2015-08-31_PERMIT FILE - C1981010A (23)

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pH values'- pH (.01M CAC12 solution and paste) (Tables 2.7-6 and 2.7-7 and Map M40) Overburden pH is probably one of the most important factors to be considered in attempts to reclaim mine spoils. Several different methods can be used in test- ing pH of soils, however, some methods are more desirable in reference to vegeta- tive response. Two different methods were used for evaluating pH. A water extract pH and a .01 molar CaC12 solution extract pH were taken frog the cores. The water extract method tends to cause pH readings to be high because sodium compounds will ionize in water and therefore raise the pH. In a CaCl2 solution extract, the pH will be consistently lower when sodium compounds are present and the results are more meaningful from an agronomic standpoint (Olsen, 1974). a. pH Class A (6.0-8.5) will support a wide variety of climatically adapted woody or grass plants. b. pH Class B (more than 8.5) will support only the most salt and alkali toler- ant plants; topsoil application may be necessary; plant establishment will be difficult. c. pH Class C (4.0-6.0) topsoil application may be necessary. A pH of Class A is obviously the most desirable from a reclamation standpoint even though all mine spoils will be topsoiled. All other pH values would have to be adjusted within this range to have a good plant response, especially for those species of plants with an extensive root system (shrubs, etc.). pH values present in the overburden strata prior to weathering are presented in Table 2.7-7 and are depicted in the cross section Map M40. Table 2.7-8 provides the measured pH values from samples that were exposed to weathering. 2-386 In defining the desirable limits of pH, the Soil Conservation Service (1971) has ' divided pH ranges into the following three categories. a. pH Class A (6.0-8.5) will support a wide variety of climatically adapted woody or grass plants. b. pH Class B (more than 8.5) will support only the most salt and alkali toler- ant plants; topsoil application may be necessary; plant establishment will be difficult. c. pH Class C (4.0-6.0) topsoil application may be necessary. A pH of Class A is obviously the most desirable from a reclamation standpoint even though all mine spoils will be topsoiled. All other pH values would have to be adjusted within this range to have a good plant response, especially for those species of plants with an extensive root system (shrubs, etc.). pH values present in the overburden strata prior to weathering are presented in Table 2.7-7 and are depicted in the cross section Map M40. Table 2.7-8 provides the measured pH values from samples that were exposed to weathering. 2-386