major concrete pour of the project on February 24th with 940 cy of concrete being delivered by Auburn Concrete trucks for part of the Tank #4 base slab.
The gravels and additional steel support of the sump areas is complete and both areas are having rebar installed. A small pour of concrete on the sump of Tank 4 was completed.
N.S. Giles and Bill Dixon Rebar are working to complete the last rebar frame/ matting for the base of Tank 1. This will complete the base slabs for both Tank 1 and 4.
Tank 4 sump area excavation complete with stone and extra steel support
Development of the rebar grid for tank 4
Enclosure for Tank 4 sump concrete pour created
Rebar grid of Tank 4 prior to concrete placement
Week of February 21st
The next phase of the Back Cove South Storage Facility Project will begin Wednesday, February 24 with the preparation for pipe installation in Preble Street, from the Back Cove soccer fields to Baxter Boulevard. Traffic control devices will be installed to provide for a safe work environment within the street ROW and will be adjusted daily as work progresses. Please adjust your driving accordingly when progressing through an active construction area. For more information please visit the Public Works website.
For the week ending February 5, 2021.
It was another active week as contractor N.S. Giles completed the second concrete pour of the project on February 4th with 843 cy of concrete being delivered by 85 Auburn Concrete trucks for part of the Tank #1 base slab.
Sargent continues on the northern excavation of the sump area with the removal of soils and the installation of additional steel bracing.
N.S. Giles and Bill Dixon Rebar have begun the third rebar frame/ matting for the continued base of Tank #4.
The City's contractor, Sargent Corporation, continues work on the northern excavation of the sump area with the removal of soils and the installation of additional steel bracing.
Everyone watches the first concrete pour cure.
And the primary subs onsite, N.S. Giles and Bill Dixon Rebar, continue with the preparation of the next rebar frame/ matting for our second pour next week.
For the week ending January 22, 2021
The City's contractor, Sargent Corporation, and N.S. Giles, our concrete subcontractor, hit a major milestone this week with the first concrete pour of the project within Tank #4. Starting under lights in the early morning, 780 cubic yards (78 truck loads) were delivered to the site on Wednesday. With over 40 people onsite either actively working or inspecting/ observing the operation went smoothly and everyone walked away from the day with a sense of accomplishment. This first pour represents approximately 5% of the total concrete that will be placed for the project.
On the other end of the excavation, the placement of the rebar matting began for Tank #1.
For the week ending January 15, 2021.
The City's contractor, Sargent Corporation, has completed the placement of the gravel borrow that will serve as the base for the tanks.
N.S. Giles, our concrete subcontractor, continues with the placement of the rebar matting for Tank #4.
The first concrete pour should be next week.
Temporary forms for the concrete pour
Water infiltration through the sheet piles. We continue to pump 24/7
Waterstop being secured
Stone for fine grading of the base
Week of January 10, 2021
The City's contractor, Sargent Corporation, has completed the excavation with the exception of the deep sumps at either end.
The placement of the gravel borrow that will serve as the base for the tanks continues.
N.S. Giles, our concrete subcontractor, has mobilized to the site.
The NS Giles crew has begun the placement of the rebar matting for Tank #4.
The City Council has approved an easement to bring CMP power onto the site.
Week ending December 18, 2020
Construction activities were slower this week as the project was dealing with vandalism which destroyed equipment and pumps over the past weekend and the snow event Thursday. Once resumed, active placement of the granular material continued. This material will serve as the base for the tanks and numerous geotechnical engineers visited the site to evaluate the material and compaction efforts. Two concrete spanning beams were placed to provide additional bracing at the bottom of the excavation between the sheet pile walls.
The team at Sebago Technics, which is providing our project oversight and inspection services, also provided us this week with the below link to aerial drone footage from the site.
Week of December 13, 2020: The City's contractor, Sargent Corporation, has reached the bottom of the excavation and has begun placing the granular material which the concrete tank will sit upon.
Week of November 30, 2020: The BCSSF hit a milestone last week with the completion of the sheet pile support bracing. Excavation continues from the mid-level steel bracing (Elevation -14) to the bottom of the proposed concrete slab (El. -25).