2007-11-01_PERMIT FILE - C1982056A ‎(4)‎

• Permit No: C1982056A
• IBM Index Class Name: Permit File
• Doc Date: 11/1/2007
• Section_Exhibit Name: 2.06 Special Categories of Mining
• Media Type: D
• Archive: Yes

• The vegetation along Fish Creek is mapped as a sagebrush/meadow vegetation type (page 2.04-60 and
Table 30, Sagebrush/Meadow Vegetation Type). The vegetation in the vicinity of the confluence of Foidel
Creek and Middle Creek is described on pages 2.04-43 and 2.04-44 and in Tables 14 and IS of the Fish
Creek Tipple Permit Application. Additional quantitative vegetation descriptions of the vegetation
including species used under agriculturally managed areas in this same vicinity are found on pages 2.04-76
and 2.04-77 and on Tables 14 and I S of the Energy Mine No. 3 Penni[ Application. Examination of these
tables with the species presented in Maas and Hoffman's Table I reveals that only two species (smooth
bromegrass, Bromus inermis and timothy, Phleum pratense) were encountered in [he quantitative vegetation
surveys. Smooth bromegrass is described as being a moderately tolerate species with respect to salinity
while timothy is described as being a moderately sensitive species. However, threshold values for these
two species were not presented and could not be used [o calculate relative yield as described in the Maas
aitd Hoffittait predictive equation. Therefore, it was decided to use alfalfa because its salinity tltresltold is
published and it is assigned a salt tolerance rating equivalent ro [hat of timothy. TCC believes that since
this species has the same ranking and is grown on agricultural lands along Fish, Foidel and Trout Creeks,
[his comparison is scientifically valid. According to Maas and Hoffinan, [he threshold values represent [he
point at which increased salinity resulted in a measurable decrease in plant yields. In order to present a
"worst case" situation and since no salt sensitive crops are encountered in the Fish, Foidel or Trout Creek
drainages, TCC elected to use alfalfa as a target species in measuring the potential impacts of using
increased salinity waters for irrigation. TCC believes [his situation represents a condition much worse than
q~pical agricultural practices because (according to the above cited tables) smooth brome represents the
most significant agricultural and economically valuable species in the area.
The management implications of using irrigation waters of increased salinity have been widely studied for
many years. In previous findings documents (page 19 of the Foidel Creek Mine C-056-82, and on page 38
• of the Energy Mine No. 3 C-84-062) the CMLRD has utilized the values contained on page 208 of EPA
(1976) (commonly called the "Red Book"). This approach grossly oversimplifies the issue and ignores the
warning that the EPA values are fora "general classification of salinity hazards ... I I that need to be
"interpreted in relation to specific soil conditions in a given locale". The result is drat this "general
classification" has been applied to each specific permit findings document prepared by [he CMLRD.
liowever, references in the EPA Red Book to the 1954 USDA Agriculture Handbook No. 60 allow for site
specific evaluations to be conducted. Examination of this long accepted standard reference oit the
management of saline irrigation waters indicates [hat the issue of predicting adverse crop response is
considerably more complex than simply measuring the salt content of the waters. Chapter 5 of Handbook
No. 60 discusses the quality of irrigation waters. On page 71, this document states ilwaters in the range of
0.750 to 2.250 mittltos/cm are widely used, and satisfactory crop growth is obtained under good
management and favorable drainage conditions, but saline conditions will develop if leaching aitd drainage
are inadequate." The issue at hand is no[ in setting a limit of 1000 mg/I (L562 mmhos/cm) as an arbitrary
standard that is contrary to "widely used" agricultural practices, but to at least adapt the proposed standard
to a "worst case" set of management practices. The purpose of [his evaluation is to determine whether or
not the potential exists, for waters of increased salinity, to adversely affect the ability of using these waters
for irrigation on areas immediately downstream of the TCC mine discharges.
In order to evaluate the potential impacts of [he potential increased salt loading associated with
a~ricultttral activities within the permit and adjacent affected areas, the following evaluation was
conducted. As depicted on Map I5, Alluvial Valley Floors and Water Rights. the initial points, wherein
salt affected waters are used are [he Corliss and Boettler Ditches on Fish Creek. The firs[ actual pain[ at
which potentially salt affected waters of Foidel Creek will be used for irrigation is below the confluence of
• Middle Creek and Trout Creek a[ the Jefferson Ditch. Since water rights are already seriously over
adjudicated on Trout Creek and ahnos[ half of the currently decreed water rights on Fish Creek have
essentially been abandoned, the probability of waters being diverted from Foidel Creek are extremely
remote. For this reason, no evaluation of the water impacts to irrigation on Foidel Creek are necessary.
M R 97- I id 2.06- 16 Revised 9/ 10/97