PERMFILE67750

• Permit No: C1981014A
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: 4.06 TOPSOIL
• Media Type: D
• Archive: Yes

EFCI contracted with Intermountain Environmental (IME) to evaluate and
compare the relative suitability of refuse and soil materials and based
upon the results, to review topsoil removal/replacement commitments and
refuse pile cover requirements. The results of IME's evaluation are
presented as Exhibit 9, Comparison of Refuse and Soil Suitabilities.
In order to evaluate coal refuse suitability. IME utilized all existing
available data on soils, overburden and refuse and completed additional
chemical and physical analyses on samples of fresh refuse, refuse three
(3), five (5), and seven (7) years old and samples from three (3) existing
refuse piles ranging between 24 and 52 years in age.
Using all available data, IME compared the suitability of refuse materials
with those soil materials which would normally be utilized under
applicable regulatory requirements tb establish the minimum four (4) foot
cover depth of suitable material over stockpiled refuse materials. This
suitability comparison indicates that further testing to verify the
suitability of refuse materials may be justified. Refuse materials, based
• upon statistical comparisons, are superior with respect to rock fragments
less than three (3) inches in size, acid-base potential, N03 - N, and Fe.
Soils are statistically superior with respect to SAR. Mean suitability
values for pH and other parameters are statistically comparable for refuse
and soils. Even though refuse SAR values are higher, available data
indicates that over a period of three (3) years, SAR levels will decline
to the point where they would be classified as "good" to "marginal" based
upon suitability guidelines for areas having similar climatic and
topographic characteristics published by the New Mexico Mining and
Minerals Division (NMMMD).

HEV7R15.REV
11/15/9311em 4.06.2R Revised - November 1993