Ageing ammonia system falls foul of EPA

USA: A cheese manufacturer has replaced its ageing ammonia refrigeration system and agreed to pay part of a $100,000 settlement for breaching the clean air act and other laws.

Swan Valley Cheese and the owner of the property in Swanton, Vermont, agreed to pay $100,000 to settle penalty claims by the US Environmental Protection Agency that it violated clean air, Superfund and right-to-know laws between 2011 and 2015.

Following two EPA inspections and an August 2015 EPA Order, the company has removed the ammonia refrigeration system, parts of which dated back to the 1950s and purchased a new refrigeration system that does not use ammonia.

According to the EPA, Swan Valley Cheese took over the site from another cheese manufacturer in 2011. The property, which is near the Canadian border, sits 1,000 feet from the Missisquoi River and near residential housing.

The case stems from a February 2015 release of about 1,650lb (750kg) of ammonia during maintenance operations when three of the plant’s 14 employees were sprayed with an oil/ammonia mixture.

In two subsequent inspections, the EPA claimed to have found numerous dangerous conditions associated with the ammonia refrigeration system. The EPA issued a notice of the potential violations in May and followed up the letter with a Clean Air Act compliance order. Swan Valley Cheese removed the ammonia from the system in September, shutting down the facility until the new system was up and running.

According to the Clean Air Act’s “general duty clause”, owners and operators of plants producing, processing, handling, or storing extremely hazardous substances – including anhydrous ammonia – must identify hazards that may result from releases, must design and maintain a safe facility, taking steps to prevent releases, and must minimise the consequences of accidental releases that do occur.

According to the EPA, the companies violated all aspects of the general duty clause. Some of the problems included lack of ventilation to prevent a fire or explosion from a buildup of ammonia vapours; widespread corrosion; broken vapour barriers on piping; a lack of ammonia detectors or alarms as well as of emergency shut-off switches; lack of a proper maintenance programme for refrigeration equipment; and poor design of the oil drain system.