With all the news surrounding central Iowa’s water quality and high nitrate levels, you might be considering adding a water filtration system to your home. But be wary of product listings — with many different kinds of filters to choose from, it’s essential to know if your system can properly treat your concerns.
Keep these tips in mind as you shop around for a water filtration system.
Do I need a water filtration system to address nitrate levels?
Drinking water goes through a series of treatments to make it safe to drink once it comes out of your tap.
It’s important to remember that public services are required to make sure your water is safe, said Catherine DeLong, water quality program manager at ISU Extension.
“We also have a bunch of really skilled, dedicated water operators who are cleaning our public water supplies for us. So there is someone working on your behalf to make sure that you’re getting safe water,” DeLong said.
In 2025, the water leaving treatment plants in the Des Moines area had nitrate levels that ranged from undetectable to 9.17 mg/L, according to Central Iowa Water Works’ 2026 Consumer Confidence Report.
The EPA limit for nitrates in safe drinking water is 10 mg/L.
Central Iowa Water Works chemist Lisa Morarend told the Des Moines Register in June 2025 that there is no need for central Iowans to buy home water-treatment systems.
Lawn watering bans in 2025 and 2026 have been put in place to reduce water demand and ensure that nitrate removal equipment at Central Iowa Water Works plants can keep water below the EPA’s limit for safe drinking water.
Which water filters remove nitrates?
Reverse osmosis systems are among the most common marketed to remove nitrates from water, but other types of systems are available. It’s also more convenient because smaller models can be installed directly under a sink.
Anion exchange units and distillers can also remove nitrates, but they drawbacks, according to the State Hygienic Laboratory at the University of Iowa.
The systems could require adjusting the pH of your water or leave you with salty-tasting drinking water, DeLong said.
Can water filters like Brita and Pur remove nitrates?
Brita, Pur and other similar carbon filters remove substances like chlorine, zinc, copper, mercury, lead and copper. But they are not designed to remove nitrates, according to the EPA.
Fridge filters are also less tightly regulated compared to other filter systems, DeLong said. But if you have a manufacturer’s safety data sheet, you can see exactly what contaminants it can filter.
What is reverse osmosis?
Reverse osmosis is a water-purification process that uses pressure to force water through a membrane to remove contaminants. Reverse osmosis is considered one of the best water treatment processes, leaving water free of bacteria, potentially toxic metals and, of course, contaminants like nitrates, which have been implicated in health risks including cancer.
What certifications should I look for when choosing a reverse osmosis filter?
Manufacturers choose which contaminants their product will reduce.
Consider looking for systems that have certifications from the National Science Foundation, which verifies that their product will do what it says it will do.
Because products can be certified to filter a variety of contaminants, be sure to check the packaging for both the standard name and a claim for specific contaminant reduction, such as nitrates, according to the NSF website.
Reverse osmosis systems fall under NSF/ANSI Standard 58.
Look out for a manufacturer’s performance data sheet as well, DeLong said. The list will name which contaminants it targets, as well as the percent reduction of each, how much water it can treat and the filter’s capacity.
You can also look for the EPA WaterSense label. The sticker indicates that a product:
How do I find NSF-certified reverse osmosis systems?
The NSF compiles lists of products that comply with its standards. Products, along with the list of contaminants they reduce, can be found at listings.nsf.org.
You can also find a list from the Water Quality Association of reverse osmosis systems that have earned the Gold Seal and Sustainability Certification Marks at find.wqa.org.
How much do home reverse osmosis systems cost?
You can find countertop reverse osmosis systems for $150 to $500, depending on features that can include heating water, tea and baby formula in addition to processing regular drinking water.
Larger whole-home systems can cost thousands of dollars.
Reverse osmosis can ‘waste a lot of water’ at a time when central Iowa is trying to reduce demand
The chief drawback to using a reverse osmosis system, according to the Environmental Working Group, is water waste.
A reverse osmosis system typically requires three to five times the amount of water it produces, with the rest going down the drain. Only 10-30% of the water that interacts with the filter will make it out of your faucet.
Reverse osmosis filters also can eliminate minerals beneficial to health and the taste of water, such as calcium, iron and magnesium, according to EWG. And some systems periodically require expensive filter replacements.
CIWW is trying to reduce water demand in order to make sure there’s enough filtered drinking water to go around. But if more people start buying reverse osmosis systems, it may counteract those efforts.
“If we’re encouraging a lot of folks to go out and buy reverse osmosis systems to treat their water, that is already treated and taken care of by professionals,” DeLong said, “It’s going to waste a lot of water.”
Lucia Cheng is a service and trending reporter at the Des Moines Register. Contact her at lcheng@gannett.com or 515-284-8132.
This article originally appeared on Des Moines Register: Want a water filter to remove nitrates? This is what to look for.
Reporting by Lucia Cheng, Des Moines Register / Des Moines Register
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By Lucia Cheng, Des Moines Register | USA TODAY Network
