WORK PLANS - Laserfiche WebLink

Home Browse Search

Cleanup in Vulnerable Communities'Initiative Final Project Reference:Bobson Cleaners Discovery and Enforcement Discovery Project Number:60688620-5.1 Investigation Work Plan recommended over the use of summa canisters for the collection of indoor air data. However, passive or canister sampling may be used so long as the sampling protocols are in accordance with the Programmatic QAPP. The DI will utilize active indoor air sampling using cannisters per the Programmatic QAPP. Active indoor air samples will be collected in evacuated, individually-certified clean, stainless-steel Summa®canisters per the DTSC vapor intrusion guidance (2011).The samples will be submitted to Eurofins Air Toxins Laboratory in Folsom, California, an accredited analytical laboratory,for USEPA Method TO-15 SIM.When collecting indoor air samples for the evaluation of potential impact of contaminant releases,the following should be considered: • Indoor air samples should be collected over a 24-hour period for residential structures, over an 8-hour period for nonresidential structures, and over a typical school day for students.After vapor intrusion is confirmed, additional sampling events should be conducted to produce representative concentrations of the monitored compounds over the anticipated daily exposure period for building occupants. • All floors, including the basement, of a residential structure potentially subject to vapor intrusion should be sampled for indoor air quality. Based on Site-specific conditions, it may be necessary to sample additional units of an apartment building. Sampling devices should be located in the breathing zone, approximately 3 to 5 feet off the ground for adults and at lower sampling heights if the receptors of concern are children as in a daycare center or school. Samples should be collected in the center of the room, away from doors.At a minimum, it is recommended that sampling points include the primary living area and likely locations for subsurface vapor entry(typically the bathroom or kitchen). • When sampling commercial or industrial buildings,the number and locations of samples should be based on Site-specific conditions. Samples should be collected from primary work areas and near the points of vapor entry to help define the potential routes of entry such as sumps, elevator shafts or floor drains. For the initial indoor air sampling event, the samples should be collected during normal operation of the building's heating and air conditioning system. • Extra canisters, pressure gauges, and flow regulators should be taken into the field in case the integrity of some of the canisters are compromised or if some flow regulators and pressure gauges malfunction. Each sampling canister should have a dedicated vacuum gauge. Flow regulators should be configured to produce a constant sampling rate. Sampling canisters, along with all flow regulators and pressure gauges,should be 6-liter individually certified clean passivated canisters and gauges and analyzed using method TO-15 SIM, reported down to the laboratory's method detection limit(MDL). When sampling indoor air, ambient(outdoor)air should be sampled concurrently.The following should be considered when collecting ambient air samples: • When deploying samplers outdoors to quantify background conditions,the samplers should be protected against rainfall and direct sunlight, both of which could bias the sampling results. • Sampling devices should be located approximately 6 feet off of the ground. • Ambient sampling should be conducted concurrently with the indoor air sampling. • Ambient samples should be located away from gasoline stations, automobiles, gasoline powered engines,fuel and oil storage tanks, chemical storage areas, and dry cleaners. • Sampling devices should be placed at least 10 feet beyond a tree's drip line. • Ambient air samples collected on the predominately upwind side of a building should be placed at a distance equal to twice the height of the building. • Three ambient samples (plus one duplicate), at a minimum, should be collected during each indoor air sampling event.The ambient air samples should be placed around the building with respect to up, down, and cross the prevailing wind direction.This placement will account for changes in the wind direction throughout the day. • Ambient air samples will be collected in batch cleaned 6-liter stainless-steel Summa canisters. • Ambient air samples will be analyzed for using method TO-15 reported down to the laboratory's MDL. Applying these considerations,the following steps will be performed: Prepared for: Department of Toxic Substances Control AECOM 15