Midwest Energy’s  Annual Yard Line Natural Gas Leak Survey is underway in several western Kansas cities.  Several rural lines will also be checked.  According to Midwest Energy spokesperson Bob Helm, the Department of Transportation (DOT) requires  all lines be surveyed for leaks every three years. Midwest Energy  surveys yard lines every year throughout their system.  Leaks are classified in several different categories. Those that need immediate attention, if found, are repaired immediately. Other leaks are repaired as necessary.  Midwest Energy is based in Hays.