One hundred forty-four (144) miles of these trunk lines, constructed out of steel, were installed before 1940. The 144 miles of old steel trunk lines are the focus of the Department's Trunk Line Condition Assessment Program (TCAP). This paper describes TCAP, a program designed to assess the condition of and prioritize those trunk lines most at risk and in need of replacement. Many of the trunk lines are deteriorating and approaching the end of their useful life. The likelihood of significant breaks, costs associated with making repairs, payments for damage to public and private property, and exposing the public to a safety hazard are increasing over time. Methodologies, priority lists, critical lengths, damage potentials, and leaks are covered.