Norwesco is North America's leading manufacturer of proprietary rotationally molded polyethylene tanks for agricultural, water, closed-top industrial and below ground septic and cistern applications. Norwesco was founded in 1939 in St. Paul, Minnesota under the name of Northwest Plastics, Inc. The name was changed in 1973 and at that time Norwesco was ranked as one of the oldest and largest plastic processors in the United States. Norwesco is your complete source for the high-performance products required for your fluid handling needs. We offer a large selection of accessory items to compliment our tanks.