Developing a Sustainable Biosolids Program Through a Comprehensive, Collaborative Approach for Arlington County

摘要

Arlington County, Virginia has recently completed a solids master plan that addresses near-term and long-term needs of the County's biosolids program. The planning process included a comprehensive evaluation of over 70 technologies. The project team consisted of representatives from engineering, operations, maintenance, and management from the County; a consultant team comprised of national and local experts; a technical advisory committee comprised of experts from consulting, utility, and academia; and representatives from community stakeholders. The planning process included multiple internal project team workshops as well as regular presentations to the community stakeholders. Feedback was received at each presentation and incorporated into the overall planning process. Ultimately, the County completed a detailed evaluation of four process alternatives including lime stabilization (representing the current process), anaerobic digestion, thermal hydrolysis pretreatment with anaerobic digestion, and anaerobic digestion with thermal drying. The four process alternatives were evaluated against nineteen criteria representing economic, operational, environmental, and social categories of the 'quadruple bottom line.' Utlimately, the County has developed a plan for a more sustainable biosolids program that includes the development of thermal hydrolysis pretreatement with anaerobic digestion to produce a biosolids product suitable for many products uses. Additionally, the program will produce a biogas that will be reused as a fuel in the region. The comprehensive, collaborative approach that included evaluating a wide range of options and engaging a large number of program stakeholders contributed to the success of the project and has provided the County with a roadmap towards a more sustainable biosolids program.