As part of their Senior Design Capstone course, Civil & Environmental Engineering students created design alternatives for water source protection in areas within and surrounding Manchester, Iowa.

The City of Manchester had levels of nitrates that exceeded the maximum contaminant level in their groundwater which they utilize as drinking water.  Manchester found that after rainfall events a spike in the quantity of nitrate in the drinking water supply was seen.  This was likely from the excessive fertilization that seeped nitrogen into the groundwater system. To deal with this Manchester treated a portion of the water with ion exchange and blended that with the contaminated water to bring the quality below the limit set by the Safe Drinking Water Act. This process was expensive and prompted Manchester to seek other solutions.

The priority of the engineering team was to create a watershed management plan for the prevention of additional nitrates entering the groundwater system. There were several ways to accomplish this, and thus multiple alternatives were considered. The alternatives included natural system approaches, well house treatment modification, and public education.

The alternatives selected were a wetland enhancement with a riparian zone, contour buffer strips, and urban education on nitrates. Wetland enhancement with riparian buffer strips were designed using resources from the EPA and Ecolotree. Contour buffer strips were sized and located for most effective remediation using the Agricultural Conservation Planning Framework (ACPF) tool. This tool utilized geospatial data from Manchester and gave the best set up to retain nutrients in crop soil. Remediating nitrates from seeping into the groundwater from urban areas were explored and researched from other cities who have educational tools put into place. Plan sets for the riparian buffer strips and a map for best locations for buffer strips in the cropland were created. An educational brochure was put together for citizen use to learn more about the importance of less fertilizer usage in lawncare.