Currently, we are not able to recover and reuse enough of the filter cartridges to offset the environmental impact and cost of return shipping them to us. Because the media is not reusable, and the drinking water filter must contain only food grade materials, and the shower cartridge is not re-sealable, the filter cartridges should be disposed of with your regular garbage, so that they can continue to offer a benefit to the environment by continuing to remove synthetic compounds from the landfill.