AC15_Session24_FMcNeill

Big Pipe… Deep ExcavaUon… Downtown LocaUon… Equals ExciUng Project… NEWEA 2015 Annual Conference & Exhibit Tuesday, January 27th Session 24 Frederick J. McNeill, P.E. City of Manchester, NH Richard V. Davis III, P.E. Jared T. O’Donnell, P.E. CDM Smith Manchester, NH Big Pipe – 60 inch ID, 72 inch OD Deep ExcavaUon – 26 feet Downtown LocaUon Verizon Wireless Arena Equals ExciUng Project PresentaUon Agenda • 
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Background Manchester’s CSO Program Contract No. 1 -­‐ Chestnut Street Project What’s Next? QuesUons City of Manchester, NH •  Largest City North of Boston -­‐ 109,000 populaUon •  Sealed in 1725 •  Evolved from Agricultural to Industrial: 1725 -­‐ 1815 •  Amoskeag Mills: Largest single mill in the world 1915 •  Post Industrial Depression: 1930 – 1980’s •  RevitalizaUon: 1990 to Present •  RevitalizaUon = “ManchVegas” WWTP – Facts and Figures • 
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1975 – 26 mgd 1994 – Upgrade to 34 mgd 2015 – Upgrade to 42 mgd Serves four communiUes Metro pop. 172,000 2014 – 24 mgd avg. “Combined” system Sewer System Facts and Figures • 
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385 Miles of sewer 11,000 SMH 10 pump staUons Over 100 miles is over 100 years old 55% combined system 5 perennial streams contribute up to 5 mgd of dry weather flow Stormwater System Facts and Figures •  180 miles of drains –  14,000 CBs –  3,000 DMHs •  Not designed for today’s populaUon •  Not designed for today’s impervious area •  Not designed for today’s wet weather events impacted by climate change Manchester’s CSO History • 
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EPA issued naUonal CSO Policy in 1994 NegoUaUons w/ EPA mid/late 1990s Manchester’s CSO Compliance Order issued 1999 Two phase approach –  Phase I: West Side –  Phase II: East Side Phase I: 1999 – 2009 West Side of City •  Scope of Work –  10-­‐year $58 million program –  Fully separated 15 basins –  8 construcUon contracts –  Over 53 miles of new or rehabilitated piping up to 60” diameter AddiUonal Benefits and Upgrades •  Road reconstrucUon (26 miles) •  Other uUlity construcUon –  Water (9 miles) –  Gas (14 miles) •  Surface reconstrucUon –  Curbing (8 miles) –  Sidewalks (6 miles) –  Pedestrian Ramps (290) Phase I CSO Abatement Program– Surpasses all Goals! •  Average annual CSO discharges decreases by 99% from 53.2 mgd to 0.2 mgd •  Goal was three-­‐month level of CSO control, program achieved two-­‐
year level of CSO control •  Merrimack River water quality increases •  Manchester’s west side received full infrastructure upgrade; sewer, drain, water, gas, road, sidewalks, and curb •  Ten year program was completed on schedule and on budget Lessons learned from Phase I -­‐ Biggest bang for $$$ •  Do all infrastructure work at once –  How do our residents benefit? •  Address sewer backups •  Address street flooding –  What do our residents want? •  Roads, sidewalks, and curbing Manchester’s Future CSO Work •  Phase II -­‐ $165 million over 20 years – 
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$20 million in WWTP improvements $3 million in system opUmizaUon $65 million for removal of Cemetery Brook $73 million in sewer separaUon $4 million in program assessment/
reporUng •  Phase III -­‐ $177 million over next 20 years Phase II CSO Abatement Program Contract No. 1 Chestnut Street Sewer SeparaUon Project •  Design – 2012 – 
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RouUng AlternaUves Modeling Cemetery Brook Conduit Cemetery Brook Conduit ConnecUon Road ReconstrucUon, new curb/sidewalk Special Structures Bike lanes (1st in Manchester) CoordinaUon with Stakeholders AddiUonal ConstrucUon Challenges •  ConstrucUon – 2013 –  4400 LF of new drain (15” – 60”) –  1640 LF of new sewer (6” – 12”) –  2670 LF of new water main (6” – 20”) •  Final Paving – 2014 •  Total Project Costs -­‐ $6.60 million RouUng AlternaUves Hydraulic Modeling •  Used SWMM model from Phase II LTCP •  Northeast Regional Climate Center (NRCC) 25-­‐year storm –  Factors more recent events to incorporate climate change •  Comparable to 50-­‐year Manchester Long Term Record Cemetery Brook Conduit •  ExisUng 10-­‐s x 8-­‐s concrete box culvert –  Built in 1926 –  18-­‐s below exisUng grade ConnecUon to Cemetery Brook Conduit •  New 8-­‐s diameter connecUon structure on top of box culvert •  Saw cut 7-­‐s diameter hole in culvert roof Special Structures •  Crossed over 60” brick combined sewer –  New 54” DI set on concrete pillars •  New Sewer passing through New DMH (exisUng uUlity congesUon) –  16” DI sleeve with 12” PVC sewer Road ReconstrucUon, new curb/sidewalk •  Road reconstrucUon (12” reclaim) and final grade adjustments •  Curb reveal adjustments •  ADA compliant sidewalk/corners Bike Lanes •  1st bike lanes in Manchester •  Groundwork for bike lane extension in future project •  Coordinated with local bike support groups CoordinaUon with Stakeholders • 
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Verizon Wireless Arena Federal Building Hillsborough County Courthouse Manchester Central Fire StaUon 60-­‐inch RC Pipe •  60-­‐inch ID, 72-­‐inch OD •  8-­‐s long secUons 60-­‐inch RC Pipe Moved into Place •  CAT 375 Excavator InstallaUon 26 feet deep •  Double stacked 10’W X 20’L trench boxes with steel plaUng Pipe Rammed Home •  Come-­‐Along Method •  Pipe Puller Manhole SecUons •  Precast 8-­‐s diameter manhole riser secUon •  Precast 60-­‐inch RCP tee secUon being lowered Next up -­‐ North Chestnut Street Sewer SeparaUon Project QuesUons?