1988-04-11_PERMIT FILE - C1981008A

• Permit No: C1981008A
• IBM Index Class Name: PERMIT FILE
• Doc Date: 4/11/1988
• Doc Name: Hydrologic Description ‎(Part 2 of 2)‎
• Section_Exhibit Name: Tab 7
• Media Type: D
• Archive: Yes

Tuttle Draw. Site SW-N1 is established in Tuttle Draw upstream of the eastern permit
boundary of the Nucla Mine. Water quality at this site has been monitored since April of
1980 (see Appendix 7-7). Table 7-43 presents a statistical summary of historic water
quality data collected at Site SW-N1 . Figure 7-24 presents a Schoeller diagram of mean
milliequivalent values for the major anions and cations for both the irrigation and
non-irrigation periods at SW-N1.
During both the irrigation and non-irrigation seasons, SW-N1 exhibits a magnesium calcium
sulfate water type (see Appendix 7-8). From Figure 7-24, it is evident that although an
increase in each ion (milliequivalents) occurs during periods of no irrigation, the
percentage of each remains consistent throughout the year, resulting in similar water
types during both seasons.
pH values at SW-N1 average 8.06 and 8.09 units during the irrigation and non-irrigation
seasons, respectively. pH has not been measured lower than 7.0, and the highest pH
recorded at SW-N1 was 8.9 units during the period of no irrigation.
TDS generally averages almost double during periods of no irrigation at Site SW-N1 (1535
mg/l versus 891 mg/l during the irrigation period). TDS ranges between 360 and 1992 mg/l
from about mid-April through mid-October, and ranges from 865 to 2336 mg/l during the
non-irrigation period. This logically results from the higher levels of the major ions
during periods of no irrigation as depicted on Figure 7-24.
Total suspended solids (TSS), total iron (Fe T) and dissolved iron (Fe D) all average lower
concentrations during the non-irrigation period. TSS, Fe and Fe average concentrations
of 46.5 mg/l , .78 mg/l and .07 mg/l , respectively, during the summer months (irrigation
period). From mid-October through mid-April , TSS, Fe and Fe average 21 .7 mg/l, .84 mg/l
and .04 mg/l , respectively.
Analyses for total manganese (Mn T) show that, during the irrigation season, MnT averages
.19 mg/l . The average value of MnT is more than double at SW-N1 during periods of no
irrigation (.44 mg/1 ).
Site SW-N3 is situated on Tuttle Draw downstream of the Nucla Mine permit boundary. Water
quality has been monitored at this site since April of 1980. Table 7-44 presents a
statistical summary of historic water quality data collected at Site SW-N3. Figure 7-25
7-123 Revised 04/11/88