By Written by Ike Morgan: Last Saturday, I toured the Dexter Water Filtration Facility with Greg Brawn as my tour guide. Brawn is Chairman of the Board of Trustees of the Dexter Utility District. The tours were open to the public in conjunction with Dexter Lakes Day and their efforts to educate residents of the importance of maintaining and protecting the areaís valuable watershed of lakes, rivers, and streams.
The idea of touring a water filtration plant may not seem like the most fun someone could have on a beautiful summer day, but I can assure readers of one thing, once you have completed the tour you will have a much greater appreciation for one of those things we take for granted every day, clean water.
It turns out that Dexterís water plant is one of the most modern and efficient systems around. Once you step into the control room you realize why. All information about the pumps, piping system, reservoirs, filtration, and disinfection methods is completely monitored by computer. When I walked into the control room a computer was displaying a schematic overlay of the entire plant. From that computer one could monitor every part of the system from the pumps, water levels, and filtration rates to the outflow and amount of usage.
If ever things were to go wrong an alarm system would kick in and actually start making automated phone calls to alert officials. The entire system is also hooked to an emergency generator in case of power loss.
Along the side wall is a control and monitoring box that gauged the three chemicals that are mixed with the water in very precise amounts. Digital readouts allowed for instant analysis of the mixture rates.
Chlorine is added for disinfection, although Brawn informed me that because of the relatively high level of purity of the water coming from Lake Wassookeag not as much chlorine needs to be added as compared to other towns and districts. Sodium fluoride is added to aid in dental health. The ingredient added that I was not familiar with was soda ash. It turns out that soda ash not only maintains a good pH level (not too acidic, not too much alkali) but it also aids in preventing older pipes from corroding as fast.
Once out of the control room you head down into the reservoir area. Even here you see some very simple yet effective methods of operation. Pipes are painted different colors so as to identify raw intake water, filtered water, and any overflow water.
The reservoirs are where the filtration is done. Raw water from the lake is pumped into big enclosed pools of about 40 feet by 40 feet. On the bottom of the pools are several layers of sand and gravel. Each layer has a purpose but the most important is the top 3 inches of fine sand that remove micro-organisms from the water.
Once the water has been filtered down through all the layers it flows into the clear well. Just before it reaches the clear well it is injected with the precise amounts of disinfectants and then it is ready for distribution to the town of Dexter.
What is amazing about this type of filtration system is that it has been in use for over 100 years and is really no different then when rain water is filtered through the ground into the groundwater.
Iím glad I took the tour, it was informational, interesting and most important of all I came away with a new appreciation of what we so many times take for granted: clean, fresh water.
For those interested in touring the filtration facility call 924-7367 "This content originally appeared as a copyrighted article in the SVWeekly.com and is used here with permission."
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