• MaxEng

    Having worked at a number of former printing facilities, and having found no contamination to speak of at any of them, I return to the definition of REC: "likely" presence of contamination.  The EP is entitled to conclude whatever he or she believes appropriate, but if I'm the Property seller I'll be very upset with the finding of REC.  Absent good evidence that chlorinated solvents have likely been used at the site ... and chlorinated solvents are the things that cause the million-dollar cleanups cited above by Pawel ... you're not likely to have a costly cleanup issue.  I've never seen a major cleanup based on MEK.

    Regardless, whether or not you're saying a REC is there, you need to provide the facts fully and present your reasoning thoroughly.

  • Tom Speight

    Hi Kyle, this is your supervisor.  See me.



    Just kidding.  That's a rather unusual way to do things-- if you're going that deep you might as well go all the way to the water table, sample groundwater, and run Johnson-Ettinger off of that.  the problem with PIDs is that chlorinated VOCs can trip regulatory thresholds at levels a usual PID won't register, and the ones like a PPB RAE that do read that low are too susceptible to interferences to be really reliable for presence/absence determinations, so MassDEP (the agency I deal with most of the time) won't allow us to rely on them for that. 

    Then again, MassDEP has had groundwater standards tailored to potential vapor intrusion since 1993, based on the Johnson-Ettinger model, so we don't get to do/don't need to do/aren't allowed to do some of the modeling that's done in other jurisdictions. 

    The general practice here in New England is to use sub-slab soil gas samples, collected from immediately below the floor slab/basement floor.  We've used several methods to penetrate and seal the floor-- most recently the Cox-Colvin Vapor Pin-- but I've also made fittings up out of the parts bins at Home Depot (suitably decontaminated!).  Purge and screen the point with a PID, run tubing from the sample point to a Tedlar bag, PUF, or Summa canister, send it off to the lab and there you go.  


  • Robert

    I wouldn't use those two terms together, as its redundant and confusing writing.

    Its like saying...

    "There is a greater than 50% probability of a less than 50% occurrence; or

    "There is a less than 50% probability of a greater than 50% occurrence; makes my head spin !

    I would use either: moderate to high potential or likely    /    low potential or not likely.

    This is not an exact science - all inferences are subjective, based on data obtained from research and experience.



  • PWoloszyn

    What about, a moderate to high potential that it's not likely? Or, a low potential that it's likely?

  • Robert

    If you said to a client there is "likely contamination", you could also say there is a "moderate to high potential of contamination"

    Likely means greater than 50% chance of occurrence.

    Moderate to high potential is also greater than 50% chance of occurrence.

    I would say there is a moderate to high potential and it's likely

    and conversely, I would say there is a low potential and it's not likely.



  • Matt Fox

    I actually think the distinction is very important.  I can tell a client that there is the potential that a release occurred, however, it's not likely and therefore is not a REC.  That scenario comes up all the time.  If the standard was "potentially present", I'd be much more conservative.

  • Robert

    Now you've got me finding definitions for likely and potentially !

    'Likely' means a high probability, whereas potentially means existing in possibility.

    'Likely' suggests a more definitive conclusion.

    When we say that a prior auto repair shop is an APEC (area of potential env, concern), it is implied that it is a moderate to high potential (i.e. more likely to occur than not).



    They're pretty much the same thing.

  • Matt Fox

    Is a release "likely" or just "possible"?  One is a REC, one isn't. You have to use your judgment to decide. 



  • Matt Fox

    In the US, we have to show that release is "likely", not just "potentially present"


  • Robert

    Printers used to use PERC and they continue to use solvents today.

    In BC, printers are considered an APEC (area of potential environmental concern - aka REC) if they are large scale operations likely to have stored drums of chemicals.

    "Large scale" is subjective so you will have to make that call.

  • Robert

    Whatever it is, it is probably not an environmental concern. I checked the 1885 Sanborn map of Vancouver and didn't see the reference.

  • ezhao

    Thank you so much for your input, I really appreciate it!

  • Jsnaqs

    Windmills have been used to pump shallow petroleum deposits in the somewhat distant past (early 20th century) but, to my knowledge, the frequency with which that occurred was markedly low relative to windmills being used to pump water. 

    Baring the possibility that you find information pointing to the contrary,  I think that you would be safe in assuming the tanks are used to store  water pumped by the windmills; especially considering it's a residential area. 

  • ezhao

    Do you know what kind of tank would be associated with a windmill, other than a water tank? 

  • Jsnaqs

    If you look directly to the left of your AOI there is an apparently identical feature with a more legible title. Based on that I would say you are more or less correct. I see "windmill & tank, elevation 65 feet".