The Milford Wastewater Facility is permitted to discharge its treated effluent into the Souhegan River.  The original facility design utilized a 'single pipe' discharge (see picture below right) which means treated water passes through a 'single pipe' into the middle of the river were it mixes with the river water.  During meetings and discussions with New Hampshire Department of Environmental Services (NHDES), it was learned that treatment facilities in the State of New Hampshire utilizing single pipe discharges will be required to modify their outfalls to incorporate a diffuser-type assembly.  Since Milford's discharge pipe was becoming more and more of a maintenance issue due mainly to debris carried downstream by the large fluctuation of flows that the Souhegan is noted for, it was decided that a upgrade be completed before it becomes a reactive situation.  A diffuser assembly incorporates a series of diffuser ports along a outfall pipe buried in the river bed (see picture below left).  By discharging the effluent through a series of ports rather than a single point discharge, it maximizes the ability of dilution which in turn minimizes the point impact on water quality and the river environment.

                   Original single pipe outlet                                                             New diffuser assembly 

Park Construction Corporation of Fitzwilliam, NH was awarded the bid for this project, construction started in mid September 2006 and was completed in late November.  The contract price was $285,000 and the project was completed within budget.

              The 24 inch Ductile Iron outfall pipe                                          A look at the Tideflex diffusers