RCH staff acted as senior air quality analysts for the 255 Cypress Avenue project in South San Francisco, CA. The project includes development of 46 residential units, 6,000 square feet of retail space, and an enclosed subsurface parking structure on one-half acre of land. RCH conducted a construction and operational air quality analysis and health risk assessment per the South San Francisco Downtown Station Area Specific Plan Environmental Impact Report Mitigation Plan. The criteria pollutant emissions inventory for the project utilized CalEEMod and emissions models for on-road vehicles and onsite equipment.

Average daily construction emissions and annual average construction emissions were determined for comparison to BAAQMD thresholds and use in a health risk assessment for existing and future sensitive receptors. The health risk assessment also included nearby permitted sources, Highway 101, major roadways, and CalTrain operations using USEPA’s AERMOD dispersion model. Mitigation measures included BMP’s for fugitive dust and tier 2 construction equipment with level 3 diesel filters.