Alkalinity Budget of the Columbia River1

Columbia River alkalinity essentially consists of carbonate alkalinity (94%) with some silicate alkalinity where dissolved silicate concentration is high. Phosphate and borate contribute insignificantly to the overall alkalinity. The river delivered 2.3 × 1011 equivalents of alkalinity to the Pacific Ocean during the water year 1963, or 11 megatons of calcium carbonate. Regardless of high seasonal flow‐rate variance, the river alkalinity near the river mouth shows little variation with an average value of 1 meq/liter.