Water System Less Taxed Than Last Summer, But Shortage Still Possible

By: Alan Pollock

A voluntary water ban is in place again this summer.  FILE PHOTO

CHATHAM — Thanks to several well-timed rainstorms, the town's water system is keeping up with demand this summer.

But officials say that, with another four weeks of summer left, it wouldn't take much more than another heat wave to stress the system beyond capacity. There are also predictions for a warmer-than-usual autumn ahead, Public Works Director Tom Temple told selectmen last week.

Water and Sewer Advisory Committee Chairman Larry Sampson said the peak day consumption is down over the past two years, from 4.2 million gallons per day in 2015 to just under 3.7 million this year. If that trend continues, once three more wells are put in service next year, the water system will be able to reach its goal of keeping 25 percent of the water supply in reserve in case of emergencies.

“That's great news,” Selectman Jeffrey Dykens said. Earlier this summer, selectmen implemented voluntary water restrictions designed to curb nonessential water use during times of peak demand.

“We're not completely out of the woods,” Sampson said, but officials are happy that the trend is improving.

Temple showed selectmen a comparison of water pumping volumes for each July from 2010 to 2017, and said that this year's consumption ranks fifth during that time period. The problem is not a shortage of water in the aquifer, but a lack of capacity to pump the water at a rate that meets demand, officials say. A new iron and manganese removal plant is currently being built which will allow two wells to be placed back online; those pumps were turned off after high levels of the minerals caused discoloration of the water. Until those wells are working again, the system will be susceptible to coming close to capacity.

That's why recent rains were so welcome, Temple added.

“This really helped offset the water uses,” he said. “I'm happy that my rain dance over the course of this year has worked,” he added with a chuckle.

In June, pumpage was down more than 27 percent compared to the previous June, and in July, demand was 9.8 percent lower.

“Then we hit August,” Temple said. The first six days of the month saw nearly 2 percent higher demand than the same time period in 2016, thanks to a hot and dry weekend on Aug. 5 and 6. When he came in the office on the morning of Aug. 7, Temple said levels in the town standpipe were down to 79 feet from a norm of 103.

Part of the problem is that many lawn sprinkler systems are set to work on Mondays, Wednesdays and Fridays, but they turn off when rain is present. The dry Friday, followed by a dry weekend and a rain-free Monday morning caused strong demand over several days.

“Come Monday morning, our voluntary water ban is not working,” Temple said. By 10 a.m., the town pumps were catching up, and the water level in the standpipe had stabilized at around 84 feet.

To do so, the pumps ran for more than 16 consecutive hours that day, which is the maximum recommended operating time before the equipment begins to suffer.

“You don't want to wear out your pumps,” Temple said. But just as importantly, with extended pumping, parts of the aquifer can have trouble replenishing.

Some of the town's wells are also quite shallow, and extended pumping can cause them to draw in bacteria from near the surface. Should that happen, the well would likely be taken offline for a time, further exacerbating the shortage.

The outlook for next summer is mixed, officials say. While work continues on the wells and treatment plant, it will probably be next August before all of the equipment is functional, just after the time of peak seasonal demand.