In less populated areas, households often rely on an individual residence treatment system, such as a septic tank or a single family lagoon. Most often, a septic tank in combination with a drainfield serves an individual home. However, some smaller communities have constructed septic systems that serve a number of homes. In a septic system, solid materials settle out in the tank and are gradually broken down by bacteria. The liquid sewage flows out into the drainfield where it is broken down by soil bacteria.
Many hazardous chemicals can destroy the bacterial action in the septic system and drainfield.
These chemicals may also pass untreated through the septic system and seep into groundwater. Storm Drains Storm drains are systems of ditches, culverts or underground pipes that collect storm water runoff from streets, driveways and parking lots. Usually the pipes empty the untreated water directly into lakes and rivers. When household hazardous waste is dumped down the storm drain, the waste can directly pollute surface water, groundwater, and threaten drinking water supplies. Household hazardous waste should never be dumped down storm drains.