So it's been raining for 2-3 days straight now here in Central VA and Friday through Sunday the weather man is calling for 60 degree sunny skies.
I figure this is a great time for me to do a soil test...easy digging with the shovel!
My question is, what exactly am I doing?
Yea, I know, digging a hole. How deep should I go? Do I just randomly send off a sample to my local field office?
Are you testing for pond building purposes or for soil content for water quality ?
water retention (seepage) properties...ie is the soil on my property suitable for holding water.
So I found this tool today on the NRCS website....it's pretty handy....basically you enter your address then outline your property and it tells you the type of soil found in the last survey...
http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx Now....for the bad news...
This is what it says comprises 100% of my property:
Atlee very fine sandy loam 100.0%
Man that tool is extremely useful..
1% slope on my property is what it says. Then when I click on suitability for excavation it says:
Headers: Unit Symbol (AT)
Map Unit Name (Atlee very fine sandy loam)
Rating Very Limited (85%)
Rating Reasons Depth to saturated zone 2.2,
Cutbanks cave
And finally, the main deal:
Pond Excavation & Pond Resevoir Area:
I get a "somewhat limited" rating on both categories....here are the reasons:
Depth to cemented pan
Seepage
Slow refill
Cutbanks cave
Depth to saturated zone
The definition of "somewhat limited"
"Somewhat limited" indicates that the soil has features that are moderately favorable for the specified use. The limitations can be overcome or minimized by special planning, design, or installation. Fair performance and moderate maintenance can be expected. "
Remember Ego; NRCS soil survey samples are taken from a depth no greater than 60", often less. We took our samples (and I believe many do the same) with the excavator, reaching to a depth below the lowest point of the proposed pond depth. Based on what I see from your original topo, I think you are a dug pond so a dam won't be necessary...but...If a dam is required and there is questionable integrity in the soils within the pond basin, a core would likely be recommended and sampling the core zone to the same depth practice noted above would be wise.
Another huge help to me was the ability to secure the water well drilling records of close neighbors from the State website; usually buried within the State DNR section. In fact, I remember getting drilling records from areas where oil wells were tested. They were interspersed with the water well records. Anyway, if you can find these drilling records for activity nearby, they usually have a table of the soils encountered during the drill and at what depths.
Thanks for the advice. What website would show that type of information? The NRCS? Where would well drilling records be archived?
And yes, you're right, this would be an excavation job so there wouldn't really be a "dam" so to speak...
By the way, if you wouldn't mind, take a look at my other thread under the Selecting A Site forum...it has pictures of my lot...I'd love to hear your input.
Seems like this would be a good topic for one of our resident geologists...
PAGING: Dave in El Dorado
Dave in El Dorado, please pick up the white courtesty phone in the main lobby....Ego, try to get Dave's (DIED) input. He's into soils and rocks and stuff (but not in a wierd way mind you).
hello?,,,,,,hello?, uh, HI.....sorry, am i late?
thanks jeff...
somehow i missed this one, but after briefly reviewing the info presented in the links provided by ewest, i really dont have any new "groundbreaking" info. to contribute........so many on this forum have the knowledge and common sense to direct you and help you identify whether or not yer soils are pond adequate.
the only thought i had, not already presented, was to conduct a percolation test. i agree that soil survey maps are very general, and the best info is obtained from on-site drilling or trenching (test pits). if you go down that road and dig some test pits, and if they dont already fill with water, which will tell you alot right there), you could put water in them and time the seepage rate out (if any). this type of test is done all the time to install septic systems (in which case you want good percolation).
water well logs should be availabe to public and on file in yer County offices (at least they are here in CA). These can provide excellent information regarding how laterally extensive certain soil horizons or rock types are in your area, however, they can also be misleading depending on the logger.....many times drillers call silt soils a clay....but its worth looking at them....the more data the better in my book.
good luck and keep us posted.