• Two gasoline stations (Sites) were operated on the southeast and southwest corners of Old Country Road and Plainview Road in the 1950’s until the early 2000’s. These stations had underground storage tank (UST) systems dispensing gasoline and fuel oil to their customers. Gasoline and oil are petroleum products that contain hydrocarbon compounds. Some of these hydrocarbon compounds have been found in the soil and groundwater beneath these Sites indicating that there were leaks and/or spills at some point during the historical operation of the gas stations.
• Once gasoline and fuel oil releases at the gas stations were discovered, they each separately performed different investigations and active cleanup at their respective Sites. After the gas stations were closed (in 1997 and 2005 respectively), cleanup was largely successful on both properties. However, the New York State Department of Environmental Conservation (NYSDEC) recognized that operations from both gasoline stations appeared to have contributed hydrocarbon impacts to the groundwater moving off-site to the southeast.
• As mentioned above, during operation of the gas stations, petroleum products entered the subsurface via leaking UST systems. Once released, hydrocarbons moved down through soil toward the water table where they mixed into the groundwater to form what is known as a groundwater plume slowly moving to the southeast. To assess and monitor the location of the plume, a groundwater monitoring well network of over 200 monitoring wells has been installed over the years (click on the tab for the Study Area map).
• In 2011, investigation and remediation responsibilities for the Sites were transitioned to Resource Environmental, LLC (RELLC). RELLC is an independent organization formed by several major oil companies and specializes in responding to and managing the clean-up of petroleum fuels in the ground at facilities throughout the United States.
• Regular groundwater sampling has been conducted since 2003, and, since taking over activities at the Sites in 2011, RELLC has overseen continued investigation work including soil and groundwater sampling, drilling and installing additional monitoring wells and groundwater computer modeling work.
• The primary goal has been to assess what human health and environmental impacts of concern, if any, are associated with this groundwater plume. To accomplish this, finding the limits and nature of the groundwater plume is required. There is no data to support any health concerns at or near the surface for residential or commercial properties in the area. Additionally, the groundwater is found deep beneath the Project Area (70 to 100 feet below ground surface) which is a large barrier between any impacted groundwater and the public. The plume margins were largely identified by the end of 2023. The continued assessment is now targeted on the farthest area to the southeast to assist the modeling of the potential extent of future plume movement and any potential impacts on drinking water in the future. Defining potential impacts on drinking water supply is still under investigation and the focus of additional monitoring wells this year includes the area farthest to the southeast.
• Groundwater is the drinking water supply for most of Long Island and it is pumped from depths of approximately 400-600 ft below ground. Many water districts supply drinking water on the Island, and both the Plainview Water District (PWD) and the Bethpage Water District (BWD) serve the area around the Sites. The closest downgradient water supply wells are PWD Plant No. 5 and BWD South Park Drive Well. These two water supply wells are the primary potential receptors of concern for the area near the Sites. Due to general concerns in the past over undetected hydrocarbons in groundwater on Long Island, the water supply companies installed activated carbon or other treatment processes. This additional processing removes any hydrocarbons that may be present in the influent groundwater.
• Once the extent of the groundwater plume is defined, the monitoring well network will be in place to keep tabs on the plume and evaluate any future movement. Under NYSDEC guidance, various cleanup options will be evaluated, planned and executed.

SUMMARY
A groundwater plume originated from two former service stations at the corner of Old Country and Plainview Roads. Original sources of the fuel leaks have been eliminated through the removal of service station USTs, piping, equipment, and near-surface impacted soil to the greatest extent possible within the former station parcels. During station operation and after closure, active remediation was conducted at both properties. RELLC continues to monitor and evaluate groundwater conditions throughout the plume, with a specific focus on the 350 to 500 ft. below ground zone to the south and southeast of the Sites. Additional well installations to delineate the plume edges at the south edges are planned.
There is no data to indicate health concerns at or near the surface for any residential or commercial properties in the area, and, to affirm protection of the groundwater, more work is being done to simulate the potential extent of future plume movement. Until agreements can be reached with NYSDEC regarding a final cleanup, RELLC will remain diligent with its ongoing investigation, monitoring, and any necessary remedial activities.