This icon is depicting a manhole or sewer cover. The object is round in shape with two rows of vertical lines inscribed in the center as if to indicate this is an open grate.
This Sewer icon is made in Material Design style
developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 5,700 icons, all in the same style and quality.