It’s All About Quality
Water quality that is! Water quality refers to many different things, such as is the water safe for drinking or swimming? Can you eat the fish caught in it? Is it a good habitat for wildlife and plants? Water quality depends on the physical, biological, and chemical environment in and around a lake. Our previous column was about invasive species; this column is about chemicals, but not the kind found in hazardous waste dumps.
The focus here is on chemicals naturally found in water, like phosphorus and nitrogen which are required by all organisms, including us. For example, phosphorus gives all cells the energy to do things, while nitrogen is found in proteins which are the building blocks for life. Phosphorus comes from the breakdown of rocks, and nitrogen is the most common gas in the atmosphere. They are reused over and over in ecosystems by a number of chemical and biological processes.
Problems arise when the level of either phosphorus or nitrogen rises above normal. When this occurs, the result is typically a rapid population growth of algae (and other aquatic vegetation), known as a bloom. Algae in lakes consist of several microscopic species, called phytoplankton as a group. During a bloom, they can turn the water as green as pea soup. What is worse than just the yuck factor, is that some species (mostly cyanobacteria, also called blue-green algae) may also be toxic to animals and humans. Deaths of pets and farm animals have been associated with algal blooms.
Excess nutrients come from many sources. Fertilizers, yard and pet wastes, some soap and detergents all contain phosphorus and nitrogen. Our lakes do not have sewer discharges, but many septic tanks line the shore and faulty tanks will leak both chemicals. Stormwater contributes these pollutants through runoff from roads and other hard surfaces. Nationally, farms in the watershed can be one of the largest sources of excess nutrients from animal manure, fertilizers, and soil erosion.
The good news is that we can, right at home, all help to prevent excess nutrients from getting into the water. Use non-phosphate soap, detergents, and fertilizers and never use more than is absolutely necessary. Make sure runoff from your house and driveway is directed away from water channels leading to the lakes. Proper maintenance of roads and drainage around the lakes, and the streams that feed the lakes, can help to minimize pollutants. Local farms can help by reducing erosion, avoiding excess fertilizer, making sure there are buffers between fields and waterways, and locating manure piles away from areas where runoff may carry waste to streams.
By Stephan Zeeman