GEOLOGY

Detailed explanation-1: -Ridding groundwater of contaminants can be difficult to impossible, as well as costly. Once polluted, an aquifer may be unusable for decades, or even thousands of years. Groundwater can also spread contamination far from the original polluting source as it seeps into streams, lakes, and oceans.

Detailed explanation-2: -1. Wastewater and sewage. Untreated sewage and wastewater has been a leading cause of water pollution for millennia.

Detailed explanation-3: -Nonpoint source pollution is harder to control than the point source water pollution. Q. Assertion :Sewage, industrial effluents, and wastewater are non-point sources of water pollution.

Detailed explanation-4: -The main point source of pollution to water is from sewage and waste water treatment, while for diffuse pollution, main sources are from farming and fossil fuel power plants (via the air).