CORRESPONDENCE_1982-1983 - Laserfiche WebLink

Home Browse Search

On the other-hand, the soil solution does strongly resemble the chemical composition of oil well brines that I have encountered. Viz, high chlorides and sodium. Even the low concentrations of bromide seem to be typical of connate brines. You will note, of course that stoichiometrically, there is more chloride than sodium in the soil solution. (40 Me/l of chloride vs 35 Me/1 of sodium.) This is to be expected, due to base exchange phenomena, much the same as a water softener being recharged with a brine. Turning now to the total dissolved solids in the soil solution, if we multiply the specific conductance by two, we will have an estimate of the specific conductance of the soil solution. Taking the case of the sample of soil from the 8' to 10' depth, we have: 2 x 3710 limhos=7420 pmhos estimated to be the specific conductance of the soil solution beneath the ponds. A conversion factor that is sometimes used to estimate total dissolved solids from specific conductance is as follows: .7 x specific conductance (in u os)= TDS in mg/1. Using this conversion factor, the TDS in the soil solution beneath the ponds at the 8'-10' depth is as follows .7 x 7420= 5194 mg/1 total dissolved solids It is my understanding that Forward, Inc. analyzed the brine in the ponds this year and the analysis showed the brine to be about 5000 mg/1 total dissolved solids. This fits very nicely with the findings described above. How much brine has leaked from the ponds? The analyses strongly suggest that the "wetting front" of the brine has gone beyond the 10' depth. In this kind of a soil, it will have taken about 30" of brine to have accomplished that kind of penetration. If the ponds leaked this much throughout their entire area, the leakage would amount to more than 1.8 million gallons. In summation, the soil sample analyses indicate that the brine j leaking from the ponds has soaked at least 10 feet beneath the pond bottoms. It is now merely a matter of time until this brine reaches the water supply of San Joaquin citizens. Scientific estimates can be made of how much water had to leak through the pond bottom to have seeped to the depth of ten feet, and the indications are that the amount of leakage is considerable, but the seepage may have penetrated far beyond that depth. Yo r truly, { Dwig C. Baier, P. E. , CPAg/SS President DCB:bb CC: Richard W. Konig