Septic tank
While a properly maintained and located septic tank does not pose any more environmental problems than centralized municipal sewage treatment, certain problems can arise with septic tanks in unsuitable locations. Since septic systems require large drainfields, they are not suitable for densely built areas.
Cesspit
On June 1, 2011, two teenagers from Farmingville in Long Island, New York, drowned after becoming overwhelmed by fumes and trapped in a backyard cesspool measuring 16-feet deep. The collapsing cesspools were mostly due to older cesspools built with brick or cinder block. These structures weakened over their lifespan leading to increased risk of collapse. Newer cesspools are cast concrete which dramatically decrease any risk of collapse. All new construction in areas without waste sewer systems use these new precast cesspools. In addition, cast concrete cesspools are used commonly in commercial construction for storm water collection.