Comments

In section 5.4.1 reference is made to multiple gas probes being installed in a single borehole. Clause 12 (a) vi of Table 4 of Schedule E of O.Reg 153/04 prohibits the installation of multiple probes in a single borehole, for MGRAs.

The 2011 version of the draft guidance included the following description in Appendix III. However it is missing from the draft 2013 version. Does this paragraph still apply? If not, is a definition of F1 and F2 fractions forthcoming?

Comment #1 This draft guidance document does not consider the most recent literature and research differentiating the attenuation response of petroleum hydrocarbon vapours in the subsurface as compared with historical databases based on chlorinated contaminant vapours migrating in subsurf

We have identified two concerns relating to the toxicity reference values (TRVs) used in the derivation of the “Recommended Health-Based Indoor Air Target Levels for Selected VOCs” (Appendix IV) proposed in the document.

Conestoga Rovers & Associates (CRA) reviewed the Ministry of the Environment’s (MOE’s) Draft Technical Guidance: Soil Vapour Intrusion Assessment (Technical Guidance) posted on the Environmental Registry under EBR Registry Number: 011 2912.