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ON‐SITE REMEDY FOR CADMIUM (IN‐SITU SOLIDIFICATION/STABILIZATION “ISS”)

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• The ISS was completed in December 1996. Contaminated soil containing cadmium greater than 10 parts per million (ppm) on the western portion of the site were excavated and relocated to the eastern portion of the Site and mixed with cement. This portion of the remedy is referred to as the “Treatment Cells.”

• Seven (7) Treatment Cells were formed and range from 6‐to‐18‐feet thick above and below the water table. A final 3‐inch thick topsoil and/or asphalt cover (the “Cap”) was then installed above these cells to prevent direct contact or the effects of infiltration and freeze/thaw. About 15 % of the Treatment Cells were “capped” with topsoil and grass, and no asphalt was present.

 

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STATE‐IMPLEMENTED MONITORING

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• Groundwater monitoring over a 30‐year time frame was required to post‐remedy to evaluate the effectiveness of the Treatment Cells in retaining the contaminants.

• Cadmium concentrations (up to 200 times greater than the groundwater standard [1,080 micrograms per liter detected in MW‐23A off‐site in 2008]) in groundwater were detected on and off site between 2007‐2018, starting almost 10 years after the remediation at the Site was complete (refer to Exhibit A and Exhibit B, Exhibit D). During this period, cadmium was also repeatedly detecte din sediment and surface waters samples (refer to Exhibit E).

• In 2006, the NYSDEC changed the site’s classification from a Class 2 (significant threat to the public health or environment‐action required) to a Class 4 (site properly closed‐requires continued management), but on January 13, 2016 the Site was reclassified from a Class 4 to a Class 2. This indicates the State was aware of a recurrent source of on‐ and off‐site contamination prior to the Cap removal. The NYSDEC responded to this in June 2016 by 1) installing a demarcation fence along Willetts Creek adjacent to the Beach Street Middle School athletic fields and the area behind the ACE Hardware Store, and 2) removed sediment and debris upstream of the two footbridges at Burling Lane and Edmore Lane in the Willet’s Creek to enhance flow during rain events. No further corrective measures, or remedy, to prevent the recurring contamination was taken.

• Starting in 2008, groundwater, sediment and surface water contamination, in particular from cadmium, was continually reported. Below are some excerpts from the NYSDEC that highlight this:

 

Final Groundwater Sampling Report by AECOM (November 2008 Sampling Event) for NYSDEC

 

“Cadmium has been present in every sample collected during all three sampling events with exceedances noted...”

 

“Cadmium was detected in both of the Willetts Creek samples…” “The concentrations in upstream sample SW‐6…significantly exceeded the 5 μg/L criterion in Round 3 at 75.4 μg/L.”

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“The samples indicate that the surficial sediments in Lake Capri and Willetts Creek remain contaminated with metals above the applicable NYSDEC Technical Guidance for Sediment Criteria, lowest effects level. Cadmium has been detected above the criterion in 15 of 18 samples collected during the three rounds of sampling.”

 

Groundwater Sampling Report by AECOM (November 2013 Sampling Event) for NYSDEC

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“Cadmium has been detected in the majority of unfiltered samples collected during the seven sampling events with exceedances of New York Class GA Groundwater criteria”

 

“The only metal of concern found consistently in off‐site wells above the Class GA criteria is cadmium.”

 

“The sediment sample data indicate that the surficial sediments in Lake Capri and Willetts Creek remain contaminated with metals concentrations above the applicable NYSDEC Technical Guidance for Sediment Criteria”

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Final Groundwater Sampling Report by AECOM (September 2017 Sampling Event) for NYSDEC

 

“During the periodic monitoring of Willetts Creek and Lake Capri sediment, anomalously high cadmium concentrations were noted in a few sediment samples.”

 

“Cadmium has been detected in every monitoring well sampled at the Site at least once during the ten sampling events.” “the cadmium plume most likely extends east of the creek towards Everdell Avenue”

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“Cadmium was also detected in Willetts Creek surface water sample SW‐5 and exceeded the criterion in eight of ten samples.”

 

“The sediment sample data indicate that the surficial sediments in Lake Capri and Willetts Creek remain contaminated with metals concentrations above the applicable NYSDEC Technical Guidance for Sediment Criteria”

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PRE‐EXISTING SITE CONDITIONS

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• Areas of remaining cadmium existed in soil above regulatory standards outside of the Treatment Cells where no cap was required, and was eventually removed during final closure of the Dzus’s facility in late‐2017. Furthermore, excavations completed in 2017 were left open and not backfilled nor protected from stormwater infiltration following closure activities, and remained open until demolition and grading in late 2020.

• A 2019‐2020 evaluation completed by the State’s consultant suggested that cadmium and chromium in some Treatment Cell areas have the potential to leach into groundwater at concentrations above standards (EA Engineering, P.C., 2021 Monitoring and Inspection Report).

• In 2018, the asphalt portion of the cap was cracked and missing in parts, had vegetation growing through it and the area also consisted of five (5) stormwater leaching structures. Refer to Exhibit C.

 

REDEVELOPMENT

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• The Treatment Cells stabilizing the preexisting contamination from Dzus were not disturbed during this work and subgrade drainage system locations and utilities were reconfigured to avoid this area entirely. The central and eastern portions of the Site were raised up to 2‐feet to accommodate design and ensure avoidance of the Treatment Cells.

• As part of redevelopment, several separate plans were prepared by the Owner and approved by the DEC to ensure compliance with the NYSDEC requirements including a Demolition Monitoring Report, Redevelopment Work Plan, Corrective Measure Work Plan, Beneficial Use Requests for Soil (2), and a Vapor Intrusion Work Plan. These are not public documents.

• Between 2021 ‐ 2024, the Owner has installed an enhanced and complete cap sitewide which included a 40‐mil geomembrane, building foundations, aggregate base and asphalt, concrete curbs and sidewalks, as well as a 12‐inch clean soil barrier above the geomembrane in locations that are not covered by buildings or parking lots. Additionally, soil testing and screening, groundwater monitoring well replacement, community air monitoring and daily reporting to the State was implemented during redevelopment to support the State and ensure Site safety.

• The Owner has conducted two independent sampling events in 2022 and 2023 to aid and support the State in the monitoring of on‐ and off‐site groundwater concentrations during this time.

• In 2024, the Owner offered to undertake additional testing to assist in determining the nature, extent, and cause of the migration of cadmium to inform the design of a remedy. The Current Owner stated in a letter to DEC dated March 28, 2024 that this work would be presented in a work plan to be submitted on April 15, 2024, with the work to be performed by May 31, 2024.

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