How Much Does a Water Filtration System Cost? Whole-House, RO and Well

A filter for the water you drink usually costs from under $100 (a pitcher or faucet filter) to a few hundred dollars (such as a reverse osmosis system). Treating all the water that enters your house costs thousands. Then come the running costs (filters, membranes, salt and water sent down the drain), which you pay every year for as long as you own the system. Compare those too, not only the price tag.

Those are the ranges in the EPA’s guide to selecting water treatment systems. For the detail, this page uses the cost estimates from two public sources: the Minnesota Department of Health and Penn State Extension. Both are rough, and the Minnesota figures are several years old, so use them to budget and to check a quote, not as a price list.

Do you need a filtration system at all?

Maybe not. Minnesota’s health department opens its home water treatment fact sheet by saying most Minnesotans don’t need home treatment to protect their health. Before you spend anything, find out what’s actually in your water:

• City water: your utility’s annual Consumer Confidence Report lists what it found. Our guide to reading your water quality report walks through it.
• Private well: testing is up to you. The EPA’s guide says well water should be tested periodically by a state-certified lab. See what to test your well for.

If the only problem is a chlorine taste, the EPA’s guide notes that you can reduce it by leaving an open pitcher of water in the fridge for a day or two while the chlorine evaporates. That costs nothing.

What decides the cost

Four things shape the price:

1. What you need to remove. No single unit removes everything, the Minnesota fact sheet says, and more than one problem can mean combining several units. A unit certified for the contaminant in your test results is the one worth paying for.
2. One tap or the whole house. A point-of-use unit treats the water at one tap; a point-of-entry (whole-house) system treats everything that comes into the house. The EPA’s guide says whole-house systems suit water with “consistent and significant contamination challenges,” usually cost several thousand dollars to install, and may need plumbing changes and professional maintenance. It also points out that toilets and washing machines don’t need treated water, and advises treating only the water you cook with and drink, and not buying a bigger system than you need.
3. Do it yourself or hire a pro. In Minnesota’s estimates, the low end of each range is a unit the homeowner installs and the high end one a water treatment professional installs. The EPA’s guide says reverse osmosis and distillation units may need professional installation and whole-house systems generally do.
4. Running costs. Every system needs maintenance: new filters or membranes, disinfecting, removing scale, backwashing. The EPA and Minnesota both warn that a system that isn’t maintained can make water quality worse, so the running costs aren’t optional.

Cost by type of system

The Minnesota Department of Health gives these ranges in its fact sheet (revised March 2024). Its footnote says they’re based on quotes from 2017 and research from 2018, and that actual costs may vary.

Treatment	One tap (point of use)	Whole house (point of entry)	What it’s designed to remove (selected)
Carbon filter	$10 to $100, plus $10 to $100 every few months for filters	$500 to $3,000, plus backwash water or disinfectant and replacement filters	Taste, odor and color; some are certified for chlorine, lead, VOCs and more
Reverse osmosis	$300 to $1,500, plus $100 to $200 every 1 to 2 years	$5,000 to $12,000, plus $250 to $500 every 1 to 2 years	A wide range, including arsenic, fluoride, lead, nitrate and PFAS
Adsorptive media (activated alumina or iron-based)	$300 to $700, plus $300 to $500 every 6 to 12 months	$2,400 to $4,500, plus $700 to $900 a year	Depends on the media: arsenic, fluoride, selenium, sulfate, uranium
Distillation	$300 to $1,200, plus the energy to boil the water	Not usually available	Arsenic, bacteria, lead, nitrate, viruses and more
UV disinfection	$150 to $300, plus $50 to $100 a year	$250 to $800, plus about $100 a year	Bacteria and viruses
Water softener	Not usually available	$200 to $3,000, plus $50 to $300 a year for salt	Calcium and magnesium (hardness), some iron and manganese
Anion exchange	Not usually available	$1,500 to $2,500, plus $700 to $900 every 8 to 10 years	Depends on the resin: arsenic, nitrate, nitrite, sulfate and more
Oxidizing media filtration	Not usually available	$1,500 to $3,000, plus backwash water, chemicals and new media	Iron, manganese, hydrogen sulfide
Aeration and filtration	Not usually available	$800 to $4,000, plus backwash water and new filter media	Gases such as hydrogen sulfide and radon, iron, manganese, VOCs
Continuous chlorination and filtration	Not usually available	$500 to $2,500, plus bleach, backwash water and new filter media	Bacteria, viruses, hydrogen sulfide, iron, manganese

Minnesota doesn’t give a range for whole-house ozonation: it says to call a water treatment professional for a quote.

General prices have risen since those quotes. The Consumer Price Index, the government’s general measure of prices, was about 37% higher in September 2026 than its 2017 average, by our arithmetic from the Bureau of Labor Statistics series. That’s inflation across everything people buy, not a measure of water treatment prices, but it’s a reason to expect quotes today to run higher than the 2017 ranges.

Penn State Extension’s tips for buying water treatment equipment (updated July 2026) give a second set of rough prices, without saying when they were gathered:

• Small faucet or pour-through carbon or activated alumina filters: often under $20.
• Countertop or faucet reverse osmosis and distillation units: $300 to $2,000, depending on how much water they produce a day.
• Most larger whole-house filters, such as softeners, anion exchange units, carbon filters, oxidizing filters and acid neutralizers: $500 to $1,500.
• UV disinfection: from $400 for a basic unit to more than $1,000 for one with a light intensity sensor, sleeve cleaner and automatic shut-off.
• Aeration and ozonation: usually the most expensive, at several thousand dollars.

What systems cost on makers’ sites

Our product guides record the makers’ own prices on the day we checked each listing. They’re a snapshot, since prices and sales change often, but they show what the categories above cost in October 2026:

Type	Price range we recorded	Running costs we recorded	Guide
Filter pitchers	$27.49 to $168 for the pitcher (Oct 11)	About 7 cents to $1.33 a gallon in filters	Best water filter pitchers
Under-sink carbon filter	$249.99 list for the Aquasana Claryum Direct Connect (Oct 15)	$91.99 cartridge every 784 gallons or six months	What carbon filters remove
Countertop and under-sink reverse osmosis	$239.99 to $539 list across six systems (Oct 9); one was on sale for $224.99	About $45 to $310 a year in filters, by our arithmetic from the makers’ schedules	Best reverse osmosis systems
Whole-house PFAS filter	$2,099 on sale (list $4,198) for the Aquasana HealthShield (Oct 10)	A $1,749 replacement tank at its 165,000-gallon capacity	Which filters remove PFAS
Whole-house UV for a well	$338.99 to $1,749 across three systems (Oct 12)	$118.65 to $125.99 a year for a lamp	Bacteria in well water

Each guide also shows which claims the certifiers’ listings back up for each product, which matters more than the price: a cheap filter that isn’t certified for your problem is money wasted.

The running costs you’ll pay every year

The purchase price can be the smaller number. In our reverse osmosis comparison, a year of filters for one system cost more than the system’s sale price that day. Budget for:

• Filters and membranes. Minnesota’s estimates put carbon filters for one tap at $10 to $100 every few months, and reverse osmosis upkeep at $100 to $200 every 1 to 2 years. Schedules vary by model and by your water, so compare the cost per gallon or per year, not the price of one cartridge.
• Water down the drain. A reverse osmosis system sends part of the water it treats to the drain. The EPA’s WaterSense program says a typical point-of-use unit sends five gallons or more down the drain for every gallon it produces, and some inefficient units up to 10. WaterSense labeled systems must send 2.3 gallons or less, and the EPA estimates that replacing a typical system with a labeled one saves more than 3,100 gallons a year on average. What that water costs depends on your water and sewer rates.
• Salt and regeneration water for a softener: $50 to $300 a year for salt in Minnesota’s estimate. The EPA’s guide says softeners also use water to regenerate, and suggests a model that regenerates on demand with low water use per 1,000 grains of hardness removed. Some local governments restrict softeners because of the salt they discharge, so check before you buy.
• Lamps and energy. Penn State says a UV bulb must be changed every year, and the EPA notes that distillation is energy-intensive and can raise your energy bill.
• Testing. Minnesota recommends testing the treated water after installation to make sure the system is working. The EPA’s guide notes that some companies offer maintenance services that send a professional to replace filters and clean the system; ask what’s included and what’s left to you.

What well water treatment costs

For a well, the test decides the system and most of the price. Matching the common problems to Minnesota’s whole-house ranges:

• Bacteria: UV disinfection ($250 to $800, about $100 a year) or continuous chlorination and filtration ($500 to $2,500). Our bacteria in well water guide explains when each fits.
• Iron, manganese or a rotten-egg smell: oxidizing media filtration ($1,500 to $3,000), aeration and filtration ($800 to $4,000) or chlorination and filtration. See iron and sulfur in well water for which one suits your levels.
• Hardness: a water softener ($200 to $3,000, plus salt). Our water softener cost guide breaks down buying, installing and running one.
• Nitrate or arsenic: a whole-house anion exchange unit ($1,500 to $2,500), or treatment at the kitchen tap with reverse osmosis ($300 to $1,500) or, for arsenic, adsorptive media ($300 to $700).

Penn State’s buying tips make a point worth weighing before a large purchase: treatment isn’t always the cheapest fix. Connecting to a nearby public water supply may cost less in the long run than extensive treatment, they say, and finding and fixing the source, such as a failing septic system or an unsealed well cap, can solve some problems outright.

What city water treatment costs

U.S. utilities treat water to meet federal standards, the EPA’s guide says, and must tell customers when unsafe levels are found. So city water concerns are usually about the water you drink, and the EPA’s advice to treat only that keeps the cost in the tens or hundreds of dollars:

• Chlorine or chloramine taste: a pitcher or faucet filter certified to NSF/ANSI 42 for it, as the EPA’s guide suggests. Our chlorine and chloramine guide explains the difference between the two.
• Lead from old pipes: a filter certified for lead reduction at the tap you drink from. See lead in drinking water.
• PFAS: a certified carbon filter or reverse osmosis system, compared in which filters remove PFAS.
• Hard water: hardness is usually treated where the water enters the house, with a softener; Minnesota notes that softeners are sometimes installed to treat only some of the water. Start with our hard water guide.

How to keep the cost down

• Test first, then treat only what the results show.
• Treat the water you drink, not the whole house, as the EPA advises, unless the problem shows up in all of your water, such as stains, smell, scale or bacteria in a well.
• Buy certified for your problem. The EPA points to certification to the NSF/ANSI standards, and Minnesota names NSF, UL and WQA as certifiers. Check the certifier’s own listing for the exact model; our guide to checking a filter’s certification shows how. Penn State adds that vendors touting “EPA certification” should be avoided, because EPA certification doesn’t ensure that equipment removes a given pollutant.
• For reverse osmosis, look for the WaterSense label to waste less water.
• Get several quotes in writing. Penn State recommends multiple estimates from reputable, established local companies, and getting everything in writing, including a detailed warranty and maintenance agreement. It warns about vendors who use colorful in-home water tests to pressure people into buying on the spot: confirm any result with an independent lab. Minnesota suggests checking that the installer is licensed, and lists the Water Quality Association’s directory of treatment professionals as one place to find them.
• Ask about help paying. Minnesota’s fact sheet lists loan and grant programs, including USDA’s Single Family Housing Repair Loans and Grants, which it describes as low-interest loans for homeowners with incomes below 50% of the area’s median and grants for people over 62. Check eligibility with USDA directly.

The bottom line

Expect under $100 for a pitcher or faucet filter, a few hundred dollars for an under-sink or reverse osmosis system, and several thousand for whole-house or well treatment, plus a yearly bill for filters, salt, lamps or wasted water. The cheapest system is the one matched to a real test result and certified for it. If your report or test shows nothing to fix, the right budget may be zero.