Master Plan for TN of 0.9 mg/L and TP of 0.05 mg/L Leads to a Conventional Treatment and Reuse Recommendation and Saves $300 Million

The objective of this paper is to summarize the Master Plan developed by the City of Durham (City) to reduce nutrient discharge into sensitive watersheds while planning capital improvements necessary to see the City's two water reclamation facilities (WRF) through expected long-term buildout of the service area. New watershed-specific regulations will require the City's WRFs to meet nutrient discharge limits as low as 0.9 mg/L total nitrogen (TN) and 0.05 mg/L total phosphorus (TP). The Master Plan evaluation concluded that the City could meet these ultra-low nutrient limits by optimizing conventional treatment and implementing a 15 million gallon per day (mgd) reuse plan, eliminating the need to implement advanced treatment technologies and saving rate payers $300 Million.The Master Plan incorporated conclusions from a sidestream treatment evaluation and facilities condition assessment, as well as biosolids strategy, wet weather and energy evaluations, and emerging contaminants workshop. This Master Plan provides the City a holistic approach to preserve the quality of the local water environment while minimizing energy usage and maximizing clean water reuse and nutrient recovery.