The last post I wrote was about the affect of industrial pollutants like PCBs and mercury on the waterways in the Great Lakes area. Shortly after I wrote the post I heard about the Riverwatch group in Indiana. This is a group of volunteers who are trained in how to monitor streams and rivers in Indiana watersheds. Because this subject was on my mind already I signed up to attend training at Gibson Woods in Hammond, IN on April 30th. (A lovely park I never knew about. I urge people to go. The pond is beautiful.)
A stream may seem like something small when thinking about what’s going on with Lake Michigan but those streams are important. Understanding what a watershed is, exactly, helps us understand that what we do impacts more than just our immediate location. A watershed is ALL the land, above and below the surface, where water that runs off/out of it ends up at one point. We all live in a watershed. You’ve probably seen the signs along highways saying that such and such and area is part of a watershed. What that means is that whatever we put onto the ground in that area or into the water ends up in our larger bodies of water, including Lake Michigan. When we hear about a body of water that’s polluted we tend to think of industry or perhaps farms causing that pollution but we need to remember that we contribute as well. In fact pollution directly from something such as a factory discharging into water is only 25% of the pollution (point source pollution). The remaining 75% is from the land use in a watershed.
How do we contribute? One way is what we put on our lawns or gardens. Nitrogen and phosphorous are ingredients in chemical fertilizers. They are also something that the Riverwatch group tests for in waterways. Just like these chemicals promote the growth of plants and grasses, they increase the growth of algae in water. This algae grows too fast, causing plant death. As the plants die and decompose, the oxygen in the water decreases and fish can die. (One extreme example is the dead zone in the Gulf of Mexico)
The picture at the right from NOAA shows this area and it's dissolved oxygen (DO) level (something else Riverwatch tests). For aquatic life to be happy the DO needs to be at least 5 ppm. On the picture that doesn't start until the lightest shade of green.
People can help to reduce their impact on the water in their area by avoiding chemical fertilizers. If possible, using native plants in your yard is a good idea. Check out Clear Choices Clean Water for details on ways to do this. To find environmentally friendly lawn care products, I recommend Clean Air Gardening.
Some of the other sources of phosphorous include manure from farm field run off or human waste from failing septic tanks or from municipal treatment discharge. A further source of phosphorous is detergents, so much so that many states are enacting bans on phosphates in detergents. This is good for the environment but many people complain their dishes aren't as clean. I've found that a product called Lemi Shine works WONDERS for cleaning dishes and removing hard water stains.
As far as nitrogen, the ways to reduce phosphorous help but the main source of nitrates in Indiana water is sewage. Unfortunately the only way to reduce that source is infrastructure investment and improvements, something I am not going to address at this time but if you want to understand some of the issues with it check out the movie "The Crumbling of America" from the History Channel. I don't see it on Netflix but it still comes on the History Channel occasionally.
I hope this post gives you some things to think about. Remember, no matter what size, we all have an impact on the environment and every little bit we can do to lessen that helps.