Most tap water in the United States meets federal Safe Drinking Water Act standards, but meeting the minimum standard is not the same as being clean. Aging distribution pipes, agricultural runoff, industrial discharge, and disinfection chemicals all contribute contaminants that a point-of-use filter is designed to address. The right water filter system depends on what is actually in your water.

Start With a Water Test

Before buying any filter, test your tap water. A certified laboratory test – not a free test offered by a filtration salesperson – costs $50-$150 and will identify TDS, nitrate level, hardness, iron content, and whether chlorine or chloramines are present. The EPA requires every municipal utility to publish an annual Consumer Confidence Report (CCR) – check yours first. If you are on well water, also test for coliform bacteria, arsenic, and radon.

Common Filter Types and What They Remove

Reverse Osmosis Systems

Reverse osmosis systems are the most comprehensive option for residential use. A 5-stage or 6-stage RO system installed under the kitchen sink will remove dissolved salts, fluoride, lead, arsenic, nitrates, chlorine, chloramines, and most PFAS compounds. Rejection rates for lead and arsenic typically exceed 97%. Modern systems run at 1:1 to 2:1 waste ratios – a significant improvement over older 4:1 systems. NSF International certifies RO systems under Standard 58 for contaminant reduction claims.

Carbon Block Filters

Carbon block filters excel at removing chlorine, chloramines, and organic compounds that affect taste and odor. They do not remove dissolved minerals, heavy metals, or nitrates at meaningful rates. A carbon filter is the right choice if your primary concern is taste and your TDS is already low.

Water Softeners

Water softeners use ion exchange to replace calcium and magnesium ions with sodium, preventing scale buildup in pipes and appliances. If your water is hard (above 7 grains per gallon), a softener protects water heaters, washing machines, and dishwashers from premature failure. The Water Quality Association (WQA) estimates that hard water affects approximately 85% of US homes.

Ultrafiltration Systems

Ultrafiltration (UF) systems remove bacteria, viruses, and particles without removing dissolved minerals. They are a good fit for households with good source water quality that primarily want microbial protection.

Water Filter Comparison Table

Filter Type	Removes Dissolved Minerals	Removes Lead/Arsenic	Removes PFAS	Removes Bacteria
Reverse Osmosis	Yes (95-99%)	Yes (>97%)	Yes (>94%)	Yes (with UV)
Carbon Block	No	Limited	Limited	No
Water Softener	Exchanges Ca/Mg	No	No	No
Ultrafiltration	No	No	No	Yes

PFAS: The Emerging Challenge in US Water Filtration

Per- and polyfluoroalkyl substances (PFAS) – sometimes called “forever chemicals” – have contaminated water supplies near military bases, airports, and manufacturing facilities across the US. In 2024, the EPA finalized the first federal Maximum Contaminant Level (MCL) for PFAS, setting limits for PFOA and PFOS at 4 parts per trillion. Reverse osmosis is currently the most effective residential technology for PFAS removal, achieving over 94% reduction for most PFAS compounds.

AMPAC USA Home and Commercial Water Filtration

AMPAC USA manufactures residential and commercial water filtration systems designed for US water chemistry. Our RO systems remove lead, coliform bacteria, and tannins that affect both safety and taste. All systems include NSF-certified components. Contact us at ampac1.com to discuss the right filtration solution for your water source.