WORK PLANS - Laserfiche WebLink

Home Browse Search

M CDIM Standard Operating Procedure 4.1 Soil Vapor Sampling "°'"""'"' Rev.1 6/30/2022 responsible for completing their tasks according to specifications outlined in this SOP, the project work plan, and other appropriate procedures. All staff are responsible for reporting deviations from procedures to the field coordinator. 3.2 Soil Vapor Probe Installation Methods Soil vapor probes can be installed to collect sub-slab soil vapor samples (typically using Vapor Pin or similar) or single-depth or nested vapor wells to collect soil vapor samples at depth. This section describes installation methods for both. 3.2.1 Vapor PinTm Approach The Vapor PinTm has a variety of applications and is a typical method for sampling soil vapor under a concrete-like surface. Standard procedures for installing a temporary or permanent Vapor Pin over concrete is provided by Vapor Pin Enterprises, Inc. and can be referred to in Attachments 1.1 and 1.2. To summarize, procedures involve drilling a 1.5-inch diameter hole to a depth of at least 1.75-inches. A Drill Guide (provided with Vapor Pin kit) is to be placed into the hole to help center and maintain vertical drilling in the next stage. A 5/8-inch diameter drill bit is then inserted through the Drill Guide and used to penetrate through the slab and approximately 1-inch of underlying soil to form a void. After cleaning the hole surroundings of dust and debris, the vapor pin can be gently hammered in place such that its silicon sleeve will establish an air-tight seal around the interior of the boring. Once installed, the sample point seal should be verified by a leak test, as described in section 3.3.5. For flush mount instillations, screw the stainless-steel Secure Cover (provided with Vapor Pin kit) onto the Vapor Pin. To achieve quality data, the protective cap is necessary at permanent soil vapor probe installations and encouraged at temporary installations, as it reduces the risk of damage to the sampling pin device by foot and vehicular traffic and minimizes the dust and debris that may enter the sample hole. For subsequent access, the Secure Cover can be unscrewed counterclockwise and removed. The equilibration time for sub-slab probes is two hours. The subslab soil vapor sampling can then commence in accordance with the guidelines outlined in Section 3.3. 3.2.2 Single or Nested Vapor Well Approach Temporary or permanent vapor wells are the preferred method for sampling soil gas at specific depths. Vapor wells can contain a single sampling interval or can be nested to include sampling ports for multiple depths. The process for installing nested wells begins with drilling at least 0.5 feet vertically past the desired sampling depth. When drilling is complete, at least 0.5 feet of sand is poured into the boring. A nested well probe is then lowered by its tubing and 3