36″ I.D. Manhole

Precast concrete manholes are an integral component of any modern sewer or storm drain system. Precast concrete manhole sections are produced in a controlled environment, thus exhibiting high quality and uniformity. CalPortland’s precast manholes are manufactured to meet or exceed the requirements of A.S.T.M. C478 specifications shown and are continually followed to assure close fit and strength for standard manhole entrances.