Overview
On December 16, 2024, M&U International, a company that repackages fragrances, essential oils, and flavorings at a facility in Branchburg Township, discharged alpha-pinene – a chemical used as food and fragrance additives – into a stormwater drain that leads to the Raritan River.
The DEP believes that this chemical, which has a very low odor threshold, entered river water intakes for the New Jersey American Water Raritan Distribution System, leading to consumer taste and odor complaints starting on December 18, 2024. DEP has issued M&U International a Notice of Violation for an unpermitted discharge in violation of the New Jersey Water Pollution Control Act.
Alpha-pinene, can be detected by smell at extremely low levels (parts per trillion (ppt)). Though extremely diluted by the time it entered the intakes, this chemical’s low odor threshold means that it could be smelled at microscopic levels measured in parts per trillion, which led to consumer complaints about odors following the incident. For more information on alpha-pinene see the Frequently Asked Questions
Alpha-pinene was detectable in the contents of the container that leaked from the repackaging facility, but after entering the stormwater drain, and eventually the Raritan River it was diluted significantly. New Jersey American, using advanced analytical chemistry testing, did not detect the alpha-pinene in finished water leaving the treatment facilities or in the water distribution system. While the odor may have been unpleasant, rigorous water quality testing has not identified any public health concerns.

Drinking Water Impact Investigation Results in Detail
The Department of Environmental Protection (NJDEP) continues to coordinate with New Jersey American Water (NJAW) regarding this incident. Out of an abundance of caution, New Jersey American conducted extensive sampling for a number of potential contaminants that were reviewed by the DEP. Throughout the investigation, the data show that NJAW’s samples have met primary state and federal drinking water standards to protect public health. 

The primary drinking water standards established by USEPA and NJDEP are designed to be protective for health impacts that may come from both short term and long-term use of drinking water. Water samples were collected from the suspected source, source water, at the treatment facility, and throughout the distribution system, and analyzed for a full list of contaminants, including:

• Volatile organic compounds
• Semi-volatile organics
• Base neutrals and acids
• Cyanide,
• Metals
• PCBs
• Ions
• Synthetic organic compounds
• Herbicides
• Pesticides,
• Disinfection byproducts

A summary of the water sampling data is described below.

• Source Water (Chambers Brook) Sampling
• All samples were not detectable (i.e. below analytical thresholds) for alpha pinene
• All samples were consistent with background monitoring results from that area, which the water treatment plant is equipped to treat.
• Treatment Plant Sampling
• All samples were not detectable for alpha pinene
• All samples were below maximum contaminant limits (MCLs) and/or health guidance values.
• Distribution System Sampling
• All samples were not detectable for alpha pinene
• All samples were below maximum contaminant limits (MCLs) and/or health guidance