The most common causes of backups in your pipes are paper products, tree and shrub roots, and sludge. Generally, the first solution you turn to when drains are clogged is a chemical drain cleaner. But while it may dissolve the sludge, it is also harmful to the environment.
Unfortunately, chemical drain cleaners are just a stopgap measure. Paper products and roots are not affected by the chemicals. Eventually, the blockage returns, and it’s usually worse than the first clog.