PERMFILE47151 - Laserfiche WebLink

Home Browse Search

Section 779.21 (a) Continued. • that all copper levels in the area are adequate for this essential element. Zinc. Heil (1976) found total zinc values on the permit area to range from 50.0 ppm to 125.5 ppm, with an average of 76.6 ppm. DTPA zinc values were found to range from 0.1 ppm to 3.0 ppm, with an average of 0.6 ppm. Berg (1973) found the DTPA value of zinc to be 3.1 ppm. Follett and Lindsay (1970) reported that DTPA zinc values in Colorado soils ranged from 0.13 ppm to 14.2 ppm, with an average topsoil value (topsoil plus subsoil) to be ].. 11 ppm. The suspect levels for DTPA zinc h2.ve been estahli=hea to be greater than 30 ppm. (Dollhopf et al., 1977). The highest DTPA zinc value encountered in the area is 3.0 ppm. Therefore, no zinc toxicities should be encountered. Ludwick, et. al. (1976) and Follett and Lindsay (1970) report that critical zinc soil tests • levels for plant growth are 1 ppm. No deficiencies are expected for this element. Cadmium. Heil (1975) reported that total cadmium levels on the proposed permit area ranged from a low of 0.030 ppm to a high of 0.133 ppm, with an average of 0.086 ppm. Gough and Shacklette (1976) report: "Cadmium is a relatively rare element that i~ rather uniformly distributed in the. most abundant rocks of the earth'a crust, which has an average content of 0.15 ppm to 0.2 ppm". They report that concentrations of more than 0.2 ppm are needed before toxicity symptoms appear. Standards published by tiie Montana Department of State Lands (Dollhopf, et. al., 1977) indicate that suspect levels of cadmium are greater than 0.1-1.0 ppm. Given the data reported by Gough and Shacklette (1976) no toxicities resulting from cadmium concentrations are likely to be encountered over the proposed permit area. • Lead. Heil (1976) encountered DTPA lead values ranging from 1.27 ppm to 6.83 ppm, with an average of 3.74 ppm. lie stated, "the 779-299