Denny's water is from a well that is fed from an aquifer refilled by Cascadian snow melt. It likely hovers around 50ppm TDS with none of the minerals we care about being over 10ppm.
Cascadian snow melt? I'm a long way from the Cascades for that to happen!
Here's my water analysis...
pH 7.4
Total Dissolved Solids (TDS) Est 164
Electrical Conductivity, mmho/cm 0.27
Cations / Anions, me/L 2.8 / 2.7
ppm
Sodium, Na 11
Potassium, K 2
Calcium, Ca 34
Magnesium, Mg 7
Total Hardness, CaCO3 114
Nitrate, NO3-N < 0.1 (SAFE)
Sulfate, SO4-S 19
Chloride, Cl 3
Carbonate, CO3 < 1
Bicarbonate, HCO3 90
Total Alkalinity, CaCO3 74