Storm manhole covers, not of metal;manhole covers, not of metal; covers and frames for manholes, not of metal; Nonmetallic construction materials, namely, non-metallic gratings; Nonmetallic construction materials, namely, drain covers and grates, not of metal; gullies, not of metal in the nature of concrete drainage structures, namely, trench drains; drain gullies, not of metal in the nature of concrete drainage structures, namely, trench drains;access chambers of nonmetallic materials in the...