REMEDIAL OPTIONS SCREENING : NORTHSTAR & BISHOP ST. COMMUNITY CAMBRIDGE

I renewed acquaintance with Tracy Hipel two days ago. Tracy has been an outspoken advocate, along with Debbie Vitez and others, in regards to the health and safety of the Bishop St. community residents. They have been victimized initially by Northstar and G.E.-Rozell via vapour intrusion into their homes that resulted from negligent handling and or disposal of Trichloroethylene (TCE) and Trichloroethane (TCA) as well as Chromium VI. In my opinion they have been further victimized at every opportunity by self-serving politicians and governments from the municipal, regional and provincial levels. Tracy dropped by and left me with three recent reports dated February, March and April 2017, written by Dillon Consulting on behalf of the Ontario Ministry of Environment.

To date I've read the first one titled "Remedial Options Screening". It is excellent in that it lists fairly clearly and concisely seven inherently different remedial possibilities namely 1) continued Groundwater Extraction 2) In Situ Chemical Oxidation 3) Thermally Enhanced Extraction 4) Permeable Reactive Barriers 5) In Situ Reductive Dechlorination 6) Containment by Solidification, Encapsulation and 7) Excavation (and Disposal or Ex Situ Treatment).

All of these technologies are proven however depending upon the geological and geophysical conditions present at a contaminated site, some are better suited than others. The other major difference is of course whether the remedial option is designed for mitigation of the adverse health effects/containment of contamination preventing it from spreading or whether it's actually designed for remediation ie. physical removal and or destruction on site of the toxic compounds.

Of the seven options there are four which potentially can be construed as either physically or chemically removing or destroying the toxic compounds mentioned in the first paragraph. Unfortunately (albeit honestly) Dillon have advised us that In Situ Chemical Oxidation (ISCO) and In Situ Reductive Declorination (ISRD), under the Bishop St. conditions and circumstances are unlikely to succeed in destroying the sources of contamination. Yes they will greatly assist in breaking down dissolved TCE and TCA in the groundwater but the likelihood of free phase DNAPL (dense non-aqueous phase liquid) present in both the Shallow Aquifer as well as the Bedrock Aquifer means that after ISCO or ISRD are used these undissolved TCE and TCA "blobs" for a better word will continue to slowly dissolve into the groundwater over decades if not centuries, hence recontaminating the groundwater all over again.

The other two true remedial technologies are Thermal Enhanced Recovery and the old, expensive but tried and true Excavation and Disposal. This is where the gamesmanship begins in regards to "ranking" of the options. There is an old saying that it's O.K. to stay within the lines as long as you are the one who has drawn the lines. Well it is not the local residents who have "drawn the lines". It is Dillon, possibly/probably in conjunction with their client, the Ontario M.O.E. who have set the criteria and rationale for ranking. They have severely under ranked the Remediation/Mitigation criteria as well as the Applicability criteria in favour of two of the six Criteria given. The two overrated criteria both relate to costs namely "Relative Capitol Cost" and "Operations and Maintenance Costs". Fully 1/3 of the criteria are about money when the biggest criteria should be about both long and short term health.

Until I've read all three reports I will withhold further comments and detailed specifics. Suffice to say to date I am not impressed with Dillon's ranking of options via their (& the M.O.E.'s) self-serving weighting and ranking of the options.