Army Corps finishes I-Denni excavation

Another page in the CNMI’s military and environmental history is done after the U.S. Army Corps of Engineers-Honolulu District finished excavating some 3,337 cubic yards of soil on Capital Hill that’s contaminated with leftover chemicals from World War II.

The Department of Public Lands, which asked the Army Corps for the remediation work a few years back, is now poised to revisit the I-Denni area for its homestead subdivision plan.

The area, also called Edoni, was previously used by the U.S. military as a waste pit during and after the war. Among the chemicals that were found at the site were polychlorinated biphenyls and lead, which cause cancer.

“The Army Corps or the Department of Defense needed an additional $3 million just to be able to complete the project. We are glad that the Army Corps committed itself to completing this project,” DPL director of Planning Division Patricia Rasa told Saipan Tribune yesterday.

The cost jumped to over $3 million because the volume of contaminated soil turned out to be much more than what was originally estimated.

The original estimate was only up to 600 cubic yards of contaminated soil, and the project was originally budgeted $603,543.73.

When the remediation work was completed, the total volume of contaminated soil excavated reached some 3,337 cubic yards—456 percent higher than initially projected.

Subcontractors were seen last week packing the equipment and other materials used in the excavation.

Hawaii-based Wil-Chee Planning Inc. is the Army Corps’ contractor for the project.

Joseph Bonfiglio, chief of public affairs at Army Corps-Honolulu District, confirmed that the remedial action was completed on May 17 and the final truckload of lead-contaminated soil was removed from the site that day.

The final bulk sack containing PCB-impacted soil was removed from the site on May 14.

“We are very pleased to be winding up another successful environmental project, which will have a positive impact on the people of Saipan. We are fully committed to ensuring public health and safety,” Bonfiglio told Saipan Tribune.

He said the Army Corps’ goal in the Formerly Used Defense Sites or FUDS program “is to reduce risk to human health and the environment through implementation of effective, legally compliant, and cost-effective response actions done to the highest standards of safety.”

Bonfiglio said no backfilling of the pit has occurred or is planned at the request of DPL.

Rasa said that DPL will reassess its plan, now that the remediation of the site has been completed.

She cited, for example, that the pit could be turned into a ponding basin, something that was not originally considered at the site where the excavation occurred.

“The original plan was to have 78 additional homesteads but now we are looking at the contour and the landscape and see whether we could turn the pit into a ponding basin,” Rasa added.

Of the estimated 3,337 cubic yards of soil excavated from the area, 1,537 cubic yards were contaminated with PCB and about 1,888 cubic yards were laced with lead, Bonfiglio said.

Bonfiglio said the highest level of PCBs reported in this project was 6.1 milligrams per kilogram, equivalent to 6.1 parts per million.

“PCBs in confirmation soil samples recently collected were not detected above the laboratory’s reporting limit of 0.012 milligrams per kilogram, which is below the CNMI environmental screening level of 1.1 milligrams per kilogram,” he said.

The highest lead concentration in confirmation samples recently collected was 35 milligrams per kilogram, below the 200 milligrams per kilogram CNMI environmental screening level, he added.

Bonfiglio said the project is completed and was cleaned up “to unlimited use level, meaning that it is safe for residential use.”

Delegate Gregorio Kilili Sablan (Ind-MP) said he’s glad that the remediation work is completed “so that DPL can proceed with its homestead project” that will house a large number of families on Saipan.

“We’re glad that Army Corps completed this. We will continue to work with them to also clean up other formerly used defense sites in the CNMI,” he said.

Rep. Stanley Torres (Ind-Saipan), who knew about the military’s use of the site as a repository of all types of waste when he was still young, welcomes the remediation completion as “welcome news.”

“I appreciate what they’ve done and hopefully there will be a continuous cleanup until all the contaminated sites in the CNMI are taken cared of. I know there are other former dump sites used by the military that have yet to be cleaned up,” he added.

Juan I. Tenorio, former chairman of the Tanapag Action Group which was a major force in ensuring that the Army Corps complete its cleanup of Tanapag of PCB in 2003, took a skeptical view of the I-Denni remediation.

“It turned out to be a major contamination site. But they went ahead to just dig up the place and ship the contaminated soil to the U.S. Did the U.S. government really allow contaminated material to enter the U.S.? Why did Army Corps treat I-Denni differently from Tanapag? And lead contaminated soil are brought to Marpi landfill just like that?” he asked.

The I-Denni project comes nine years after the completion of the $20 million PCB contamination cleanup in Tanapag in 2003 involving 40,000 tons of PCB-contaminated soil.

The Army Corps treated the contaminated soil in Tanapag onsite and shipped the treated soil to the U.S. mainland.

Saipan was the site of heavy fighting between U.S. and Japanese forces during World War II. To this day, live ordnance and chemicals from the war are still being discovered in several areas of the island.

Besides I-Denni, there are other FUDS on Saipan that require remediation, including the Hospital Dump Site, American Memorial Park, Naftan Bomb Storage, Ordnance Plan, Naftan Ordnance Disposal, North Field, Marpi Point Field, Tanapag Fuel Farm, and the Koblerville Naval Supply Center.