Generating Low Nitrogen Class A Reclaimed Water Achieved by Coupling Satellite MBRs with a BNR Activated Sludge System
The LOTT Alliance in Olympia WA has created an integrated system-wide plan for managing flow and nitrogen emissions by linking a series of satellite reclamation plants (SRPs) to the main Budd Inlet Wastewater Treatment Plant (BIWWTP) that uses BNR activated sludge. At specific times during the year, their NPDES permit requires that flow be capped to the main treatment plant and stringent mass-based discharge limits be imposed for nitrogen and BOD. The SRPs are equipped with membrane bioreactors (MBRs) with biological nitrogen control that remove a constant flow from interceptor sewers and provide treatment to meet groundwater recharge criteria. Flow may be distributed between the main treatment plant and the SRPs to off-load the main treatment plant and meet its flow, nitrogen and BOD constraints during these crucial periods of discharge. To manage the flow, nitrogen and BOD within this system, a simulation tool was developed that optimizes the use of existing capacity at the main treatment plant and minimizes investment in new capital facilities. This paper describes the distributed wastewater management plan, the simulation tool and performance data from the initial stages of plan implementation.