There are lots of reasons to use water filters. They can make water taste better, remove major and minor contaminants and purify water to the point where it is safe to drink. The downside: Water filters need to be replaced often, leaving you with a big hunk of material that may seem destined for the trashcan. Some water filters can be recycled without much effort. Others are harder to deal with. If you are considering a new water filtration system, it is worth checking with the manufacturer first to find out if its filters are recyclable. Below, we share information about a couple common brands (plus some water filter 101) to get you started.

Different water filters serve different purposes

Water filters come in several different forms. The most common are filters that fit in specially designed pitchers or over the tap to improve the taste and quality of tap water. Those living in areas with arsenic in their water must have water filters, which are often mounted on the counter or under the sink. Backpacking enthusiasts or people traveling to different countries may have powerful portable water filters so they can drink water from lakes or wells without danger. If your refrigerator has a water and ice dispenser in the door, it will be equipped with a water filter as well. More than a dozen water-filtering technologies exist. Here are the ones homeowners are likely to use:

• Carbon, including carbon block and granulated activated carbon — Water passes through a block of carbon, which removes contaminants. Filters of different types and compositions can do anything from improving the taste of water to removing seriously harmful elements like lead and mercury.
• Ion exchange — Water runs over a plastic material that exchanges unwanted ions for more favorable ones. These are often used for “softening” water in areas where there is a lot of calcium or magnesium in the water.
• Reverse osmosis — This is what you need if you have arsenic or other dangerous compounds in your water. The filter forces water through a semipermeable membrane and stops everything bigger than a water particle. These types of filters can waste quite a bit of water, so they are not the best choice for everyone (especially those of us in drought-ridden areas).

For a handy guide on different types of water filters, and the pros and cons of each, check out the Environmental Working Group’s website.

What are water filters made of?

Besides the filtering ingredient itself (carbon, plastic, etc.), most water filters are held together with some sort of plastic or metal casing. Different companies use different products; Brita’s filters are made with polypropylene (also known as PP or by the recycling #5), while Everpure filters contain a fair amount of aluminum. The method for recycling each depends on its composition.

How to recycle water filters

People with Brita water filters can recycle them through a program called Gimme 5, which is run by Preserve. The Massachusetts-based manufacturer makes products like plates, cutlery, food storage containers and toothbrushes from recycled plastic. Whole Foods is a major partner in the Gimme 5 initiative and has #5 plastic collection bins in many of its stores. If you do not live near a Whole Foods, you can mail all your #5 plastic to Preserve using the address on their website. There is no charge to recycle these plastics other than the cost of shipping. Brita recommends that before you place your filters in a recycling bin you let them dry out for a couple days, then wrap each one in a plastic grocery bag. Everpure promises its water filters are 100% recyclable. Customers can contact the company through its website to obtain a list of recycling locations or get an address where they can mail unwanted filters. Mavea water filters’ website claims that it is “the only company that supports its filters with a comprehensive filter take back and recycle program.” However, the website offers very little information about the company’s recycling program. Filters can go in recycling bins in stores (whether they mean their own or Gimme 5 bins is unclear) or can be mailed back to the company in Elgin, IL. If you have a Mavea water filter, inquire with the company for more instructions. It is definitely worth recycling their water filters because they contain valuable silver that can be reused in many types of products. In 2011, GE made a commitment to recycle all water filters in its refrigerators at no charge to consumers. When you purchase a new water filter it is supposed to come with a postage-paid envelope so you can mail back your old filter. Contact GE for more details about its program.

Can I dispose of the contents of a water filter myself?

Some websites advise dumping the charcoal or other filtering medium in the garden or on a gravel path. This is not a safe practice. Opening the water filter will allow all the contaminants trapped in the filter material back into the environment. In addition, some filters contain items that should not go in your garden, such as the silver mentioned in Mavea filters. If you cannot recycle your water filter, it is safer to throw it in the trash.