Matawan's drinking water no longer contains inappropriately high levels of trihalomethanes, according to a public notice mailed to borough homeowners this week.
Trihalomethanes are, "four volatile organic chemicals that form when a chlorine disinfectant reacts with natural organic matter in the water," the notice explains.
Matawan residents have been receiving quarterly notices since the water system first tested too high for trihalomethanes in 2011, which violates drinking water standards.
The water distribution samples collected and analyzed between the second quarter of 2012 and the first quarter of 2013 were below the maximum contaminant level (MCL) for the organic chemicals, according to the notice.
The problem was addressed by the borough as well as by New Jersey American Water. The borough undertook an $800,000 storage tank rehabilitation project while NJAW installed a new disinfection process converting from chlorine to chloramines, according to the notice.