This study presents the results of numerical modeling performed in support of the evaluation of the feasibility of conveying sanitary wastewater flows handled by Erie County Sewer District (ECSD) No. 6 Lackawanna Wastewater Treatment Plant (WWTP) to the Buffalo Sewer Authority’s (BSA’s) Bird Island WWTP for treatment. The Lackawanna WWTP has a rated capacity of 4.5 million gallons per day (mgd).
A coupled hydrologic/hydraulic/hydrodynamic/water quality numerical modeling approach was developed to properly capture and evaluate the range of potential environmental benefits and impacts of eliminating discharge from the Lackawanna WWTP to Smokes Creek. The results showed that over 95 percent of the ammonia and TKN concentrations would be removed from lower Smokes Creek. Lead and zinc concentrations would be reduced by approximately two-thirds. Eliminating the Lackawanna WWTP discharge would result in only minor reductions in current Smokes Creek flow velocities and water levels
The potential impacts of redirecting the ECSD No. 6 flows to the BSA were evaluated by using the XPSWMM model of the BSA sewer system. The results showed that the Bird Island WWTP would be well suited to accept sanitary wastewater flows from ECSD No. 6. The Bird Island WWTP excess capacity would only be reduced by about 10 percent to treat flows from ECSD No. 6, thus maintaining flexibility. Potential additional combined sewer overflow (CSO) volumes from the BSA system due to the additional flow from Lackawanna are expected to be about one percent or less. These CSO impacts would be distributed throughout all water bodies along the Buffalo waterfront.
In summary, the study showed that redirecting the ESCD No. 6 flows would allow decommissioning of the Lackawanna WWTP and removal of most treated wastewater discharges to Smokes Creek, leading to significantly improved water quality in Smokes Creek. In addition, the overall contaminant loading to the Niagara River watershed would be reduced. These environmental benefits in turn would enhance regional efforts to develop Smokes Creek into a recreational area. Planned Buffalo Outer Harbor development along the waterfront corridor also presents an excellent opportunity to accommodate collection of wastewater flows in support of conveying ECSD No. 6 flows to the BSA.