PERMFILE66227

• Permit No: C1981010
• IBM Index Class Name: Permit File
• Doc Date: 3/20/1989
• Doc Name: Regraded Spoil Sampling
• Section_Exhibit Name: Appendix W 1988 Report Section 4.0
• Media Type: D
• Archive: No

SECTION 4.0 Regraded Spoil Laboratory Results
As agreed in Trapper Mine's approved Mining and Reclamation Permit Application (C-81-010), recornoured
spoil will be sampled for various chemical and physical properties to ensure suitability as a plant growth
medium. Section 2.7.2 of Trappers permit discusses the parameters to be sampled, sampling irnensity and
suitability ranges for various spoil parameters.
4.1 Methods
Composite samples were taken on approximately 50-ft to 100-ft centers for each mapping unit. Mapping
units in 1988 were determined by visual and textural difference of surface spoils. A sampling density of
approximately one sample per five acres of reclaim area was accomplished. Each sample was a com-
posite irom at least one foot of spoil material. The samples were analyzed for pH, EC, CaC03, O.M., NO3-
N, P, K, 2n, Fe, Mn, Cu, Se, Ca, Mg, Na, SAR, % Saturation, texture, Hg, F, Total S, and acid-base potential.
If a large negative acid-base potential would have been found, then additional analysis to include pyritic
Sulfur and SO4 S was to be run for that sample. No samples exhibited a negative acid-base potential. The
final mapping units were then transferred to the spoil history map, M4-1. Each delineation on this reap was
idenYrfied as to year sampled, texture, and lab analysis number.
4.2 Results
• Spoil laboratory analyses were conducted by the Colorado State University Soil Testing Laboratory aril are
provided in Table 4-1. A comparison of the laboratory results and the suitability ranges for each sample
parameter (Permit Table 2.7-2a) indicates all samples were within the allowable suitabilRy range with the
exception of an elevated SAR in lab sample number 2818. The composite sample exhibited an SAR of 14.0
which is higher than our current suitability criteria will allow, however is still under the unsuitability criteria
as described in most literature. Sodium adsorption ratio (SAR) values of spoil areas adjacent to this loca-
tion range from .4 to 4.9 (x = 1.6). Because this sample was unusually high (not representative) the area
was re-sampled (as required in our permit) using the same sampling criteria as previously used and as
described in methods section. The sample results are reported in Table 4.2. The SAR value of the re-
sampled area was 5.5, well within the suitability criteria. Trapper concludes the initial sample (#2818) was
probably not representative of the true spoil nature of this area, as all areas adjacent to it were very low.
However, Trapper will continue to visually monitor this area for potential vegetation establishment
problems.
4.3 Discussion and Recommendations
As stated previously, the purpose of spoil sampling and analysis is to demonstrate that a surface spoil layer
has been replaced with acceptable physical and chemical properties to promote plant growth and
successful reclamation. The data strongly indicate Trapper Mine has accomplished this goal within the
sample area. With the addition of suitable topsoil, these regraded spoils will provide an excellent medium
for plant growth for any postmine land use desired. Trapper proposes no additional spoil sampling be
conducted in the 1988 sample area.
WA/jsb [CMLRD\88REPT]