seasonal high water table

[cemorway]

Hello all...
I am looking for good information on estimating the seasonal high water table elevation. (without setting a monitor well and observing for a year). This would be used for purposes of determining the minimum bottom elevation for infiltration areas (2' above the SHWT). I know sometimes "mottling" of the soil is used, but I have done plenty of borings where such evidence is not found, even though GW was found. thanks in advance.

 

[CESSNA1]

CEMORWAY:

There is nothing like digging a hole after a year of 100 year storms. Short of that however, the city or county should have information on the SHWT for your area.

Regards
Dave

 

[semo]

In the US you might check with the local office of the USDA NRCS (old Soil Conservation Service). In some states they have done soil surveys which could include the seasonal high water table. I know they do in Missouri.

Their website might even have some info.

 

[daddymem]

This is one method in Massachusetts that may give you some clues for your location:

http://www.mass.gov/dep/brp/wwm/localoff/files/sech4.doc

You mention borings and mottling, I am a soil evaluator in Mass. (septic system requirements) and from experience, you aren't likely to see the redoxymorphic features without a deep hole test pit. If you don't find mottling, you can pick the bottom of the pit as the seasonal high groundwater level and add a safety factor if you wish. Here is more on redoxymorphic features:

http://nesoil.com/properties/eshwt.htm