Work underway on former gas building

PENN YAN--Work has begun on the former manufactured gas plant (MGP) building located along Water Street as part of a multi-year remediation project in Penn Yan. While the work on the building began this year, it will also include dredging work in the Keuka Outlet between the Main and Liberty Street bridges that will continue into May, 2018. The cleanup activities will be performed by New York State Electric and Gas (NYSEG) with oversight from the New York State Department of Environmental Conservation (NYSDEC).
According to the DEC, the goal of the cleanup action for the site is to achieve levels that protect public health and the environment. The cleanup for the site includes excavation and off-site disposal of contaminated soil from the site and sediment in the Keuka Lake Outlet immediately adjacent and downstream of the site. The cleanup includes removal of coal tar "source areas" as well as residual contamination impacted by the source areas.
The building site includes a currently vacant masonry "gas house" building which was formerly used for gas manufacturing operations. This building has been designated as a historic structure by the New York State Office of Parks, Recreation and Historic Preservation. An MGP was constructed on the site in 1899 and operated until 1931. Gas was manufactured using a coal gasification process by the Penn Yan Light Company. A gas holder and some accessory buildings were demolished sometime following the cessation of the gas manufacturing activities in 1931.
After gas manufacturing ceased, the gas house was redeveloped into a malt house and wood storage facility. At some point, a warehouse structure was erected and attached to the west side of the building. The building and warehouse were used for a wine distribution center and later as an auto sales and repair business. The warehouse was demolished in 2004, but its concrete floor was left in place. The concrete floor was recently covered with soil to deter recreational use of this area.
The remediation goals for the site include excavation and/or removal of the following materials:
• Exposed surface soil exceeding restricted-residential soil clean up objectives (SCOs).
• Sub-surface soils exceeding 500 milligrams per kilogram (mg/ kg) of total semi-volatile organic compounds.
• Sub-surface soils exceeding 10 mg/kg of total volatile organic compounds.
• Soils visibly impacted with non-aqueous phase liquid (NAPL) or NAPL sheens.
• Sub-surface former MGP structures to the extent practicable.
• Sediment with visible NAPL, sheen or which produce a visible sheen when agitated.
• Sediment in the Keuka Lake Outlet which contains greater than 43mg/kg total polycyclic aromatic hydrocarbons (tPAHs).
The cleanup will be completed in three phases, each phase during 2015, 2016 and 2017, respectively. The work to be completed in 2015 includes stabilization of the building on the former MGP property, and excavation of the former MGP gas holder foundation. The work to be completed in 2016 includes dredging cells one through four, which extend from just upstream of the former railroad bridge downstream to the Keuka Lake Outlet dam. The work to be completed in 2017 includes dredging cell five, which is in the waterway adjacent to the opposite shore from the former MGP property. it will also include draining and excavating cell six in the waterway adjacent to the former MGP property and excavating the upland area on-site and around the former MGP building.
The dredged and excavated sediments and soils will be stabilized and dewatered on-site and then transported off-site to a thermal desorption facility. The concrete and other structures that will be removed during the work will be broken down and disposed offsite in a nearby landfill. Clean materials and equipment will be staged for on-site used in a "material laydown area" on Water Street, directly across from the former MGP property.
A site cover will be installed consisting of either on-site structures such as buildings, pavement and sidewalks, or a soil cover. The soil cover will include two-feet of soil meeting the SCOs for soil cover placed over a demarcation layer. The top six inches of the soil cover will be of sufficient quality to maintain a vegetation layer.
After completion of the cleanup activities, NYSEG will prepare a Final Engineering Report. The Final Engineering Report will describe the cleanup activities completed and certify that cleanup requirements have been achieved or will be achieved.
Remedial investigations occurred at this site from 1991 to 2008 which helped to characterize the nature and extent of MGP impacts at the site. In 2012, a feasibility study was submitted to NYSDEC which assessed different alternatives for the site cleanup. Based on this report, NYSDEC issued a record of decision (ROD) which identified the selected cleanup for the site. The ROD also incorporated public comments generated during a public notice period.
Additional site details, including environmental and health assessment summaries, are available on NYSDEC's website athttp://www.dec.ny.gov/ctinx/extapps/derexternal/haz/dctails.cfm?Paeid3&progno862OO9.