If you are relying on groundwater from a spring or well, you might also want to check the surrounding area for groundwater pollution, especially if there are any industries located in your area.  More and more we are finding that industrial products and wastes have been improperly stored and are leaking into the groundwater.  In heavily fertilized areas, such as farming communities, nitrates from decomposed ammonia fertilizer infiltrate the groundwater and pollute it.  Nitrate-rich water leads to a serious disease in infants known as methemoglobinemia.

Animal feedlots provide a huge volume of water compared to their size.  For example, a 10-acre feedlot, with 1,000 head of cattle produces wastes equivalent to those of a town of 6,000 people.  One public water-supply well in northwestern North Dakota continued to be contaminated by livestock wastes more than 40 years after a nearby livery stable was abandoned.  If you are buying in a farming or livestock area, always have the available drinking water tested before you purchase property there.

If you are looking at land that is in a floodplain and if there are several other homes in that floodplain that use septic tanks and wells, it is very possible that the effluent from the septic tanks will pollute the groundwater.  Check with the local heath officials to see if there are periodic outbreaks of hepatitis due to an increase in coliform bacteria during times of high water.

If you suspect some kind of pollution of the ground water in an area you are looking at, check witht he local health department to see if they can give you any information.