Table 12. Comparison of ground-water-quality samples collected from wells with selected U.S. Environmental Protection Agency maximum and secondary maximum contaminant levels for public drinking-water supplies
(Contaminant levels from U.S. Environmental Protection Agency, 1991, 1996. Results of sampling individual wells are listed in appendix table 1.)
[All constituent or characteristic concentrations are in milligrams per liter except as indicated; --, no established level; N/A, not applicable]
|
Constituent or characteristic |
Maximum contaminant level (MCL) |
Percentage and number of samples collected from Wasatch aquifer that exceed MCL |
Percentage and number of samples collected from coalbed aquifers that exceed MCL |
Secondary maximum contaminant level (SMCL) |
Percentage and number of samples collected from Wasatch aquifer that exceed SMCL |
Percentage and number of samples collected from coalbed aquifers that exceed SMCL |
|---|---|---|---|---|---|---|
|
Chloride |
-- |
N/A |
N/A |
250 |
0 |
0 |
|
Fluoride |
4 |
0 |
0 |
2 |
0 |
0 |
|
Sulfate |
500 |
38 (3/8) |
0 |
250 |
38 (3/8) |
0 |
|
Dissolved solids |
-- |
N/A |
N/A |
500 |
86 (6/7) |
77 (10/13) |
|
pH, standard units |
-- |
N/A |
N/A |
6.5-8.5 |
25 (2/8) |
0 |
Table 13. Comparison of ground-water-quality samples collected from wells with selected State of Wyoming standards for domestic use
(Standards from Wyoming Department of Environmental Quality, 1993, p. 9. Results of sampling individual wells are listed in appendix table 1.)
[All constituent or characteristic concentrations are in milligrams per liter except as indicated]
|
Constituent or characteristic |
Domestic-use standard |
Percentage and number of samples collected from Wasatch aquifer that exceed standard |
Percentage and number of samples collected from coalbed aquifers that exceed standard |
|---|---|---|---|
|
Chloride |
250 |
0 |
0 |
|
Fluoride |
11.4-2.4 |
212 (1/8) |
2 31 (4/13) |
|
Sulfate |
250 |
38 (3/8) |
0 |
|
Dissolved solids |
500 |
86 (6/7) |
77 (10/13) |
|
pH, standard units |
6.5-9.0 |
0 |
0 |
1Dependent on the annual average of the maximum daily air temperature: 1.4 milligrams per liter corresponds with a temperature range of 26.3 to 32.5 degrees Celsius, and 2.4 milligrams per liter corresponds with a temperature of 12 degrees Celsius and below.
2Percentage and number of samples presented for concentrations equal to or exceeding lower standard (1.4 milligrams per liter).
