When it comes to stray current leaking from metro's light rail system. The world class Texas Medical Center finds itself on the wrong side of the tracks.

After months of research, a firm hired by the Texas Medical Center has concluded that stray current leaking from METRO’s light rail line is impacting parts of the center including one building at Texas Children’s Hospital.

11 News first reported this story last fall when Texas Medical Center officials were concerned enough about METRO’s problem and its impact on the hospitals foundations that it hired an outside company to examine the risk.

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Metro rail

Almost 2 miles of the 7.5-mile light rail line runs through the medical center.

In an eight page executive summary of a report prepared by Corrpro for the Texas Medical Center, and reviewed by 11 News, experts discovered worrisome levels of stray current in the foundation walls of the Meyer Building, part of Texas Children’s Hospital, and the Thermal Energy Corporation’s piping system, which supplies water to the all of the hospitals and medical buildings.

Corrpro said these two facilities “had stray current effects sufficient to warrant continued surveillance to detect and respond to possible increases.”

Electricity can corrode the steel rebar enveloped in concrete which is used in foundations and over time could eventually compromise structures.

Inconsequential effects of the leaking current from the light rail line were found at Methodist Hospital, UT Medical School, St. Luke’s Medical Tower, Memorial Hermann Professional Building, Fannin Holcombe Garage, Ben Taub Hospital and Parking Lot E of the Meyer Building.

No stray current was detected in other areas at Texas Children’s Hospital, Memorial Hermann Hospital and the M.D. Anderson Cancer Prevention Center.

Over time, corrosion experts said, all of these facilities could see stray current levels increase.

“Transit system rail stray currents tend to increase as the system ages,” the report stated. Corrpro said the Texas Medical Center “should expect to continue a monitoring program for the life of the rail system.”

Right now, there are 84 permanent stray current test points at various institutions within the medical center installed within the last few months.

"The light rail today, the insulation it has to protect against stray current is as good as it's ever going to be,” said Stephen Swinson of Thermal Energy Corporation, whose group administered the study. “With time it's only going to degrade.

"You have a pipe that corrodes so what's in it comes out. you have structural foundations that become weakened, and in a worst case scenario fail."

METRO, responding to 11 News' original report in the fall of 2006, said the amount of stray current is only equal to a 9-Volt battery.

It continued damage control Wednesday after the release of the medical center’s findings.

In a prepared statement, METRO said it “is pleased that the results confirm stray current is posing no danger to infrastructure in the area.

“Tests conducted at 13 facilities in the TMC show four had no detectable levels of stray current, seven had levels deemed “inconsequential,” and two had “stray current effects sufficient to warrant continued surveillance to detect and respond to possible increases,” the news release continued.

Since April 2006, METRO has not been able to figure out why stray current is leaking from its light rail line.

According to the study, two of the building's surveyed had enough stray current to warrant continued monitoring and

that the only time no levels were present was the few hours in the early morning when light rail isn't running. The obvious question:  who should pay for the ongoing cost of monitoring that will be needed for the life of the system.

The Texas Medical Center paid Corrpro $100,000 for the study. It’s uncertain whether METRO will reimburse the TMC.