Acidity
"The quantitative capacity of water to neutralize a base, expressed in ppm or mg/L calcium carbonate equivalent. The number of hydrogen atoms that are present determines this. It is usually measured by titration with a standard solution of sodium hydroxide." (Lenntech, 2019)
Sources
Lenntech. Water glossary: An explanation of terminology concerning water related issues. Accessed March 4, 2019. Available at: https://www.lenntech.com/water-glossary.htm