One of the primary ways in which California pipeline safety standards exceed the minimum federal standards is in pipeline integrity testing. Federal regulations mandate that a pipeline system be hydrostatically tested before initial operation begins. California law mandates that each pipeline system be tested at least every five years by an independent third-party approved by the Office of the State Fire Marshal (OSFM). Testing results are submitted to OSFM for review and concurrence. Tests are randomly witnessed by OSFM Pipeline Safety Engineers to verify compliance with the OSFM Pressure Testing Requirements. In certain cases, OSFM may also approve the use of internal inspection tools "smart pigs" in lieu of hydrostatic testing. In these cases, the test results are also submitted to the OSFM for review and concurrence.