First, it was a spermaceti candle factory that made whale oil for lamps. Then in 1859, it became a manufactured gas plant and supplied Sag Harbor with fuel for heating, cooking and lighting.
For most of the 20th century, it stood vigil as the big blue gas ball that emblemized the village’s industrial past — and unfortunately, its legacy of pollution. And finally, the structure, officially known as a Hortonsphere, was demolished in 2006.
Now, after a decade of cleanup and monitoring at the one-acre parcel on the corner of Bridge Street and Long Island Avenue, the New York State Department of Environmental Conservation has determined that the former state Superfund site “no longer presents a significant threat to public health and/or the environment.”
In a December 5 release, the DEC said it was reclassifying the property as a Class 4 “inactive” hazardous waste disposal site after the successful excavation of 14,000 cubic yards of tar-contaminated soils to a depth of 10 feet; removal of the pollutants; backfilling the resulting pit with clean soil; installation of recovery wells to collect residual below-grade tar, and years of site monitoring.
But the DEC pledged to remain watchful at the site, which is owned by National Grid, and it could resume remedial activities if needed.
To safeguard against potential exposure risks, it is adhering to a site management plan that will restrict groundwater use without necessary treatment, prohibit ground-intrusive activities that might stir up any remaining contaminants, bar vegetable gardens at the site and evaluate the possibility of future vapor intrusions.
The initial pollutants date back to the post-Civil War period: At the height of its use as a manufactured gas plant, the site included four gas storage tanks, three purifying houses, several oil tanks, a tar separator and several other production buildings, according to data on National Grid’s website.
Some of those facilities were destroyed in village fires and the rest were later dismantled and hauled off the site. In 2006, the Hortonsphere, which was used to store natural gas and doubled as a beacon for homebound mariners, was decommissioned and dismantled.