'Spring' in the Bible

A spring cannot pour both fresh and brackish water from the same opening, can it?

My brothers, a fig tree cannot produce olives, nor a grapevine figs, can it? Neither can a salt spring produce fresh water.

So be patient, brothers, until the coming of the Lord. See how the farmer waits for the precious crop from his land, being patient with it until it receives the fall and the spring rains.