Pervious concrete has a common strength of  though strengths up to  can be reached. There is no standardized test for compressive strength. Acceptance is based on the unit weight of a sample of poured concrete using ASTM standard no. C1688. An acceptable tolerance for the density is plus or minus  of the design density. Slump and air content tests are not applicable to pervious concrete because of the unique composition. The designer of a storm water management plan should ensure that the pervious concrete is functioning properly through visual observation of its drainage characteristics prior to opening of the facility.