Military property contains a lot of unexploded ordnance and polluted groundwater, two of the trickiest types of contamination.

ECONOMIST: Shutting military bases

Environmentalists say public knowledge of the chemicals can help landowners near oil and gas projects know what types of pollution to test for in their groundwater.

NPR: Judge Sides With Wyoming In Fracking Chemical Suit

Additionally, groundwater contributes to sustain many different types of eco-systems upon which people depend.

UNESCO: World Water Assessment Programme (WWAP)