Williams Creek Management led design engineering for a retrofit design/build project for an existing entrance and parking area at the 165 acre Alcoa Engineered Products plant (now Arconic) in Lafayette, Indiana. The site currently discharges under a NPDES permit requiring runoff to be treated through spent mushroom compost filters for the removal of groundwater pollutants assumed to be entering the stormwater collection system.

The retrofit aimed to reduce stormwater runoff entering the Storm Sewer System from the parking area and courtyard in order to become a Zero Runoff facility. Pervious concrete sidewalk, curb and gutter, subsurface stone storage infiltration trenches, and infiltration basins were installed to achieve this goal while treating
runoff through the mushroom compost system.

Williams Creek constructed all natural system stormwater management elements of the project, in addition to leading the design engineering. All direct labor and equipment for constructing the GI technologies including parking lot linear bioretention basins, perimeter constructed wetland basins, and upland prairie buffer areas were constructed by Williams Creek. The implementation of these techniques further improved the operation and performance of the on-site stormwater treatment mitigation facility constructed to comply with special conditions of an NPDES permit related to observed groundwater contamination being leached into the sewer system, and subsequently improved the quality of stormwater of a larger system.

Additionally, Williams Creek has been providing long-term maintenance of stormwater management areas since 2016 for long-term sustainability of the site.