Heavy oil contamination 4

[Aim2000]

This is about Auto Centre Project which has some contamination. We removed the 500 gallons waste oil UST (steel) from the ground a few weeks ago. UST was located along the wall outside the building (south side of the building) in front of the second service bay area. Soil samples taken from north wall, east wall and west wall have values above the regulatory guidelines for F4 TPH (C34-C50). North wall is just below the foundation wall and is contaminated. We drilled one bore hole about 6 feet inside the building from the wall and it was okay. Few boreholes about 8 feet from the contaminated walls were also drilled on west, east and south side of the excavation outside the building.



My Questions is

1. How do you remediate the soil below the foundation wall? Some contamination encroaching inside the building too.

2. How do you remove the contaminated soil which is 8 feet deep and 29 feet in length along the wall? Do we need to make 3:1 slope along the foundation wall while removing the soil or building underpinning?

3. Any other alternative or suugestion to remediate the heavy oil contaminated soil below the foundation wall and inside the building close to the wall


I would appreciate if you give me any suggestion how can I deal with it in this situation.

 

[brodgers]

While excavation of the soil will provide an immediated and cost effective solution, its location to the building makes this alternative undesirable. Depending on the soil type and permeability, I would probably try and bioremediate the soil, if possible. TPH is amenable to bioremediation, but the subsequent monitoring cost can add up. Usually, waste oil tanks will halogenated compounds but you only reported the presence of TPH. Did you test for halogenated compounds?

 

[bashabo]

You should probably think first in-situ remediation instead of traditional excavation. You should delineate the area (both vertically and laterally) before you design any in-situ system. Depending on the soil parameters, you can probably use a SVE (soil vapor extraction ) method of remediation. SVE is very goood for porous soil. If excavation is the only solution, then have adequate shoring soldier pile) before you start excavtion. You should have a competent structural/geotechnical engineer design the shoring system for you.

 

[BigH]

Why is it necessary to remediate? Is the high concentration considered a health problem for those working inside the building? If there is little to no chance of the contamination spreading outside the existing limits, then contamination of "good" soil would be, at best, minimal and within the property. Now, when selling the property, it will be a different story. You could use some form of barrier system to confine the leftover contaminated soils. (Questions like this - contamination, not the engineering) is why I stayed out of the geo-environmental stuff the best I could.)

 

[Aim2000]

Thanks everyone for your usefull tips for the remediation of waste oil contaminated soil.

Brodgers! To your question whether I have tested for halogenated compounds. No! I havn't tested for halogenated compounds yet.

bashaboo! As you have suggested for Soil Vapour Extraction. IS SVE is a good choice to remediate soil with heavy oil contamination.

I have contacted bioremediation company and working on that now and seems to me a useful solution to solve this problem so far.