Ron Struss, University of Minnesota Extension Educator

“When it rains it pollutes” is an easy shorthand for stormwater pollution. It is what happens when rain and snowmelt washes pollutants from streets, parking lots, yards, and storage areas and into lakes, rivers, and wetlands. Stormwater pollution, along with agricultural runoff pollution, are two main reasons we are not meeting “fishable and swimable” goals for our nation’s rivers and lakes.

Stormwater problems dates back to the earliest cities. The basic structures of cities, roofs and paving, prevents rain from soaking into the ground and leads to flooding during storms. The Indus city of Mohenjo-Daro (now West Pakistan) dealt with this problem in 3000 B.C. by building drains into their streets. The Romans built drainage systems in 1000 B.C. that not only handled stormwater runoff, but also overflows from public baths and fountains.

Stormwater is piped largely untreated to lakes and rivers – what washes off the land goes into the water!

Stormwater drainage systems soon led to sanitary sewers. Once it was noted that a good rainfall would flush a storm drain clean, people started putting household waste in them in anticipation of the next rain. However, when rains were infrequent, unsanitary and repulsive conditions would result. The solution was to cover over the drainage ways and create what the Romans called cloacae and we call sewers. Initially, sewers dumped untreated waste directly into receiving waters. By the 1930s wastewater treatment became common in developed countries.

When North American cities were built, combining stormwater runoff and sanitary waste into one sewer was common practice - a practice stopped in the 1960s in the interest of water pollution control. Combined sewers ended up at wastewater treatment plants. Runoff from small storms would be treated along with sanitary waste – a good thing. But runoff from large storms would overwhelm treatment plants, causing raw sewage to be dumped into rivers and lakes – a bad thing.

Now for the most part, storm sewers are separate from sanitary sewers. This means stormwater and the pollutants it picks up are routed largely untreated into surface water, resulting in:

• sediment from road sand and construction sites clogging waterways;
• nutrients from leaves, grass clippings, and fertilizer causing algae blooms;
• bacteria from pet waste, urban wildlife, and illegal sanitary connections causing beach closing; and
• toxics entering our water when people dispose of wastes down storm drains.

“Best management practices” are being promoted to reduce stormwater pollution. Included are innovative designs for new developments, “good housekeeping” practices to keep pollutants from being washed away by rain, education to keep people from using stormwater drains as disposal sites, and constructed practices such as ponds and wetlands to provide a degree of stormwater cleanup before it is released into lakes and rivers. A good basic publication on yard care practices can be found at: www.moea.state.mn.us/campaign/garden/.

Barb Liukkonen, Water Resources Extension Coordinator

Of course, you wouldn’t do that on purpose - you’re probably careful to select and plant native species. However, hitchhiking exotics might come along with those native plants that you are planting to improve the shoreline.

Recent research, funded by Minnesota Sea Grant and MN DNR found that 92.5% of wetland and aquatic plant orders included unintended plants or animals! Kristi Maki, advised by Sue Galatowitsch, in the University of Minnesota Horticulture Department, studied how often and what types of invasive species came along with plant orders, how easy it was to obtain regulated invasive plants, and how certain species are adapting to our colder Minnesota climate.

In the first phase of her research, Kristi surveyed which exotic aquatic plants are sold commercially. Her database, including 119 vendors and 39 invasive aquatic plants, showed that more vendors sell aquatic plants via the internet than from mail order catalogs and that 6 regulated aquatic plants and 4 regulated terrestrial plants (sold as aquatics) are commercially available.

Then Kristi placed orders with a variety of vendors across the US. She ordered individual plants or assemblages from water gardening or aquarium specialists and general garden businesses, with 30 vendors outside Minnesota and 4 from within the state. Regulated species were ordered 14 times and were received, without question, in all but one case!

When plants arrived, Kristi carefully examined them and identified unordered hitchhikers that were hiding in the packaging, tangled in roots, or included in the soil. Here’s a very brief summary of what she found.

• 90% of the purchases contained plants that hadn’t been ordered
• 80% included animals (usually invertebrates, but twice she received live fish!)
• 62.5% included algae, moss, or fungi
• 41% included seeds

Many of the hitchhikers were viable plants or seeds, as Kristi found when she planted them. In some cases, hitchhikers were federally regulated plants, including purple loosestrife, hydrilla, curly pondweed, and giant salvinia. It turns out that the unintended transfer of illegal species only occurred about 10% of the time, but when you think of how many plants we’re planting to restore shorelines, there’s a huge potential to introduce invasive exotic species.

So, what can you do to help stop the spread of invasive aquatic species as you are restoring a shoreline or cultivating a water garden?

• Learn what exotic species look like
• Be careful when sharing or transplanting plants (remember you need a permit to move plants from one part of your lake to another!)
• Order from reputable growers and ask how they prevent hitchhikers when they package or deliver plants
• Expect your plant sources to follow the laws and use sound practices
• Don’t order via internet web sites without evidence that they’re concerned about exotics
• When you receive plants, carefully examine them to remove hitchhikers before planting Never introduce anything from your water garden into a stream, lake, wetland, or drainage ditch.

Karen Sherper Rohs

I was first introduced to the concept of light pollution during an astronomy class in college. Although I had sympathy for the astronomers and the difficulty presented to their work as the areas around the observatory became increasingly lit at night, it didn’t seem very relevant to me personally. Until I moved home about ten years later. I discovered that the town five miles south of our hobby farm has so much lighting that a haze persists through the night. Some of my most vivid childhood memories include the sky — gazing into it with my brother as we waited for the school bus on early mornings, or whispering about its wonders as we came home late at night. These days the stars are more difficult to see.

Nighttime satellite image of the United States courtesy of Darksky

What is light pollution?

Light pollution is light that goes beyond where it is meant to be going or light being used when it is not needed. Three of the most serious problems in shoreland lighting include glare, light trespass, and sky glow. Sky glow refers to the washing out of the night sky due to exterior lighting shining upward and making cities “glow” at night. Examples include billboard lights that shine upward, street or parking light - ing bouncing off of pavement, and commercial or residential lighting open to the sky. Glare is the light going beyond what the fixture is meant to illuminate. This might be caused by poor design or poor installation. On shoreland, it can hamper the vision of boaters, pedestrians, and drivers and actually be a safety concern. Light Trespass is usually caused by glare; it’s the illumination of adjacent or nearby property not meant to be lit by the fixture. On the waterfront, water reflects glare from shoreland lights onto distant properties. The reflective nature of water is one of the most challenging aspects of sensible shoreland lighting!

What can be done?

• Provide adequate light for an evening activity, but don’t over-light. Choose lights that meet the needs without lighting beyond what is required for the task.
• Choose lights that do not emit light above the horizontal or retrofit existing fixtures with shields to reduce glare.
• Use high-efficiency lamps.
• Avoid dusk to dawn security lights; consider motion detectors.
• Position lights above and in front of signs, keeping the light aimed at the sign surface.
• Learn more about light pollution and recommendations for exterior lighting guidelines designed for local planning authorities.

Why care about light pollution?

The Institution of Lighting Engineers states: “All living things adjust their behavior according to natural light. Man’s invention of artificial light has done much to safeguard and enhance our night-time environment but, if not properly controlled, obtrusive light (commonly referred to as light pollution) can present serious physiological and ecological problems.” A quick scientific literature search produced studies indicating connections between artificial nighttime lighting and disruptions in migrations of birds and salmon, disruption of plant development, decreases in moth populations, behavior impact on fireflies, and disruption of turtle and frog reproduction. In addition to reducing the impact of artificial lighting on nocturnal biological activities, eliminating light pollution will reduce energy usage, save money, and reduce distraction to nighttime drivers. Perhaps less tangibly, eliminating glare will once again open up the nighttime sky for gazing by professional astronomers and amateurs alike. David Crawford, Executive Director of the International Dark Sky Association says: “Light pollution is not a matter of life and death. Yet it is important nonetheless, profoundly so. We human beings lose something of ourselves when we can no longer look up and see our place in the universe. It is like never again hearing the laughter of children; we give up part of what we are.”

Resources on Shoreland Lighting, Light Pollution, & Stars

• Sensible Shoreland Lighting: Preserving the beauty of the night. Publication by David S. Liebl, Robert Korth, University of Wisconsin-Extension.
• International DarkSky Association Fact sheets, satellite imagery, links to research, additional light pollution information, and tips for choosing exterior lights.
• University of Chicago Yerkes Observatory Photographs, presentations, sample ordinances, and additional website links.
• New England Light Pollution Advisory Group Newsletters, tips, website links.
• Minnesota Sustainable Design Guide Recommendations for exterior lights.
• University of Minnesota: Astronomy
• April 23, Wed., 7 pm presentation, Marshall W. Alworth Planetarium, Duluth. Lights of Our Atmosphere: Natural vs. Unnatural.