Mount Vernon Water Test Results
Mount Vernon Brew Club
Friday, May 17, 2024
This is Part 1 of a two-part series going over Mount Vernon's water chemistry. In Part 2, we will cover the application of the theory discussed in Part 1 and what this application looks like in practice.
We recently got a sample of water from Mount Vernon's municipal supply tested, and we wanted to share the results of this test with you.
The pH of the water sample was 8.4. Recall that a perfectly neutral pH is 7, and pH is recorded on a logarithmic scale. This means that a pH of 8 is ten times more basic than pure water (with a pH of 7).
The water sample also had an estimated 166 parts per million of total dissolved solids.
The electrical conductivity of the water sample was 0.28 mmho/cm, or millimho per centimeter. The electrical conductivity is a measure of the ionic activity of a solution regarding its ability to transmit current. TDS and electrical conductivity are actually reasonable comparable in dilute solution, but labs will report both values. Very pure (distilled, deionized) water is a very poor electrical conductor, having a conductivity of about 5.5 x 10-5 mmho/cm. Seawater has a conductivity of .5 mmho/cm.
The water tested 3.1 me/L (milliequivalents per liter) of cations and 2.8 me/L of anions. Cations and anions are positively and negatively charged ions, respectively. Calcium, magnesium, and potassium are examples of cations, while chlorine, iodide, and fluorine are examples of anions. Because cations and anions are oppositely charged, they are also attracted to each other.
If you are building a water profile, you can use these figures to build that profile.
| Dissolved Solid | Parts per Million (PPM) |
| Sodium (Na) | 16 |
| Potassium (K) | 4 |
| Calcium (Ca) | 15.3 |
| Magnesium (Mg) | 18 |
| Calcium Carbonate (CaCO3) (Water Hardness) | 113 |
| Nitrates (less is better) | 0.1 (Threshold is approx. 10 PPM) |
| Sulfates (less is better) | 13 |
| Other chlorides | 13 |
| Other carbonates | 1.4 |
| Other bicarbonates | 99 |
| Alkalinity (CaCO3) | 83 |
| Fluoride | 0.25 |
| Iron (Fe) | Not detected/below detection limit |
Please note that the testing lab did not distinguish exactly which chlorides, carbonates, and bicarbonates were tested for. We infer that the first four rows (the metals) are actually referring to the chloride, carbonate, or bicarbonate form of these metals. That is, we think that sodium is actually referring to sodium chloride, since the water doesn't explode when it comes out the tap.
Citation
Mount Vernon Brew Club. (2024). Mount Vernon Water Test Results. Mount Vernon Brew Club. https://mountvernonbrewclub.org/site/index.php/ontap/mount-vernon-water-report-details/.
This work is licensed under Creative Commons Attribution 4.0 International.