Most people do not need to purchase a home treatment device (e.g., a water filter) to make tap water safe because it already meets very strict government regulations for quality. Customers considering a home treatment device because of health concerns should make sure that the device is certified by the California Department of Health Services (DHS). DHS certifies more than 350 home treatment devices that claim to reduce toxic chemicals or provide better health protection. All devices making such claims must be state-certified in order to be legally sold. Regulated devices include those that use carbon filters, distillation, reverse-osmosis, ion-exchange, and ceramic filters. Call DHS at 916-327-1139 for more information about their certification program or log onto the DHS website. Performance of water treatment devices is also certified by the independent National Sanitation Foundation (NSF). For more information call 800-673-8010 or log onto the NSF website. Following are some considerations for purchasing a home treatment device:

• Don't be fooled by a sales demonstration that shows material settling to the bottom of a glass of tap water. The material is usually nothing more than minerals that naturally occur in water.
• Home treatment devices must be properly serviced to work well. If they aren't maintained according to manufacturer's instructions, water from the device may be less safe than water straight from the tap.
• Water that is treated by a home treatment device is usually much more expensive than water straight from the tap, considering the costs of device purchase and maintenance.
• Determine what the device removes from tap water. Not all home treatment devices remove the same things. Customers with a severely weakened immune system should talk to their doctor about the best type of home treatment device to use.