NPCA, the National Precast Concrete Association, is a trade body serving the precast concrete industry, with a focus on products like manholes, box culverts, utility structures, and other underground and site work.
Its plant certification program and quality-control manual are a common benchmark for precast producers. When a specification or a DOT asks for an NPCA-certified plant, it is a shorthand for a documented quality system: controlled mix designs, inspection routines, and records. Many QC checklists in the industry, including the ones in modern precast software, are grounded in NPCA and PCI practice.