Caltrans has reestablished the Material Plant Quality Program (MPQP) that affects ready mixed concrete, precast concrete, cement treated base, hot mix asphalt, and asphalt rubber binder plants, as well as concrete volumetric mixers.  To prequalify, Caltrans requests producers contact district weights and measures coordinators.  Recommended 2 weeks advance notice to be given and scheduling will accommodate existing projects first.

All weighing devices (for example, truck scales, weigh bridges, hopper scales) shall be mounted on concrete slabs in accordance with Caltrans specifications.

All safety guards, rails, fire extinguishers, eye wash stations, and other implements shall be in place and functioning in accordance with Caltrans specifications.

Obtaining plant certification:

Contact the appropriate Caltrans district weights and measures coordinator (WMC) to inquire about approval requirements for your plant and schedule an appointment at least 2 weeks prior to the requested date. Priority will go to those proportioning material plants producing materials for a Caltrans project. The WMC will witness the calibration of the proportioning material plant and approve it if deemed compliant with Caltrans requirements. A scale company (Registered Service Agency) is required when calibrating.

California certified traceable masses shall be present with enough mass to prove the scales. The county WMC may be contacted to prove the scales for the county at the same time.

• Material Plant Quality Program Manual (July 2008) [pdf]
• California Test 109 (CT 109) [pdf]
• Form CEM-4204, “Material Plant Safety Checklist.”

Caltrans web site link http://www.dot.ca.gov/hq/construc/mpqp.html