Army Corps details NFSS 'balance of plant' remediation

Alternative 3 plan is choice among 5 options

Corps estimates alternative 3 cleanup at $24.5 million

By Terry Duffy

Editor-in-Chief

Roughly 60 participants learned more on the Army Corps’ alternative 3 “balance of plant” selection plan for the 191-acre Niagara Falls Storage Site in Lewiston during an Oct. 21 virtual presentation.

The next phase in the Army Corps’ remediation plans for the government facility on Pletcher Road, the alternative 3 plan follows on its feasibility study issued in 2019 for the balance of plant on the operable units at the NFSS, as well as ground water units. It comes off the Army Corps’ record of decision on the $490 million remediation project announced earlier for the 10-acre Interim Waste Containment Structure at NFSS to completely remove the cell’s radioactive contaminants.

“A record of decision was signed for the Interim Waste Containment Structure in 2019. The selected remedy was to completely remove the contents … the most significant source of contamination at the site,” the Army Corps said. “Since then, the district has actively pursued the development of the remedial design contract. … We expect to award this design contract in 2021.”

With regard to contamination, the Army Corps presentation revealed, “areas of contaminated media above preliminary remediation goals that warrant cleanup” at NFSS. Included were “radionuclides of concern” in soils, in building 433 and the foundations of former buildings 433, 431 and 432 on the north central and northeast areas of the NFSS. Contaminants include uranium, thorium-230 and radiu-226.

Chemicals of concern revealed volatile organic compounds found in soil and groundwater, polychlorinated biphenyls in pipeline sediments, water in drains at building 401 and its concrete foundation, and the presence of polycyclic aromatic hydrocarbons on surface soils and building foundations. Other areas impacted include 5,400 cubic-yards of soil and road bedding on the site, 1,000 cubic-yards of contaminants along the sides of the building 431 and 432 foundations, and 727 cubic-yards of impacted materials around the foundation of former building 401 and its drains.

In its review of the corrective measures considered for the site, the Army Corps presented five alternatives. Included was alternative 1, no action. This option was issued for comparison purposes, but is viewed as being not protective of human health and the environment.

Other options include alternative 2 – complete removal; alternative 3 – removal with building decontamination; alternative 4 – removal with building decontamination and “in situ” remediation (a method of breaking down and purifying hazardous substances in soil and groundwater); and alternative 5 – removal with building 401 decontamination, scarification of building 433, and the foundations of buildings of 430 and 431/432, and the aforementioned “in situ” remediation.

The Army Corps stated it found alternative 3 comparable to alternative 2. It calls for all impacted soils, contaminated building foundations and the building 401 foundation and impacted drains that exceed preliminary remediation goals to be removed and disposed of in a permitted off-site facility. In addition, volatile organic compound-contaminated soils and groundwater in the plume in the north area would be removed and backfilled.

Alternative 3 also calls for building 433 and the foundations of former buildings 430, 431/432 to be left in place and decontaminated (scarified) to remove risks associated with the foundations.

The Army Corps also indicated in its plans for alternatives 2 through 5, that, “following removal of all materials exceeding the feasibility study preliminary remediation goals, the excavated areas would be backfilled, the site would be restored and would be suitable for industrial land use.”

In its comparative analysis, using balancing criteria under the federal government’s Comprehensive Environmental Response, Compensation and Liability Act (aka CERCLA or Superfund), the Army Corps said it found alternative 3 rated “high” in long-term effectiveness and permanence; “low” in reduction of toxicity, mobility or volume through treatment; “low” in short-term effectiveness; and “high” in implementability.

“Each alternative in the feasibility is evaluated against the balancing criteria for comparison purposes,” the Army Corps said. “Alternative 4, removal with building decontamination … is our preferred alternative.”

As far as cost, the Army Corps estimated the total cost under alternative 3 remediation would be $24.5 million, with a completion timeframe of 29 months. Comparing the total cost of alternative 3 ($24.5 million) to that of alternative 2 ($35.2 million), the Army Corps said, “Alternative 3 achieves the same level of protectiveness for less money and in the same amount of time as alternative 2.”

Public commentary on the alternative 3 plan and other options presented Oct. 21 for the NFSS balance of plant remediation is being taken by the Army Corps until the close of business Saturday, Dec. 5. Email comments may be sent to [email protected].

Written comments may be sent to: U.S. Army Corps of Engineers, Buffalo District, Environmental Project Management Section, 1776 Niagara St., Buffalo, NY, 14207-3199. Include “Niagara Falls Storage Site” in the subject line.