Which is true about cleaning up contaminated groundwater?

question 5 options:

it usually involves time and money, and rarely returns to its original state.

it will occur naturally over a period of weeks.

it is relatively quick and easy.

it is always difficult and expensive, but can be returned to normal.

The truth about the cleaning up of contaminated groundwater is that:

It is always difficult and expensive, but can be returned to normal.

Explanation: Groundwater are water that are found close to household environment, that is why when they are contaminated it is very difficult and expensive to treat them.