Environmental advocates say Northfield’s night sky continues to become more colored by artificial light.
To combat that, Environmental Quality Commission Board member Kim Smith introduced proposed amendments to the city’s Dark Sky policy Thursday to the Northfield Planning Commission that would limit artificial light exposure at night and grant the city power to remove the nuisance.
A concern of the EQC cited by Smith, a Carleton College professor of environmental studies and political science, in proposing the amendment has been the change of nighttime lighting to blue-rich light, a brighter form. She said that type of light emulates natural light, suppressing residents’ melatonin production, resulting in sleep loss.
Smith told the Planning Commission Thursday the EQC has fielded complaints from residents regarding light pollution since Xcel Energy installed blue-rich street lights. She said Xcel Energy has gotten feedback on the style of their lighting and wants to convert to a warmer LED light.
“Recent research shows that exposure to this blue-rich light at night may contribute to health risks such as cancer, obesity, heart disease and diabetes,” the proposed amendment states. “It has similar negative impacts on wildlife. In sum, light pollution interferes with the city’s goals as stated in the 2008 Comprehensive Plan, which include promoting healthy lifestyles and preserving and enhancing its natural resources.”
The Planning Commission did not act on the request, and it is unknown when or if the Northfield City Council will address the proposal.
Under the proposed amendment, residents cannot cause “unreasonable interference” with neighboring properties or with the public’s opportunity to observe the Northfield night sky.
The proposal gives the city administrator the ability to give anyone violating the section notice to remove the nuisance. If the offender does not comply, the administrator could remove the nuisance.
Under the changes, city staff or a designee would perform audits of all city outdoor lighting at a minimum rate of every 10 years. The audits would identify shielding, maximum illumination, color temperature and trespass that does not meet the standard. The results would be made public.
Lighting reductions will not be required for outdoor lighting consisting of one light fixture, lighting required by code for steps, stairs, walkways and building entrances, lighting governed by a special use permit in which operation times are identified, businesses operating on a 24-hour basis and for lighting the city deems necessary for safety reasons or for special events.
Data reportedly shows in 2006, Northfield’s night sky was three to five times brighter than natural levels. In 2016, an estimated 40 percent of Northfield was five to 10 times brighter.
“It’s been getting much brighter,” Smith said. She noted people have expressed concern over artificial lights from buildings with large glass walls.
“I do think that is an issue,” Smith said. “And I don’t know if this is the best way to address it, but I thought perhaps the best way would be to require lighting controls if it’s an interior light that’s visible through a large glass wall.”
Smith said in crafting the proposed amendments, she looked at model ordinances for cities in Utah and northern Minnesota.
During the meeting, Planning Commission board members asked what the city could do to incentivize certain lighting rather than punishments for not having proper lighting standards, and whether the Environmental Quality Commission has considered a partnership with other community organizations to reduce costs associated with meeting any new standards.
Smith said the EQC had not looked into the possibility of partnering.
The city began addressing light pollution with the Dark Sky regulation in the Land Development Code.
“But that regulation does not address the color temperature of night lighting,” the proposed resolution states. “It does not cover sources of light pollution that don’t require a building permit, and it does not provide for enforcement after a building is permitted. The City Code should address these issues.”