Lignes directrices á l’intention des laboratoires v 3.1

  • A Tier I method involving an initial evaluation to assess whether the benzene, toluene, ethylbenzene and xylene(s) (BTEX) and/or total petroleum hydrocarbon (TPH) concentration minus BTEX has exceeded a generic risk-based screening level. This procedure reports the volatile petroleum hydrocarbons (C6-C10) including BTEX (VPH analysis), the extractable hydrocarbons (>C10-C32) (EPH analysis), the modified TPH (sum of C6-C32 less BTEX) as well as Return to Baseline at C32 (see Section 3.7 for criteria). Refer to Section 4.1 for changes to the Tier I reporting format.
  • A Tier II method to assess site-specific risk conditions. As in the Tier I analysis, the procedure consists of a VPH analysis, an EPH analysis as well as the calculation of modified TPH. In the Tier II analysis, both the VPH and EPH ranges are subdivided into aromatic and aliphatic fractions and narrower carbon ranges are reported as well. Refer to Section 4.2 for the Tier II reporting format.