WORK PLANS - Laserfiche WebLink

Home Browse Search

M CDIM Standard Operating Procedure 4.1 Soil Vapor Sampling '"°'"""'"' Rev.1 6/30/2022 CDIM Standard Operating Procedure 4.1 Soil Vapor Sampling 1 PURPOSE This Standard Operating Procedure (SOP) establishes guidelines and procedures for collecting vapor samples from the subsurface. Several methods may be used to collect subsurface samples from boreholes; the more common drilling methods and sampling procedures are described below. Proper collection procedures are necessary to assure the quality of all subsurface vapor samples. Additional specific procedures and requirements will be provided in the project work plans, as necessary. Sampling of subsurface vapor is generally conducted to: 1. Evaluate whether releases of hazardous substances have occurred from underground or surface sources which may impact indoor air, outdoor air and groundwater. 2. Determine the extent of a hazardous release. 3. Design and monitor the performance of a soil vapor extraction system. 4. Map soil vapor plumes to select buildings for indoor air monitoring. 5. Provide confirmation subsurface vapor data following remediation. 2 DEFINITIONS 2.1 Borehole Any hole drilled into the subsurface for the purpose of identifying lithology, collecting soil, water, or vapor samples, and/or installing monitoring wells. 2.2 Subsurface Vapor Volatile Organic Compounds (VOCs) Subsurface vapors are chemicals that are emitted from certain subsurface solids or liquids and include a variety of chemicals. Samples that will be analyzed should be collected and contained in a manner that minimizes dilution or contamination of the sample, which could result in inaccurate results. Volatile organic compounds (VOCs) in subsurface vapors are typically analyzed using United States Environmental Protection Agency (USEPA) Method TO-15 for samples collected using Summa canisters. 2.3 Shroud An enclosure that is placed over all soil vapor sampling equipment, including the sampling container and the soil gas well annulus. In the interest of this SOP, a tracer gas (helium) is pumped into the shroud for the leak test prior to sample collection and during soil vapor sample collection.