Vapor Intrusion Mitigation System Implementation And Inspection In Palo Alto, CA

April 5, 2022
soil management plan, subslab depressurization system, Vapor Intrusion, Vapor Intrusion Mitigation System, Vapor Intrustion Mitigation

Terra-Petra has overseen the implementation of the vapor intrusion mitigation system design (a combination passive venting and sub-slab membrane system) for the Porter Drive Redevelopment in Palo Alto, CA and is now wrapping up inspections of the installation of the system.

The development consists of the following: A new one level below grade structure having two stories above grade with an approximate 11,080 SF footprint.

We followed our standard inspection process which included the following:

  • Document review prior to site visit
  • Jobsite kickoff meeting
  • Pre-installation field inspection
  • Substrate preparation field inspection
  • Application observation field inspection
  • Testing field inspection
  • Final approval

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.

Terra Petra Contracted To Design Vapor Intrusion Mitigation System (VIMS) For Development In Irvine, CA

February 11, 2022
Soil Gas, soil management plan, Vapor Intrusion, Vapor Intrusion Mitigation System, Vapor Intrustion Mitigation

Vapor Intrusion Mitigation System (VIMS) Design - Irvine, CA

Terra-Petra Environmental Engineering is pleased to have been contracted to provide environmental engineering services for the design of the vapor intrusion mitigation system (VIMS) for a development in Irvine, CA.

The proposed development will consist of a new slab on grade tilt-up warehouse building having an approximate 140,000 SF footprint. Our client is electing to design, on our recommendation, a combination sub-slab membrane and passive venting system with the ability to convert to active if deemed necessary.

What makes this project unique is that the impacted soil contributing to the vapor intrusion issues at the site will be remediated and removed from the site by the seller of the property. Confirmation sampling and a subsequent Health Risk Assessment will not be completed until after the new buyer takes ownership of the property. The design for the new building is currently underway and the developer does not have time to wait for a VIMS design to be started after the confirmation sampling is completed due to the expedited construction schedule. As such, Terra-Petra is designing a system that will meet the design schedule and can be scaled up or down depending on the Health Risk Assessment that is completed.

Terra-Petra’s responsiveness and flexibility to meet to our client’s unorthodox requirements sets us apart from our competitors.

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.

Terra-Petra can design a system for you. We routinely design these passive and active Vapor Intrustion Mitigation Systems across numerous cities and counties governed by many different agencies.

Among our many capabilities, Terra-Petra offers:

  • A Civil Engineer, Registered Environmental Assessor, Registered Geologist and Certified Engineering Geologist on staff.
  • Years of experience designing code compliant Building Protection Systems for numerous governing agencies.
  • Easy to read comprehensive plans including project specific details and specifications.
  • Passive and Active Design Capabilities.
  • Plan coordination with project Architect, Civil, Structural, Plumbing, HVAC as well as the Landscape Architect.
  • CAD Draftsmen on staff carry an Associates of Science Degree in Computer Aided Drafting Technology and Certificates in Architecture and Design for Drafting.
LEARN MORE ABOUT OUR VAPOR INTRUSION SERVICES

Soil Management Plan Implementation – Richmond Oil Field

March 18, 2021
Oil News, Soil Gas, soil management plan, Terra-Petra News, Terra-Petra Press

Terra-Petra recently mobilized to a development within the Richmond Oil Field in Yorba Linda, CA after the grading contractor working on the site encountered what they described as “black colored material”. Soil that carries these characteristics is suspected of being impacted by petroleum-contamination, pesticide impact or other hazardous materials and needs to be tested by a laboratory to verify the actual presence of contaminants and at what concentrations.

In this particular case, Terra-Petra elected to run the following tests on the soil samples we collected from the site under a strict chain of custody protocol.

  • EPA 8260B by 5035 – Volatile Organics by GC/MS + Oxygenates/Gasoline Range Organics
  • EPA 6010B by 3050 – Title 22 CAM 17 Trace Metals by ICP-OES
  • EPA 7471A – Mercury by Cold Vapor Atomic Absorption
  • EPA 9045C – pH
  • EPA 8270C-SIMS Polynuclear Aromatic Hydrocarbons

With the laboratory results Terra-Petra was able to conduct a site assessment to delineate the potentially impacted area, which was approximately 90’-180’ .  The Soil sampling was implemented in accordance with the site-specific Soil Management Plan (SMP), which is essential for any development where impacted soils may be encountered. Within an SMP should be a section describing the specific response/remedial actions that will need to be carried out for any impacted soils.

Numerous agencies can become involved with remedial actions for projects in Orange County in particular. For example, the Orange County Health Care Agency (OCHCA) and Orange County Fire Authority as well as the local planning department will be notified and involved in such matters. Additionally, the Regional Water Quality Control Board, the California Department of Conservation, Geologic Energy Management Division (CalGEM) and South Coast Air Quality Management District may become involved until a no further action status is attained.

In the coming days and weeks Terra-Petra will be drafting and submitting a Work Plan to carry out the remedial activities under the oversight of the local agencies involved.