Case Study: Vapor Intrusion Mitigation System - Le Lycée Français High School Los Angeles, CA
1 Level Below Grade | 30,611 SF Footprint
THE CHALLENGE
Terra-Petra was originally brought in to design waterproofing and drainage systems for:
- Below-grade parking garage
- Above-grade decks
- Service driveway to second-floor loading dock
- Second-floor planters
Mid-excavation, the project took a turn:
- Hydrocarbon-contaminated soils were discovered, likely from the adjacent freeway right-of-way
- Immediate concern for student and staff health
- New Risk: project delays, redesign, regulatory complications
SOLUTION
Instead of bringing in another consultant and slowing everything down, Terra-Petra expanded scope in real time.
Key actions:
- Leveraged in-house expertise in soil gas vapor mitigation
- Designed a sub-slab vapor mitigation system to address contamination risk
- Integrated mitigation seamlessly with the existing waterproofing and drainage design
- Coordinated quickly with the architect to keep the project moving
OUTCOME
- Health risks mitigated without compromising the design
- No project delays despite unexpected site conditions
- Avoided additional consultant onboarding and redesign lag
- Maintained continuity across waterproofing + vapor mitigation systems
TAKEAWAY
Most firms don’t have the ability to handle this kind of change and project expansion.
Terra-Petra’s edge is the ability to solve adjacent problems quickly, without slowing the job down.
Not just expertise — project protection.