City Water: Complete Filtration Guide
Municipal water is treated — but not contaminant-free. Lead from pipes, PFAS, and disinfection byproducts still reach your tap. Here is what city water actually contains and how to address it.
What City Water Treatment Actually Does (and Doesn't Do)
Municipal water treatment is a multi-stage process: coagulation and flocculation settle suspended particles, filtration removes remaining solids, and disinfection with chlorine or chloramines kills pathogens. What arrives at your tap is regulated to meet EPA standards — but those standards set legal limits, not health ideals. The MCL for lead is 15 ppb. The health-protective level, per the CDC and the American Academy of Pediatrics, is zero. That gap matters when you have children or are pregnant.
The second thing city water treatment doesn't do: control what happens in your building's plumbing. The utility tests at the treatment plant and at a sample of taps — not at your specific faucet. If your home has pre-1986 plumbing with lead solder, or if your street has a lead service line (LSL), your tap water can have significantly higher lead levels than what the utility reports. The only way to know is a first-draw tap test.
The Five City Water Contaminants That Actually Matter
| Contaminant | Source in City Water | EPA MCL | Health-Protective Level | Filter Solution |
|---|---|---|---|---|
| Lead | Service lines, indoor plumbing (pre-1986), solder | 15 ppb (action level) | 0 ppb (no safe level) | NSF 53 certified filter or RO |
| PFAS | Industrial discharge, AFFF foam from military/airports | 4 ppt (2024 rule) | Below 4 ppt; EWG recommends 1 ppt | Certified PFOA/PFOS claim (NSF/ANSI 53 or 58) or RO |
| Chlorination Byproducts (THMs/HAAs) | Chlorine reacting with organic matter in distribution | 80 ppb THMs / 60 ppb HAAs | Below 40 ppb; minimize chronic exposure | NSF 42 / 53 activated carbon block |
| Chlorine / Chloramines | Added intentionally for disinfection | 4 mg/L chlorine / no MCL for chloramines | Taste/odor threshold: ~0.5 mg/L | NSF 42 carbon filter (catalytic carbon for chloramines) |
| Nitrates | Agricultural runoff into source water | 10 mg/L | Below 5 mg/L for infants; pregnant women | RO system (removes 88-92%) |
How to Read Your Consumer Confidence Report
Your annual Consumer Confidence Report (CCR) is the starting point. Most utilities post it online; the EPA Safe Drinking Water Information System (SDWIS) has links. Search "[your city] water quality report 2025."
MCLG (Maximum Contaminant Level Goal)
The health-protective target — often 0 for carcinogens like lead and arsenic. This is the number your water should be at, not the MCL.
Action: If your water has any detected level of a contaminant with MCLG of 0: filter.
MCL (Maximum Contaminant Level)
The legal enforceable limit — always equal to or higher than MCLG. Water can legally contain detectable lead (up to 15 ppb) and still be compliant.
Action: MCL compliance does not mean safe for all populations. Check the MCLG.
Range (Low to High)
Measured variation across all samples in the system. Your specific tap may differ — especially for lead, which varies by individual plumbing.
Action: If the high end of the range is near the MCL, consider testing your specific tap.
"ND" or "Non-Detect"
Below the reporting detection limit — not necessarily zero. Reporting limits for PFAS were set at 2 ppt; some compounds may be present below that threshold.
Action: For PFAS specifically: ND is reassuring but not absolute zero. Check if your utility has done comprehensive PFAS screening.
Violation Notice
Your utility exceeded an MCL or failed to test. Even a past violation is a signal — find out what caused it and whether it was resolved.
Action: Any violation in the past 3 years: get an independent tap test before concluding the problem is fixed.
Filter Recommendations by City Water Concern
Chlorine taste/odor only (pre-1986 home excluded)
LowBrita Elite Pitcher ($42, NSF 42/53)
Carbon filter certified to NSF/ANSI 42 and listed under NSF/ANSI 53 for lead. Removes chlorine taste and odor and reduces lead 96.9%. Most cost-effective entry point for basic city water improvement.
Annual filter cost: $60/year
Pre-1986 home or any detected lead above 1 ppb
Moderate–HighAquasana AQ-5300+ Under-Sink ($149, NSF 42/53/401)
Certified to NSF/ANSI 53 for lead and PFOA/PFOS, rated 800 gallons. Also certified to NSF/ANSI 42 and 401. Most cost-effective under-sink option with real NSF 53 documentation.
Annual filter cost: $60/year replacement
PFAS detected or utility near industrial/military sites
HighAquasana AQ-5300+ Under-Sink ($149) or, for renters, PUR Plus Pitcher ($30) or ZeroWater 10-Cup ZR-0810N ($35)
PFOA and PFOS reduction claims are certified under NSF/ANSI 53 or 58. WQA lists the AQ-5300+ under NSF/ANSI 53 for lead and PFOA/PFOS. For renters who cannot install: IAPMO lists the PUR PPF951K filter for lead and total PFAS, and the ZeroWater ZR-0810N for lead, PFOA and PFOS (confirm the ZeroWater model number). Listings checked September 2026.
Annual filter cost: $60-250/year
Comprehensive city water protection (lead + PFAS + chlorine + nitrates)
Broadest listed coverageWaterdrop G3P800 Tankless RO ($649, NSF 42/53/58/372)
Reverse osmosis removes 95-99%+ of lead, PFAS, nitrates, fluoride, arsenic, and TDS. The G3P800 is listed under NSF/ANSI 58 for lead, fluoride, TDS, cadmium, barium and radium, and under NSF/ANSI 53 for PFOA/PFOS. Its listings do not include nitrates, so retest after installation if nitrates are a concern.
Annual filter cost: $120/year filters
Your CCR Is a System Average — Your Tap May Differ