Thursday, July 7, 2022

MORE DETAILS ON MECP CRITICIM OF LANXESS/STANTEC DRAFT RISK ASSESSMENT (RA)

 As per page 2 the Ministry of Environment (MECP) are not amused that Stantec unilaterally and without justification dismissed the MECP's suggestion that all past relevant comments and reports from the MECP be included in the Draft RA  Also as the Ministry has previously raised they would like to see post-remediation confirmatory sampling in areas of the Creek on the Lanxess site that were either capped or excavated nearly twenty years ago. 

The MECP state that   "...the exclusion of groundwater as a complete pathway for the Farmer/Resident (Table 5-2) is not supported." Apparently the Region of Waterloo had requested "... that groundwater samples from the deep-water aquifer should be assessed based on potable water limits." Furthermore certain risk management strategies by both the Region and the Township and an understanding of the risk associated with groundwater needs to be clearly communicated in the HHERA (RA)."

The MECP are unhappy with the qualitative analysis versus a quantitative analysis requested by them. This is for exposure pathways including incidental ingestion, dermal contact and also trespasser scenarios. The MECP have also made clear that they expect more sampling and delineation of the extent of contaminant impacts in the areas of higher concentrations ("hot spots"). Also exposure point concentrations are a problem for the MECP. They feel that Stantec's methodology "...is understood to be a conservative mean estimate that is representative of a central tendency estimate, however it would not be representative of a reasonable maximum estimate." Doing this would provide an indication of potential issues from the elevated concentration areas or "hotspots". 

Interestingly the MECP state that there is insufficient justification for toxicity reference values (TRV) used in the HHERA (Human Health & Ecological Risk Assessment). They then advise that using the MECP's TRV values is NOT sufficient justification of TRV selection. Wow?

The Ministry (MECP) are not happy with the qualitative versus quantitative assessment of the risks associated with consumption of fish. There are concerns that there are problems with the assumptions used that may not account for the developmental and reproductive effects of dioxins/furans and hence these assumptions may not be applicable to this risk assessment. Further problematic assumptions include a lack of addressing soil-to-plant uptake. This potential pathway of  exposure through plants needs much more work. There are also issues with the consumption of free range chicken eggs and that the analysis is not adequately protective of human consumption of possibly contaminated eggs.

Lastly the MECP actually give Stantec a blast for their use of the term "acceptable" risk. They state that it is not appropriate as a risk communication language "as acceptability can be subjective to an indiviual's perspective of risk."                                                                                                                     

Between today and Tuesday's posting here we can see that the MECP are politely albeit highly critical of the Draft RA. My experience is that these criticisms and comments will be easily addressed, brushed aside, ignored or token efforts made to reduce them. Rarely does the MECP advise a polluter or his consultants that the errors and omissions are such that they should throw out their report and start over. That is unfortunate because self-serving, client driven technical reports are the norm not the exception. 



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