Water pollution is caused when certain chemicals build up to levels dangerous to wildlife and humans. This can come from improper disposal of industrial or household hazardous waste (HHW). Most products that contain hazardous chemicals are clearly marked, with instructions on how to dispose of the remainder or empty containers. The EPA recommends finding out about local recycling and disposal options, and making sure not to throw batteries, paint, and other HHW in the trash or down the drain. By separating and disposing of HHW properly, they can be kept from landfills where the degrade and pollute the groundwater and aquifer. Another option is to reduce the use of explicitly harmful chemical products in favor of biodegradable products, which are increasingly common. While any chemical product is toxic at the appropriate dosage, some are more toxic than others at lower dosages, and so can build up faster and cause more damage. Local garbage facilities, transfer stations, and government facilities will have more information about specific products.