A Georgia consulting firm hired by state utility regulators to investigate five explosions in Indianapolis Power & Light’s downtown underground network recommends that IPL do a better job of finding and documenting equipment failure.

Overall, however, Atlanta-based O’Neill Management Consulting LLC called IPL’s downtown network “well designed and regularly maintained.”

“Notwithstanding a higher incidence of recent events … the risk to the citizens of, and visitors to, Indianapolis has historically been low; lower in fact than in many other major cities,” the report said.

The report may do little to calm nerves after explosions in recent years that sent manhole covers flying, including one that damaged a car parked atop an underground electrical vault this fall.

IPL’s flying manhole covers also have alarmed city leaders preparing for the Super Bowl in February, when streets will be packed with visitors. IPL recently installed 100 blast-resistent covers to reduce odds of injuries should another explosion occur.

O’Neill recommend IPL put an “immediate emphasis” on addressing leaks in steam lines operated by Citizens Energy Group that are in close proximity to underground electrical equipment.

The consulting firm also recommended that IPL consider changing design of equipment used and standards specified for maintenance and construction. For example, it suggested IPL find alternative ways to terminate primary power cables into network transformers, where some of the failures have occurred in recent years.

Without making such changes, IPL can probably expect three  to five such incidents a year, O’Neill wrote in its report released Tuesday by the Indiana Utility Regulatory Commission.

IPL responded that it had made a number of inspections in recent months and notified Citizens of potential problems with its steam lines.

The IURC plans a public hearing on the report on Dec. 19 at its headquarters downtown.

IPL’s downtown underground system had three explosions in 2010, and a handful of others in previous years.

Former IPL executive Dwane Ingalls warned several years ago that cost-cutting following IPL’s acquisition by AES Corp. in 2001 amounted to maintenance deferral that likely would result in increasing problems in the future. 

It’s unclear whether IPL changed its underground maintenance practices following its acquisition but Ingalls was proved prophetic about the increase in explosions.