text_combined: update el paso nm pipeline testing el paso proceeding nm pipe integrity testing el paso natural gas received approval u department transportation office pipeline safety ops conduct internal inspections rebuilt new mexico pipeline ruptured august 19 killing 11 people see daily gpi aug 22 since explosion flows line runs west texas california reduced 85 capacity 920 mmcf ops said el paso line already repaired put hydrostatic testing passed hydrostatic testing checks cracks forcing high pressure water line el paso green light begin smart pig testing examine internal integrity line device called pig sound makes inspections sensors placed inside line detect dents deformities changes wall thickness neither ops el paso released timetable pigging would occur long would take however testing completed results evaluated ops would determine line safe commercial use ops issued actual regulations smart pig use become increasingly sophisticated widely used even though hydrostatic testing actually detect certain flaws invisible smart pigs pigging process considered complement water testing ensures integrity test results ops requires pipe undergo least one hydrostatic test construction although mandated ops also proposed requiring pipelines transport liquid petroleum products use direct assessment methods pigging evaluate pipeline integrity types inspections include using magnetic particles ultrasound measure pipe wall thickness