Roebic K-77, 2 LB Root Killer, Keeps Sewer & Drain Lines Free From Tree & Shrub Roots, Harmless To Septic Tanks & Cesspools, Contains Copper Sulfate. Note: Not for sale or available in Connecticut, the Bay Counties of California and the City of Golden in Jefferson County, CO. Banned for use in Septic Systems in Florida and Massachusetts. 2LB ROOT KILLER: Clears roots from pipes and stops new growth. Keeps lines free from clogging tree and shrub roots. Roots have a fantastic ability to seek out small openings in pipelines in search of water. Once a pipe is penetrated, rapid growth in the pipe causes blockage. This formula is proven by years of success in clearing sewers and drains of root growth, etc. Fast and easy-to-use. Harmless to bacteria in septic tanks and cesspools. Guaranteed to prevent root blockage for a full year. 2 lb. bottle.