The 800-mile-long Trans Alaska Pipeline System (TAPS) is protected by three separate leak detection systems that are monitored at the Operations Control Center in Valdez. The Line Volume Balance system senses leaks by checking the pipeline's total oil volume every 30 minutes. The Transient Volume Balance monitors oil volume in pipeline segments between pump stations. And the Deviation Alarm system detects leaks by tracking oil pressure, flow volume and flow rate.