Presentation on theme: "Dredging our Ports and Harbors in Today’s Risk-Averse Environment Risks from the Perspective of Owner and Contractor: Contracts, Operations, Environmental."— Presentation transcript:
Dredging our Ports and Harbors in Today’s Risk-Averse Environment Risks from the Perspective of Owner and Contractor: Contracts, Operations, Environmental Jeffrey B. McWilliams CH2M HILL Houston, TX, USA
CH2M HILL is a Global leader in transportation and infrastructure consulting, with offices worldwide Port and Harbor design, planning, construction, dredging engineering, and security Flood control Design/build Highway and rail Environmental science and engineering Water and wastewater Selected to manage 2012 Olympics (London) 18,000 employees worldwide
Major risks related to dredging and port operations: What is the material type, where do we dispose of it, and how do we get it there? Contractual (easiest one first) Operational (day to day things) Environmental (we’ll save the best for last!) Guayaquil, Ecuador
Contractual Risks 1.Three types: Firm Fixed Price-Most of risk on Contractor, Owner assumes some (1 MCM x $1/CM = $1,000,000) Lump sum/turnkey-All risk to Contractor T&M or Rental-Most of risk to Owner 2.Most contracts are firm-fixed price (most owners willing to do research enough to accept a little risk, get better price). 3.Some common contracts are rentals; Lower Mississippi River, Mobile Bay and River, Alabama. 4.Turnkey projects are rare, and mostly seen on larger construction projects; more risk to contractor = higher price to owner. Bean Dredging’s TSHD ‘Stuyvesant’
Operational Risks In a free market, all responsible bidders can submit a bid…but how is the Owner protected? Provide bid, performance, payment bonds (lower risk projects) Provide a license (lower to mid-risk projects) Provide experience records or be pre- qualified (higher risk projects Submit to interviews (years of company experience, references, personnel CVs, equipment details such as HP, size, provide work plans, mobilization plan, etc., for high risk projects) Prepare a detailed answer to a Request for Proposals (for difficult to execute projects) Courtesy C.F. Bean LLC
Operational Risks: Equipment Selection (Specific types for specific jobs) Trailing Suction Hopper Dredge Made for ocean disposal, or beach construction if outfitted with pump-off High production rates in soft to medium hard material (stiff clays) in relatively straightaway channels; disposal should be nearby Self-propelled; can work offshore in seas up to 2.5 meters
Operational Risks: Equipment Selection (Specific types for specific jobs) Cutter Suction Dredge Designed for upland disposal, but can pump into barges for offshore High production rates in soft to medium hard material (stiff clays). Can dredge hard materials such as rock if designed with stiff enough ladder and enough cutter power Most are not self-propelled; can work offshore on anchors in seas up to 1- 1.5 meters; discharge pipes on larger dredges run 500 – 900 mm dia.
Operational Risks: Equipment Selection (Specific types for specific jobs) Mechanical Dredge Designed for offshore disposal (load into barges) Medium to lower production rates, disposal area should be distant Not self propelled, can dredge soft and unconsolidated up to hard with heavy buckets (as shown) Can work offshore (on anchors) in seas up to 1-1.5 meters (depending on barge size). Bean Excavation’s ‘Maricavor’
Operational Risks: Equipment Selection (Specific types for specific jobs) Ancillary/Specialty Drill/Blast barge: For rock Booster barge: For cutter or hopper, pumping long distances Special design for environmental projects (Miami River, New Bedford) Courtesy CF Bean LLC Bean Environmental’s ‘Barredor del Rio’ TSHD engaging booster barge
Operational Risks: Construction Dredging Is the channel depth properly defined? Start with selected upper tidal level and subtract: Static draft of design ship Tide range (maximum or design) Allowance for meteorological conditions Change in water density Squat (including trim and list) Wave response (for offshore) Net under keel clearance (pilots) Allowance for bed uncertainty Shoaling between maintenance dredging = Depth! Now correct for datum to get elevation!!
Operational Risks: Construction Dredging Has proper coordination occurred between pilots and local municipalities, other concerned parties (i.e., Navy)? Who is responsible? (Example: Pier Bravo, San Diego, Deepening Project, San Diego) Have things such as underground utilities, tunnels, structures been located and protected? Is this responsibility of engineer, owner, contractor? Pier Bravo Ammunition Pier Naval Air Station North Island, CA
Operational Risks: Construction Dredging Was the wharf/pier/structure designed for the dredge depth? Damage and/or failure can occur! Is contractor’s equipment and positioning (EPS) adequate to prevent damage to structures when dredging alongside? (Example: Miami Harbor)
Operational Risks: Maintenance Dredging & Emergencies In U.S., maintenance of Navigable Waterways carried out by USACE (100% paid @ depths 13.7 meters and shallower, deeper 50% paid.) Some ports shoal infrequently (Los Angeles, Seattle), some shoal regularly (Oakland, Houston). In U.S., maintenance paid from Harbor Maintenance Trust Fund (sort of user tax), not all funds expended due to funding environment. Emergency response/shoaling: Often handled by USACE through modifying an existing contract. (Example: Tropical Storm Alison) Without coordinated maintenance schedule, can shut down operations. Houston Ship Channel
Environmental Risks The biggest single obstacle to overcome when getting a project started, generally (also funding). Not long ago, PANY/NJ required three years to get an environmental permit for a maintenance dredging project! One step done incorrectly can set project back indeterminately. Good news: Learn from mistakes to develop procedures. Bad news: States, municipalities different.
Environmental Risks Is the site contaminated? Preliminary site assessment Review existing information Industry in area/sources Take a few samples Lab analysis Historical information New Bedford Harbor, MA, Superfund Site
Environmental Risks Identify decision criteria and restraints Stakeholder interests (port, technical, and regulators) Site characteristics and contaminant Volume, type, and physical characteristic of the material and contaminant THESE WILL ALL AFFECT THE MANAGEMENT STRATEGY MOVING FORWARD!
Environmental Risks Determine problem, objective, data needs What is the cleanup objective? What has to be done, bottom line? Risk comes into discussion now. What level is acceptable? What constraints are imposed on the project (regulators, etc.)? This is the problem. Based on above, what are data needs. MUST BE VERY CLEAR ON THIS. What data is needed, what tests must be run on the sediment samples? (Example: New Bedford) Use experienced consultants to help guide you on these steps, or will cost $$ and time.
Environmental Risks Site Assessment Volume, distribution, and degree of contamination needs to be determined as precisely as possible in this phase; remove all the contamination, but ONLY the contamination Expensive to do correctly, but not as expensive as dredging/remediation Sampling and testing, but do the correct tests! Determine spatially (three dimensions) through modeling techniques Determine if remediation is required based on laws, regulatory agencies, risk assessment CVN Wharf, NAS North Island, CA Contaminated Area
Environmental Risks Conduct risk assessment, economic, and management decision analysis Implement interim controls (restricted access, fishing bans) if necessary; look into source control if not already done Perform feasibility studies, design, selection of optimal processes. Need properly experienced ‘hands-on’ scientists and engineers in both remediation and dredging, etc. Don’t forget legal aspects…who ‘owns’ the sediment (generator).
Environmental Risks Develop and implement management plan May include pilot projects (but don’t overdo it). Often worth the effort, but look at overall cost in time and effort. Cost/Benefit! Courtesy Bean Environmental
Environmental Risks General comments Always special handling of material Main concern is safety and health of personnel and public; try to engineer risk out of project first, not overdo personal protective equipment on personnel. Many concerns; two major include water and air quality Treatment options are commensurate with level of contamination, and can include capping, geotubes, mechanical dewatering, landfill disposal Sediment Processing Plant Courtesy Boskalis Dolman bv
Thank you! Questions ? Jeffrey B. McWilliams, P.E*. Global Market Segment Leader CH2M HILL, Inc. 7600 W. Tidwell Road, Ste. 600 Houston, TX USA 77040 +1 (713) 462-0161 *Professional Engineer