Date of Award
Fall 2020
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Civil, Construction, and Environmental Engineering
First Advisor
McDonald, Walter
Second Advisor
Parolari, Anthony
Third Advisor
McNamara, Margaret
Abstract
Cities rely on sewer systems to transport wastewater and stormwater, but sometimes these systems are overwhelmed, and their capacity is exceeded due to excess water in the system from rainfall derived inflow and infiltration. This can lead to overflows and backups that can be detrimental to health and property. Excess water from rainfall derived inflow and infiltration enters a sewer system through a multitude of ways, including downspout connections, foundation drains, pipe joints, and broken pipes. Identifying these sources individually can be time intensive and expensive if entire service areas need to be addressed. High level screening tools are therefore needed that can apply readily available data to identify areas and sources of rainfall derived inflow and infiltration in a sewer system. This study seeks to address this challenge by using monitoring data from Milwaukee, Wisconsin to derive correlations between known sewershed characteristics and rainfall derived inflow and infiltration. Results show that pipe length per acre, number of parcels, and medium intensity land use are positively correlated to inflow or fast direct flows into the system. In addition, imperviousness, pipe length per acre, low intensity and medium intensity land use are negatively correlated with infiltration or slow inputs from groundwater sources. These findings can be applied by water reclamation managers to narrow the search areas for rainfall derived inflow and infiltration sources within their sanitary sewer systems.