portland harbor dredge and cad cell project
TRANSCRIPT
Portland Harbor Dredge and CAD Cell Project
South Portland City Council Workshop July 2, 2019
1. Introductions
2. Project Need
3. CAD Cell Overview 4. Dredge Overview 5. Permitting 6. Costs and Funding 7. Schedule 8. Discussion
Agenda
• Cities of Portland and South Portland • The Portland Harbor Commission • Maine Department of Transportation • Friends of Casco Bay • The Casco Bay Estuary Partnership • Pier and Marina Owners • Lobster and Fishing Community • The Waterfront Alliance • Maine Congressional Delegation
Project Stakeholders, Proponents and Collaboration
Why Dredge?
• Historic sedimentation has made portions of immediate waterfront unusable
• Sediments not suitable for offshore disposal
• Legacy contaminants in sediments impacting benthic community and water quality
All harbors needs dredging eventually
Aspasia Marina during an astronomically low tide
Why Dredge?
Why Dredge?
Over 900 Boat Slips Support multiple yards and boat service businesses
South Portland’s vessel berthing assets are a regionally significant resource for boating and access to the water
Dredge and CAD Cell Overview
• In 2008 Normandeau completed Alternatives Analysis. Additional alternatives evaluated as part of 1998 and 2013 Environmental Assessments for Portland Harbor Dredge.
• A CAD Cell is the most cost effective and environmentally sound disposal option.
Why a CAD Cell?
Normandeau 2008
CAD Cell Fundamentals
CONCEPT • Between 250,000
and 300,000CY • 3:1 Slope in sides • ~ 50’ deep below
current bottom
CAD Siting
Criteria Technical considerations (Average) 1. Technical feasibility (CAD construction) 2. CAD Construction Cost 3. Area available for CAD (square footage) 4. Operational efficiency (during use of the CAD) 5. Influences on cap integrity 6. Land title Environmental/Habitat/Fisheries (Average) 7. Mapped shellfish beds 8. Water Quality (MEDEP rating) 9. Tidal Wading Bird Waterfowl Habitat 10. Lobster fishery (greater the effort the lower the score) Permitting/Public Feedback/Public Uses (Average) 11. State and Federal Agency feedback 12. Public uses (proximity to residential/recreational uses) 13. Public feedback 14. Navigational impacts (Federal Channel, moorage…) Scoring
Stakeholder Meeting July 18, 2016
CAD Cell -49 MLLW (with 1FT OD to -50MLLW) : 278,810 Cubic Yard Capacity
9.5 acres 800’x (400-600’ wide)
Geotechnical Boring/Sub-Bottom Profiling
CAD Cell Site Conditions
Site Characterization January 2017 Lobster Survey December 2017
CAD RIM Suitability Suitability Determination Remaining 14,000 cubic yards Testing requirements
• Owner outreach and dredge feedback
• 32 pier/waterfront owners • Dredge footprints/volumes for
permitting and CAD sizing • Over half of current dredge
volume from South Portland
Target Dredge Areas
Dredge Site Conditions
Sample locations prioritized based on the following:
• Representative dredge depth • Location relative to CSO or
storm-water outfall/historical use
• Inner and outer portion of dredge area
• 30 vibracore locations • 15 composite samples
Sampling and Analysis
Vibracore Sampling
Eelgrass Surveys
Lobster Surveys
• Multiple permitting project meetings with agencies
• Umbrella permit by the Portland Harbor Commission for wharves and marinas
• CAD Cell permit through the City of Portland and South Portland
• Submerged Lands Dredge Leases
Applications
Project Costs and Funding
Up to 278,000 cubic yards of material Approximate Dredge Costs $15,000,000 Approximate CAD Costs $15,000,000 Funding Sources (assumed) Municipal Funds (Portland and South Portland) Tipping Fees – Private and Public State Transportation Bond Funds Federal “BUILD” Grant (TIGER) Federal Port Infrastructure Discretionary Grant
• Permit submittals- October 2019 • Permits received- May 2020 • BUILD grant application- July 2020 • CAD cell construction- winter 2021/2022
• Harbor dredging- 2022-2027
Project Schedule
Discussion/Questions