Minus ‘significant’ rain, NPU can foresee limits

Levels at 60 percent of capacity would trigger measures

Norwich — Norwich Public Utilities’ two reservoirs were at 99 percent of capacity on June 3, but could drop to 60 percent in the coming weeks, a level that would trigger mandatory water conservation measures, a utility official said Tuesday.

Mark Decker, NPU water integrity manager, told the Board of Public Utilities Commissioners on Tuesday that the combined water level at the utility’s two reservoirs was down to 70 percent of capacity by Sept. 9 and 65 percent by Sept. 23.

At 65 percent, the reservoirs contain a 215-day supply of water, while full capacity — 1.8 billion gallons in the two reservoirs — is a 321-day water supply for the city, NPU spokesman Chris Riley said.

NPU issued a water supply watch on Monday, continuing in-house conservation measures, including ceasing routine hydrant flushing, repairing leaking valves and delaying repairs with high water use.

The utility also is urging customers to reduce nonessential water usage, such as lawn and garden watering, pool filling and car washing.

Decker said the utility would issue a water supply warning if the reservoir level drops to 60 percent, and would include both voluntary and mandatory conservation measures.

“Without significant rain events, we’re going to go into mandatory water conservation within two to three weeks,” Decker said.

By that time, lawn and garden watering and swimming pool filling will be mostly done for the season, he said.

NPU General Manager John Bilda attributed a water quality problem in the Norwich Free Academy area last week to the persistent drought and a sudden rainstorm early last week. Bilda said the sudden rain flushed large amounts of organic material into the low-level reservoirs in one night, upsetting the chemical treatment balance in the system.

The organic material caused an “earthy” smell and taste in what Bilda called a “slug” of water that made its way into the water mains feeding the Chelsea Parade area. He said the William W. Backus Hospital did not experience the problem, but the water entered the NFA tap water system.

NFA officials noticed the unusual smell and taste of campus tap water the evening of Sept. 20. NFA officials contacted NPU that evening and utility officials responded and tested the academy’s water repeatedly throughout the week. All tests showed the water was safe to drink.

NPU, which received several other similar complaints from residents in the area, flushed hydrants in the NFA area and tested water in other locations upstream and downstream of the campus. NPU contractors applied treatments of copper sulfate at NPU’s two reservoirs to counteract the slightly elevated level of organic materials, and NPU increased flow rates in the Mohegan Park and Occum water tanks to improve water movement.

“During this time, NPU was responsive, supportive, and sensitive to NFA as a customer and to our unique needs as a school,” NFA spokesman Geoff Serra said Tuesday in an email response to questions about the water-quality issue.

NFA used bottled water for drinking and cooking from Wednesday, Sept. 21, through Friday, Sept. 23, “transitioning” back to normal operations on Monday, Serra said. Drinking water fountains were turned on at the end of the school day Monday.

“Currently the ‘unusual’ taste and smell of the water noted last week seems to have resolved and the transition to city water has been smooth,” Serra wrote in the email.