Recently completed a job on a commercial building in a dense/downtown commercial district. Our building was clean in terms of prior uses, but the adjacent (attached) building had been a dry cleaner continuously for the last 50+ years. Client was advised of this REC and testing inside our building was done along the common wall shared between the two buildings. Interestingly enough no elevated vapor concentrations were found. However, indoor air samples were also obtained and were found to be high for VOCs (HVAC system was suspected to be sucking in cleaner emissions).
The soil in the area is urban land. Currently the target site is surrounded by paved parking lots, streets, and warehouses.
Even pre-1940? Chlorinated solvents weren't prevalent yet.
Based on my personal experience, a former dry cleaning plant within 50 feet is, without question, both a VEC and a REC. Gas station 50 feet away and not adjoining, probably not.
I'm not a big fan of the term "clean Phase I". Lack of RECs does not mean the site is clean, that just means there are no RECs. People tend to assume that because a Phase I missed something that the Phase I was deficient.
We do a ton of work for mining companies and I've done a lot of due diligence on aggregate mines throughout California. All sorts of things will and can be buried in the old quarry pits. In California, things are pretty well regulated (at least currently) but in other states, not so much. If possible, try and interview the old quarry operators to get some history and try and obtain the reclamation plans and mining plans...they may have some old history. Also, the quarries are commonly very remote and require their own fuel (underground or aboveground tanks). Other things to be aware of might be wash out pits if there was a concrete batch plant associated with it, and if there was an asphalt plant, watch out buried asphalt oil tank (tank railcars, etc) for truck spray areas....they commonly used diesel fuel/oils to lubricate the asphalt trucks so the material slides in and out easily.
We just recently finished a big cleanup on an old dump/fill area included not only inert materials such as cement wash out area and rubble, but trash, woody materials, etc., It was a huge mess and super expensive for our client to deal with. Another consultant had done the Phase I (it was clean) and I reviewed aerial photos of the area...their was no indication from the aerials of this dump/fill area from the aerials. Basically, CYA as anything is possible.
There is not enough information to make a definite statement about whether a VEC exists. You need a line of evidence to rule out the VEC. As noted in E2600, you have to make a decision and it is suggested you use terminology such as a VEC exists, a VEC likely exists, a VEC cannot be ruled out, or a VEC does not exist. Based on the limited amount of data you provided, you might use terminology such as a VEC cannot be ruled out.
There is information you can attempt to gather based on your indication of the historical gas station location. Where are the subsurface utility lines (any between your site and the gas station)? Are there any other barriers to vapor migration? What is the vadose zone soil type (e.g. clay rich, a soil type that tends to limit the potential for vapor migration)?
This is a good exercise in the possible vs. likely determination. Is it possible that something was dumped in the gravel pit? Sure. Is it likely (and not de minimis)? You have to make that determination based on the totality of the available information and your experience. If it's not likely then it's not a REC.
I can't tell you if it's a REC or not, you'll have to make that call on your own, but doesn't sound like any obvious red flags, other than it was a gravel pit.
Pre-1940, probably not.
It was operational in the 50s and 60s. Fairly small area, in terms of gravel pits. There was residential close by.
Aerials show no discernible objects (such as dumped cars) seen on the subject property or surrounding area.
Much of the surrounding just looked like vegetation was cleared; there appeared to be a small depression in the area in the late 1950s, but this was not seen in the 60s. Vegetation was making a comeback in the late 1960s and more so into the 70s. Vegetation is presently flourishing on the subject property.
Was it filled ? It was such a small area, possibly graded with surrounding earth
No regulatory listings.
The local jurisdiction only says "they think it was a gravel pit", let alone landfill
No geotech report.
Depends. What do the aerial photos show? Is the gravel pit located in an industrial area in NJ or a rural area in TX? Was it filled? If it was filled, when was it filled? Any regulatory listings? Do the local agencies know anything about it? Is there a geotech report available? If so, does it identify any unusual fill conditions? Etc.
I see a hose clamp on it, which sort of indicates it probably wasn't a high pressure line. I'm thinking old water or drain line, but could be just about anything.
It's too small for a fill pipe and doesn't look like a vent pipe.
The bakery may have had a natural gas appliance in this area. Maybe its an old natural gas line ?
Delineating a subwatershed is a whole different beast and not really necessary for a Phase I. If I have 2 sites on opposite sides of a hill then I would generally consider them not hydologically connected. In any case where I'm hesitant to make the call though I just review the file to be safe. You just have to make your best judgement and be ready to defend it.