An investigation by the US Chemical Safety Board (CSB) into the massive spill of 4-methylcyclohexyl methanol (MCHM) from a storage tank at the now insolvent Freedom Industries in the state of West Virginia last January has revealed that lax inspections and a lack of proper maintenance were at least partly to blame for the incident.

The spill that for days contaminated the drinking water supplies of up to 300,000 local residents, leaving them without fresh water. According to CSB, 369 patients were treated for nausea, skin rashes and vomiting.

The board said it had found no record of a formal, industry-approved inspection performed on any of the speciality chemical company's storage tanks prior to the incident.  

CSB said the chemical spill resulted from two small corrosion holes in the bottom of the tank that probably resulted from water leaking through holes in the roof and settling on the tank floor.

Investigators also found similar damage in nearby tanks containing the same chemical.

Rafael Moure-Eraso, chairman of CSB, called for "stricter regulations in areas where we find self-policing is not preventing accidents."

Freedom Industries has concluded a preliminary $2.9 million out-of-court settlement with lawyers for local residents and businesses whose water supply was disrupted. The agreement must still be approved by a bankruptcy court and a federal district court.