NTM Engineering conducted a Stormwater Reuse Study for the Pennsylvania State University (PSU) Office of Physical Plant (OPP) to assist project design professionals in the evaluation of stormwater reuse options for University building and renovation projects.
The primary objectives of the study were to:
- Research current state-of-the-art practices in rainwater and stormwater collection, storage, treatment and use, their applications and benefit/costs.
- Develop a design guidance document for use by design engineers to consistent implementation of stormwater harvesting and use as part of future campus building and renovation projects.
- Develop a PSU University Park Campus specific stormwater harvesting & use calculator to determine required cistern storage volume based on local rainfall data and irrigation and/or toilet flushing demands.
- Outline the process for evaluating the feasibility of implementing a stormwater harvesting and use system in proposed designs including system type, determining design loads, calculation procedures, costs, and maintenance issues.
The design guidance document presented an overview of stormwater harvesting and use design elements, outlined the process for evaluating the feasibility of stormwater reuse as an element of campus building and renovation projects, and identified specific design criteria for use on the University Park Campus including system type, design loads, calculation procedures, costs, and maintenance issues.
Campus specific average rainfall and irrigation data was used to develop the Penn State Stormwater Harvesting Calculator. The calculator can evaluate required cistern volume and/or required irrigation area to achieve regulatory volume management standards. It can also be used to evaluate rainwater supply available for toilet flushing and other non-potable uses. The calculator also includes a dry year option to evaluate designs based on historic drought periods.
The guidance document includes three (3) example design applications of the stormwater harvesting calculator for the following sites selected in collaboration with Penn State Office of Physical Plant staff:
- Old Main lawn – large turfgrass area.
- Fenske building – building application with possible toilet use. The use system was limited to harvesting rainwater from roof areas to provide for control of water quality.
- Field Hockey artificial turf area performance irrigation application.