SJRE has been selected to perform sampling, abatement oversight and contractor compliance for the 32nd & Syracuse remediation project at the former Stapleton International Airport.
Previous investigations confirmed the presence of ACM, arsenic, polynuclear aromatic hydrocarbons (PAHs), and total petroleum hydrocarbons (TPH) at levels above Stapleton numeric criteria (SNC) in subsurface soils at 32nd & Syracuse. There are two (2) areas that contain ACM based on prior pothole investigations.
SJRE is overseeing the remediation of ACM in soil where the contaminated soil is being excavated horizontally until no ACM is observed, and vertically to a depth commensurate with the future land use. The first area on the site that contained ACM is a 50 foot by 100 foot area containing 2 grid cells along the eastern boundary of the site. The second area with ACM consists of 2 excavations by LVI where pieces of Transite were found during excavation.
The largest area with SNC exceedances is along the western boundary, and contains PAHs and TPH concentrations that were found to be above SNC, as well as arsenic above the Sand Creek Superfund Site limit of 8.6 mg/kg. The second area of SNC contamination corresponds to TPH concentrations above SNC and arsenic above the CDPHE risk-based limit of 11 mg/kg. The third area of contamination corresponds with TPH concentrations above SNC and the fourth area of contamination has a SNC exceedance for benzo(a)pyrene. The fifth area of contamination also has a SNC exceedance for benzo(a)pyrene. The depths of excavation will include removal of the landfill material in these areas so that SJRE certified Asbestos Inspectors can collect confirmation samples from native soil.
Once the ACM areas have been cleared and excavated as required, these areas will be backfilled. SJRE Asbestos Inspectors will conduct confirmation sampling to determine if the excavations successfully removed impacted soils. Clean overburden overlying impacted soils will then be excavated and stockpiled adjacent to the excavation area for use as backfill. SJRE will oversee the removal of the contaminated soil from this area and will be directly loaded onto lined trucks and transported for disposal.