It used an untested wet refuse-derived fuel process, and operated only for about a year before it was shut down due to mechanical failures, labor and payment disputes, unpleasant odors that could be smelled two miles (3.2 km) away, and concerns about toxic dioxin emissions.

[12] However, the technology was untested, and the plant suffered from mechanical failures and emitted an unpleasant odor that was unbearable even two miles away, and reportedly caused shoppers at a nearby mall to vomit.

[16] Parsons & Whittemore suspended the plant's operations in March 1980 as part of a dispute with the Town of Hempstead over the installation of odor-reducing equipment and the payment of fees.

[13][17] The following month, the U.S. Environmental Protection Agency (EPA) reported that traces of dioxins had been found in its emissions, for which it had not yet set permissible levels, preventing the plant from reopening.

[15] However, Parsons & Whittemore defaulted on its bonds in 1983, and the decision was made to sell the plant to another operator and modify it from a wet to a dry process.

[12][18] Construction of the new plant was motivated by a 1990 deadline by the New York Department of Environmental Conservation to close town landfills due to their threat to groundwater, the source of Long Island's drinking water.

[6][7] In 2022, workers at nearby New York TRACON had complained about ash from the plant damaging their cars; this and other concerns led the Federal Aviation Administration to engage the Occupational Safety and Health Administration and the Centers for Disease Control and Prevention about potential impacts to worker health.

[21][22][23] NYSDEC completed its review of documents submitted by Jenner & Block LLP related to the management of ash residue at Covanta Hempstead.

These documents included Covanta's engineering calculations, instructions to the crane operator, residue/ash truck tracking log sheets, ash management plans, ash testing results, and various e-mail correspondence provided by the Covanta Hempstead’s attorney as well as DEC’s historical files.