Illinois Private Client Food Processing Complex Stormwater Master Planning

Challenge: This private client food processing complex, consisting of East and West Campuses with multiple business units and production operations, was managing stormwater on a per-business unit basis rather than as an integrated site. The client needed to understand the existing stormwater flow conveyance, comply with National Pollutant Discharge Elimination System (NPDES) permit requirements, and identify necessary improvements to increase their stormwater capacity and reduce the risk of discharges. The East Campus required stormwater retention basin capacity for a 100-year, 2-hour storm event, while the West Campus required a minimum design storm of 25 years with a 24-hour duration.

Solution: HR Green conducted a hydrologic and hydraulic (H&H) study to analyze storm sewer systems, detention basins, and pump stations across both campuses. Three stormwater management strategies were considered: infiltration, detention, and conveyance. Due to unfavorable soil conditions and the runoff volumes, infiltration was deemed ineffective. Instead, our team recommended storage volume improvements focusing on detention and conveyance, including:

• Installing internal weirs to maximize the storage volume of existing detention basins.
• Constructing additional detention basins.
• Implementing additional storm sewer infrastructure.
• Cleaning and maintaining pipes to achieve optimal flow conveyance.

Benefit: By implementing these stormwater management improvements, this private client enhanced stormwater capacity across its  complex, reducing the risk of discharges while ensuring regulatory compliance.