Design of an underground storage tank involving water collection for water reuse to irrigate the campus green area of the UAB Campus.

摘要

The UAB Campus Recreation Center is located in the Birmingham city block whose boundaries are University Blvd., 10th Avenue South, 14th Street South, and 16th Street South. The water supply of the UAB Campus Recreation Center is based on a natural underground water source, which is use such needs as pool water. The underground water is continuously pumped from its foundation in order to avoid flooding the basement of the Recreation Center. As a result, in addition to the water usage of the Recreation Center, the additional water pumped underground could be utilized to irrigate the campus green area. A metering device has been installed, allowing the amount of water that is being pumped to be monitored, and this quantity of water, approximately one million gallons annually, is estimated to provide the water needed for irrigating the UAB campus green area adequately.;In this project, the methodology is specifically a case study for the UAB Campus Green area, and research was performed to analyze the feasibility of whether the pumped and drained underground water and roof runoff could irrigate the campus green area, focusing on the irrigation requirements of grass. The roof water from precipitation events is considered for collection by the roof drain as a possible irrigation water source. This project primarily focused on the hydrological field, referring to the fundamental equation of hydrology P -- R -- E -- T -- G = DeltaS, where P is precipitation, R is runoff, E is evaporation, T is transpiration, G is groundwater flux, and DeltaS is the change in storage. Because the UAB Campus Green area was recently constructed in 2008, three years of historical precipitation data for the Birmingham area was gathered in an effort to predict the rainwater amount during drought periods and determine a normal precipitation pattern for estimating the rainwater amount. In addition, the possibility of whether the collected rainwater supplements the demand of grass land irrigation was determined. Based on the fundamental hydrological equation, the runoff is the water that can be collected for further usage on different land types, such as grassy lands, roof areas, paved areas, and concrete areas. These areas were measured using NRCS method to estimate the runoff amount. In addition, the amount of grass irrigation water for different months was calculated, addressing evaporation and transpiration by considering factors that affect the irrigation water quantity and time, such as weather conditions.;To achieve this goal, a rainwater harvesting system was designed, and the use of Underground Storage Tanks (USTs) was assessed for their ability to store the collected rainfall water for further usage. The Facilities Management Department of UAB has designed and installed an UST near the University Boulevard Office Building (UBOB) parking deck with the same purpose as this project, so that designed UST can serve as a model. However, due to different situations, the UAB Campus Green has a significantly larger land area and different topography, and several USTs would need to be installed to reduce construction costs and improve UST performance. Therefore, the size of the USTs and their location will be determined by the precipitation pattern and topography, respectively.;This research analyzed whether it was advantageous due to financial issues, to build a similar UST system to replace the irrigation water supplied by Birmingham Water Works Board. Based on the aforementioned methodology and data, the analysis of the cost and payback has been performed to demonstrate the feasibility of this potential water resource being used to replace current irrigation systems and cost analysis by estimating investment quantity and payback period.