PERMFILE112211

• Permit No: C1981016
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: start 2.04-22 end pg 2.05.26
• Section_Exhibit Name: Rule 2 ‎(rest of Sec. 2.04 to 2.25
• Media Type: D
• Archive: No

•
drained by the Minnesota Creek and the North Fork of the
Gunnison River is evidenced in the similarity of the chemi-
cal composition and dissolved solids concentration of the
water samples collected from these two systems. The
dissolved solids concentrations of the samples collected
from upper stations on the Minnesota Creek varied from 18 to
150 mg/1 while concentrations from the North Fork of the
Gunnison River samples varied from 54 to 135 mg/1,
The variability in dissolved solids concentrations at a
given station on the Minnesota Creek and the North Fork of
the Gunnison River is largely because of a seasonal pattern
of runoff. Concentrations are lowest in the months of high
discharge {July), and greatest during low flow (January and
April) when groundwater constitutes a greater proportion of
the flow. This seasonal pattern is typical of a snowmelt
stream. However, the timing and duration of flows, and thus
dissolved solids concentrations, have been modified by irri-
gation developments.
Biological Parameters
Periphyton
The term periphytin is defined here as the assemblage
of microscopic plants (Algae) which grow attached to under-
water substrates. Although most species are microscopic and
are recognized largely by the colored slippery film they
produce on substrates, many of the colonial species form
large streamers or mats which are very conspicuous.
Source.
In swift rubble bottom streams, such as those occurring
on the Mt. Gunnison No. 1 Mine study area, periphytic algae
are the main producers. Many species of benthic macroinver-
tebrates and some species of fishes utilize algae as a food
Diatoms (Bacillariophycea) were the predominant group
of periphytic algae identified from the streams on the Mt.
Gunnison No. 1 Mine study area and accounted for more than
70 percent of the species identified. In general, diatoms
were also present in the greatest abundance, covering
available substrates with golden-brown films. Green algae
(Chlorophyta) and blue-green algae (Cyanophyta), although
represented by relatively few species, were sometimes pre-
sent in abundance. Most of the species of green algae and
blue-green algae identified were colonial and were usually
conspicuous. Many species of periphytic algae were iden-
tified from all streams; however, a few species were limited
to just one stream. The North Fork of the Gunnison River
had the greatest number of species not shared by the other
2.04-69