The City of Mandan retained AE2S to conduct facility planning for its wastewater treatment facility and collection system. The existing treatment facility includes pretreatment, extended aeration “Biolac” secondary treatment, RAS/WAS pumping, UV disinfection, effluent pumping, facultative sludge holding, and liquid sludge hauling. AE2S quantified the capacity of each unit process and developed alternatives to maximize the use of existing treatment infrastructure.
AE2S also developed a computer model of the existing wastewater collection system, including the gravity and force main components. Flow monitoring was conducted to determine areas of high infiltration and inflow (I&I) during rain events. Lift station monitoring devices were also used to determine the actual pumping capacity of Mandan’s lift stations. Data collection from the flow monitoring effort allowed AE2S to calibrate the model and to size and locate future collection system components
An integrated capital improvement plan (CIP) was developed that included both collection and treatment system components, and a phased implementation was developed to better fit the City’s budget. The CIP planning effort has proved to be very timely, as the City was recently contacted by a significant wet-industry about possible development in Mandan.