Gulf 'dead zone' shrinkage baffling | Article

LAST summer, scientists who study the so-called "dead zone" in the Gulf of Mexico were startled to find that the area had shrunk to 3,000 square miles -- just half of the zone's average size and far below the 7,500-8,500 square miles forecasted for 2009.

National Oceanic & Atmospheric Administration scientists theorized that the unexpected shrinkage of the hypoxic zone was due to the year's weather conditions, but they were curious enough to call for additional study. Measurements of the dead zone will continue this year.

The finding did not surprise the Missouri Water Quality Commission, which had successfully kept the Army Corps of Engineers from dumping phosphorus-laden sediments into the Missouri River since early 2008. The Missouri River is a major tributary to the Gulf.

Others are now joining in the call for a study to determine if agriculture is simply taking the blame for nutrient loading in the nation's waterways when the nutrients are actually coming from other sources.

Since part of the upper Missouri River watershed is in North Dakota, state agriculture commissioner Doug Goehring said in a January statement that Missouri's problems with the Corps have "serious implications for North Dakota and for American agriculture."

Where's EPA?

So far, the federal government has been slow to investigate the impacts of the Corps' project to create habitat for the endangered pallid sturgeon, which involved dumping the massive amounts of phosphorus-laden sediments into the Missouri River.

Interestingly, the Environmental Protection Agency, which has numerous heavily funded efforts to clean up the Gulf hypoxic zone, did nothing to block the Corps' sediment dumping despite taking enforcement actions against private companies on far lesser erosion threats to the same river basin during the same time period.

The Corps had planned several construction projects that included digging 25 ft.-deep "side channels" across bends in the river to create a habitat for the pallid sturgeon. The rich riverbed sediment dredged from the new channels was slated to be dumped back into the river's main channel, and that was the crux of the pollution issue.

The projects in Missouri came under fire from the Missouri Clean Water Commission in 2007, and there currently is a moratorium on the dumping until a National Academy of Sciences study -- under contract from the Corps -- is completed. The study, by the academy's Water Science & Technology Board, is expected to be released soon.

Meanwhile, the Corps has quietly moved at least one of the projects to build the side channel chutes for the fish to Kansas in a stretch of the river known as the Dalbey Bottoms.

Missouri Clean Water Commission chairman Ron Hardecke called out EPA on the issue in a January letter to William Rice, the agency's Region 7 chief in Kansas City, Mo., noting that the commission was aware that the Corps' dumping projects were not "held to the same standards to which private citizens must comply."

In fact, Hardecke noted that the Corps applied for the construction permit for the Dalbey Bottoms project on the very same day last August that EPA announced a consent decree with a private land development company. The decree came after EPA claimed that the company was polluting the river with 8.67 million lb. of construction sediment. EPA fined Cooper Land Development Inc. based on pollution concerns under the Clean Water Act.

Meanwhile, EPA has not taken action on the much larger pollution threat from the Corps, and its permit application for the Kansas project has since been approved. That project involves allowing 34 million metric tons of "spoil piles" dredged from a new fish channel to be side cast on the riverbank and eroded into the main channel, according to Hardecke's letter.

State officials perplexed

The issue and its potential impacts on the Gulf hypoxic zone gained the attention of the nation's top state agricultural officials earlier this month after a presentation by Sen. Christopher Bond's (R., Mo.) office during the annual meeting of the National Association of State Departments of Agriculture in Washington, D.C.

It has raised important questions about the common practice of making agriculture the convenient culprit when phosphorus pollution degrades water quality, and it has prompted a call for investigations of all sources of nutrient loading.

Also, Goehring believes there is a pattern of blaming agriculture for degrading water despite the complex interrelationships of all other water uses.

"Agriculture has been taking the brunt of the blame for water quality problems and hypoxia issues," he told Feedstuffs.

"We've seen hypoxia become more and more of an issue in Lake Erie, the Chesapeake Bay and the Gulf" in past 20 years, but during those same years, he pointed out, "agriculture has stepped up to the plate and adopted new technology, new practices and new farming systems" that buffer waterways and minimize runoff from farm fields.

With those improved on-farm practices, Goehring said the agricultural component of water pollution logically should be decreasing, so it makes no sense to him that agriculture continues to be blamed for increasing pollution loads. He believes that warrants a look at what else is going on in the watershed.

Phosphorus issue

The Corps' issue is not a small matter. The nutrient-laden sediment, which the Corps originally intended to dump as a slurry into the river's water, was enough to cover 40,000-60,000 acres to a depth of 5 ft., according to its calculations.

While the Missouri Clean Water Commission did not object to creating the endangered fish habitat, it concluded that the massive dumping would seriously degrade water quality.

The sediment flowing downstream contained natural phosphorus tied up in the soil particles. While that phosphorus would be stable in fresh water, it would be chemically released when it hit the salty water in the Gulf, the commission noted.

Pointing to Clean Water Act requirements, the commission demanded that the Corps dispose of the soil in a way that would not load phosphorus into the water.

Using the Corps' own figures, the commission calculated that the proposed dumping would add 548 million tons of soil to the water with a whopping 358,403 tons of total phosphorus, according to Kristin Perry, a Missouri attorney and former chair of the Missouri Clean Water Commission. She was the chair when the commission refused to issue permits and ordered the Corps to stop the dumping in 2007.

She said the Corps' soil test showed that the dredged river sediment contained 653 parts per million of phosphorus, but she noted in a briefing paper that EPA's Task Force on Hypoxia "recommends that all municipalities limit their discharge to 0.03 ppm of phosphorus. Hog lagoon effluent, by comparison, is less than 100 ppm, (and) hog lagoons are not dumped into any river."

News that the Gulf's dead zone shrank to half its average size in 2009 -- after the dumping stopped in early 2008 -- prompted Perry to note, "We can't say the moratorium caused the reduction. We are saying we don't know, and no one is investigating. It is an amazing coincidence, and there needs to be further investigation."

Meanwhile, Goehring worried not only about phosphorus pollution from the dumping but the Corps' scheme to wash it down the river.

"The U.S. spends an estimated $2 billion annually to save some 450 million tons of soil. Surely, the Corps can find a better use for this valuable resource," Goehring said.

Daily Commentary provided by Farm Futures, a sister publication of Feedstuffs