📋 Case Study
Industrial Park Stormwater Master Plan in Indianapolis, IN
Achieving 90% annual phosphorus load reduction while accommodating truck traffic and hazardous material spill containment
🏗️ Project Overview
320-acre logistics park with 87% impervious cover, legacy soils (HSG-C), and proximity to White River TMDL restrictions
🎯 Challenge
Achieving 90% annual phosphorus load reduction while accommodating truck traffic and hazardous material spill containment
🔧 Design Approach
Phosphorus-sorbing filter media (Alum sludge + iron oxide) in forebays, constructed wetlands with emergent macrophytes, and spill-containment berms integrated with pretreatment vaults
📐 Design Diagram
AI-generated project design illustration
📐 Key Calculations
P Removal Efficiency
E = 1 − (C_out/C_in)
Result: 93.4%
Validated via 18-month synthetic runoff testing
Wetland Footprint
A = Q_annual / (HLR × 365)
Result: 8.7 acres
Based on 0.5 cm/d HLR for P uptake
Spill Containment Volume
V = 110% × max_container_volume
Result: 12,500 gal
Meets EPA SPCC Rule 40 CFR 112
📊 Results
Certified by IDEM as ‘Tier 3’ BMP-compliant; eliminated need for off-site treatment; secured $1.8M Brownfield Revolving Loan💡 Lessons Learned
- •Alum-based media requires pH buffering to prevent leaching
- •Wetland performance drops >35% below 4°C — winter bypass required
- •SPCC integration adds 11% upfront cost but avoids $420k/year insurance premiums
✅ Key Takeaways
- 1Alum-based media requires pH buffering to prevent leaching
- 2Wetland performance drops >35% below 4°C — winter bypass required
- 3SPCC integration adds 11% upfront cost but avoids $420k/year insurance premiums