Using Water Filters Effectively

By Naomie Baptiste, Director, National Society of Black Engineers (NSBE) Environmental Engineering Special Interest Group

The Environmental Protection Agency (EPA) provides tap water standards under the Safe Water Drinking Act, which provides guidance on public water systems, protection of underground sources of water, emergency powers and general provisions. The EPA defines more than 80 regulated contaminants in drinking water, including arsenic, E. coli, chlorine and lead.

For areas with contaminated water supplies, such as Flint, Mich., water filters may be a solution. NSF International, previously known as the National Sanitation Foundation, is a safety-based risk management provider. Consumers can search for certified drinking water treatment units and water filters on the organization’s website.


For consumer transparency, the site provides a database of service cycle, flow rate and reduction claims for water filters and filtration systems.

A water filter that eliminates every contaminant known to man does not exist. It’s best, first, to know which contaminants your household needs to target. Community water systems are required to provide an annual drinking water quality report to the consumers they service, by July 1 each year. The report, named a Consumer Confidence Report (CCR), tells consumers where their water comes from and what’s in it. If you haven’t received your CCR, you can find the information here. The report tells you what’s in the water in your area. However, to know what’s coming directly through your pipes, you must conduct a test on the water coming from your tap. The EPA’s Safe Water Hotline at (800) 426-4791 can help you find a state-certified laboratory to test your tap water.

Residents of Flint, Mich., should refer to Section 1417 of the Safe Drinking Water Act (SDWA), which establishes the definition for “lead-free” as a weighted average of 0.25 percent lead calculated across the wetted surfaces of a pipe, pipe fitting, plumbing fitting, and fixture and 0.2 percent lead for solder and flux. The Act also provides a methodology for calculating the weighted average of wetted surfaces.

Consumers must use water filters appropriately as defined by the manufacturers. Filtration systems must be changed regularly. Most filters use carbon, charcoal or a bend to reduce contaminants either by mechanically trapping them in the pores of containments or by absorbing the contaminants to the surface of the filter media. The frequency with which consumers should change their filters is dependent on the service cycle: the useful life of the filter. Manufacturers define the service cycle as a specific number of gallons or an estimated number of months of use before the consumer should change the filter. Choosing the right replacement cartridge is critical as well. Consumers must use the certified cartridge recommended by the manufacturer to remove the specific contaminants in their water, to ensure that the water is safe for drinking or other uses.

Keep in mind that although the best water filters are designed to remove/absorb many contaminants from water, human error must always be taken into account. Please carefully review the manufacturer’s instructions on how to install water filters and replace cartridges.

For more information, please join the National Society of Black Engineers (NSBE) Environmental Engineering Special Interest Group (SIG) to continue the dialogue about Flint’s water crisis.

Research References:
Environmental Protection Agency:
Green America:
NSF International, The Public Health and Safety Organization: