All of our plants have undergone an extensive investigation and evaluation process by an outside consulting engineer to assure we are producing "Quality Concrete". During the certification process the engineer is on the plant checking aggregate flow, volume, and weights as we produce concrete. The NRMCA issued a strict guideline for all engineers to follow and a complete list of items to check and verify. This is not a rubber stamp but a thorough investigation. The investigation and certification are renewed each year.