Contaminants Guide

What's in your water — and how to remove it

Each contaminant has a specific filter type that addresses it. This guide matches the two so you know exactly what you need.

Find out what's actually in your water: Every US water utility publishes an annual Consumer Confidence Report (CCR) listing all detected contaminants and their levels. Search for "[your city name] CCR water quality report" or visit EPA.gov/ccr. If you're on well water, get a private water test — lab testing kits start at $50.

Lead

Also: lead pipes, lead solder

⚠ High health risk

Source: Older home plumbing (pre-1986), lead service lines, or brass fixtures. City water may be lead-free at the treatment plant but pick it up in transit through aging pipes. Especially common in homes built before 1986.

There is no safe level of lead exposure — particularly for children, where it causes irreversible developmental and cognitive damage. The EPA's action level (15 ppb) is not a safety threshold; it's a trigger for utility action. Many experts consider any detectable lead a concern.

Lead is invisible, tasteless, and odorless. The only way to know if it's in your water is to test for it ($20–$50 home test kits; certified lab tests give more reliable results).

Which filters remove lead

Reverse osmosis (95–99%) NSF 53 certified under-sink Clearly Filtered pitcher (partial) Standard pitcher filters — No Faucet-mount — No Water softeners — No

PFAS / PFOA

Also: "forever chemicals," GenX

⚠ High health risk

Source: Industrial discharge, military bases (AFFF firefighting foam), non-stick cookware manufacturing. Found in the majority of US municipal water systems as of 2024 EPA testing. Does not break down in the environment or body.

PFAS (per- and polyfluoroalkyl substances) are linked to cancer, thyroid disruption, immune suppression, and developmental problems. The EPA set a maximum contaminant level of 4 parts per trillion in 2024 — nearly zero — recognizing there's no safe exposure threshold.

PFAS are now found in a majority of US public water systems and in virtually all Americans' blood. Standard activated carbon filters do not reliably remove them.

Which filters remove PFAS

Reverse osmosis (90–99%) NSF 58 certified filters Activated carbon (partial, inconsistent) Pitcher filters — No Faucet-mount — No Water softeners — No

Chlorine & Chloramines

Also: disinfection byproducts (THMs)

✓ Low risk at regulated levels

Source: Added intentionally by water utilities as a disinfectant. Safe at regulated levels but causes noticeable taste and smell. Chloramines (chlorine + ammonia) are used by some utilities and are harder to remove than chlorine alone.

Chlorine at normal utility levels (under 4 ppm) is not a health risk — it's the reason city water is safe to drink. The issue is taste and smell, which can be significant. Disinfection byproducts (THMs), formed when chlorine reacts with organic matter, are more concerning at high levels.

This is the easiest water problem to solve. Any activated carbon filter addresses chlorine taste and odor effectively.

Which filters remove chlorine

Any activated carbon filter Pitcher filters Faucet-mount Under-sink Reverse osmosis Whole-home carbon

Nitrates

Also: nitrites

⚠ High risk for infants

Source: Agricultural runoff (fertilizers, animal waste), septic systems. Common in well water in farming regions. Can also appear in city water near agricultural areas. Colorless, odorless, tasteless — not detectable without testing.

Nitrates cause methemoglobinemia ("blue baby syndrome") in infants under 6 months — potentially fatal. The EPA maximum is 10 ppm; some health experts recommend lower. Adults generally handle normal levels but pregnant women and infants should not drink high-nitrate water.

If you're on well water in an agricultural area, or have an infant, nitrate testing is essential.

Which filters remove nitrates

Reverse osmosis (85–95%) Ion exchange (specific resins) Activated carbon — No Pitcher filters — No Faucet-mount — No Water softeners — No

Hard minerals (Hardness)

Calcium, magnesium — measured in GPG or ppm

ℹ Not a health risk

Source: Naturally occurring in groundwater as it passes through limestone and chalk deposits. Over 85% of US homes have hard water. Hardness is measured in grains per gallon (GPG): under 3 is soft, 3–7 is moderate, over 7 is hard.

Hard water isn't a health risk — calcium and magnesium are actually beneficial minerals. The problems are practical: scale buildup in pipes and appliances (reducing water heater efficiency by 20–25%), spots on dishes and glassware, dry skin and hair after showering, and shortened appliance lifespan.

A water softener is the only complete solution. Other filter types don't remove hardness minerals.

Which filters address hard water

Salt-based water softener (removes minerals) Salt-free conditioner (prevents scale, doesn't remove) Reverse osmosis (partial, drinking water only) Carbon filters — No Pitcher filters — No

Sediment

Sand, rust, silt, dirt, particles

⚠ Appliance damage risk

Source: Aging municipal pipes, well water, disturbed service lines. Often appears after heavy rain, nearby construction, or when older pipes corrode. May have a rust tint or appear cloudy. Can carry bacteria in well water situations.

Sediment itself isn't usually a health hazard in city water, but it clogs appliance screens, damages water heater elements, wears out pump seals, and shortens the life of other filters. In well water, sediment can carry bacteria and should be tested.

A sediment pre-filter is often the first stage in any multi-filter system — it protects more expensive filters downstream.

Which filters remove sediment

Whole-home sediment filter Under-sink multi-stage (first stage) Reverse osmosis (pre-filter stage) Pitcher filters (coarse particles) Water softeners — No

Know your contaminant — now find the right filter.

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