(a) An underground force main pipe joint must include either push-on rubber gaskets or mechanical joints with a pressure rating equal to or greater than that of the force main pipe material.(b) Exposed force main pipe joints must be flanged or flexible and adequately secured to prevent movement due to wastewater surges.(c) American Society for Testing and Materials, American Water Works Association, or other widely accepted national reference standards for the joints must be included in the project specifications.