In 1979, Carroll E. Taylor & Associates, Consulting Engineers of Auburn, Maine, and their sub consultants, completed an in-depth land treatment study which concluded that soils in Eagle Lake were not suitable for conventional land treatment, therefore, a unique system of land treatment cells and collection ditches was developed. A test section was then constructed and data collected for a period of approximately six months
In 1980 the District requested that the Maine Dept. of Environmental Protection classify this system as "innovative" by EPA regulations and therefore eligible for 100% state and federal funding. The DEP acted favorably on the request.
In 1982, plans were completed for the treatment plant and collector and interceptor sewers needed to serve the plant. Contracts were awarded for all three projects to S. G. Phillips Corporation of Waitsfield, Vermont.
Three grinder pumps, three minor pump stations, and approximately five miles of gravity sewer deliver the sewage to the influent pump station on Main Street. A comminutor at the pump station shreds the large particles and the sewage is then pumped approximately one-half mile (200 feet in elevation) to the treatment site where it flows into one of two aerated treatment ponds. Each pond has a capacity of five days detention at the design flow. The normal flow of sewage is series from one treatment pond to the next. Sludge or solids settle in the treatment ponds which are designed to hold three feet of sludge.
From the treatment ponds, sewage flows to aerated storage ponds designed to hold the sewage over the winter months with a total storage capacity of 200 days.
In the spring, valves in the storage ponds will be opened allowing the pretreated sewage to be pumped through the irrigation pipes to the land treatment area. The sewage is applied to the land by low trajectory impact sprinklers which can be removed for winter. The groundwater table has been lowered in the land treatment area by the construction of collection trenches which remove ground and surface water. This water flows to two sedimentation ponds at the lower end of the site. These ponds prevent eroded material from being discharged into the cedar bog and swampy area which contribute to Thibadeau Brook and ultimately to Eagle Lake. Berms upslope of the collection trenches prevent the sprayed water from flowing into the trenches.
|Lagoons||No.1||No. 2||Storage 1||Storage 2|
|Volume||0.73 MG||0.73 MG||14.6 MG||14.6 MG|
|Aeration||Fine Bubble||Fine Bubble||Fine Bubble||Fine Bubble|
|Lagoon Sizes||120'l x 200'w x 18'd||120'l x 200'w x 18'd||222'w x 534'l x 22'd||222'w x 534'l x 22'd|
|Number of Units||32||16||10||10|
|Lagoon Acreage||0.55 acres||0.55 acres||2.72 acres||2.72 acres|
|Design Flow||0.146 MGD|
|Actual Flow||0.060 MGD|
|Discharge To||Land Application|
|Design Engineers||Taylor and Associates|
|Septage Received||1,500 gallons per day|
|Collector System||6 miles of gravity sewers, 125 manholes, 4 pump stations|
|Staff Size||3.5 Full Time|
|Number of Users||750 services|
|Billing Software||Moody Data Systems|
|Comments||Facility has a sewered population of 1,350. Spray irrigation system has 704 sprinkler heads. Facility has 16 land treatment areas about .4 acres in size each. Application rate is 1.6 in./week. Irrigation pumps (2) are 30 hp and are rated at 1,150 gpm.|