The current LTCP phase is the final phase of a three-phase process implemented by the BSA to develop its system-wide LTCP. Phase 1 consisted of the three stages and concluded with submittal of the 2004 LTCP to the NYSDEC. Phases 2 and 3 resulted from the NYSDEC and USEPA requesting additional evaluations and an update to the 2004 LTCP.
Phase 1, Stage 1: System Mapping, Data Collection, and Model Development
The goal of Stage 1 was to create a consistent analysis tool to support evaluation of alternatives in Stage 2 and development of the LTCP in Stage 3. Stage 1 consisted of:
- System mapping
- Field data collection
- Collection system model development and calibration
System mapping and data collection occurred simultaneously. The product of the system mapping effort was a Geographic Information System (GIS) of the BSA’s interceptor and trunk sewer system that served as the basis for the network of the system-wide collection system model. The product of the field data collection effort was a set of flow and precipitation data that could be used in the calibration of the model, as well as water quality data that was used to perform a water quality assessment and calculate pollutant loadings to the receiving water bodies. The model development and calibration effort produced a consistent system-wide tool that was used in Stage 2 in the evaluation of CSO abatement alternatives.
Phase 1, Stage 2: District-Specific CSO Planning
For Stage 2, the system-wide model developed in Stage 1 was separated into three Districts: the North District, the Scajaquada District, and the South Central District. Each District model was submitted to a District Consultant, who was responsible for evaluating and recommending CSO abatement alternatives in their local District. The end product of Stage 2 was a list of evaluated alternatives, recommended actions, and discarded alternatives, for each District.
Phase 1, Stage 3: System-Wide LTCP Development
Stage 3 brought the District-specific alternatives into a system-wide comprehensive plan for CSO abatement. Each of the three District Consultants provided modeling files and a report summarizing alternatives for CSO abatement within each respective District. During Stage 3, four alternatives were developed, based on the District-specific recommendations as well as additional technologies.
The objective of Stage 3 was to develop and evaluate four system-wide alternatives, to establish system-wide control objectives, and to recommend the most economically-feasible alternative that meets those objectives. Stage 3 also included a financial capability assessment, and the development of an implementation schedule for the recommended alternative that considers BSA’s financial capability.
Phase 2 LTCP Engineering
Phase 2 LTCP engineering consisted of additional evaluations requested by the NYSDEC and USEPA following their review of the 2004 LTCP. This additional work was started in 2008 and consisted of:
- Supplemental flow and rainfall monitoring
- Receiving water quality sampling
- Collection system model refinement
- Receiving water quality model development
- Financial capability analysis revisions
Phase 3 LTCP Engineering
The Phase 3 work used the tools generated or refined under Phase 2 to build upon the alternatives presented in the 2004 LTCP and incorporate innovative and emerging technologies into the alternatives analysis. This included updating the 2004 preferred system-wide alternative to meet new bacteria control in the Class C receiving waters and using this alternative as benchmark against other system-wide alternatives using innovative and/or emerging technologies such as real time control (RTC), green infrastructure (GI), and a new high rate treatment (HRT) facility in the northern portion of Bird Island.
The results of the alternatives evaluation, along with the updated financial capability assessment were used to select the recommended system-wide LTCP program for the BSA.