In some older homes some lead pipe may be found in waste lines. As long as such pipes are functional they can continue to be used and don't pose a hazard. If problems arise or such pipes are found during remodeling, they should be replaced with ABS or PVC pipe.

Note: some older water coolers, fixtures and old buildings may contain lead material in the drinking water system and this can be a health concern. Some older copper pipe may contain solder with a high lead content.

A lead pipe in an older home in use as a vent in a basement drain. The pipe has a dent that reduces air flow. Due to the relative softness of lead such damage is common.