Under-Sink Reverse Osmosis Systems
in Pomona, CA

Pomona’s local groundwater averages 4.8 ppb of hexavalent chromium (Chromium-6), with readings ranging from non-detect to 13 ppb, according to the most recent water quality report. California’s 10 ppb limit applies to Pomona as of October 1, 2026, and the city says it treats affected wells so the water it delivers meets all drinking water standards. Chromium-6 is suspected of being a carcinogen and shouldn’t be ingested above legal limits. We’re not alarmists, but if you’re concerned about the quality of your drinking water, consider a reverse osmosis system. Reverse osmosis is the only readily available system that removes up to 97% of Chromium-6.

Reverse osmosis is a sophisticated multi-stage filtration system capable of removing up to 97% of the dissolved minerals from your water. It’s designed to make water that’s at least as good as the water you buy in bottles, and often better. This reduces waste in landfills by cutting down on bottled water, which makes reverse osmosis environmentally friendly.

Yes. The Culligan RO system uses multiple processes, including reverse osmosis, to make great tasting, low sodium drinking water. Reverse osmosis removes about 97% of the TDS (total dissolved solids), including salt and sodium, from the water. Read the labels on bottled water and you’ll find reverse osmosis is the same process most bottlers use, so in effect you’re getting “bottled water without the bottle.”

Refrigerator filters are usually just carbon, and while carbon filtered water is better than no treatment at all, it’s limited in what it can remove. Only reverse osmosis can remove dissolved minerals and chemicals like arsenic and hexavalent chromium from your water.

Filtered water and purified water aren’t the same thing. Filtered water may still contain minerals or other dissolved solids while having been purged of sediment, chlorine, and other contaminants. Purified water may have been deionized or distilled to reach the highest level of purity. Culligan’s reverse osmosis systems remove 99% of all contaminants, though your water may still contain trace minerals.

Ion exchange filters differ from reverse osmosis filters. RO filters use a semi-permeable membrane that helps remove contaminants, including bacteria, viruses, chlorine, and other dissolved solids. Ion exchange filters work with a resin bed in Culligan water softeners. They remove minerals such as magnesium or calcium and replace them with sodium or potassium ions.

Reverse osmosis is an effective method for removing lead. If your home’s piping may have lead fixtures, or you’re concerned about lead in Pomona’s water supply, schedule a free water test today.

Reverse osmosis is effective at removing chlorine from water. Chlorine is added to municipal water systems to disinfect against germs and contamination, but it can alter the taste and odor of tap water. Many people find this unpleasant, and reverse osmosis takes care of it.

Yes, you can rent a Culligan reverse osmosis filter system. See the Reverse Osmosis Rental section below for details.

A reverse osmosis system is effective at treating and removing nitrates. Pomona’s local groundwater averages 3.5 ppm nitrate and has tested as high as 6.8 ppm. Results vary depending on your water’s nitrate levels, so get your water tested by a Culligan expert to determine if a standard RO filter will work or if a more advanced filter is needed.

Culligan recommends replacing your pre-filters and post-filters at least once a year, depending on usage. The membrane filter, which is the main filter in your system, may last longer. Culligan offers RO filter maintenance services so you don’t have to worry about it. Set a schedule that suits your needs and enjoy the best tasting water!

An RO filter can be installed within one day for a standard under-sink household application connecting the system to your water source and faucet. Proper calibration matters, so don’t try to install a Culligan reverse osmosis system without a licensed expert.