When I used to think of water pollution, I imagined an industrial building with a pipe spewing smelly, vile-colored liquid into a river. I’ve never witnessed such pollution, but I do remember the stream that ran through my college campus 25 years ago. There was a paper mill nearby that produced toilet paper, and you could tell what color tissue they were making by the color of the water flowing downstream from the plant.
Now when I think about water pollution, the image that comes to mind looks much more benign than a factory dumping chemicals into a river. I imagine a small town street with a man pushing one of those rotary contraptions that spreads lawn fertilizer, a woman nudging her dog off the sidewalk into the edge of the street to do its “business,” and a teenage kid changing the oil of his old pickup truck in the driveway. That’s a scene I’ve walked or driven by countless times, never imagining that what I was seeing were major sources of water pollution in northern New England. It took a fall kayak trip on Lake Champlain and paddling into the green slime of a major algae bloom for me to realize that pollution makes its way into New England waterways from sources other than factories.
I learned that there are both “point” sources of pollution (specific places such as factories or sewage treatment plants) as well as “nonpoint sources” (such as stormwater runoff that includes dog waste and lawn fertilizers). New England rivers and lakes have three major types of water pollution: excessive levels of phosphorus, bacteria, and toxic chemicals.
Phosphorus is a naturally occurring nutrient necessary for plant growth. It’s a major ingredient in many lawn and garden fertilizers. Phosphorus becomes a problem when excessive amounts of it end up in a body of water and cause increased plant growth and algae blooms like those we paddled through in Missisquoi Bay. Many smaller ponds and slow-moving areas of the Connecticut River grow telltale green coats of duckweed and other plants later in the summer. Besides being unsightly and hard to paddle through, plant overgrowth causes oxygen depletion, which hurts trout and other fish.
Where does all of this phosphorus come from? Three main sources of phosphorus are stormwater runoff, wastewater and sewage discharges, and agricultural runoff. Stormwater runoff occurs when rain or melting snow flows over roads, parking lots, and lawns, and then flows into streams and lakes. Inadequate or overburdened sewage treatment facilities and septic systems also contribute to pollution as sources of both phosphorus and bacteria.
And then there are the cows. Vermont and the Connecticut valley are known for their dairy products, and all those cows produce a lot of phosphorus-rich manure. Unless the manure is properly stored and handled, its nutrients will run into rivers and lakes during heavy rains and snowmelt.
Increased levels of bacteria in bodies of water, including E. coli and giardia, can cause serious health hazards. Every summer, a number of New England beaches are closed to swimming for days at a time because of excessive bacteria counts. The bacteria come from many nonpoint sources, including dog waste and leaky septic systems.
Although less common in nonpoint source pollution, chemicals and heavy metals also find their way into local waterways. Improper disposal of chemicals down household drains, oil leaks from cars in parking lots, and chemical spills on roadways all flow downstream through storm drains.
It’s harder to stop nonpoint source pollution than point source. Instead of one factory to clean up, there are many smaller contributors, mostly caused by people who aren’t aware they are polluting their local streams. Luckily, there are simple ways for individuals to help reduce the amount of pollution flowing into bodies of water in their neighborhoods. Here are a few:
• Properly maintain your septic system by pumping the tank every few years.
• Wash your car with non phosphorus and biodegradable soap on your lawn rather than on your driveway so that excess water and detergents can soak into the grass.
• Do not use unnecessary fertilizers; first, have your soil tested to see what nutrients you need.
• Do not pour chemicals or motor oil down storm drains or into septic systems.
• Use non-phosphorus soaps or detergents.
For more information about nonpoint source pollution and tips for stopping it, see the Homeowners Guide to Nonpoint Source Water Pollution on the Connecticut River Joint Commissions website (www.crjc.org).