If you are interested in learning more about water filtration options for your home, the information here can help you get started.
Point-of-entry (POE) systems, treatment that is installed near the location where the water service line enters a home, can be effective for reducing contaminants from the water entering the home. It will not reduce contaminants that are released from plumbing inside the home. It is not as reliable as point-of-use (POU) devices for lead reduction because there are multiple potential sources of lead in household plumbing, as described here. Lead can dissolve into water passing through household plumbing after it has been treated by a point-of-entry system.¹,²
It is important to select point-of-entry devices that are certified to reduce the contaminants you are concerned about. Certification standards and product markings are described here.
References:
- ¹ “Point-of-Entry (POE) or Point-of-Use (POU) Water Treatment Systems... Which Type Do You Need?” Point-of-Entry and Point-of-Use Water Treatment Systems, http://www.kdfft.com/POEorPOU.htm
- ² US EPA “Point-of-Use or Point-of-Entry Treatment Options for Small Drinking Water Systems”, EPA Report 815-R-06-010, 2006, epa.gov/sites/production/files/2015-09/documents/guide_smallsystems_pou-poe_june6-2006.pdf
Point-of-entry (POE) systems, treatment that is installed near the location where the water service line enters a home, can be effective for reducing contaminants from the water entering the home. It will not reduce contaminants that are released from plumbing inside the home. It is not as reliable as point-of-use (POU) devices for lead reduction because there are multiple potential sources of lead in household plumbing, as described here. Lead can dissolve into water passing through household plumbing after it has been treated by a point-of-entry system.¹,²
It is important to select point-of-entry devices that are certified to reduce the contaminants you are concerned about. Certification standards and product markings are described here.
References:
- ¹ “Point-of-Entry (POE) or Point-of-Use (POU) Water Treatment Systems... Which Type Do You Need?” Point-of-Entry and Point-of-Use Water Treatment Systems, http://www.kdfft.com/POEorPOU.htm
- ² US EPA “Point-of-Use or Point-of-Entry Treatment Options for Small Drinking Water Systems”, EPA Report 815-R-06-010, 2006, epa.gov/sites/production/files/2015-09/documents/guide_smallsystems_pou-poe_june6-2006.pdf
You may want to consider point-of-use (POU) treatment or filtration because of sources of lead in your plumbing, sample results for your home, information from your water supply, or from hearing about lead in the water in other communities. You should use filtered or treated water for drinking, cooking, or preparing formula if you have a lead service line, or if you have a pregnant woman or children under 6 years old in your home.
Always follow the manufacturer’s instructions when installing or using any water treatment system. You will need to replace the filter cartridge on a schedule as instructed by the manufacturer.
All tests for drinking water treatment devices are completed using cold water, so you should only use cold water in your treatment device at your home. Most faucet mount filters have a bypass that you can use for washing dishes with hot water.
When a device has an indicator that tells you when to change a filter cartridge, the indicator device typically measures the time the treatment unit has been in use or measures the water flow through the device. In most cases, the indicator does not measure when the filter is no longer reducing contaminants from the water.
The Michigan Department of Health and Human Services (MDHHS) has made YouTube videos to explain how to install¹ and replace² Brita faucet mount filters.
References:
- ¹ “Brita Faucet Filter Installation”. YouTube, uploaded by the Michigan Department for Health and Human Services, February 12, 2019, youtube.com/watch?v=fdGjZWAF6RU.
- ² “How to Replace your Brita Water Filter.” YouTube, uploaded by the Michigan Department of Health and Human Services, November 4, 2015, youtube.com/watch?v=plsOvmH___0
It is important to select water treatment devices that are certified to reduce the contaminants you are concerned about.¹ The device package should clearly indicate that the treatment device meets at least one drinking water certification standard, and the package should list the contaminants that it is certified to reduce as in the example below. The USEPA has developed a tool to help consumers recognize the markings on certified filter packages.³
NSF/ANSI 53, NSF/ANSI 58, and NSF/ANSI 42 are the drinking water treatment certification standards you are likely to see. If you are selecting a device to remove lead, the package needs to state that it meets NSF/ANSI 53 or 58 for the reduction of lead.
NSF International (formerly known as the National Sanitation Foundation) is an independent, not-for-profit organization that writes standards, and tests and certifies point of use treatment devices. NSF International uses a consensus-based process to develop national standards which means that regulators (including the U.S. Environmental Protection Agency (USEPA)), consumers, academia, and industry are involved in developing standards. NSF International drinking water certification programs are accredited by American National Standards Institute (ANSI).
NSF/ANSI Standard 53 for Drinking Water Treatment Units is the nationally recognized standard for evaluating and certifying drinking water treatment systems for the reduction of contaminants from drinking water. NSF/ANSI Standard 58 is the national recognized standard for Water Treatment Systems that use reverse osmosis technology. Water filters are tested and certified to NSF/ANSI 53 and 58 to ensure they reduce contaminants, including lead, per the requirements of the standards.
The NSF/ANSI standards define specific tests that treatment devices must pass to be certified as effective for reducing an individual contaminant. Filters can be certified to reduce multiple contaminants.
NSF/ANSI 42 is used to evaluate and certify filters that reduce aesthetic impurities such as chlorine and taste/odor. These can be point-of-use or point-of-entry treatment systems. Both NSF/ANSI 42 and 53 cover adsorption and filtration which is a process that occurs when liquid, gas, or dissolved/suspended matter adheres to the surface of, or in the pores of, an adsorbent media. In contrast, NSF/ANSI 58 uses reverse osmosis system that uses reverse pressure to force water through a semi-permeable membrane. Most reverse osmosis systems incorporate one or more additional filters on either side of the membrane.5
References:
- ¹ “Certified Product Listings for Lead Reduction.” Listing Category Search Page Results | NSF International, info.nsf.org/Certified/DWTU/listings_leadreduction.asp
- ² Minnesota State Health Department. “POU Fact Sheet” health.state.mn.us/communities/environment/water/factsheet/poulead.html
- ³ United States Environmental Protection Agency. A Consumer Tool for Identifying Point of Use (POU) Drinking Water Filters Certified to Reduce Lead. EPA/600/F-18/335, 2018, epa.gov/sites/production/files/2018-12/documents/consumer_tool_for_identifying_drinking_water_filters_certified_to_reduce_lead.pdf.
- 4 Bosscher, Valerie, Darren A Lytle, Michael R Schock, Andrea Porter, Valerie Bosscher, Darren A Lytle, Michael R Schock, and Andrea Porter. 2019. “Toxic / Hazardous Substances and Environmental Engineering POU Water Filters Effectively Reduce Lead in Drinking Water : A Demonstration Field Study in Flint , Michigan.” Journal of Environmental Science and Health, Part A 54 (5): 484–93. doi.org/10.1080/10934529.2019.1611141.
- 5 “NSF Standards for Water Treatment Systems.” NSF RSS, nsf.org/consumer-resources/water-quality/water-filters-testing-treatment/standards-water-treatment-systems
It is important to select point-of-use (POU) and point-of-entry (POE) water treatment devices that are certified to reduce the contaminants you are concerned about. These devices are certified using the NSF/ANSI certification program as described here.
The NSF/ANSI standards define specific tests that treatment devices must pass to be certified as effective for reducing an individual contaminant. All drinking water treatment devices are tested using cold water. They are not tested for contaminant reduction at higher temperatures that you might use for showers or dishwashing.³ The lead reduction certification test uses water containing 150 parts per billion (ppb) of lead. The treatment device must reduce lead to 10 ppb or less¹ to be certified. A recent peer reviewed study found that certified filters reliably bring lead down to non-detect levels even when lead levels in the tap water are higher than the 150 ppb required in the certification test.4
References:
- ¹ United States Environmental Protection Agency. A Consumer Tool for Identifying Point of Use (POU) Drinking Water Filters Certified to Reduce Lead. EPA/600/F-18/335, 2018, epa.gov/sites/production/files/2018-12/documents/consumer_tool_for_identifying_drinking_water_filters_certified_to_reduce_lead.pdf.
- ² Minnesota State Health Department. “POU Fact Sheet” health.state.mn.us/communities/environment/water/factsheet/poulead.html
- ³ “Certified Product Listings for Lead Reduction.” Listing Category Search Page Results | NSF International, info.nsf.org/Certified/DWTU/listings_leadreduction.asp
- 4 Bosscher, Valerie, Darren A Lytle, Michael R Schock, Andrea Porter, Valerie Bosscher, Darren A Lytle, Michael R Schock, and Andrea Porter. 2019. “Toxic / Hazardous Substances and Environmental Engineering POU Water Filters Effectively Reduce Lead in Drinking Water : A Demonstration Field Study in Flint , Michigan.” Journal of Environmental Science and Health, Part A 54 (5): 484–93. doi.org/10.1080/10934529.2019.1611141.
- 5 “NSF Standards for Water Treatment Systems.” NSF RSS, nsf.org/consumer-resources/water-quality/water-filters-testing-treatment/standards-water-treatment-systems
Water Filter Information
More Water Filter Resources
Identifying Certified Drinking Water Filters
View/Download A Consumer Tool for Identifying Point of Use (POU) Drinking Water Filters Certified to Reduce Lead from the EPA (PDF).
Choosing Home Water Filters & Other Water Treatment Systems
Visit Choosing Home Water Filters & Other Water Treatment Systems on the Centers for Disease Control and Prevention (CDC) website.
Point-of-Use Filter Installation, Use, and Maintenance
Review Point-of-use (POU) filter installation, use, and maintenance (PDF) with this guide developed by Greater Flint Health Coalition, Community Foundation for Greater Flint, US EPA, Flint Neighborhoods United, Genesee Health System, Wayne State University, and the University of Michigan.