Woodsville plant honored for drinking water

by Marianne Farr

Journal Opinion of Bradford, Vermont

WOODSVILLE—Last fall, the Woodsville Water and Light Department's water treatment plant received an award that few people know about. The State of New Hampshire Department of Environmental Services presented the plant with a Surface Water Treatment Optimization Recognition award for providing clean and safe drinking water in the face of many challenges.

The plant draws its water from the Ammonoosuc River, which flows from Mount Washington all the way down through Woodsville. Water treatment plant chief operator Bill Harris said that the plant faces many challenges due to the ever-changing nature of the river's conditions and explained that a lot of water departments take their water from a pond or a lake where water properties remain fairly stable.

The river, on the other hand, is affected by many variables including weather, wildlife, runoff from local farms and other man-made activities. Surprisingly, dirty muddy water is the best to treat, according to Harris.

One of the most stubborn things to treat involves the tannic acid that comes from pine trees. When the water takes on the quality of a cup of tea, it means that there is tannic acid present, he said. Tannic acid lowers the PH of the water.

"You have to burn the color out of the water before you can make a floc," Harris said, explaining that a floc is made when chemicals are added to the water in order to cause the tiny particles to clump together into larger masses.

Another challenge is the frequency of updates to state and federal regulations.

"The EPA is changing regulations constantly," he said. One new change is the tightening of limits on the amount of chlorine byproducts, Total Trihalomethanes and Haloacetic Acids, that can be present in the water. Harris is currently trying to figure out how to lower the amount while keeping costs low.

Since the plant was built, there have been several significant upgrades. One involved the addition of a second water tank. Harris said that before the second tank was added, they decided to rent a tank in order to conduct a "jar test" to prove that a longer detention time with chemicals would improve the process.

The contact time used to be three minutes, but the test proved to be accurate and the contact time is now an hour.

"The new tank has taken away about 80 percent of our problems," Harris said.

Another change that improved things at the plant was the installation of a manual switch that could control the system. A computer system runs the systems at the plant, so if there was a lightning strike and power went out, there was no way to get the system running again until power was restored. Now, they can just flip the switch if the system goes down.

A new computer system, called Supervisory Data Control Acquisition, has further enhanced the operation. The system enables them to tighten the parameters and fine-tune the chemical feed.

"We can trend everything," Harris explained. That means that if the state comes in asking for conditions from a certain date in the past, it can be pulled up right on the computer, he added.

Harris's own stringent standards help to ensure that the water is of the highest quality. While the state allows up to .3 units for turbidity, or particles in the water that float, Harris considers the max to be .1 units. The state allows 15 color units, but Harris allows none. The cost involved is minimal, $100 per year, Harris said, and it ensures maximum safety.

Built in 1989, the plant used to be office space and vehicle storage, according to Woodsville Water and Light Superintendent Robert Fagnant. The project came in at about $2.1 million and there are seven or eight years left on the payment plan.

Before that the district's water came from the Wild Ammonoosuc River, an Ammonoosuc tributary, and was basically untreated.

"Whatever came down the Wild Ammonoosuc is what we were drinking," Fagnant said.

Now the district bills 600 water meters every month. They service all of Woodsville, as far as Horse Meadow Road in North Haverhill, about a dozen customers in Bath and 40 customers in Swiftwater. In addition to the two tanks at the Woodsville site, there is also a 1.1 million gallon reservoir on Swiftwater Road.

This year's proposed budget is $349,000, with a $1,000 per day cost of operation. The biggest expense is labor, then electricity and lastly chemicals, Harris said.

The plant runs 365 days a year and there is an operator on site 24 hours a day. In addition to Harris, there are three other part-time operators.

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