A farmer has just tested his well, and it has high alkalinity, which can affect a plant’s ability to absorb water. Which of the following BEST explains the source of this problem?
a. An algal bloom in a nearby pond is leaching into the watershed.
b. The groundwater is flowing through rocks containing carbonates.
c. Acidic rain in the region is seeping into the groundwater.
d. Nitrates from fertilizer have been poured into the groundwater.
The correct answer is b. The groundwater is flowing through rocks containing carbonates.
Carbonates, such as limestone or dolomite, are naturally occurring minerals that can dissolve in water. When the groundwater flows through these rocks, it can pick up high levels of alkaline compounds, resulting in high alkalinity in the well water.