Project Description

Maintenance dredging of 5 NBSD Piers. Processing approximately 47,000 cy of dredge material containing radiological objects and munitions and explosives of concern in an upland confined drying facility. Dutra designed a facility to handle identifying and isolating RO’s and MEC objects and tracking them through manifests. Once the final gamma walkovers indicated that all objects were isolated and removed, The Naval radiological compliance agency RASO approved the Gamma data from each 2,000m2 pad so Dutra could truck that material off to a local land fill. Managing a subcontractor certified in handling radiological objects and munitions and explosives of concern was crucial piece of the project.                  

Major Challenges

There was a major risk taking on a guaranteed unit price in this design/build project.

• The award schedule was pushed to the 11th hour. We had a very short window to complete this project.
• We had to test and develop methods quickly and successfully in a very short time.
• This is a design/build unit price project. One of the first for a project like this so there was no pre-existing map or template to develop the project by. We developed all the processes and methods to complete the project on site. It took a lot of research and skill. It took a lot of oversight and management involvement. The RWP (radiological work plan) and ESS (explosive safety submission) included a lot of involvement of controls that took a lot of coordination to successfully complete this work.

Project Scope

The scope of all the processes involved started with dredging the impacted areas. That material had to be loaded through two screening processes on two barges. The final dredge screening was a 3” grid. The material was then relegated to a much smaller explosive arc that could be easily managed in the confined drying facility where it was offloaded. That initial wet mud was then treated with quicklime to facilitate quick drying. When the material was dry enough it was put through a ¾” power screen. That process as well as the larger 12” and 3” screens on the scows created a debris stream that was checked for RO’s and MEC. The screened material was then laid out on pads with very specific dimension requirements. A sensitive gamma walkover instrument was then towed across every inch of those pads to determine if any small RO’s went through the screens. Once those gamma walkover data packages were developed, they were sent to RASO for approval. Once approved, the pads are stripped and the material was trucked to a local landfill. The debris was checked by hand, all MEC was either demilitarized or blown up. The radiological objects we put into sealed and manifested drums to be transported to a proper receiving facility.

Project Description

This design-build project consisted of designing the new marina, demolishing the existing wood docks, piles and gangways, and dredging to a depth of -12 feet. Over 100,000 cubic yards of sediment were removed, with disposal of 15,000 cubic yards of contaminated material at an upland site.

The project consisted of furnishing and installing new concrete docks to create 385 slips of various lengths and widths, driving over 400 piles, upgrading utilities services, and building a fixed sheet pile wall breakwater. The capstone of the project involved design, fabrication and installation of a 225 foot floating wave attenuator to protect the marina entrance.

Major Challenges

Keeping the marina operational and existing facilities intact during construction was a major challenge. Dutra implemented a strategic project phasing plan that allowed for up to two hundred boats of varying lengths to remain inside the marina throughout construction.

Project Scope

• Demolition of existing floating docks, piles and gangways.
• Fabrication and installation of new floating concrete docks to create a modern 385 slip state-of-the-art marina.
• Replacement and reconfiguration of the gates, platforms and gangways.
• Dredging, capping, and upland disposal of contaminated sediments.
• Seawall repair and new seawall construction.
• Fixed sheet pile wall and floating concrete breakwater construction.
• Installation of a new sewer pump out station.
• New electrical, water and communication services; fire suppression systems, security system and lighting service on all docks.
• ADA access to several slips.
• Landscaping.
• Renovation of the Harbormaster building.

Project Description

The Project was Phase I of the San Francisco South Bay Pond Restorations Project, which will ultimately restore 15,000 acres of former salt ponds to managed tidal wetlands.  Phase I involved the restoration of 950 acres, with the goal of providing enhanced habitat for plant and wildlife species including the endangered Clapper Rail and Salt Marsh Harvest Mouse.  The existing levees were constructed with dredged materials, underlain with Bay Mud, resulting in poor overall structural conditions. 

Major Challenges
The project involved working with endangered species restrictions and coordination with other contractors working simultaneously with the project site.

Project Scope

• Execute dredging operations within a sensitive tidal creek.
• Removal and improvements to dilapidated levees.
• Construction of new levees and berms.
• Excavation of channels and levee breaches.

Project Description

Dutra was contracted as the primary subcontractor to perform this multi-phase, multi-year project restored the entire Upper Newport Bay Basin, and minimized the need for future maintenance of sensitive habitat areas and recreational boating waterways. As one of the few wetlands in Southern California, the Upper Bay provides critical habitat for migratory waterfowl, shorebirds and other endangered species.  Rapid urbanization of the area’s watershed led to an increase in sediment infill and this project returned the Upper Bay to an optimal ecosystem.

Major Challenges
All dredging and disposal operations were subject to strict quality control and environmental protection measures including protection of water quality and endangered species. Scheduling challenges included dredging sedimentation during the busy summer sailing season and coordination between tugboat operators, coast guard and the City of Newport to alert sailing clubs of impending barge traffic.

Project Scope

• Removal of 1.5 million cubic yards of contaminated material.
• Mobilize an amphibious excavator for semi-submerged dredging and capping.
• Clearing and construction of islands as viable habitat for the endangered California Least Tern.
• Precision grading of on-site materials, and placement of coarse-grained sand cap.
• Shallow water pipeline dredging to isolate and protect existing nesting sites for endangered species.

Project Description

The Crescent City Harbor is historically vulnerable to Tsunami events. This project consisted of constructing a Tsunami Resistant Marina within a functioning marina basin over two environmental windows for in-water work. The project consisted of shoreline demolition and re-work, removal and demolition of existing docks and piles, with related utilities, reconstruction of the harbor rock slope protection and upland pedestrian facilities.

Major Challenges

The major challenges associated with this project were the remote location which has no freeway access, long marine routes, and very limited resource availability. Installation of the new piles required drilling them into place rather than simply driving them.  Casting large Tsunami barriers on-site due to their massive size and weight, and tight plumb tolerances necessitated by the extreme tide ranges the facility was designed to accommodate.

Project Scope

• Phased work involving shifting vessels from existing to new berths during construction.
• 173 drilled HDPE sleeved guide pile installation.
• Fabricate and install 51,000 Square Feet of Design Build Concrete Docks.
• Fabricate and install of 6,500 Square feet of massive Tsunami Barrier floats.
• Removal and disposal of 70,000 tons of slope protection.
• Installation of 50,000 tons of new slope protection rock.
• Installation of Electrical and Mechanical Systems.
• Demolition and disposal of old marina piles and floats.

Project Description

As 50/50 joint venture partners, Dutra performed 50% of the work to deepen the federal channels of the Oakland Harbor and Port-maintained berths from -42’ to depths of over -50’. Over 6.5 million cubic yards of material was excavated by a combination of hydraulic and clamshell dredging.

The dredge spoils were used to create environmental enhancement and wetland habitat at the Middle Harbor Enhancement Area, and the Hamilton Army Airfield Wetlands Restoration project (HWRP) in Novato.

Over 5 million cubic yards of material dredged was deposited for beneficial re-use at the HWRP with 547 acres of planned habitats including tidal wetlands, seasonal wetlands, upland ponds, upland grasslands, tidal ponds, a wildlife corridor, an intertidal channel and a mudflat area. Material was pumped up to seven miles to the HWRP site using a system of five pumps.

Project Scope

• Widening and deepening of the Harbor Entrance, Outer and Inner Harbor channels, two turning basins and deepening the Federal Shipping Channel -50 feet Mean Lower Low Water.
• New work dredging with hard sand (San Antonio Formation)

Project Description

On June 3, 2004, at approximately 7:50 a.m. a levee breach occurred on the west levee of the Upper Jones Tract in the southern region of the Delta in San Joaquin County.

The break occurred approximately 1/4 mile north of the Woodward Island ferry exposing the tract to flooding from Middle River. Governor Arnold Schwarzenegger declared a State of Emergency and Dutra Construction was hired to close the breach. Dutra Construction completed closing the breach on June 30, 2004, approximately

20 days ahead of schedule. The closure occurred several days before an astronomical high tide was due. This high tide would have resulted in a rise of the island water surface elevation to its highest level since the day of the breach. As a result of the closure and completion of the protection efforts, there were no problems due to the high tidal period or winds.

Project Description

The project goal was to remediate and restore a heavily impacted “Toxic Hot Spot” wetland slough.  The impacted property had been in continuous industrial use since the 1900’s as a copper ore smelter and then a pyrite roaster which contaminated a slough vital for ensuring drainage capacity and maintaining tidal influence in the surrounding marshes.  The innovative, “first of its kind” solution involved realignment by means of dredging a new winding slough, and capping of the previously contaminated area.  The new sinuous design provided foraging habitat for birds and fish while isolating the contaminated sediments preventing them from flowing into the Bay.  

Major Challenges

Native Suisun Song Sparrows and Salt Marsh Common Yellow Throat nesting locations existed within the construction site.  Mason’s Lilaeopsis, a rare plant, also existed in the site and was successfully relocated out of the construction zone.  Performing work in active tidal wetlands areas required placing fill at low tides whenever possible to reduce impacts.

Project Scope

• Marine Demolition.
• Dredge realignment slough along a winding course parallel to existing contaminated slough.
• Construct a one mile soil containment cap to isolate contaminated sediments.
• Construct 5 acres of new wetlands including new habitat atop soil cap and enhance 200 acres of existing wetlands.
• Construct associated Tide Gates, Brush Fence and Erosion Control.
• Construct Bulkhead and Shoreline Protection.
• Demonstrate strict adherance to Dredge Spoils Management, Environmental Protection, and Water Quality Management “best business practices”.