An internal investigation following a deadly East Harlem explosion in March shows that Con Edison workers had lapses in their qualifications.
The report, which was turned over to the state, reveals flaws in how the utility company trained workers who install the plastic pipes that carry natural gas in parts of the city.
Con Ed said some of its workers who were trained to connect sections of gas mains made of plastic had failed to comply with safety regulations.
The utility said 186 Con Edison employees and 115 contractor employees had lapses in their qualifications, some of which lasted more than a year.
The agency did say, however, that the workers who replaced the gas pipes at 116th Street site are not among them.
Six people died in the explosion.
A federal investigation into the blast has yet to yield a cause.
The company said it's confident that the lapses found in the report did not compromise the integrity of its gas system.
Con Ed said it will continue to test the plastic pipes for leaks as well as work to ensure more timely requalification for its workers.