Homer Glen Sees the Light

A Will County village passes a groundbreaking outdoor lighting ordinance with big implications for nature.

by Stephanie Folk

The Chicago region is awash in artificial light.

Whether you gaze skyward from downtown Chicago or a suburban neighborhood, all but the brightest stars are washed out by the glow of electric lights. It can seem as if the night sky that inspired poets and scientists has vanished, and only daytime and twilight remain.

Residents may notice only the most irritating examples of excess lighting, such as a streetlight blasting through a bedroom window or a glaring billboard. But poorly designed outdoor lighting can also waste energy, impact quality of life, and contribute to health problems. And it can have serious consequences for wildlife.

Recently, the northern Will County village of Homer Glen took a big step toward curbing its own light pollution. On December 18, the village board adopted a new ordinance designed to preserve a dwindling natural resource — darkness.

“This ordinance is very different from any ordinance regarding lighting in the Chicago region,” says Homer Glen Village Trustee and Environmental Committee Chair Margaret Sabo. “We hope it can be used as a model for municipalities, townships, and counties.”

“We wanted to make a statement that we recognize the night sky as a natural resource,” says Russell Knaack, a village trustee and engineer who helped develop the ordinance. “We also wanted to conserve energy and protect residents against nuisances.”

Debra Norvil serves on the village environmental committee and started working on lighting issues in 2001. For her, protecting wildlife was a big concern. “We realized we want to have some green space, but we have all this lighting,” she says. “It’s affecting the flora and fauna tremendously.”

In researching the subject, Norvil found a valuable resource in the 2006 book, Ecological Consequences of Artificial Night Lighting, edited by Catherine Rich and Travis Longcore of The Urban Wildlands Group.

“In the big picture, lighting disrupts the natural pattern to which all living things are adapted,” Dr. Longcore says. He explains that some of the impacts of light pollution are obvious, while others are more subtle and not as well understood. In the Chicago region, migratory birds offer the most dramatic example of animals that suffer serious, often deadly, consequences. Lighted buildings and towers can attract and disorient migratory birds. “Especially during inclement weather, birds will fly around these buildings until they are totally exhausted or until they crash into a building,” says Shawn Cirton, a wildlife biologist with the U.S. Fish and Wildlife Service. He says songbirds including warblers, tanagers, and thrushes are common victims.

During the spring 2007 migration alone, the Chicago Bird Collision Monitors found nearly 1,500 dead or injured birds of more than 100 species in downtown Chicago. To stop the carnage, Audubon, the City of Chicago, the Building Owners and Managers Association of Chicago, and The Field Museum teamed up to create a voluntary program called Lights Out Chicago. Participating buildings turn off or dim lights at 11 p.m. during migration seasons, saving thousands of birds every year.

But even far from downtown, the hazy “night glow” of urban areas creates a constant twilight. Throwing off the balance of light and dark changes how animals behave and alters relationships between species. This sustained glow can cause some daytime species such as squirrels and crows to stay up later searching for food. It can also put them in closer contact with nocturnal species such as owls.

Light pollution affects other species as well. Longcore points to frogs and salamanders as an example. Some species of amphibians are most active during the darkest part of the night, and artificial lighting can cause them to cut feeding and mating behaviors short. “Frogs and salamanders are incredibly sensitive to light,” says Longcore. “And when you turn the natural pattern into constant moonlight, it will ultimately result in lower species diversity.”

Artificial light can also impact ecosystems starting near the bottom of the food chain. Studies by Wellesley College limnologist Marianne Moore show that zooplankton in urban and suburban lakes change their nightly migration patterns in response to artificial light. Normally, they migrate toward the water’s surface at night to graze on algae. But the glow of artificial lighting reduces both the distance that they migrate toward the surface and the number of individuals migrating. While the exact impacts of this change need more study, Moore’s research suggests that the zooplankton’s grazing will be reduced, and algal blooms that contribute to poor water quality could become more common.

Animals aren’t the only organisms affected by light. Longcore says artificial lighting alters the development of plants. For example, trees near bright lights hold onto their leaves longer in the fall. This delay in winter dormancy stresses trees, making them more vulnerable to harsh winter weather and shortening their lifespan. Artificial lighting also shifts growth patterns of plants. A guide from the Purdue University Department of Forestry and Natural Resources states that artificial light can change flowering patterns and can even make trees more susceptible to air and water pollution.

“All biological life operates on some sort of circadian rhythm, so it can all be affected by light pollution, including humans.”

— Dave Robson, Forest Preserve District of Will County

Dave Robson, a natural resources manager with the Forest Preserve District of Will County, says it’s difficult to measure all of the indirect impacts of light pollution, but it’s clear that there is an effect. “All biological life operates on some sort of circadian rhythm,” he says, “so it can all be affected by light pollution, including humans.”

“Anyone who’s sat outside in the summer when it’s dark — you see the amount of bugs around a street light,” he says. “That has to have some effect, because they wouldn’t normally be congregating in that place for so long and in such numbers.”

Shawn Cirton says the effect is significant enough for the US Fish and Wildlife Service to take notice. He says hawk moths — which pollinate the federally threatened eastern prairie fringed orchid — are drawn to lights.

“That would put them at increased risk of predation, as well as reduce pollination opportunities for the orchid,” Cirton says. “So if there’s a development proposed near an area where the orchid grows, we’ll make recommendations for reducing the impacts on the species.” When an industrial development was proposed near Midewin National Tallgrass Prairie in 2006, Cirton recommended that the site’s lighting be designed with the moths, and the orchids, in mind.

The Forest Preserve District of Will County has also taken action to protect natural areas from light pollution. They used earthen berms, trees, and shrubs to keep car headlights from disturbing nesting herons and egrets at the Lake Renwick Heron Rookery. And they work with neighboring property owners to keep excess lighting out of other natural areas.

Studies from around the country show that some species cope with a brighter nighttime environment better than others. Ultimately, though, it may be the difficult-to-measure accumulation of stresses — the combination of light, sound, air, and water pollution, as well as other environmental changes — that affects the greatest number of organisms.

How to Stay in the Dark

For guidance in crafting its ordinance, Homer Glen turned to the International Dark-Sky Association (IDA), which provided model ordinances and advice. IDA president Bob Gent says that good lighting doesn’t mean turning everything off. It’s about using the right amount of light, and only when and where it’s needed.

To make sure that outdoor lighting follows this basic principle, the Homer Glen lighting ordinance specifies how much lighting can be used on properties, and how bright the lights can be. It also requires businesses to dim outdoor lighting within an hour of their closing time.

The ordinance is also designed to ensure that light is directed at the area that needs to be lit, rather than into neighboring properties or out into the night sky. Lights such as parking lot floodlights must be full-cutoff luminaries. This means that fixtures are shielded so light shines down onto the intended area, rather than out in all directions.

Gent says that aiming light where you need it improves visibility and saves energy. “Wasted energy accounts for around 30 percent of outdoor lighting,” he says. “That’s 38 million tons of carbon in the U.S. alone in wasted lighting, or around 10 billion dollars.”

Gent says communities don’t have to sacrifice safety for darker skies. Roads are safer when streetlights illuminate the roadway rather than shining in drivers’ eyes. And while bright lights may create the feeling of safety, studies show that they don’t actually prevent crime. Rather than leaving bright lights on all night, people concerned with safety are better off using security lights that are activated by motion detectors.

Homer Glen also discovered that better lighting benefits human health. People sleep better in the dark, and our bodies need darkness to produce melatonin, which protects against cancer. The National Cancer Institute recognizes that women who are exposed to bright lights while working the night shift may be at increased risk of developing breast cancer.

Better lighting also makes towns more attractive and prevents businesses from getting into light wars, says Debra Norvil.

Norvil and other proponents of the Homer Glen lighting ordinance built unanimous support for the measure by discussing it with all the interested parties. “We gave presentations to the Homer Township Chamber of Commerce, the Zoning Commission, Planning Commission, and the Village Board,” she says. “All I used was my house lamp, a shade, and a light meter to demonstrate good and bad lighting.”

Norvil recognizes that even with the ordinance, Homer Glen will still be impacted by sky glow from surrounding communities. She hopes that could change if other communities follow Homer Glen’s lead.

Russell Knack agrees. “If anyone has any questions, give us a call. We’re certainly hoping that this will set an example.”

Read the full ordinance at Homer Glen’s website, or call (708) 301-0632.

Related Articles:
Homer Glen Passes Breakthrough Ordinance, CW Fall 2006
The Vote for Green Towns, CW Summer 2001
“Lights Out” Program in Chicago Saves Birds, CW Spring 2002