This article, published in the May 2004 issue of NJ Municipalities Magazine, has been withdrawn from this "Tools" section. A more up-to-date article was published in the January 2008 issue of the magazine (see Tool #1, Controlling Light Pollution above)
Let's All Reduce Light Pollution
By John Batinsey 1/19/04
(This article was submitted to the League of NJ Municipalities and was published in the 5/04 issue of NJ MUNICIPALITIES magazine)
I've been a member of the Eatontown Environmental Commission for about twenty years and I have never seen a more misunderstood environmental problem than light pollution. It affects everyone, but strange as it sounds, most people are not aware that anything can be done to minimize it. Most people think that all that glaring bright light must be necessary. We need light to see at night and it is assumed that if we want light, that's what we get. The more such light the better we see. Right? Not really. Lets now analyze this common hypothesis.
NJ LIGHT POLLUTION STUDY COMMISSION
In 1995, a State Commission was formed to study light pollution. Ten months later, in April of 1996, the New Jersey Light Pollution Study Commission completed its report and submitted its findings and recommendations to the Governor and Legislature (a copy of the Commission's report is available from the League of NJ Municipalities).
The reports recommendations are predicated on the following four principles:
- Most glare can and should be prevented. Glare affects the ability of drivers to perceive objects or obstructions clearly. Particularly sensitive to this problem are elderly drivers.
- Energy is wasted when excessive levels of illumination are used. Inefficient luminaires can spill unwanted light well outside of the intended target area.
- Light trespass may be viewed as an invasion of privacy. Most obtrusive lighting conditions can be avoided.
- Inappropriate use of outdoor lighting can deteriorate the natural nighttime environment, particularly in areas preserved for wildlife. In addition, sky glow reduces the ability to observe the starry night sky.
Eatontown adopted its lighting ordinance in 1993 and has been effectively controlling light pollution ever since. For those who are unfamiliar with Eatontown, we are a densely populated developed suburban municipality in Monmouth County. The ordinance is based on the same lighting practices recommended by the Commission and is probably the first complete ordinance to control light pollution enacted in New Jersey. Here are some of the key elements in the ordinance.
- Cutoff light fixtures must be used for most applications such as parking lots and streetlights, that confine the light to the intended target area. The cost is about the same as non-cutoff light fixtures.
- Illumination levels cannot exceed or fall below the recommendations of the Illuminating Engineering Society of North America (IES), the foremost authority publishing lighting practices in the United States.
- After normal business hours, most retail/industrial lighting is reduced to a lower property security level.
- Lighting plans submitted to the Borough must be complete, and as a result, potential problems are identified and resolved before any construction begins.
I'd like to show you how well the ordinance works by giving you a few examples of the almost 100 lighting plans submitted to the Planning Board during the past 10 years.
- An automotive dealer lighting plan utilizing floodlights contained illuminance levels as high as 174 footcandles (fc) in some parts of the property. The Board approved a maximum level of 30 fc that only applied to the front row feature display area, representing about 10 percent of the total property. The remaining areas being illuminated were considerably lower following IES recommendations. All lights installed are cutoff types instead of the non-cutoff lights originally submitted, that would have projected outrageous levels of glare in unwanted directions.
- A mid sized shopping mall that includes a Burger King restaurant and several large retail stores has been illuminated at an average of 2.5 fc. Many fast food restaurants are lighted at averages ranging between 15 and 20 fc - and some with glary non-cutoff lights.
- Monmouth Mall, a regional sized facility with over 150 stores and more that 100 acres of illuminated outdoor parking has cutoff lighting with maximum illuminance levels of 6.0 fc. Similar malls elsewhere often have maximum illuminance levels 2 or 3 times higher.
- An adult condominium village lighting plan specifying 22 glary non-cutoff post top decorative street lights were replaced with a more efficient fixture that required 72 percent less energy. IES illuminance recommendations were fully met saving taxpayers unnecessary energy costs amounting to more that $2,000 annually.
- Gas stations in Eatontown, in the pump island area, are illuminated at less than 20 fc and have light fixtures in the canopy without drop globes. Many gas stations have illuminance levels of around 100 fc utilizing light fixtures with drop globes that cast severe glare onto roadways.
- A lowe's home improvement center will soon be built in Eatontown with exterior lighting that will be different from other similar facilities. All luminaires will be full cutoff. Lamp wattage has been reduced and many unshielded wallpacks have been replaced with cutoff wall fixtures. Eighty percent of the lights will be truned off after closing hours. All of these changes which follow IES guidelines, will lower energy costs by over $25,000 annually.
EATONTOWN LIGHTING TOUR
Some readers may not be familiar with illuminance levels expressed as footcandles (fc). I would highly recommend the lighting tour offered by the local Environmental Commission to actually see how effective these lighting levels are. You will be shown examples of both good and bad lighting. Most people who take the tour are quite surprised at how the various footcandle readings appear visually and how effective the IES recommendations we follow actually are.
For parking lots, the IES recommends average illuminance levels that range between 1.0 and 2.5 footcandles, with an average to minimum ratio of 5:1. This provides excellent uniformity. Appropriate maximum to minimum ratios will avoid overly bright areas beneath the lights that make normal minimum areas from appearing dark. This kind of lighting will provide safe and secure conditions. Moreover, the IES states that the 2.5 fc average will provide twice the light necessary for facial identification in a police line-up.
OUTDOOR LIGHTING ORDINANCE GUIDE
An Outdoor Lighting Ordinance Guide, prepared by the Environmental Commission is available from the League of NJM. It includes a model ordinance based on the Eatontown Ordinance and options to consider that would be applicable to local needs and conditions. Also included are some of examples of both "good" and "bad" light fixtures.
WHY IS THERE SO MUCH LIGHT POLLUTION?
About a dozen New Jersey municipalities have adopted ordinances to control light pollution to date and there are several more seriously considering doing the same. With well over 500 municipalities in NJ, why so few? The Commissions recommendations were quite clear: Light pollution can be reduced, a benefit to everyone. But those Departments of State and the major electric utilities who were included in the Commission's membership, have not really followed their own representative's recommendations.
NJ State roads are probably the most light polluted in the nation. The State has still not provided guidelines or training to counties and municipalities on how to control light pollution. Most State facility outdoor lighting can be improved. Environmentally sensitive areas remain unprotected from unnecessary light pollution. Electric utilities will not install cutoff streetlights to reduce glare, unless a municipality makes it clear that non-cutoff lighting is unacceptable.
IT'S TIME FOR STRAIGHT TALK
Media coverage generally presents the light pollution issue from an astronomy perspective, and as a result, many people will define light pollution simply as sky glow. The people interviewed are often from the astronomy sector who clearly and passionately express their inability to view the night sky. Even though the other elements of light pollution are mentioned, the astronomy concerns usually dominate in the articles.
Misleading or partial information is often accepted as being complete and factual causing confusion and inappropriate action from those on opposite sides of the issue. Here are a few samples.
- If you use cutoff streetlights you will be able to reduce the lamp wattage and save energy.
- Using cutoff streetlights will require closer spacing increasing cost and energy use.
Both of these statements are not true. We asked Cooper Lighting to prepare a photometric grid of three cobra head fixtures, on a typical residential street 30 feet wide, at 30 foot mounting heights, all with the same lamp wattage. One fixture had a drop lens (non-cutoff), The second a flat lens (full cut-off) and the third a sag lens (cutoff). To meet IES average illuminance recommendations the drop lens fixture actually had to be spaced 20 feet closer than the cutoff types. Reducing lamp wattage would have brought the illuminance below IES recommended levels. We found similar comparisons with decorative post top streetlights. Over all, I would rate the comparison between cutoff and non-cutoff a draw. However, by reducing even low levels of unnecessary glare we all see better.
- Parking Lots
- Mandating cutoff type light fixtures over non-cutoff will increase cost.
Here again, overall cost is about the same. Chose efficient light fixtures with good uniformity. High priced fixtures may not be good as less expensive ones. The photometric grid ordinance requirement showing illuminance points every 10 feet will help the designer to make the right choice. Some manufacturers may even prepare a grid for the local engineer.
- Restricting pole heights to 16 feet or lower, will reduce light pollution.
For small parking lot lighting, this may be the perfect height. For larger sized parking lots requiring greater mounting heights, light pollution will not be increased over the use of shorter poles. In fact it can increase cost and even use more energy. For a mid to large sized parking lot requiring 30 foot mounting heights, reducing the height to 15 feet could increase the number of poles needed about 4 times to light the same area (inverse square rule). One 400 watt lamp could equate to four 100 watt lamps. The lumen per watt ratio is about 50 percent better for the higher wattage lamp, thereby saving energy.
- Low pressure sodium (LPS) lamps are the most energy efficient and should be used for all street and parking lot lighting.
It is important to use LPS lamps in areas that include major astronomical observatories, allowing astronomers to filter out the narrow yellow color wavelength form of sky glow. These special filters, however, are really not available to amateur astronomers. The LPS monochromatic light does not provide any color rendition unless other "white" light is added. All colors appear as varying shades of greyish brown. Also, vision reaction time at low LPS levels is slower than with other lamp source lighting. I see no benefit to anyone in NJ, including amateur astronomers, in a LPS lighting mandate.
- Illuminance Levels
- Lighting illuminance should be the minimum adequate for the intended light task.
This type of wording, requiring only minimum illuminance levels, can be misunderstood to mean that a municipality might be denied light levels that they're entitled to. For instance, the IES has one set of parking lot average illuminance recommendations that fall between 1.0 fc (Basic) and 2.5 fc (Enhanced Security). Eatontown allows a business to choose a level anywhere within this range, which has been met with both business and public approval.
- Electric Utility Floodlights
Here are some excerpts from floodlight promotional literature:
"...a well designed floodlighting system; ...a crime free zone; ...safety and security every night of the year; So rest easy; Peace of mind."
Such statements of assurance are not realistic and should not be made. Unfortunately, many of these floodlights are not installed properly throughout the State and spill light well outside the intended parking lot area. In some cases the lamp wattage is too high. When aimed incorrectly, such lights cast glare into the vision range of motorists that can be distracting and even hazardous. When Eatontown adopted its lighting ordinance, 120 of these floodlights were already installed in the Borough. Many were repositioned or had external visors added to control the glare. We are still waiting for a few more that still need adjustment or replacement. The state of Connecticut has recently passed a law that requires proper installation. Perhaps New Jersey should do the same.
WHY ADOPT A LIGHTING ORDINANCE?
If you don't want the public who live, work and shop in your town to be exposed to abusive lighting that causes them to squint and strain their eyes just to see where they're going, then you want to regulate lighting. Glary or excessive lighting can affect your visibility, causing pupal contraction and combined with other mechanisms in the eye, can cause adaptation problems when leaving a light pollution area and entering a roadway. These problems affect seniors even more than younger people. The IES recommendations are optimum lighting levels that allow you to see effectively without discomfort or any visual disability.
Professor Narisada, Vice-President of the International Lighting Commission (CIE), stressed the cost of unnecessary power generation from over-lighting and inefficient lights that cause glare and obtrusive light. He noted that below and above certain levels of light humans do not feel comfortable, just as with temperature or noise levels. There is a right level for information flow and over-lighting is as bad or worse than under-lighting. No one believes any more that "the more light the better".
We all have an opportunity to fix this problem in New Jersey. Let's do it!