By SILKE SCHMIDT
Wouldn’t it be nice to learn from our mistakes and make sure they don’t repeat themselves? Yes indeed, but in the case of Lake Erie, a problem thought to have been addressed with great success in the 1980s reared its ugly head again in 2011: the lake experienced its largest algal bloom in history, three times bigger than any of the previously recorded blooms.
However, while the end result was very similar, the culprits of the 21st century are notably different from those of the 1960s and 1970s. Back then, the excessive accumulation of phosphorous, also called eutrophication, was caused primarily by wastewater running from municipal sewage treatment plants right into the lake.
Legislation and upgrades of these sewage treatment plants by both the United States and Canadian governments helped reduce the phosphorous loadings in Lake Erie by more than half of the 1970s levels in the mid-1980s. The lake’s swift recovery was a globally recognized success story; it also confirmed that reductions in phosphorous input were crucial for improving water quality.
In the early 2000s, however, phosphorous loadings started to rise again. This time, their primary source was not sewage plants, but runoff from fertilized farm fields, lawns, and impervious surfaces, such as streets and parking lots.
Since the bulk of phosphorous is transported by runoff water into Lake Erie during spring snow melts and heavy rainstorms, the problem is worsened by the effects of climate change: more frequent and more intense extreme weather events, such as heavy spring rains in 2011, flush big loads of phosphorous into the lake at one time, and warmer water temperatures create more favorable conditions for massive algal growth.
Reducing land use-related phosphorous input requires very different strategies than upgrading sewage plants. To help U.S. and Canadian policymakers develop, prioritize, and implement specific phosphorous reduction strategies, the Lake Erie Ecosystem Priority (LEEP) project was created by an International Joint Commission (IJC) in 2012.
In August 2013, the IJC published its first LEEP Summary Report. It is currently considered a draft version that is available for public comments. More information about its fifteen specific policy recommendations and instructions for submitting comments can be found here.