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Phosphorous in Lake Erie | Water Quality Series: Part 3

ERIE COUNTY, OH - For our third installment in a series on water quality, Cassandra O. Lagunzad interviews Dr. David Baker, professor emeritus and founder of the National Center for Water Quality Research (NCWQR). The NCWQR founded in 1969, is affiliated with Heidelberg University in Tiffin, Ohio. Baker discusses the history of water quality in Lake Erie and how it relates to the center’s research, focusing on phosphorus levels accumulating in the lake through the surrounding watershed.

According to Baker, the over-enrichment of phosphorus in Lake Erie has been a serious and unmitigated concern since the 1960s.  He said even then its effects were obvious; dead fish with excessive amounts of algae washing onto shore, producing undeniably foul odors. However, it wasn’t until the Cuyahoga River caught fire that the federal government took action, realizing the immeasurable value of Lake Erie. The need to determine all sources of phosphorus went so far as to  involve the U.S. Army Corp. of Engineers. Because of the times, neither the EPA or the Earth Day Coalition were in existence. The government authority was the Federal Water Pollution Control Administration (FWPCA), established in 1965.

Baker claimed the obvious causes were initially addressed. Point-source pollution, where contamination comes from a definite and specific location – such as a pipe from a factory – were easy to identify.  To regulate this, the excessive use of phosphorus in detergent was banned. Unfortunately, this alone was  an insufficient solution. In 1981, the lab found that for every 1 pound (.45 kilograms) of phosphorus that came from point source pollution, there was 3 pounds (1.35 Kilograms) from non-point source.

Non-point source pollution does not come from a specific or easily traceable source.  This usually comes from agricultural runoff, golf courses, parking lots, lawns, etc. The tests conducted at that time found a large quantity – much more than expected – of phosphorus running into rivers from agriculture use.  The reaction was to reduce the maximum loading of phosphorus permitted, so that if phosphorus was kept at the target load then the water would recover and not suffer over-enrichment.

The lab advocated this solution: reduce sediment particles by reducing erosion through no-till farming.  This meant not plowing and allowing crop-residue and stems to protect soil from erosive rain impact. This was considered a best management practice (BMP) as Baker put it, “to use land for necessary purpose, but minimize [ecological] impact.”

He went onto say that the 1980s saw a push for farmers to adapt BMPs, which was fairly successful.  The research showed that it worked.  There was reduced sediment export and reductions in the loading of a particular type of phosphorus. Phosphorus loading was set at 11,000 ppb, a number in which fisheries claimed was too low and that the reduction went too far. Lake Erie did recover for a while. However, since the 1990s Lake Erie began to deteriorate again. Satellite photos showed excessive algal growth, algal soup, and worsening of oxygen depletion in deep water.  Scientists, the NCWQR among them, wondered, “Why?”

The initial phosphorus reduction had appeared to be successful, but dissolve phosphorus runoff went up dramatically. Some point the finger at the introduction of zebra mussels, an invasive species.  Others blame the elusive non-point sources.

Baker offered two primary reasons.  The first is the combination of no-till farming, phosphorus stratification, and rain runoff.  The second was a change in farming system practices, broadcasting rather than injecting phosphorus fertilizer.  In addition to the two main factors, Baker mentioned another: decreased snow cover during winter. This transforms December and January into high flood months, increasing loss of fertilizer, and increasing sediment runoff.

In terms of a solution, Baker suggests salt tests for agriculture to keep from excessive applications of phosphorus fertilizers.  He also suggested that as farmers become more concerned with their returns, coupled with the rising price of phosphorus fertilizers, they should be more cautious about wasting fertilizer by broadcasting it. As the agricultural industry becomes more aware of their possible losses, changing the best management practice standards may benefit water quality and the environment.

Baker advocated adaptive management or “using information-intense management to produce food we need at low cost to consumer and protect the environment.”

He went on to say, “[we] cannot wait for more information, but have to act now with the information we have.” He acknowledges that the information itself is complicated.  He mentioned the measurement of sediment follows a specific and somewhat misleading pattern during storms. Initially, storms lead to spikes in sediment content, and then a decrease.  Baker also stated that sometimes it is difficult to link watersheds to what happens in certain fields.

Even with uncertainty dragging its feet, research and documentation is important to the process of improving the health of Lake Erie.  According to the NCWQR website, the lab was granted a $1 million grant from the Great Lakes Protection Fund in 2007 to aid in their efforts.

For more on this topic, check out our series on water quality.

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