PERMFILE111851

• Permit No: C1982057A
• IBM Index Class Name: Permit File
• Doc Date: 5/1/2003
• Section_Exhibit Name: Tab 07 Hydrologic Description
• Media Type: D
• Archive: Yes

MgCa-HC03504 type (1980), 523 and 541 waters are characterized as a t1g-504 water type. •
Site 545 (Dry Creek drainage) is also characterized as a Mg-504 water type.
Schoeller diagrams of Sites 51, 55, 57, 523, 541, and S45 are shown in Appendix 7-7. The
diagrams plot ion chemistry in units of mi lliequivalents per liter (meq/1). Overall, the
diagrams show parallel trends for 51, 523, and :i45, indicating little seasonal variability
and consistent water chemistry for the time periods represented by the samples. The lack
of complete, quarterly, geochemical data from springs in the drainages precludes any
quantitative interpretation of year-round seasonal trends.
The Schoeller diagram of 57 indicates there was considerable variation of Mg, C7, and 50
4
between the time periods represented by the seven samples. The diagram for 541 shows a
trend similar to 57. For Sites S7 and 541, Mg and 50
correspond with an increase in TDS,
4
whereas, C1 corresponds with a decrease in TDS. This information suggests that when
seasonal evapotranspiration rates are high or the amount of seasonal recharge is lower,
the TDS content of the spring water increases, particularly Mg and 50
concentrations.
4
When evaporation rates are lower and/or the amount of annual recharge is greater, the TDS
of the water is lower and so are the concentrations of Mg and 504. Generally, the TD5 •
content of spring water increases from the late spring to early fall when ambient air
temperatures are highest.
The water chemistry of 525 was first noted in July, 1979 as unique because of its high
concentration of dissolved solids. Several ideas were offered to explain the water
chemistry at this site, but it appears that the water quality is natural and
lithologically controlled. Evapotranspiration may contribute at a small level to the high
solids content of the water at 525. Such a high TDS concentration (26,566 mg/1 average)
in water at 525 categorizes it as saline water since the TDS level exceeds 10,000 mg/1.
This spring has high fluoride and nitrate concentrations, which are probably due to
natural conditions as well. Spring Site 523 is also quite high in dissolved solids.
Suitability. Spring water suitability at Seneca II-W was evaluated by comparison of
sample analyte concentrations to the most stringent standards established by State and
Federal agencies based on categories of ultimate use. State agencies, Colorado Department
of Health (CDOH) and Colorado Mined Land Reclamation Division (CMLRD), and Federal
agencies, U.S. Environmental Protection Agency (EPA) and the Office of Surface Mining •
Reclamation and Enforcement (OSMRE), have established limits for analyte concentrations in
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