Master Planning 1 Billion of New Wastewater Facilities Using an Innovative Computer Modeling Approach

One of the major challenges in planning new wastewater facilities today is the uncertainty over future regulatory requirements. This regulatory uncertainty, combined with the increasing focus on watershed management and development of effluent pollutant loading limitations, has put a tremendous demand on planners and engineers to evaluate the advantages and disadvantages of a wider range of master planning alternatives than in the past. These alternatives include the traditional structural end-of-pipe solutions as well as the nontraditional but growing need to evaluate nonstructural alternatives such as nonpoint source pollutant reductions and “watershed offsets”.Sacramento Regional County Sanitation District (District) recently faced this challenge in assessing the Districts' needs for new wastewater facilities over the next 20 years. The District owns and operates a 181 mgd secondary wastewater treatment plant which discharges to the Sacramento River, the largest source of freshwater supply for municipal and agricultural uses in California. In order to fully explore all of the alternatives and to actively involve the many stakeholders vested in the outcome of this planning process, the District decided to implement the comprehensive use of computer modeling.This paper presents the overall approach, major features and benefits in using a computerized master planning model for working with stakeholders and for managing the uncertainty of future regulations.