Town of Mansfield
Mansfield Four Corners Sewer & Water Project

July 22, 2009:  Chapter 2 -- The Sewer Facilities Planning Effort

 

After being told by the DEP in 2004 that the Town had to do something about the continuing wastewater problems in the four corners area, the Town embarked on a wastewater “facilities planning” study of the area to determine the extent of the wastewater disposal problems and to plan for a long-term solution.  Several consulting firms were interviewed and the firm of Earth Tech (now AE Com) was hired to complete this study.  The study began in 2006 and was completed in 2008.

 

The tasks that were conducted in the facilities planning study included evaluating the existing conditions in the study area, developing future wastewater flow estimates, investigating alternative wastewater conveyance and disposal options and developing a recommended plan to support existing and anticipated development in the planning area consistent with the Town’s Plan of Conservation and Development.

Development within the study area currently relies exclusively on individual subsurface wastewater disposal systems for disposal of sanitary wastes with varying degrees of success.  After a review of prior studies (there were several dating back to the 1970’s), regulatory agency records, wetlands maps, soils mapping data, zoning regulations, conservation and development plans and sensitive environmental area data, a lot-by-lot survey of septic system functionality was conducted.  This investigation determined that many properties have had, and continue to have, chronic wastewater disposal difficulties due to a combination of density of development, lot size and site constraints.  Continued reliance upon onsite subsurface wastewater disposal systems will result in continued exposure of the public to the health hazards associated with exposure to untreated wastewater, degradation of surface waters, severe limitations for potential development, and a failure to provide for tax base growth due to the inability to capitalize on potential commercial and higher density residential economic development opportunities.

To evaluate future wastewater treatment and disposal system needs over the 20 year planning period, historic trends in the study area, available land and other factors affecting residential, commercial/industrial development, water uses and population growth were all considered.  Wastewater flows are projected to increase from approximately 47,000 gallons per day to 170,000 gallons per day over the 20 year planning period.

The facilities planning study then evaluated a number of wastewater treatment and disposal alternatives that are capable of reliably and cost effectively meeting the wastewater disposal needs in the 4 corners area.  Collection system alternatives considered included traditional gravity sewer collection systems in combination with pumping station(s) and force main(s) as needed, pressure sewers and vacuum sewers.  Community or centralized wastewater treatment alternatives considered included subsurface wastewater disposal systems serving multiple properties or communities, small pre-engineered packaged wastewater treatment facilities and connection to a centralized wastewater treatment facility such as the UConn wastewater treatment plant.  The most feasible and cost effective methods of wastewater collection and disposal were determined to be a traditional gravity sewer collection system transporting wastewater flows to the UConn treatment plant for disposal.

Three collection system alternatives were developed for this study with estimated costs ranging from $5.1 to $5.4 million dollars.

The report’s recommended sewering plan, which is also the lowest cost alternative, includes a gravity sewer collection system serving the four corners community sewer service area, a wastewater pumping station and a force main to convey the wastewater from the pumping station to the existing UConn wastewater collection and treatment system.

The facilities plan also depicted a recommended sewer service area which included about 60 properties in the four corners area.  As part of the review of this plan, the Mansfield Planning and Zoning Commission recommended some minor changes to the sewer service area boundaries.  The four corners sewer planning advisory committee is studying further modifications of the proposed sewer service area boundaries in order to provide the most cost-effective sewering plan for the Town (for example, including a few additional adjacent parcels in the service area could have the effect of lowering the assessments on all the included properties).

The recommended sewer service area is shown on the figure below in black.  The conceptual location of the gravity sewer pipes is shown in red, and the force main in blue.

 

 

For more information …

Contact:                                                         

Lon Hultgren, Director of Public Works
Audrey P. Beck Municipal Building
4 South Eagleville Road
Storrs, CT 06268-2599

Phone:  (860) 429-3332
Fax:     (860) 429-6863
E-mail: HultgrenLR@MansfieldCT.org   

Aerial View of the Intersection of Rtes 195 and 44

View Previous Reports:

June 16, 2009:  Chapter 1 -- The Environmental Context and History of the Four Corners Area