Status of WWTF Nitrogen Reduction October 2007 Angelo Liberti Chief of Surface Water Protection RIDEM Ext 7225

RIDEM Efforts to Reduce WWTF Nitrogen Levels WWTFs required to reduce ammonia encouraged to reduce TN XXXX increased WWTF flow to an impaired water 2005 Permit modifications issued to remaining WWTFs impacting the Providence and Seekonk Rivers 2006 EPA agreed to develop plan to require TN limits for 5 MA WWTF

Status of RI WWTFs 9 Completed construction (2 issued permits that require further TN reduction) 2 - Permits and compliance schedules issued 1 - Permit anticipated

Goal of Reducing RI WWTF TN by 50% Goal based on levels from 11 WWTFs impacting the Upper Bay Required reductions - 65% dropping to 48% as WWTF flows increase to approved design flows. Current reduction approximately 35%

Status of MA WWTF 3 Permits drafted, comment period ended –Upper Blackstone Water Pollution Abatement District (5 mg/l) »Attleboro (8 mg/l) –North Attleborough (8 mg/l) 2 Remaining –Grafton –Uxbridge