Advanced Drainage Systems is the world’s largest producer of corrugated HDPE pipe and related drainage products. ADS serves the storm and waste water industry through a global network of 56 domestic and international manufacturing plants and 27 distribution centers. In addition to its flagship N-12 pipe, the company offers a complete line of fittings and other accessories including, Nyloplast drainage structures, and various geotextiles. The 4 in. Polyethylene Septic Tank Tee is designed to join a 4 in. single-wall corrugated polyethylene drainage pipe and septic tanks in leach field applications. Color: Black.