Terra-Petra Environmental Engineering is providing inspection services for the installation of the vapor intrusion mitigation system (VIMS) design for the project located at 4840 Mission Street in San Francisco, CA.

The site will be redeveloped into a mixed use space which will include 137 units of affordable housing, a 10,000 SF space for a nonprofit health clinic, and 5,000 SF of retail space.

The footprint of the redevelopment overlays a parking garage of 40 cars and bicycles, with four at-grade residential apartments, lobby, mechanical, electrical, trash, and maintenance rooms occupying the first story. The building footprint is approximately 44,000 SF.

More about Terra-Petra’s vapor intrusion mitigation system design services:

Vapor Intrusion refers to the migration of Soil Gas Vapors emanating from the earth into an occupied space or structure. The particular vapors of concern are volatile organic compounds (VOCs), including chlorinated solvents, petroleum hydrocarbons, methane, hydrogen sulfide and semi volatile organic compounds (SVOCs) to name a few. Terra-Petra can prevent these vapors from intruding into your structure.

Some governing agencies will require any new structure built on a contaminated site to protect the occupants from potential soil vapor intrusion with a Subslab Building Protection System, while some developers elect to do so voluntarily because of a potential human health risk down the road. Regardless of the reason, Terra-Petra can design a system for you. We routinely design these passive and active Building Protection Systems across numerous cities and counties governed by many different agencies.

A typical Building Protection Systems consists of an impermeable soil vapor membrane and a pressure relief system. Where deemed appropriate, Terra-Petra can design mechanical vapor extraction systems, electronic gas detection and alarm systems; employing the latest technologies.