Corinna, Maine - Corinna Sewer District
When Corinna’s advanced wastewater treatment facility went on-line in September 2005, a key component of a multi-faceted plan to improve Sebasticook Lake quietly fell into place. No longer will treated and untreated wastewater feed algae blooms that have clouded the waters for decades.
In the 1990s, state biologists determined that discharges from the Corinna Sewer District (CSD) had to be removed for water quality to improve. For 35 years, these discharges to the East Branch of the Sebasticook River transported phosphorus to the lake, significantly contributing to the growth of nuisance algae. Without the added phosphorus, the lake stands a better chance of achieving its natural balance.
Removing the discharges was an eight-year project requiring the pooled financial resources of several state and federal agencies. The first phase involved replacing most of the old sewer system to eliminate three “combined sewer overflows” (CSOs) that discharged a mix of untreated storm water and sewage to the river. It also involved reducing the wastewater flow that would ultimately be treated by a new facility.
The second phase was the construction of that new facility with the necessary pump station and force main to complete the system. Now treated wastewater is land applied using spray irrigation instead of being discharged to the river and, ultimately, Sebasticook Lake.
Cost of the CSD project exceeded $9 million. The bulk of the funding ($5 million) came through a state grant made possible by voter-approved bonds. Three federal funding sources provided the balance.
Removing Corinna’s direct discharges complements numerous pollution prevention projects around the lake. Other initiatives, including annual lake drawdowns to flush out the nutrients and the construction of a new wastewater treatment facility in Dexter, have also been employed to improve water quality. These efforts represent an additional $14 million in local, state and federal spending.
The Corinna Sewer District (CSD) discharges treated wastewater from its treatment plant and untreated combined storm water and sewage from three Combined Sewer Overflows (CSO) to the Sebasticook River above Sebasticook Lake. For years the Sebasticook Lake has had a water quality problem stemming from excess nutrient addition. Over the previous twenty years approximately $14 million in Federal, State, and local monies have been expended to abate the water quality problems. The CSD discharges are the largest identifiable sources of phosphorus loading to Sebasticook Lake and by removing them there will be measurable improvements in the lake’s water quality.
On October 17, 1996 the Town’s largest employer and sewer user, a textile mill, closed causing the loss of many jobs and placing the Town and the Sewer District in severe financial hardship. The estimated cost to remove the discharges from the lake’s tributary is $9 million. The proposed treatment system will increase the local sewer user rate from $232 to $445, the latter being 2% of the Median Household Income (MHI). To make this project viable for the citizens of Corinna, a number of State and Federal agencies pooled their financial resources.
v Prior to the sewer upgrade and treatment plant replacement, the Corinna Sewer District (CSD) discharged treated wastewater from its treatment plant and untreated combined storm water and sewage from Combined Sewer Overflows (CSO) to the Sebasticook River above Sebasticook Lake.
v For years the Sebasticook Lake has had a water quality problem stemming from excess nutrient addition to the lake from both point and non-point sources.
v For over twenty years the Department has conducted research and implemented corrective actions to reduce the trophic state of Sebasticook Lake.
· Over $12 million in Dexter to remove their discharges and construct a spray irrigation system.
· $1.3 million in projects to reduce Non-Point Source (NPS) contributions to the lake.
· $0.6 million in a draw down project to flush out surplus nutrients from the lake.
v On October 17, 1996 the Town’s largest employer and sewer user, a textile mill, closed causing the loss of many jobs and placing the Town and the Sewer district in serve financial hardship.
v State biologists determined that the Corinna Sewer District was the largest identifiable source of phosphorus loading to Sebasticook Lake and by removing the discharge from above the lake there will be measurable improvements in its water quality.
v In 1997 the Department conveyed to the CSD that pursuant to Maine law, 38 M.R.S.A., §464 (4) (A) (3), the discharge from the wastewater treatment facility must be removed from the East Branch of the Sebasticook River as the river is a tributary to a Class GPA waterbody.
v In 1998 CSD received a $94,000 State grant and a $74,000 CDBG grant to upgrade their headworks grinding system and install a new aeration system to better treat the reduced wastewater flows after the mills closure. Total project cost of $171,000.
v In 1999 CSD received a $3,750 State grant as 25% funding for the preparation of a Pollution Abatement Facilities Plan. Total project cost of $15,000.
v As a result of the facilities planning process a two-phase project was implemented to (1) replace the leaky sewers and eliminate the CSOs, and (2) remove the District’s discharge from the river by constructing a spray irrigation system. A two-phase approach to the project was taken to better establish the design flows for the second phase in an effort to reduce the project cost to within the funding budget.
v The June 2000 Facilities Plan estimated the design and construction costs for the project at about $9 million.
v On August 20, 2001, construction was started on Phase 1, Sewer Rehabilitation.
v On July 30, 2004, construction was started on Phase 2, Pump Station, Force Main and Spray Irrigation Wastewater Treatment Facility.
v On September 15, 2005 flow was diverted from the old treatment facility to the new spray irrigation wastewater treatment facility.