At a special noontime meeting Monday, the City and Borough Assembly decided not to approve a proposal by the Alaska Department of Environmental Conservation to store excess contaminated soil at a site off Spur Road.
At work for the past two months remediating long-term contamination at the former Byford junk site, ADEC, NRC Alaska and other contractors had found significantly more affected soil than first anticipated. Since taking on the project, initial estimates of only 4,000 cubic yards of contaminated material have been upped to 18,000, making the heretofore used method of transporting soil southward for treatment and disposal too expensive.
Waste services manager for NRC, Shane O’Neill explained the soil being excavated is primarily contaminated by lead and petroleum products, as a result of decade’s worth of vehicles and batteries being kept there. Extensive caches of the latter have been unearthed beneath the soil, and after components have been separated and removed for disposal the contractor estimates 15,000 cubic yards of soil will be left over for storage.
That amount equates to 1,500 standard dump truck loads, or about 1,200 shipping containers’ worth. With costs of the already $4,000,000 project set to increase significantly as a result of transporting this unforeseen material, NRC put together a conceptual proposal for consigning a portion of contaminated soils locally in the form of a monofill disposal site.
Lead-containing soils would be treated with a product called EcoBond, a non-hazardous compound used for the past 16 years at similar sites for heavy metal remediation. It would chemically stabilize the lead within the soil, reducing its ability to leach out and its relative bioavailability by up to 75 percent.
The Byford soil was already being stabilized thusly in order to allow its transfer south for disposal, being held in an on-site stockpile for up to two years. Work on the project is just under halfway finished, just now getting to the most contaminated portions.
Asked for alternative site ideas, city staff found only a few borough-owned properties that may be suitable for long-term disposal. Among these was the rock pit up Spur Road, which already has contaminated and noncontaminated materials stored there from previous projects.
ADEC Contaminated Sites Program unit manager Sally Schlichting explained that an engineer will need to examine the site, determine whether it would be a suitable location within the ADEC’s storage conditions and draw up a design.
If given the go-ahead, non-hazardous material already at the rock pit would need to be either removed or used to construct the fill’s berm. Byford soils would then be transported to the pit and arranged for storage, covered with a plastic lining, buried beneath further soil and vegetated over.
“No doubt there are some long-term responsibilities with this site,” Schlichting said.
After establishing the monofill the ADEC would require 60 months of visual monitoring by the city, to ensure both that the site remains undisturbed by vehicles or heavy equipment and that no signs of leaching are evident. After that, monitoring could be reduced to an annual basis. The site could never be built upon as the lead content would remain in the soil, but its surface area could be used for various recreational purposes. For example, she suggested another site which could be used for a monofill in that vein would be the running track east of Evergreen Elementary.
Assembly members were wary of the proposal’s long-term effects. With the rock pit site, Mark Mitchell wondered whether water runoff would need to be controlled. Stephen Prysunka questioned whether groundwater monitoring would be needed.
Schlichting responded that those site-specific questions would be answered with an engineer’s analysis. Assembly members fielded ideas for sites on the island further away from town, such as either of the two rock pits in the vicinity of Pats Lake. Both are owned by the State of Alaska.
“I would rather look at one of those pits,” said Assembly member Dave Powell.
Taking a roll call, the proposal was rejected unanimously in a 6-0 vote. After the Assembly’s rejection of the idea, O’Neill explained the project’s scheduling will not be affected by the decision. Treated soils will still be kept onsite in stockpile cells until a permanent home can be found for them.
The Assembly approved moving forward with Wood Street paving, opting for a longer-lasting concrete finish over asphalt for an extra $23,000. The full project is estimated to cost $947,745 – including a five-percent contingency – of which $90,000 will be paid through Wrangell’s sales tax street fund. The majority of the cost will be covered by Alaska Department of Commerce, Community and Economic Development.
A contract was awarded to Rock-N-Road for the amount, and a further contract amendment was approved to PND Engineers for contract administration and inspection services not to exceed $105,860. Those funds would also by paid by ADCCED.
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