Portsmouth customers have already seen an improvement in water quality courtesy of new treatment plants, according to a news release from the Portsmouth Water and Fire District.

Quarterly water samples collected from February 2014 through November 2014 indicate that the Portsmouth Water and Fire District is in compliance with the state and federal regulations for Total Trihalomethanes (TTHMs). TTHM compliance is measured as a four-quarter, running annual average of four sample sites within a water distribution system and the EPA maximum level for TTHMs is 80.0 parts per billion. The TTHM four quarter, running annual average for the District’s most recent compliance period was 71.8 parts per billion.

In September of 2014, the District issued a news release and mailed a notice to customers indicating that it had exceeded the TTHM regulations. That excedance was based on the four-quarter running annual average of 89.2 parts per billion for the period of November 2013 through August 2014. The most recent quarterly testing in November 2014 resulted in a TTHM average for the quarter of 24.6 parts per billion, which brought the District’s four-quarter, running annual average into compliance.

William J. McGlinn, the General Manager and Chief Engineer for the District, indicated that construction of the new Lawton Valley Water Treatment Plant in Portsmouth and the renovation of the Station One Water Treatment Plant in Newport made an immediate difference in the TTHM levels for Portsmouth Water, Newport Water and the Navy – the three island water suppliers. The water treatment plants project was constructed by the City of Newport and both plants were put on-line in the second half of 2014. Due to the challenging water quality of the City of Newport’s nine reservoirs, Advanced Water Treatment processes have been incorporated into the two water treatment plants in order to assure compliance with drinking water standards, particularly the TTHM standards. The total project cost is $84 million, which is being funded for through the water rates of all water users on the island.

Update, 1/22/15 5:16pm: An earlier version of this story included an incorrect expansion of the acronym "TTHM." It stands for Total Trihalomethanes, rather than just "Trihalomethanes." This error was present in the press release from the Portsmouth Water and Fire District, and was pointed out by a reader. My apologies for letting this slip through.

Editorial note: Written from a press release.