Official identification company that caused a foul smell and taste in New Jersey’s drinking water

State environmental officials said Monday that an aromatic chemicals plant in Somerset County was responsible for “an improper discharge” that briefly changed the taste and odor of the area’s drinking water.

Residents in dozens of towns in Somerset, Union and Middlesex counties reported the foul taste and smell of their tap water last Tuesday.

Six days later, the New Jersey Department of Environmental Protection announced that it had located the source of the problem at a facility operated by M&U International in Branchburg Township.

The company, which produces synthetic and natural aromatic chemicals, food additives and essential oils, is based in Shanghai, China, according to its website. The American headquarters is in Branchburg, with another location in Walnutport, Pennsylvania.

The Branchburg facility is located within the watershed and upstream of New Jersey American Water’s surface water intake, the DEP said.

A chemical leak at the plant last Monday prompted a response from the Somerset County Office of Emergency Management, which arrived on scene that night and conducted an initial cleanup operation.

The exact chemicals were not identified, but the DEP statement suggested that several compounds were involved, particularly alpha-pinene, a clear colorless liquid used in fragrances and food additives.

State officials notified the facility on Monday that it had violated the Water Pollution Control Act, the DEP said.

New Jersey American Water, which manages the affected Raritan water system, previously said its water quality testing determined there was no risk to public health. Drinking water in the region continues to meet state and federal quality standards, the company added.

“To address the taste and odor issues, NJAW has proactively adjusted its treatment processes and is continuing targeted hydrant flushing throughout the system,” the DEP said Monday.

“NJAW has also coordinated with the New Jersey Water Supply Authority,” it continues, “for the release of additional water from Round Valley Reservoir to flush their source water.”