Wolfeboro's New Sewage Treatment System Brings New Problems

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Treated wastewater- about 400-thousand gallons a day- is pouring into basins that sit on top of a hill in Wolfeboro.
The soil up here contains large amounts of coarse sand and gravel.
The sand filters the water, removing any remaining pollutants before it seeps to an aquifer.
That’s the way the treatment system is supposed to work.
But Public Works Director David Ford says not everything is running as smoothly as expected.
“98 6:06 we had some unexpected conditions, it’s not so much where the water is going in the ground, it’s where it comes out of the ground.”
This summer, the water hit a finer layer of sand.
So instead of filtering down, the water flowed horizontally, making its own exit midway down the slope of the hill.
In addition, earlier in the year a 100-foot section of soil was sheared off the hill, exposing tree roots.
Ford says both problems happened when the system was discharging 600-thousand gallons of water a day – as high as their permit allows.
“93 6:33 that’s the time when we were doing the maximum, we were trying to push the basins so had we had maximum flow going in the ground and in hindsight we probably should not have gone so high right off at the beginning.”
While treatment systems like this have been tested in other parts of the state, it’s new for Wolfeboro.
And unlike others in the state, a brook - that eventually flows into Lake Winnipesaukee - lies at the base of the hill.
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Ford walks down to the bottom of the hill near the brook.
(92 1:25 on those rocks in July and August there was some algae growing there that was different from the moss we see now and we really don’t know why, although there is a little bit open in the canopy and the sun was very high in July the sun can kick off the algae grow pretty quickly.)
Algae can also grow because of excess nutrients such as nitrogen and phosphorus coming from wastewater.
It can deprive a brook of its oxygen.
Ford says this outbreak was not caused by the problems with the wastewater treatment plant.
But the affect the treatment system might have on the brook is one of the concerns of neighboring Tuftonboro.
102 “it was an occurrence that we thought could happen and it did happen.”
That’s Commissioner Gary Chehames with the Tuftonboro Conservation Commission.
Before it was built, he opposed the treatment system, which sits on the border with Tuftonboro.
And he says the recent problems don’t ease his mind.
1:02 “The fact of the matter is the facility is there and now it’s a question of trying to make it operate as safely as possible and so we have not been looking back we’re just looking to the future, i.e. will this happen again.”
Wolfeboro tests levels of pollutants at areas around the basins and since the problems they’ve added more test sites.
Tuftonboro Conservation Commissioners are monitoring as well, and say they found algae this summer on another stream that flows into the brook.
The Department of Environmental Services has ordered Wolfeboro to build two more basins on top of the hill.
Public Works Director David Ford says it will prevent wastewater from seeping down in the same spot.
6:30 We anticipate putting in another 25 or 30-thousand square feet, of basin and it will look very similar to this, it will be at this elevation, so the top of the hill will be knocked off and that will allow us to push some of the water in different directions so we won’t have any more unexpected conditions like we had in the area below.
Ford says in the meantime, Wolfeboro has slowed down its flow of wastewater into the basins.
He says that should allow the water to filter down like it’s designed to.
So far, it’s working.
For NHPR news, I’m Amy Quinton.