Yesterday I attended an informational tour of the town’s RIB (Rapid Infiltration Bed). The town was represented by Dave Ford, various employees and contractors involved in the town’s wastewater disposal efforts, an engineer from Wright-Pierce who designed the system, and a Wolfeboro Selectman. Others were some Tuftonboro Selectmen, some Tuftonboro Conservation Commissioners, a representative of the state DES, a reporter from the Grunter and a few civilians like me.
Dave Ford did a good job of recounting the history of the project and explaining the ongoing issues. Anybody who has had dealings with Dave knows that he doesn’t sugar-coat things. The presentation was direct and factual. We walked in the woods and he pointed out the “Unexpected Issues” that have developed, and then presented an assessment of the current effluent disposal situation and options. To me he seems to be saying that while not ideal, the situation is manageable.
The RIB consists of five sunken beds with sandy bottoms on top of a hill that are alternately flooded with treated effluent. The effluent subsequently percolates down through the sand, giving up most of its phosphorus, then follows saturated or granite layers to daylight someplace. The unexpected issues involve about half of the effluent finding it’s way out of the hillside prematurely causing sinkholes, erosion and sand migration. So far, these problems have been managed with an improvised system of pipes and sand traps, but the situation begs a more comprehensive solution.
In spite of the difficulties, monitoring shows that the RIBs are doing the job of removing phosphorus, and due to innovative improvements made at the Wastewater Treatment Plant, the nitrogen levels of the flow as it enters the site are well below the anticipated and permitted levels.
A significant consequence of the blowout problem is reduced capacity, particularly during wet periods when rainfall increases the natural flow down the hill. This has required re-commissioning of some of the old spray-fields and a proposal to set up a new one. We need to renew our permits from the state to operate both the RIBs and the spray fields. I think that will be forthcoming.
Tuftonboro representatives seem to be concerned about the recent developments, as well they should be. The improvised network of pipes and sandbags have the look of a post disaster landscape. Also, trees in the immediate area of the surface water are dying and being replaced with other vegetation that is better suited to the changing conditions. There is no denying that this facility is having a profound impact on the surrounding area, but it should also be noted that much of it was anticipated and while different, its not necessarily bad. But while they may see these unexpected issues as a complication, there is another side that should be considered: The annual flow through the facility and ultimately to waterways like Nineteenmile Brook are and will probably continue to be half what was originally anticipated, and the nitrogen content of the effluent is half what was allowed in the originally approved design. So the way I see it, our nitrogen disposal there is 75% less than originally expected.
There was no attempt to place blame or wallow in hindsight. Dave Ford knows that his problem is getting rid of an annual 150,000,000 gallons of our showers and flushes, and that is not easy in the Granite State when you are many miles from a moving river. He is just going straight ahead with managing the problem week to week with the resources that he has. That includes programs to further reduce the load (I&I), and disposal at the RIB and spray-fields as conditions allow.
Something to think about next time you pull the chain. I don’t have any better ideas.