Welcome to Midwest Municipal Supply. Supplying waterworks material to the St. Louis metro area and southwestern Illinois since 1989. Our new facility located in Caseyville, IL features over 4 acres of outdoor storage and 7,500 square feet of warehouse space to house our $2 million inventory. Let us help you with your project. Whether it's water, sanitary sewer, storm sewer, fire suppression, treatment plants, drainage, or anything else underground, we have what you need.