Does the water source affect contamination?
If your drinking water comes from a lake, stream, reservoir or surface water, it can become contaminated in a number of ways. Rain water, melting snow and other drainage carry impurities into surface water sources. Common examples are bacteria and chemicals from farm animal activity, sewage run-off from malfunctioning septic systems or industrial discharges. Surface water sources are unsafe for drinking, unless the water is filtered and treated to destroy harmful micro-organisms. If you get your drinking water from a well, contaminants may enter through cracks in the casing, poorly fitted lids or other structural faults. Private wells can become contaminated with bacteria, nitrates or other chemicals if they are close to sources of pollution.
