Residential Water Treatment by Contaminant Chart

Not all water contaminants are easy to detect—many have no taste, no smell, and can’t be seen with the naked eye. Yet, they can pose serious health risks or affect the quality of your home’s water over time —like arsenic, lead, nitrates, and fluoride. This chart is designed to help homeowners identify and understand these invisible contaminants. For each contaminant listed, you’ll find a brief description, its common sources, and the most effective treatment options available at the residential level. Whether you're on city water or a private well, this guide will help you take informed steps toward safer, cleaner water for your household.

Contaminant	Description	Origin	At-Home Treatment Options
Nitrates	Naturally occurring compounds found in fertilizers. Harmful in high concentrations, especially for infants.	Agricultural Runoff, Septic Systems, Well Water	Single Faucet: Reverse Osmosis System Whole Home: Nitrate-specific ion-exchange media
Bacteria (E. coli / Coliform)	Microorganisms that can cause gastrointestinal illness and infection.	Contaminated Surface Water, Septic Leakage, Well Water	Single Faucet: UV Disinfection + Sediment Filtration Whole Home: Whole Home UV System w Sediment Filtration
Viruses	Microscopic pathogens smaller than bacteria that can cause illness.	Human/Animal Waste in Water, Poorly Maintained Wells	Single Faucet: Reverse Osmosis System Whole Home: Whole Home UV System
Arsenic	A toxic heavy metal that can accumulate in the body over time.	Natural Deposits in Bedrock, Mining, Industrial Waste	Single Faucet: Reverse Osmosis System, Whole Home: Specialized Whole Home Media
Fluoride	Added to municipal water to prevent tooth decay, but some may worry about fluoride toxicity.	Municipal Water Treatment	Single Faucet: Reverse Osmosis System
Lead	A highly toxic metal harmful to brain and organ development.	Corroded Plumbing, Old Solder, Lead Service Lines	Single Faucet: Activated Carbon Block (NSF 53 certified), Reverse Osmosis System Whole Home: Wh ole Home Lead Reduction Fil ter
Chlorine	Disinfectant added to municipal water, but may cause taste/odor issues.	Municipal Water Treatment	Single Faucet: Activated Carbon Filter Whole Home: Whole House Carbon Filter
Chloramine	Disinfectant added to municipal water but a more stable disinfectant than chlorine, harder to remove.	Municipal Water Treatment	Single Faucet: Catalytic Carbon Filter Whole Home: Catalytic Carbon Whole Home System
PFAS (Forever Chemicals)	Synthetic chemicals linked to health risks and very persistent in the environment.	Industrial Waste, Firefighting Foam, Non-Stick Coatings	Single Faucet: Reverse Osmosis System
Iron	Metallic taste, orange/brown staining on fixtures and laundry. Can support bacterial growth.	Natural in Groundwater, Rusting Pipes	Whole Home: Air Injection Oxidation (AIO) Filtration System
Manganese	Can cause black staining and metallic taste. Often found with iron.	Naturally in Groundwater	Whole Home: Air Injection Oxidation (AIO) Filtration System
Hydrogen Sulfide	Rotten egg smell. Can corrode pipes.	Naturally Occurring in Wells, Groundwater	Whole Home: Air Injection Oxidation (AIO) Filtration System