Date of Award


Document Type

Open Access Master's Report

Degree Name

Master of Science in Environmental Engineering (MS)

Administrative Home Department

Department of Civil and Environmental Engineering

Advisor 1

Alex Mayer

Committee Member 1

Jennifer Becker

Committee Member 2

Kari Henquinet


Management of wastewater treatment plants (WWTPs) has been found to be especially challenging in small, rural communities of the developing world. This study examined maintenance of two small WWTPs in Leymebamba and Palmira, Peru through interviews with local authorities, observation of maintenance practices, wastewater measurements, and prediction of effects from maintenance with modeling using a wastewater process simulation software, BioWin. Challenges and motivations related to maintenance were investigated with semi-structured interviews, and maintenance practices were recorded during observations. It was found that outside supervision was a key motivating factor, and the existence of an operator who is supported by the administration was important as well. The maintenance practices in Leymebamba and Palmira were graded with a quantitative scale and were given 35% and 22% of the possible points, respectively. Measurements of influent and effluent biochemical oxygen demand (BOD) and total suspended solids (TSS) were taken at the plants, and the removals were estimated using the measurements. A BioWin model was developed based on the Leymebamba WWTP, and its performance was compared to that of the actual plant. The BioWin model performed over one standard deviation below the mean with respect to the plant’s average BOD removal, and it performed within one standard deviation of the mean with respect to the plant’s average TSS removal. The effects of maintenance were simulated in BioWin, and it was found that the performance was not significantly impacted by the alternate maintenance scenarios. However, maintenance is still recommended to prevent undesirable environmental problems and keep the WWTPs in working condition. The BioWin software was found to have limitations when modeling Imhoff tank systems with low maintenance, and future work is needed to further explore maintenance scenarios described in this study.

BioWin_Base_Model_Proper_Maintenance.bwc (1807 kB)
BioWin base model of WWTP from study