There are several potential impurities that can be present in water sources, including:
1. Groundwater: Impurities in groundwater can include heavy metals such as lead, arsenic, and mercury, as well as nitrates, pesticides, and volatile organic compounds (VOCs).
2. Surface water: Impurities in surface water can include bacteria, viruses, parasites, algae, and other microorganisms, as well as sediment, industrial pollutants, agricultural runoff, and chemicals such as chlorine and fluoride.
3. Tap water: Impurities in tap water can include disinfection byproducts, pharmaceuticals, hormones, heavy metals, pesticides, and industrial chemicals.
4. Well water: Impurities in well water can include bacteria, viruses, parasites, nitrates, pesticides, heavy metals, and volatile organic compounds (VOCs).
It is important to regularly test water sources for impurities and treat water as needed to ensure it is safe for consumption.