Detroit — The city’s Public Lighting Authority on Monday is expected to complete the replacement of nearly 20,000 defective LED streetlights that caused premature dimming and failures.

The replacement, which is expected to cost between $7 million to $8 million, is ahead of the lighting authority’s goal earlier this year to swap out fixtures on 19,500 lights by the end of the year. The authority, which is funding the project, is seeking reimbursement from the lighting manufacturer, California-based Leotek Electronics USA.

“We’re just doing what we set out to do and we’re ready to move on and focus on keep the lights that are out there on,” Public Lighting Authority Executive Director Beau Taylor told The Detroit News.

The replacement effort came after a routine survey of the lighting system last year revealed the defective lights by Leotek were "charred, burned, or cracked," according to the lighting authority's law firm.

Officials expressed concern in May that the defective lights, which represent about a third of the city’s streetlight system, would put the overhaul of Detroit's streetlight system in jeopardy. The city has a pending lawsuit against Leotek Electronics.

“The lights were in various stages of dimming,” Taylor said. “The ones that were installed earlier were on their last breath so to speak. The ones that were later installed still had some additional life left in them, but it became apparent that the problem we were dealing with was systemic. The ones that were still functioning were not only at risk, we were fairly certain it was going to go out.”

Thor Scordelis, general manager of Leotek US, said Sunday that the company has been in close communication with the Public Lighting Authority through direct conversation or through their attorneys since the dispute arose in December.

"This was a design flaw that was isolated and not all installations experienced problems," Scordelis wrote in an email. "We have moved quickly to replace units that did not meet performance specs. We have made every attempt to resolve this matter."

Scordelis said since June, Leotek provided the city 8,179 units of replacement lighting.

The lighting authority has installed 1,500 replacement lights from Leotek, which Taylor said is a different model. The manufacturer provided the lights to the city at no cost.

“The same issue shouldn’t reemerge,” Taylor said.

Lighting authority officials declined to comment further on the replacement lighting from Leotek due to ongoing litigation.

Other lights in the replacement are America's Green Line, General Electric and Cree Inc.

The authority paid $3.9 million in 2014 to purchase 25,320 lights from Leotek. Installation costs for the lights were about $5.2 million. According to the lighting authority, Leotek, per its 10-year warranty, said it would correct and replace any defects.

In December, Leotek acknowledged in a letter to the lighting authority that it had experienced "a higher number of reports of failures" in models dimming city streets, primarily in west side neighborhoods and a number of Detroit's major thoroughfares.

In the letter, Leotek administrator Hy Nguyen apologized for the problem and offered to work with the city to correct the problem.

The lighting authority filed a federal lawsuit in May against Leotek asking the court to grant judgment against Leotek for warranty violations. Scordelis said both parties are expected to enter mediation in late October.

Crews started replacing the defective lights in June by working 10-hour days, six days a week to swap between 1,500-2,000 lights each week.

“We looked at when the kids were returning to school and when the days become shorter,” Taylor said. “It felt it really made sense to accelerate that timeline so we weren’t in a position where kids were walking home from school and practice in the dark. That was our primary driver of accelerating the timeline.”

Detroiter Danny Craig said if there had been an issue with the street lighting, he hadn't noticed. A resident on the city's west side, Craig said he's been pleased with lighting in the city during the past five years.

"The lighting has been pretty good," he said. "Much better than it’s been in the past."

cwilliams@detroitnews.com

Twitter: @CWilliams_DN