The Devil’s Element in Our Water
Everyone wants clean water in Door County. I don’t believe it’s a partisan issue because no one is in favor of polluting our waters. Despite this, phosphorus continues to contaminate our waters.
The Devil’s Element refers to phosphorus in Dan Egan’s new book by the same name. Phosphorus is an essential natural element that allows all life forms to proliferate. In fact, without phosphorus, life would not exist. It is a necessary element needed for plants to grow. It is, therefore, a prime ingredient in fertilizers on farm land. It is also present in manure, a natural fertilizer. However, too much phosphorus pollutes our waterways. It can cause blue-green algae blooms after washing off the land and into our waters. People can’t swim, fish, or recreate in water with blue-green algae present.
The problem is that the sheer quantity of phosphorus currently being deposited into our waters is overwhelming the capacity of our waterways and Mother Nature’s ability to handle it. So where is all this phosphorus coming from? The Fox River contributes more phosphorus to Lake Michigan via the bay of Green Bay, than any other Lake tributary. The river is also the second largest contributor of sediment to Lake Michigan. U.S. Geological Survey scientists monitoring the river recently gave us some important phosphorous data in their report entitled, “Changes in Phosphorus and Suspended Solids Loading in the Fox River, Northeastern Wisconsin, 1989-2021.” These scientists report that the dissolved phosphorus in the water at the mouth of the Fox River has decreased. This sounds like a good thing, that conditions have improved, right? But wait, these scientists also reported that total phosphorus loads entering the bay have increased from 793,664 pounds in 1989 to 1,227,974 pounds in 2021!
Dale Robertson, a USGS hydrologist and author of the report, says that even though concentrations of phosphorus in the water are less, recently, increased rainfall is causing more of it to be washed into the bay. So, two seemingly opposing observations are possible, while the water coming out of the Fox River into the bay is cleaner, the total amount of phosphorus entering the bay has increased significantly since 1989. The concentrations of phosphorus are improved because the volume of water flow has increased, thanks primarily to more rain and greater river flow.
The prevailing water current in the bay is basically counterclockwise. Lake Michigan water enters the bay through the Rock Island and Deaths Door passages and proceeds down the Michigan side of the bay to the city of Green Bay where it picks up the Fox River water and comes back up the Wisconsin side, eventually to Door County. Although diluted, contaminants in the river are, potentially coming to Door County, unfortunately. The Fox River, however, is not the only source of phosphorus in Door County waters. Some phosphorus enters our waterways here in Door County from both point and nonpoint sources. Point sources are identifiable sources, such as factories and wastewater treatment plants. Nonpoint source pollution is runoff from the broader landscape including agriculture. While the Clean Water Act sets limits for pollutants from point sources, surprisingly, phosphorus and nitrogen are not included in these regulations. The laws do not include nonpoint sources, like agriculture, which account for more than 80% of phosphorus in Wisconsin waters! Why not? How are CAFOs that produce as much waste as a city the size of Green Bay not considered point sources of pollution?
Streams in Door County are also adding to the amount of phosphorus in our waters. The Wisconsin Department of Natural Resources identifies four Door County streams that are now impaired by phosphorus and adding to the pollution of the bay and the lake. Where is all this phosphorus coming from? It comes from many sources such as natural sources (waterfowl, plant decomposition) or human-induced (agricultural and urban runoff, industrial and domestic sewage), but certainly agriculture is one of the main sources.
Additional phosphorus monitoring in the Door County watershed is needed. I believe we need to establish baseline phosphorus data for all Door County’s streams, rivers, and bays. Only then can we accurately determine if our phosphorus concentrations are improving or worsening. Currently, there is very little phosphorus data for Door County waters. Having phosphorus information can help us determine what conservation practices are working best and where watershed improvement practices need to be prioritized and improved upon.
Your Door County Environmental Council is working on gathering the necessary data. However, it takes resources, including time and money. Can you help? We simply can’t wait for things to get worse. What is Door County without clean water?
By Steve Eatough, President, DCEC
This article was adapted from “Decades-long Phosphorus Study of Lower Fox River Shows Why It’s a Big Problem for Lake Michigan,” an article written by Caitlin Looby and published by the Milwaukee Journal Sentinel Newspaper on January 31, 2024.
“Changes in Phosphorus and Suspended Solids Loading in the Fox River, Northeastern Wisconsin 1989-2021.” https://pubs.usgs.gov/ publication/sir20235112. December 28, 2023.
Egan, Dan. The Devil’s Element: Phosphorus and a World Out of Balance. W.W. Norton. March, 2023.
