Water hardness can vary depending on the season due to the changing levels of stream flows and minerals in our water.
In reviewing our historical water measurements, the average for Eagle is 14 grains per gallon of calcium carbonate, which is considered "very hard" in the classification scale according to the United States Geological Survey as displayed in the table below.
Hard/soft classification
Because it is the precise mixture of minerals dissolved in the water, together with the water's pH and temperature, that determine the behavior of the hardness, a single-number scale does not adequately describe hardness. However, the United States Geological Survey uses the following classification into hard and soft water.
Classification | hardness in mg/L | hardness in mmol/L | hardness in dGH/°dH | hardness in gpg | hardness in ppm |
Soft | 0–60 | 0–0.60 | 0-3.37 | 0-3.50 | less than 60 |
Moderately hard | 61–120 | 0.61–1.20 | 3.38-6.74 | 3.56-7.01 | 60-120 |
Hard | 121–180 | 1.21–1.80 | 6.75–10.11 | 7.06-10.51 | 120-180 |
Very hard | ≥ 181 | ≥ 1.81 | ≥ 10.12 | ≥ 10.57 | > 181 |