Over the past two years, Bloomington streets have been washed with blue lights at night. But why are once-white LED streetlights turning blue?
It’s not due to the city trying out a new energy-saving light or to make it easier to see the road lines in the dark. The answer is simpler than that: a manufacturing defect.
The standard illumination color for an LED streetlight is a bright, white light. But with the manufacturing defect, one of the many color layers necessary to make the white light is missing. The most common way the blue light, which is the natural color of LEDs, is exposing itself by the flaking and peeling of the phosphor layer.
Bloomington isn’t the only area of the country experiencing blue tint, according to Christina Smith, special projects coordinator for the Bloomington Department of Public Works. The odd hue has been reported in Iowa, California and even Canada.
“It's very common in the manufacturing of streetlights,” Smith said. “And they buy in huge quantities. So that's why it's taking so long to track all of them down.”
The problem in Bloomington has been identified as an issue with a subcontractor who works for Duke Energy. Duke leases the streetlights to the city. The city pays for the equipment costs, installation, energy usage and maintenance costs of the 3,300 Duke Energy lights in Bloomington. But Duke oversees the maintenance. Smith said it can be difficult for maintenance crews to determine the light color because they typically do their work during the day.
“If they can't determine that it is a blue light,” Smith said. “It's hard for them, they can't replace it.”
READ MORE: Bloomington in the midst of transitioning to LED streetlamps
The streetlights function the same whether they’re blue or white, and there aren’t any harmful environmental impacts.
“It is below the industry standard for any environmental harm to any insects,” Smith said. “I have not seen any evidence that a blue light harms the driving, it's just not as bright.”
The city is asking residents for help finding the blue lights. Smith said the Department of Public Works and Duke Energy do not know when a light goes out and they rely on community reports.
“It's just really essential that people help us out,” Smith said. “If you help us out, then we can get the light replaced.”
There are many ways to report a blue streetlight in Bloomington. You can go on the city’s website and file a uReport and Duke Energy also has a light repair page. Smith said that the Department of Public Works also takes reports directly through email and over the phone, along with the Street Operations Division. When making a report, be as detailed about the lamp's location as possible.
