Question

if you pumped contaminated water from an aquifer, cleaned the water and pumped it back in what would happen?
a the water would be clean and stay clean
b its impossible to know what would happen
c the water would clean the aquifer
d the water would be re-contaminated by rock and soil in the aquifer

Explanation:

Aquifers are underground layers of rock/soil that originally held contaminated water. When cleaned water is pumped back, residual contaminants in the aquifer's rock and soil will leach into the clean water, re-contaminating it. Option a is wrong because the aquifer's contaminants remain. Option b is incorrect because we can predict this interaction. Option c is wrong because a single pump-back of cleaned water cannot counteract the existing contamination in the large aquifer system.

Answer:

d. The water would be re-contaminated by rock and soil in the aquifer