4.9 Google
Sub-slab & soil-vapor sampling for VOCs · Screened against EPA OSWER, ASTM E2600 & state TACO levels · Mitigation if needed
We identify where vapors are most likely to be entering the building and lay out the sampling plan — sub-slab points beneath the slab, soil-vapor probes outside the footprint, and the VOC analyte list. You get a clear, budget-conscious quote before any work begins.
An Environmental Professional drills a small sealed port through the slab, attaches a vacuum (Summa) canister, and draws soil gas under negative pressure for about 30 minutes. The valve is closed and the canister is shipped under chain-of-custody to an accredited laboratory.
Lab results are screened against EPA OSWER, ASTM E2600, and state TACO levels. Your Soil Gas report states clearly whether vapor intrusion is a concern — and if levels are high, we design a passive or active mitigation system tailored to the property.
A Soil Gas Investigation is a focused form of Phase 2 work aimed at the vapor pathway — the way VOCs migrate from contaminated soil or groundwater into the air people breathe indoors. It is triggered when a Phase 1 ESA flags a vapor intrusion concern, or alongside a broader Phase 2 ESA.
"We were running up against some deadlines, and they jumped through hoops to get everything completed on time."
"The A3E team did a great job on our Phase 1 report. They were quick, thorough and professional."
"They were able to give me all of the information that I needed. Highly recommend A3 Environmental."
Lab-validated sampling
Small business (WOSB)
Environmental consulting
Google Reviews
A Soil Gas Investigation assesses vapor intrusion — the migration of volatile organic compounds (VOCs) from contaminated soil or groundwater, upward through porous building foundations, into the indoor air people breathe. Unlike soil or groundwater contamination that stays underground, vapor intrusion is a direct inhalation health risk inside occupied buildings. The investigation answers a single question: are harmful vapors entering the building, and are concentrations above the levels regulators consider safe?
You order a Soil Gas Investigation when a Phase 1 ESA flags a Vapor Intrusion Condition (VIC) or Vapor Encroachment Condition (VEC), or when a known VOC-impacted site — a former dry cleaner, a leaking petroleum tank, an industrial solvent user — sits at or near a building. Vapor intrusion became an EPA priority in 2013 and is now part of the ASTM Phase 1 standard (E1527-21), so it increasingly surfaces during routine due diligence. It is a specialized form of Phase 2 work, focused entirely on the vapor pathway.
A Soil Gas Investigation tests for VOCs only, because only volatile compounds turn into vapor and migrate — primarily chlorinated solvents such as trichloroethylene (TCE) and tetrachloroethylene (PCE), and petroleum hydrocarbons. Heavy metals do not volatilize, so they are deliberately outside the scope. For sub-slab sampling, our Environmental Professional drills a small sealed port through the slab in a suspected high-concentration area, attaches a vacuum (Summa) canister, and draws soil gas under negative pressure before sending it to an accredited laboratory. Results are screened against the EPA OSWER 2015 Vapor Intrusion Technical Guidance, ASTM E2600, and state screening levels such as Illinois' Tiered Approach to Corrective Action Objectives (TACO) — which sets different thresholds for residential versus commercial buildings.
If concentrations come back below screening levels, the report serves as proof for lenders, buyers, sellers, or agencies that the property is safe. If levels are high, A3 Environmental designs a mitigation system tailored to the building and your goals — passive measures such as sealing cracks, epoxy-coating slabs, filling floor drains, and installing sub-slab membranes, or active measures such as sub-slab depressurization with fans, mechanically similar to radon mitigation. We treat mitigation design as a deep, probing conversation, not a template. A3 Environmental serves Illinois, Wisconsin, Michigan, Indiana, and Iowa, with deep regulatory fluency across all five state programs and a 4.9★ Google rating since 2015.
