Orange County Department of Parks, Recreation and Conservation
Posted on June 12, 2015
Client: Orange County Department of Parks, Recreation and Conservation
Location: Glenmere Lake Property
Project Type: Site Investigation/Remedial Design and Interim Remedial Measure
Project Cost: $430,000
In 2008, D&B was retained by the Orange County Department of Parks, Recreation and Conservation (the County) to perform a Site Investigation, Remedial Alternatives Analysis and Interim Remedial Measure at the Glenmere Lake Property, located in the Town of Chester, Orange County, New York. The project was funded by the New York State Department of Environmental Conservation (NYSDEC) Environmental Restoration Program (ERP). Due to the depletion of funding of the ERP, the State transferred the project to the State Superfund Program in 2012. Given our experience with the Site, D&B was retained directly by the state to provdie engineering services in support of the overall project. Under our current engineering standby contract with the NYSDEC.
The Glenmere Lake Property consists of a 10-acre parcel of land that includes a mixture of woodland and overgrown fields with four dilapidated buildings located in the western most portion of the property. In addition, a concrete and stone structure is located on the easternmost portion of the property. The property is located on the northernmost shoreline of Glenmere Lake which serves as the nearby Village of Florida’s drinking water supply.
Based on limited historical information, the Glenmere Lake Property was originally part of a 1,440-acre estate owned by Richard Goelet in the 1940’s under the name “Glenmere Lake Estates, Inc.” The Glenmere Lake Property includes the estate’s former servant’s quarters, maintenance facility and stables. The on-site facilities and buildings have been abandoned for nearly 30 years. Given the age of the dilapidated buildings, it was assumed that they likely contained asbestos and lead-based paint.
The objective of the project was to characterize the nature and extent of site contamination, including the presence of asbestos and lead-based paint in the dilapidated buildings, and to formulate and design a remedial strategy to address the identified contamination with the understanding that the County will eventually develop the property as parkland.
Investigation Scope of Work
In order to meet the project objectives, investigation activities undertaken by D&B included.
- Geophysical Survey
- Asbestos and Lead-Based Paint Survey
- Fish and Wildlife Impact Analysis
- Surface Soil and Shallow Subsurface Soil Sampling
- Soil Probe and Subsurface Soil Sampling
- Groundwater Probe Sampling
- Surface Water Sediment Sampling
Glenmere Lake contains one of the largest known populations of the Northern Cricket Frog (Acris crepitans) in Orange County, and possibly in the state of New York, and is an endangered species in the State of New York. In order to ensure that the investigation and remediation of the Glenmere Lake property did not harm the frogs or their habitat, an intensive spring migration study was completed by D&B in the spring of 2008. The study involved the construction of drift fences around the site designed to funnel any wildlife attempting to enter or exit the site to hide boxes and traps. The hide boxes were opened and inspected twice daily. All frogs and other animals were identified, counted and released on the lakeside of the drift fences. While cricket frogs were observed on the easternmost portion of the Glenmere Lake property, no cricket frogs were observed or captured in the western portion of the site or in the vicinity of the dilapidated buildings during the study.
Surface soil samples collected from within the area and downgradient of the dilapidated buildings were found to contain metals, in particular lead and arsenic in excess of NYSDEC Soil Cleanup Objectives. Given the shallow nature of the soil, these contaminants are potentially accessible to the public and wildlife. Therefore, the presence of the metals in shallow soil represents a potential exposure pathway.
Surface water sediment samples collected from Glenmere Lake downgradient of the dilapidated buildings also contained elevated concentrations of several metals, including lead, arsenic, mercury and copper. While direct exposure to humans is not expected, aquatic organisms could be exposed to these contaminants under current conditions.
Lastly, the results of completed lead and asbestos investigations clearly identified asbestos and lead-based paint throughout the dilapidated buildings.
Interim Remedial Measure
D&B developed an Interim Remedial Measure (IRM) work plan for the removal of the four Underground Storage Tanks (USTs) and one Aboveground Storage Tank (ASTs) from the property, as well as any petroleum impacted soil associated with each of the tanks. In September 2009, the NYSDEC approved the work plan and shortly there after, D&B developed a bid solicitation package ffor the County’s use to retain a qualified contractor to perform the work. With the assistance of D&B, the County selected a remediation contractor and the work was performed in August 2010. The contractor successfully located, excavated and removed all USTs and the AST for off-site disposal. Upon removal of the tanks, additional soil was excavated and removed for off-site disposal, and end point documentation samples were collected and compared to 6 NYCRR Part 375-6 Commercial Use, Protection of Groundwater and Protection of Ecological Resources Soil Cleanup Objectives. Upon approval of the end point documentation sample results, the excavation areas were restored with clean backfill material to grade and seeded. Following the completion of the remedial activities, D&B prepared a Final Engineering Report to certify that all activities were performed in accordance with the IRM work plan and in substantial conformance with the Division of Environmental Remediation (DER) Technical Guidance for Site Investigation and Remediation (DER-10).
Based on the results of the investigations and the IRM performed at the site, the NYSDEC issued a Record of Decision (ROD) for the site in March 2011 which included the following remedial alternatives:
- Demolition and removal of all dilapidated structures and associated equipment.
- Removal of various miscellaneous debris from the site.
- Removal of shallow surface soil in and around the dilapidated buildings/structures containing elevated levels of lead and, to a lesser degree, arsenic.
- Removal of contaminated wetlands sediment and lake sediment.
- Backfill all below grade structures and foundations.
- Restore excavated and disturbed areas.
D&B was subsequently retained by NYSDEC to prepare the Remedial Design contract documents for the implementation of the selected remedial alternative. As part of the assignment, D&B implemented a Pre-Design Investigation in order to further define the extent of surface soil and lake sediment requiring excavation and disposal. Between October 2012 and January 2013, D&B completed two phases of surface soil and lake sediment sampling, including Vibracoring sampling from a vessel on Glenmere Lake. A total of 66 sediment samples and 15 surface soil samples were collected for metals analysis.
Utilizing the results of the Pre-Design Investigation performed, D&B and NYSDEC were able to determine the horizontal and vertical extents of surface/subsurface soil requiring removal and off-site disposal. D&B continues to work closely with NYSDEC wildlife and wetland experts, and the design has had to take into account the complications of protecting the endangered Cricket Frog and restoring the wetland habitat following excavation, as well as protecting Glenmere Lake, which is the water supply for the Village of Florida. D&B anticipates completing a final design by the end of 2013. Construction activities are anticipated to begin in the summer of 2014.
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