Soil Permeability 1

[chicopee]

Could someone direct me to references regarding subject matter. The type of soil would be the type encountered in automotive recycling yards (junk yards) where surfaces are compacted and such surfaces may be contaminated with oils.

 

[LRJ]

I would wager that it is actually 'hydraulic conductivity' that you are interested in - geotechnical engineers incorrectly call it 'permeability' which is actually a value used to calculate hydraulic conductivity. Wikipedia has some good articles on it - the design equations are also stated.

 

[oldestguy]

What are you using the value for? With inclusion of oil or other non-soil material, conventional tests may not apply.

 

[cvg]

you will need the actual soil type and probably a field test for conductivity. this may be done with a double ring infiltrometer.

Is it sand, silt, clay, gravel or some combination thereof? If you know this, you might be able to make a very rough estimate.

"...the type encountered in automotive recycling yards..." is not an adequate description to estimate hydraulic conductivity

 

[chicopee]

At this point in time, the nature of the soil is unknown. I have been at the site and the terrain where most of the activities of removing oils, dismantling ,crushing, storing parts and reclaiming liquids is typical of several junk yards that I have seen. It will be some times before soil conductivity tests will be brought up to the owner.

 

[cvg]

suggest you look at the soil survey of your area. you can find them on the NRCS online web portal.
this will give you a general indication of the soils in your area and will give information on hydraulic conductivity and other properties

online

http://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx

 

[chicopee]

I'll check the link from cvg, however my gut feeling is that I will not be getting the answer. The soil in my OP is laden with hydrocarbon and compacted from the use of heavy equipment such as front end loaders but not totally impervious. In all likelihood soil conductivity tests will be necessary.

 

[Ron]

chicopee...your description leaves a bit to be desired! A junk yard? Where? What type of soils? Do you know it has been contaminated? What about the areas that are not contaminated. I'm reasonably familiar with junk yards. The do get contaminated with oil and other petroleum residue; however, not every area gets that. Have you ever noticed that weeds grow in junk yards.....even weeds don't grow in petroleum contaminated areas.

Hydraulic conductivity.....permeability...tomato...tomahto

The goal is to see how water flows through the soil. As OG noted, if contaminated, you will not see the same response as for non-contaminated soils. Petroleum will not allow the same permeability of through soil as will uncontaminated areas.

 

[LRJ]

Hydraulic conductivity.....permeability...tomato...tomahto

It's not a trivial difference - if you confuse the two you'll get a result that is several magnitudes out. And given that it only appears to be geotechnical engineers who are making this confusion, I would suggest they start calling it the correct word.

Actually, a quick check of some ASTM standards indicates that the standards are now using the correct word (hydraulic conductivity), so it is really just the geotechnical Grognards who need to update their phrase books.

 

[cvg]

so far chickopee has not give any idea of why he needs the permeability or if he needs the conductivity or if he needs a runoff coefficient f or this site. if this is a drainage study than no estimate of permeability is needed, just use the runoff coefficient C = 0.90. if this is for recharge, than I would think that a basin would be excavated and the oily soil would be removed. the bottom would be aerated. if this is for a drywell than soils at depth would need to be investigated and percolation tests using infiltrometer rings would be required.

 

[oldestguy]

cvg: Chances are he is getting a guard dog, a "junk yard dog" and needs to know if he needs any special "bathroom" area to let it soak in

http://www.azlyrics.com/lyrics/jimcroce/badbadleroybrown.html

 

[chicopee]

The issue on the magnitude of runoffs from the site in question during storm events is to be addressed. Presently, it is assumed that any storm water in area where soil is laden with hydrocarbon will not percolate but this assumption is undoubtedly wrong. I am just amazed that I have found literature addressing this subject since the inception of clean water act.

 

[cvg]

percolation is limited by the compaction. any potential hydrocarbons might reduce the percolation a bit, but the effect is likely minimal since compacted gravel and asphalt parking lots and roadways are assumed to have about 90 to 95% runoff anyway.