2. Range of Services to be Performed by Consultant. Task 1: Conduct watershed hydrology and water quality modeling that generate accurate pollutant loadings to support Reasonable Assurance Demonstrations for compliance with the TMDLs (Total Maximum Daily Load), Phase I MS4 Permits, alternative watershed compliance pathways (MS4 Permit Provision B.3.c), and other regulatory-required studies. Use Environmental Protection Agency (EPA)-approved tools that aid in the design of control strategies for managing stormwater and dry weather flows prior to the discharge to waterways to meet water quality regulations. • Conduct hydrologic/hydraulic and water quality modeling using accepted watershed models such as Better Assessment Science Integrating Point and Nonpoint Sources (BASINs), Loading Simulation Program C++ (LSPC), System for Urban Stormwater Treatment and Analysis Integration (SUSTAIN), EPA Storm Water Management Model (SWMM), Structural BMP Prioritization and Analysis Tool (SBPAT) or other public domain software. • Use the Modular three-dimensional finite-difference flow model (MODFLOW) to simulate watershed hydrology, emphasizing groundwater–surface water exchange to assess connectivity, baseflow contributions, and the response of streams and aquifers to current and projected water management scenarios. • Incorporate climate change scenarios into models to assess potential impacts on hydrology and water quality under future precipitation, temperature, and land use conditions. • Use Geographic Information System (GIS). • Use public domain or approved equivalents hydrologic and hydraulic software. • Quantify the reduction of pollutants treated by BMPs using the best available industry standards of care. • Model results should be able to help with the placement of structural and potentially nonstructural BMPs and aid in the understanding of sources of pollutants in a watershed. • Provide a defensible reasonable assurance quantification as required by the San Diego Regional Municipal Stormwater Permit (“Permit”, NPDES Permit R9-2013-001 as amended by R9-2015-0001 and R9-2015-0100)...
