Water quality, explained clearly
Plain-language guides on what's in your tap water, how filters actually work, and how to choose the right one for your situation.
Contaminants
What each contaminant is, where it comes from, and what the research says about health risks.
Nitrates in Well Water: What It Means for Your Family (and What to Do About It)
Just got a high nitrate result on your well test? Here's exactly what it means, who's most at risk, whether you can shower in it, and which filters actually remove nitrates.
Read guide →Microplastics in Drinking Water: What the Research Actually Shows, and Which Filters Remove Them
Microplastics have been detected in tap water, bottled water, and even human blood and tissue. The science on health effects is developing — no country has yet set a regulatory limit. Here's the current state of research and which home filters actually remove microplastics.
Read guide →Does Your Water Filter Actually Remove Lead? What Brita Won't Tell You
Most Brita filters don't remove lead — and the ones that do have limits. Here's exactly which filters are certified for lead removal, what NSF 53 means, and our top picks at every price point.
Read guide →Hard Water: What It Actually Does to Your Home, Your Health, and Your Appliances
Hard water affects 85% of US homes. It's not a health risk — but it quietly destroys water heaters, clogs pipes, and leaves scale on everything. Here's what hard water is, where it's worst, and what actually fixes it.
Read guide →Fluoride in Drinking Water: What It Is, What the Research Shows, and How to Remove It If You Want To
Fluoride is added to most US municipal water supplies to reduce tooth decay — and it's become one of the most contested topics in drinking water. Here's what the science actually says, where the disagreements are, and which filters remove fluoride if you choose to.
Read guide →Disinfection Byproducts in Drinking Water: What TTHMs and HAAs Are, Why They Form, and How to Reduce Them
Disinfection byproducts form when chlorine reacts with organic matter in source water. They're present in virtually every chlorinated municipal water system in the US — including cities whose water otherwise tests clean. Here's what they are, what the research shows, and what actually removes them.
Read guide →Chromium-6 in Drinking Water: The 'Erin Brockovich Chemical' With No Federal Limit
Chromium-6 contaminates water supplies for more than 200 million Americans — and the federal government still has no specific limit for it. Here's what the science shows, where regulation stands in 2026, and what filters actually remove it.
Read guide →Chloramine in Drinking Water: What It Is, Why Cities Use It, and Why Your Brita Won't Remove It
More than 1 in 5 Americans drink water treated with chloramine instead of chlorine — and most filters designed for chlorine won't remove it. Here's what chloramine is, what the health evidence says, and what filtration actually works.
Read guide →Arsenic in Drinking Water: Why the Federal Limit May Not Protect You
Arsenic is a potent carcinogen with a federal limit of 10 ppb — a standard the EPA itself acknowledges is a trade-off between health protection and treatment cost. Here's what the science says, who's most at risk, and what filters actually remove it.
Read guide →PFAS in Drinking Water: What "Forever Chemicals" Actually Mean for Your Home
PFAS contamination affects an estimated 176 million Americans. Here's what the science says about health risks, how to find out if your water is affected, and which filters actually remove them.
Read guide →Buying Guides
Buying advice tailored to specific situations — renters, older homes, well water, and more.
How to Test Your Well Water: What to Test For, When, and Which Services Are Worth the Money
Private well water is not regulated the way municipal water is — no utility tests it for you. The EPA recommends annual testing, but most well owners test rarely or never. Here's what to test for, when, how, and how to choose between DIY kits, mail-in labs, and professional services.
Read guide →Best Whole-House Water Filter 2026: What Type You Need, What to Skip, and Top Picks
Whole-house water filters treat every tap, shower, and appliance in your home. The right system depends on what you're actually filtering — and many 'whole-house filters' sold online are glorified sediment screens. Here's a guide to the real system types, what each removes, and the best picks by use case.
Read guide →Best Water Filter for Older Homes: Lead Solder, Galvanized Pipes, and What to Actually Buy
Homes built before 1986 have lead solder at pipe joints. Before 1960, many have galvanized steel pipes that trap lead particles. Neither problem shows up in your utility's water quality report — but both affect the water at your tap. Here's what to do.
Read guide →Best Water Filter for Well Water: Match the Filter to Your Actual Problem
Well water filtration isn't one-size-fits-all. Iron needs different treatment than bacteria, which needs different treatment than nitrates. This guide helps you identify what's in your water and find the right filter for it.
Read guide →Best Water Filters for Renters in 2026: No Drilling, No Landlord Drama
The right water filter for a renter depends on two things: what's in your water and how much you can modify your space. Here's the exact filter for your situation — no fluff.
Read guide →Best Water Filter for Baby Formula: What Infants Need, What's Actually Dangerous, and What to Buy
Infants consuming formula mixed with tap water face different risks than adults — lead at any detectable level, nitrates above 10 ppm, and fluoride for dental fluorosis prevention. Here's what contaminants actually matter for formula water, and which filters are certified to remove them.
Read guide →Best Water Filter for Apartments: No Drilling, No Landlord Permission, Clean Water
Renting shouldn't mean drinking unfiltered tap water. The best apartment water filters require zero installation, no tools, and no landlord permission — and some remove lead, PFAS, and chloramine just as well as under-sink systems. Here's what actually works.
Read guide →Best Countertop Water Filter 2026: Pitchers, Gravity Filters, and Countertop RO -- Compared Honestly
Countertop water filters cover a huge range: basic carbon pitchers, high-performance pitchers, gravity-fed stainless steel systems, and countertop RO units. The right choice depends entirely on what you're trying to remove. Here's the breakdown by contaminant, format, and budget.
Read guide →Berkey Water Filter Review 2026: The Honest Breakdown of What's Happened, What It Filters, and What to Buy Instead
Berkey is the most searched gravity water filter brand in America. But 2024–2026 has been chaotic for Berkey: a Stop Sale Order from the EPA, a consumer class action lawsuit, no genuine Black Berkey filters currently in production, and an ongoing certification controversy. Here's the full picture.
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Best Under-Sink Reverse Osmosis Systems (2026)
The top under-sink RO systems that actually remove PFAS, lead, arsenic, and nitrates -- with honest tradeoffs between certified workhorses and modern tankless designs.
Read guide →Local Water Quality
Deep-dives into water quality for specific cities and regions.
Tucson Water Quality 2026: PFAS Contamination, 22 Wells Offline, and What Residents Need to Know
Tucson has removed 22 drinking water wells from service due to PFAS contamination from Davis-Monthan Air Force Base and the Tucson Airport Superfund site. The city sued the federal government in February 2026. Here's the current status and what to do.
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Tampa–St. Petersburg Water Quality 2026: MacDill PFAS, Elevated DBPs, Radium, and the Blended Supply System
Tampa Bay Water serves 2.5 million residents across Hillsborough, Pasco, and Pinellas counties with a blended supply of groundwater, river water, and desalinated seawater. The contaminant profile includes PFAS from MacDill AFB, TTHMs exceeding the federal limit in some years, naturally occurring radium, and chloramine disinfection. Here's what's in the water and what removes it.
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Seattle & Pacific Northwest Water Quality 2026: One of the Cleanest Municipal Supplies in the Country — With Caveats
Seattle Public Utilities draws from two protected mountain watersheds — the Cedar River and South Fork Tolt River — and consistently produces some of the cleanest municipal water in the US. PFAS is essentially non-detect in the main supply. But lead in older homes, chloramine disinfection, seasonal taste variation, and significant PFAS contamination in several suburban systems complicate the picture for the broader region.
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San Diego Water Quality 2026: Colorado River Supply, Hard Water, and the Sweetwater PFAS Story
San Diego draws 80–90% of its water from hundreds of miles away — the Colorado River and Northern California. That imported water comes with high hardness, elevated DBPs, and now a live PFAS situation at Sweetwater Authority serving 200,000 South County residents.
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Sacramento & Central Valley Water Quality 2026: Arsenic, PFAS, Nitrates, Chromium-6, and the Groundwater Crisis Beneath California's Farm Belt
Sacramento city water comes from the Sacramento and American Rivers — relatively clean surface water sources. But the region's groundwater tells a different story. Arsenic up to 701x EWG guidelines, PFAS above EPA MCLs, agricultural nitrates, chromium-6, and radium affect wells and small water systems across the Central Valley. Here's what Sacramento and Central Valley residents need to know.
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Pittsburgh, PA Water Quality 2026: Lead, Chromium-6, and What Residents Should Know
Pittsburgh's tap water meets federal standards and lead levels are at a 20-year low — but the city has chromium-6 at 27x health guidelines, high disinfection byproducts, and ongoing lead risk in pre-1986 homes. Here's the full picture.
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Phoenix Water Quality 2026: Arsenic, Hard Water, and What Residents Should Filter
Phoenix tap water is legally compliant but contains arsenic at levels 1,000x above EWG health guidelines, chromium-6 at 20x safe levels, and some of the hardest water of any major US city. Here's what's actually in Phoenix water and what to do about it.
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Philadelphia Water Quality 2026: Lead Service Lines, Delaware River PFAS, and a $500M Replacement Challenge
Philadelphia's water comes from the Delaware and Schuylkill Rivers. The city's treatment is good — but the lead service line challenge is massive, PFAS treatment upgrades are still in planning, and 360,000 properties received service line inventory letters in late 2025. Here's what Philadelphia residents need to know.
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Newark Water Quality 2026: How the Lead Crisis Unfolded, What Changed, and What Residents Still Need to Know
Newark had one of the worst lead contamination crises in US history — and then became the largest city in New Jersey to fully replace its lead service lines. Here's the full picture: what happened, what's been fixed, and what risks remain.
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New Orleans Water Quality 2026: Lead Found in 7 of 10 Homes, Replacement Delayed Until 2027
A February 2026 investigation by Verite News found lead in about 70% of tested New Orleans homes. Pipe replacement won't begin until late 2027 at earliest. Here's what's happening, who's most at risk, and what residents can do now.
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Minneapolis–St. Paul Water Quality 2026: Mississippi River Source, 3M PFAS Legacy, and What's in Your Tap
Minneapolis and St. Paul both draw from the Mississippi River and meet all federal standards. The bigger PFAS story is in the eastern suburbs — 3M's Cottage Grove manufacturing legacy has contaminated groundwater across the east metro, with 420 private wells flagged in 2024 alone. Here's how to read the Twin Cities water picture.
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Milwaukee Water Quality 2026: 65,000 Lead Pipes, New State Rules, and What Residents Should Do
Milwaukee Water Works draws from Lake Michigan and scores well on most metrics — but 65,000 residential lead service lines remain. Wisconsin just signed new PFAS and lead regulations in March 2026. Here's what Milwaukee residents need to know right now.
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Las Vegas Water Quality 2026: The Hardest Major City Water in America
Las Vegas has some of the hardest water in the United States — up to 18 GPG — plus the challenges of a Colorado River supply under long-term drought stress. Here's what's in Vegas tap water, what the testing shows, and what residents should actually filter.
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Jackson, Mississippi Water Quality 2026: An Ongoing Crisis, a Third-Party Manager, and What Residents Need to Know
Jackson's water system collapsed in August 2022, leaving 150,000 residents without safe water. A federally appointed third-party manager has stabilized the system — but the $2 billion rebuild is only partially funded, and the fights over governance and rates continue. Here's the current picture.
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Houston Water Quality 2026: Harvey's Legacy, PFAS Monitoring, and What's Actually in the Tap
Houston draws water from a petrochemical-corridor river system, has active PFAS monitoring underway, and nearly 2.5 million residents. Here's the honest breakdown of what's in the water, what Hurricane Harvey's legacy means for long-term contamination, and what to filter.
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Flint, Michigan Water Quality 2026: What's Actually Fixed, What Isn't, and What Residents Should Still Do
Flint replaced its last lead pipe on July 1, 2025. The water has been in compliance for 10 straight years. The EPA lifted its emergency order. So why do most residents still filter? Here's the honest, current picture.
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Detroit Water Quality 2026: Great Lakes Source, Lead Pipe Replacement, and the Detroit River Industrial Legacy
Detroit draws from some of the cleanest large water sources in North America — Lake Huron and the Detroit River — and the Great Lakes Water Authority runs a sophisticated treatment system. The real risks are lead from pre-1945 service lines and PFAS in some suburban systems. Here's the current picture.
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Dayton, Ohio Water Quality 2026: What's in the Water and What Residents Can Do
Dayton's Ottawa Well Field has PFAS levels 3–4x above new EPA limits, traced to contamination migrating from Wright-Patterson Air Force Base. Here's what's happening, what the city is doing, and how residents can protect themselves now.
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Colorado Springs Water Quality 2026: PFAS from Military Bases and What Residents Can Do
Colorado Springs has documented PFAS contamination in its water supply traced to Air Force Academy and Peterson Air Force Base firefighting foam. Here's the current status, what the city is doing, and how residents can protect themselves.
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Chicago Water Quality 2026: The Lead Pipe Problem Most Residents Don't Know About
Chicago has more lead service lines than any other city in America — about 412,000 of them. The city missed federal notification deadlines, won't finish replacing them for decades, and most residents have no idea their pipes are lead. Here's what to do.
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Baltimore Water Quality 2026: Lead Pipe Inventory, Free Replacement Deadlines, and What Residents Need to Know
Baltimore City and County have launched parallel lead service line programs in 2025–2026. Baltimore City surprisingly has no city-side lead service lines — but older homes have lead solder and interior plumbing risk. Here's the current status and what to do.
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Atlanta Water Quality 2026: The Chattahoochee River's Disinfection Byproduct Problem
Atlanta's water is soft and federally compliant — but it has among the highest disinfection byproduct levels of any major US city. Here's what's causing it, what the health evidence shows, and what residents should actually filter.
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Arizona Well Water Quality: Arsenic, PFAS, Uranium, and Why Arizona Has Some of the Most Contaminated Private Wells in the US
Arizona has the highest rate of arsenic in private wells of any state. Add naturally occurring uranium, radium, chromium-6, PFAS from military bases, and fluoride from volcanic geology — and Arizona well owners face a contaminant profile unlike anywhere else in the country. Here's what to test for and what filters actually work.
Read guide →More guides coming soon
We're working on guides for lead in older homes, nitrates in well water, how to read your Consumer Confidence Report, and more. In the meantime, check your ZIP code for a personalized recommendation.