BRAWM Team: Your Methodology for Obtaining Your East Bay Soil Samples
I am interested in knowing what your methodology is for obtaining your soil samples in the East Bay. Your rainwater sampling methodology is well detailed and understandable for the lay person.
Do you use "core" samples - i.e. taking a sample straight down for 12 inches or so. Or do you line out a sampling area - i.e. 3' X 3' - and scrape an inch or two off the top of that area. OR do you use a different methodology altogether?
I'm curious as to your technique as it would probably make a difference in the amount of radiation in the sample because, as I understand it, most of the radiation(C134 & C137)is still close to the surface this year...in the top 2 or 3 inches due to our clay soil. A "deep" sample probably wouldn't contain as much radiation as a "wide" sample would.
An answer to this question would help me to better understand just what I am dealing with in my garden soil. After all, our problems mostly deal with the soil right now...until the rain comes again.
Thank you...
Hi Gardening Gal, The
Hi Gardening Gal,
The samples we took are from the top 1 inch of soil, and an area of about 20 × 30 centimeters. These dimensions are approximate, but the idea was to take the top inch of soil. You're right — the particular type of soil will determine how deep the cesium diffuses, so it might only be present in the top couple inches.
The soil samples from San Diego give an idea about the depth profile of cesium in typical soil. The top layer (3–4 inches deep) shows cesium but the layer below does not. I'll post the data for the lower layer later today. We could try this for the Bay Area as well, but I suspect it will be similar.
Mark [BRAWM Team Member]
Thank You, Mark (BRAWM Team)
Thank you, Mark, for your prompt reply to my inquiry. It is good to know that the radioactive materials are still close to the top and that the measurements taken are for surface area...which means it is a more concentrated sample. Some of the soil in my yard is standard clay...and some of it is "fluffy" (amended with compost, sand, mulch, etc.). Have many sunflowers planted in these areas.
My post below concerns the soil IMMEDIATELY UNDER THE GRASS (SOD). PLEASE sample the soil immediately beneath the grass (to a depth of an inch or two or three) that you are taking measurements (of grass) from in the EAST BAY. You might even include the dirt in the roots of the sod (grass).
THEN compare the "bare" soil sample with the "soil under the grass" sample...is there an appreciable difference? Is the grass helping to "remove" or "phytoremediate" the Cesium from the soil? OR are the samples reading about the same?
I wouldn't request this if I could do it myself...
Thanks for all you do, Mark...and BRAWM Team!
Please Mark
I would love to see the soil tested just below the grass also since soccer season is about to start. It concerns me that the surface soil is contaminated and the dry soil and grass will get kicked up during play and practice and be inhaled by our kids. Please Mark see what you can do. Thank you for everything you have done till now!
Soil Samples from Below the Grass Tested
Since the Cesium levels appear to be declining in the grass samples, would you please consider testing the soil below those samples. It might tell us that the grass has phytoremediated the soil by "wicking-up" the Cesium if none is present in the soil below the grass....OR that the Cesium is "binding to the soil" if it is still present in the samples tested.
Thank you for all you do.
Forgot to add my name to this post
Posted by: Gardening Gal
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