Unique situations lead to unique solutions and completing environmental restoration work in remote areas of the often frozen Alaskan tundra presents no shortage of distinct challenges.
Fortunately, the U.S. Army Corps of Engineers (USACE) Alaska District has a team that excels at thinking outside the box to develop innovative and cost-efficient solutions to the difficulties encountered at Northeast Cape Formerly Used Defense Sites (FUDS). This ability recently gained them the Secretary of the Army award in the Environmental Restoration -- Installation category.
"The Alaska District has been dedicated to the completion of the environmental cleanup activities at Northeast Cape since day one," said Ken Andraschko, chief of the Formerly Used Defense Sites program. "The collaboration conducted with local communities and other agencies throughout the process has led to success in the form of open communication, logistical cost savings, a stellar safety record, and most importantly, the remediation of the environment. It is a huge accomplishment for everyone involved."
The project site, previously home to a 4,800-acre aircraft control and warning station, was used by the U.S. Air Force in the early 1950s to early 1970s to provide radar coverage to reduce potential vulnerability to bomber attacks in the region. When the facility closed, PCBs, arsenic and fuel that leeched into the soil remained.
Cleanup of these contaminants involved excavation, transportation and disposal of more than 44,000 tons of contaminated soil; work that could only be accomplished between July and September when weather conditions permitted. During peak operations the crew handled 15,500 tons during two field seasons in 2013 and 2014, logging 93,000 man-hours, with no lost-time incidents or accidents.
Early on, USACE decided to leave heavy equipment, a remote camp, vehicles and shipping containers on site for the multi-season project rather than barging them in and out each year. This not only saved $1 million, but it also extended both field seasons by allowing work to begin prior to ice breakup in July and continue into the fall after barge operations typically cease.
The contractor performing the work also built a custom suction dredge to remove loose sediment from the sensitive wetland drainage area. This creative solution eliminated the need for access roads across the tundra and prevented excessive erosion from bank undercutting. The sediment and water was sucked up and pumped to a central processing area to be treated and routed to large tubes. These tubes retained the sediment, allowing water to drain through fabric. Excess water then was treated and released to the ground surface.
Prior to digging, the crew used an ultraviolet screening tool that indicated how much fuel-contaminated soil needed to be removed. This, too, saved substantial time and money.
Another component of the Northeast Cape project that proved valuable was an on-site laboratory. Technicians analyzed soil samples for PCBs and petroleum compounds, and results were available within 24 hours. Otherwise, these samples would have been flown off-site for testing, resulting in an approximately seven-day delay confirming whether excavations met cleanup levels or whether the area needed additional excavation.
Petroleum-contaminated soil was processed using a rock screen plant to remove oversized rocks greater than two inches. This reduced the volume of contaminated soil packaged and shipped offsite because the oversized rock could be left behind and used for backfill. That alone decreased the amount of material disposed of by 30--50 percent.
When tests verified the soil was clean, it was used as backfill. Contaminated soil was transferred into bags for disposal off-site. Reseeding was successfully completed by October 2014.
This is one of the highest priority projects overseen by the Alaska Department of Environmental Conservation (ADEC), and USACE's Alaska District coordinated closely with ADEC during the remedial action. They also coordinated closely with community members to keep them abreast of the progress.
Two Native village corporations jointly own the land, which is now used for traditional subsistence hunting, gathering and recreation. A community relations plan for the project kept local residents and other stakeholders informed about project activities from start to finish. Also, a Restoration Advisory Board held regular meetings to exchange information and discuss project successes and challenges. USACE also held meaningful government-to-government consultations with federally recognized tribes throughout the project.
Actions at the Northeast Cape site reduce future liability at this property, and the lessons learned there will help lower remediation costs and increase project effectiveness at the sites. For example, USACE's Alaska District manages 27 Native American Lands Environmental Mitigation Program (NALEMP) Cooperative Agreements with 19 tribes.
Remote locations with both FUDS and NALEMP projects can share equipment, barge capacity and contractor expertise. This type of sharing on a concurrent cleanup project at Northeast Cape saved the NALEMP program between $500,000 and $1 million.
The Alaska District Northeast Cape FUDS accomplishments will compete against other military services' program successes in the Secretary of Defense Environmental Awards Program later this year.