Zep® 2 lb. Root Kill is an effective solution for ridding your sewer pipes, drain and septic field lines of shrub and tree roots. Plant roots can penetrate through small cracks and poorly sealed joints of sewer lines. If not controlled, these small roots will continue to grow larger causing breakage, reduced flow, and eventually flow stoppage. Root Kill's powerful granular formula dissolves these pipe-clogging elements on contact without harming the target tree or bush.