In 2012, Pinnacle Engineering began assisting a North Dakota client with environmental issues related to an existing four-track (40 cars each) facility that transloaded crude oil from trucks to rail cars in North Dakota. Pinnacle provided additional services for the client by preparing a feasibility study for a loop track transloading facility, which would enable the client to dramatically reduce loading and shipping costs. The study expanded to a double loop track transloading facility where crude oil could be brought to the site by truck and pipeline, then piped into three 90,000 bbl (oil barrels) storage tanks, enabling the owner to off-load crude oil into unit trains. These studies provided the client with the information needed to authorize the preparation of plans and specifications for a complete rail loop transloading facility.
As lead engineer for the client’s project team, Pinnacle provided the civil engineering design for the approximately 200-acre facility, and retained another civil engineering firm to design track and switches as well as a bridge required for crossing to the inside of the loop. Pinnacle also assisted the client with environmental services, including environmental due diligence for land acquisition; acquisition of an air permit, wetland fill permit, construction stormwater permit, and industrial stormwater permit; and completion of an SPCC plan, FRP, construction SWPPP, and industrial SWPPP.
Civil engineering design tasks on the project included completing the earthwork balance design (involving the movement of nearly 400,000 cubic yards of fine clay material), SWPPP design/plans, drainage design, secondary containment design, and wetlands mitigation design services. Due to existing silty soil conditions, soil cement was used as an innovative solution for stabilization under all rails and switches and for heavily traveled trucking areas, increasing the durability of the truck roads while minimizing construction and maintenance costs. The use of soil cement enabled Pinnacle to reduce the amount of imported crushed rock required to carry both heavy truck and train car loads.
Pinnacle designed secondary containment systems for the storage tank farm (three 98,000 barrel tanks), the rail loadout building, and the truck unloading area to meet federal SPCC requirements. The storage tank containment was constructed of clay that was native to the site, and was proved acceptable for use through tests conducted by the Pinnacle team. The design of the approximately 650-foot long loadout building integrated several measures for the collection and containment of spills. The floor of the rail loadout is sloped to the middle of the building into the track pans, and track pans are installed on both sides of the rail and in the middle of the rail. The track pans’ cross sections drain to the south to a common header pipe that eventually gravity feeds to an oil/water separator (OWS), which collects oil and discharges clean water to a stormwater ditch. A manhole downstream of the OWS is equipped with an oil stop valve, which will close in the event of a significant spill and divert the flow of oil to the secondary containment (three 10,000 gallon USTs).
The 200-foot by 70-foot truck unloading area was constructed with a secondary containment system consisting of a concrete slab that slopes to a center sump manhole that drains each truck unloading area. The center sump manholes are piped in series and gravity fed to an OWS which collects the oil and discharges clean water to a stormwater ditch. A manhole downstream of the OWS is equipped with an oil stop valve, which will close in the event of a significant spill and divert the flow of oil to the secondary containment (10,000 gallon UST).
During construction of the facility, Pinnacle provided construction administration, site observation and oversight, and construction staking. Pinnacle also managed the materials testing program and provided ongoing engineering design changes in a design/build capacity to address the evolving operational goals of the facility. As construction of the facility began, it was determined that a new crossing signal was required for three crossings of a County road. Pinnacle coordinated the client’s application for grant money for the construction of the signal system, provided a design/build package for contractor bidding, and managed the construction process for the client.
The facility was fully operational in January 2014, and construction of final improvements was completed later in 2014 while the facility was operating. The rail loop currently allows 120 tank car unit trains to ship crude oil from the Bakken Oil Fields in North Dakota.