Wastewater Basis of Design Document

Summary report on proposed natural wastewater
management system design for the Yestermorrow campus
This summary report was prepared by the YM 2013 Constructed Wetland class, instructed by Barton Kirk PE, Pete Munoz PE, and Harold Leverenz PE.  The student design team was Sean Powers, James Kinnie, Brittany Schroeder, and Alexander Van Steen.  Kate Stephenson provided guiding principles for the wastewater design to the team in order of priority:

  1. Plan for evolution, versatility and resilience
  2. The nature of the land, its healthy functioning, its living systems, and physics inform the structuring of human habitat
  3. Scaled modules of design to allow a kit-of-parts approach for ease of phasing, budgeting, flexibility, diversity, reuse at a residential scale
  4. Design to limit operational expenses
  5. Campus systems should be accessible and visible for educational demonstration purposes

Additional objectives for the design developed by the class are as follows:

  • Provide an opportunity for education
  • Minimize impacts on groundwater
  • Minimize electro-mechanical systems, e.g., gravity operation and passive design as much as possible
  • Low operation and maintenance requirements
  • Mechanical systems and other systems that require vehicle access for maintenance to be located in a centralized area

A number of assumptions were necessary for the design process.  The assumptions are generally related to the maximum number of people that would be present on campus during regular operations.  The water usage and constituent loading used in the design is based on textbook and other reference data sources.  One assumption is that portable toilets or other facilities will be made available during events that would result in a higher population on campus that the design values.  The May 2013 YM master plan was used as the primary reference for population and flow estimates.  A summary of the population and flow data is presented in Table 1.  Because of the relatively small change in flowrate between planning Phases 1 and 2 / 3, the design presented in this report is expected to accommodate the flows for all phases of the campus expansion.  Therefore, the proposed system would be constructed during the Phase 1 expansion and new buildings constructed at later construction phases would be connected to the system without substantial expansion.  The proposed system was selected from four general design scenarios considered for the campus.  A summary of alternative scenarios is listed in Appendix B.