Wastewater Treatment Facility

Date: Tuesday November 9, 2010
Place: Wastewater Treatment Facility, Franklin New Hampshire 
Weather: Drizzling/ Raining/ Overcast


Today, we went to visit the Wastewater Treatment Facility in Franklin, NH. It was a little smelly at first but after you got over that it was fine. Our tour guild was Ken Noyes the Chief Operator of the plant. Ken has been working at the facility for 22 years. The plant in Franklin process waist from a large portion of the Lakes Region.(See Picture 1) The water that comes, mostly residential, in stays for about 13 hours in total to be processed. 

Picture 1

The water enters the plant at the Headworks(A). At the Headworks most of the suspended solids are taken out of the water. This is done by taking the water from a speed of about 3ft per second down to 2ft per seconds. 


After the Headworks, the water goes on to the Primary Clarifiers(B). Here the settleable solids are taken out of the water. The water enters in the middle of the big round tank and slowly travels to the outside where it leaves. Here about 60% -65 % of the settleable solids are removed and between 35% and 40% of BOD's. BOD or Biochemical Oxygen Demands is the amount of oxygen that pathogens need to survive in the water.  When we watching the tank there were about six sea gulls sitting on the sweeping arm, witch skims the remaining floating solids out of the water, eating some of the solids. When we asked Ken about it he told us simply that: "Sea gulls are nasty birds." 



From the Primary Clarifiers the water goes onto the Aeration Tanks(C), witch is the main treatment unit, where lots of air is put in to the water along with microorganisms or "bugs" to remove the organic content. The "bugs" work hard to get the dissolved solids out the water. The water will spend 6 hours here being cleaned by the workers. In the summer time less "bugs "are needed than during the cold winters. If the number of "bugs"falls below the legal limit then they go to other wastewater plants and take some of their bugs to help boost their population. When the "bugs" have done their work they are then sucked off the bottom of the tank to be used again. Ken told us that if he was going fall into one of the tanks it would not be one of these because the aeration process makes it impossible to swim. 


After the Aeration Tank the water goes to the Secondary Clarifiers(D). This is another big round tank that looks a lot like the Primary Clarifiers. This tank removes the residual solids. These solids are because of the microorganisms in the aeration tanks. 




The last stop for the water before it goes back to the river is the Disinfection System(E). In this building the water looks just like "Mountain Dew," according to ken, because of the UV lights. The UV system was put in place in 1997. Prior to this the plant used chlorine tablets. The chlorine system is still in place for high flow times. From here the water flows right into the Merrimack River. The water that we saw flowing out of the Disinfection system was very different from the water we saw entering the headworks. The water at the beginning was a dark grey almost black color and smelled like sewage and the water we saw leaving was clear and looked and smelled just like normal river water. 

At the end Ken told us: "I love the work I do, I love cleaning the rivers." This was very satisfying to hear. The entire time that Ken was talking to us he seamed excited about what he was talking about. Being the Chief Operator of a sewage treatment plant may not seam like a glorious job but it is a very important one in my opinion. 

All Photos are from "The Winnipesaukee Rive Basin Program" pamphlet.