New Louisiana plan relies heavily on diversions to reduce nutrients causing Gulf ‘dead zone’

By Mark Schleifstein, The Times-Picayune
13 February 2014


When nutrient-rich freshwater creates a layer atop the saltier Gulf waters, nitrogen and phosphorus feed huge algae blooms. When the algae die, they sink into the saltier water below and decompose, using up oxygen to create the dead zone. (See infographic below for more details)

Louisiana plans to use existing and proposed sediment and freshwater diversions as part of a new plan for removing a small share of the fertilizers and other nutrients from the Mississippi and Atchafalaya rivers that are linked to springtime low-oxygen "dead zones"along the state’s coastline each year.

The plan also relies on a series of existing programs to voluntarily reduce the release of nutrients from farmlands, urban wastewater treatment plants, rural homes and industries in the state. The plan was developed by the state Coastal Protection and Restoration Authority and Departments of Agriculture and ForestryEnvironmental Quality, and Natural Resources.

Environmental groups said the plan wouldn’t do enough to reduce the problem. 

The dead zone is created each spring when nutrient-rich freshwater from the Mississippi and Atchafalaya rivers triggers blooms of algae at the Gulf’s surface. The algae dies and sinks to the bottom, where its decomposition uses up oxygen in the saltier water layer there. The low oxygen levels kill organisms living in bottom sediments and cause shrimp and fish able to escape to move to more oxygen-rich waters.

In recent years, the low-oxygen areas have covered as much as 8,000 square miles of relatively shallow water along the coast, extending at times into Texas and Mississippi. In 2013, it covered 5,840 square miles

The state strategy contends that the diversions will eventually be able to remove nitrogen equaling more than 250 percent of the amount believed generated within the state’s borders, and phosphorous equaling about 40 percent of that generated in the state. But that represents less than 5 percent of the total nitrogen and phosphorus carried by the river to the Gulf, mostly from farmland in Midwestern states.

"Our Master Plan and nutrient management strategy contemplate sending cleaner, more dispersed water into the Gulf," said Garret Graves, chairman of the Coastal Protection and Restoration Authority. "The objective is achieving as many win-win-wins as possible: reducing the dead zone, restoring the delta-building process, reducing navigation dredging, thwarting continued saltwater intrusion northward, etc."

The plan calls for the state to continue participating in voluntary measures with upriver states to attempt to reduce their nutrient load.

Environmental groups are already criticizing the new strategy as not going far enough to reduce nutrients, both within the state and in upstream states. 

The groups, including the New Orleans-based Gulf Restoration Network, have called the state and EPA to adopt regulations that would force both point sources of nutrients such as industries and non-point sources of nutrient runoff, such as farms, to reduce their nutrient releases to levels that would dramatically reduce the size of the dead zone within a few years. 

They contend the state should also be placing more pressure, including legal challenges, on upstream states to reduce their nutrient loads.

"We don’t see this plan as moving the ball forward in removing nitrogen and phosphorus in the Mississippi basin and in other waters in Louisiana," said Matt Rota, a spokesman for Gulf Restoration Network.

Graves says Louisiana doesn’t have the authority to force other states to reduce nutrients within their borders. The Clean Water Act, which governs nutrient pollution, calls for states to work collaboratively with each other and the EPA.

"We do not see it as the state’s role to address nutrient inputs in other states," Graves said. "That responsibility lies solely with the federal government and states that input such nutrients.But Graves said the state has been looking into whether it may be possible to set up a water quality credit system, where the state could sell credits to upriver states based on the ability of Louisiana wetland restoration projects to capture nutrients.

"We have also been very vocal about the potential for using our RESTORE Act funds (BP oil spill fine money that would be used to build restoration projects in Louisiana) to partner with EPA, (Natural Resources Conservation Service), and upper basin states to carry out incentive programs to help reduce nutrient inputs in the river," Graves said. "These investments would be done under the umbrella of a comprehensive approach that would include sediment diversion enhancements that are designed to increase nutrient uptake."

Louisiana’s plan differs greatly from a 2010 watershed implementation plan designed to dramatically reduce similar nutrients in waters flowing into theChesapeake Bay by 2025, which was approved by EPA and states within the bay’s watershed. 

That strategy called for the federal government and the states to set combined goals for nitrogen and phosphorus reductions for both specific point sources, such as waste treatment plants and industries, and non-point sources, like farmland and other rural properties where nutrients are found in rainwater runoff, rather than in a specific pipe or other release point.

The Chesapeake plan was hammered out in part as a result of lawsuits filed by environmental groups challenging the lack of action on reducing nutrients in the East Coast bay by EPA and the states surrounding it.

The Gulf Restoration Network and other environmental groups filed a similar lawsuit in New Orleans pertaining the Gulf dead zone. As a result, a judge has ordered the EPA to determine whether new regulations are necessary to reduce nutrients flowing into the Mississippi system. 

That decision and a lower court ruling upholding the Chesapeake Bay program have been appealed by the American Farm Bureau Federation, the American Fertilizer Institute and by a number of state attorneys general, including Louisiana’s Buddy Caldwell. They challenge argues that the court rulings in favor of environmental groups are an unconstitutional grab of states’ rights to regulate pollutants as they see fit, and that the rulings also overstep the bounds of the Clean Water Act.

In drafting its own strategy, Louisiana officials argue that recent research indicates the existing Davis Pond, Caernarvon, Naomi and West Pointe a la Hache freshwater diversions can remove 4,381 tons of nitrogen compounds and 129 tons of phosphorus compounds each year.

The state’s Master Plan for coastal restoration calls for at least eight additional river diversion projects to be completed over the next 5 to 50 years, which would remove another 53,749 tons of nitrogen and 1,088 tons of phosphorus.

The two chemicals, constituents of fertilizers used in the Midwest and in Louisiana, are removed from the water by either binding with sediment particles that become part of wetland areas or drop to the Gulf floor, or are taken up as nutrients into the wetland plants, where they are again captured in the sediment when the plants die and decompose.

But Louisiana produces only 2 percent of the nutrients that flow out of the Mississippi and Atchafalaya rivers, with the rest coming from upstream states.

Rota says relying on construction of the diversions means the state’s efforts won’t affect the dead zone for a number of years.

"We’re looking at 5, 10, 15, 20 years out for multiple large-scale diversions to be in place, and we need to be doing something about the dead zone long before that," he said. 

Environmental groups also are concerned about some studies that indicate high quantities of nutrients in wetlands built with diversions result in weak plant roots that can be uprooted by hurricanes.

Graves contends those studies are outweighed by others that indicate the root problems can be overcome if the diversions are operated properly and the wetlands are properly monitored.

The voluntary measures in the state’s strategy include programs aimed at reducing the use of nitrogen and phosphorus fertilizers by farmers through modern precision farming practices and assistance with the handling of wastes by concentrated animal feed operations like chicken and pig farms. 

Other voluntary measures to reduce nutrients include:

– Planting border strips around farmland to capture nutrients before they run into creeks and rivers.

– Incentives for industries to reduce the release of nutrients from their plants

– Asistance programs for improving the operation of urban sewage treatment plants and the creation of urban rain gardens and other measures to collect nutrients before they end up in drainage systems.

– Programs to improve the operation of septic tanks in rural areas.

The state does place limits on the release of nutrients from point sources, including industry and sewage treatment plants.

Where control over nutrients has run into trouble nationwide has been at agricultural operations, which are considered non-point sources. The Clean Water Act does not give EPA and the states the authority to control the release of nutrients from agricultural operations through a permitting process.

But the law still requires states to determine whether interstate water bodies within their borders are impaired by nutrients, by determining their "total maximum daily load" necessary to be used as a source of drinking water or for fishing and swimming, and to develop plans to restore them to those uses.

Even as the state has developed its strategy to reduce nutrients – aimed at reducing the size of the dead zone – the state’s Department of Environmental Quality has repeatedly refused to list three coastal segments west of the Mississippi River as requiring the development of total maximum daily loads that would lead to the development of response plans upstream in the state.

The state contended that a 2008 Gulf Hypoxia Action Plan, created by EPA and Mississippi River states, already formed the framework for addressing low oxygen in Terrebonne and Barataria basin coastal bays and Gulf waters and in bays and coastal waters along the west side of the Mississippi.

But that 2008 plan, which also relied largely on existing point source regulations and voluntary non-point source programs, called for striving to reduce the five-year average size of the dead zone to below 1,930 square miles by 2015. As of 2013, the five-year average was closer to 5,400 square miles.

In a July 18, 2013 letter, EPA notified the state it was listing the three segments as impaired over the state’s objections.

At the same time, EPA has been the subject of repeated critiques from its own inspector general for not taking its own steps to reduce nutrient pollution from upriver states.

"Critical national waters such as the Gulf of Mexico and the Mississippi River require standards that, once set, will affect multiple upstream states," said the inspector general’s first report in 2009. "These states have not yet set nutrient standards for themselves; consequently it is EPA’s responsibility to act."


EPA did create an online tracking system to determine what states have or are planning to set criteria for nitrogen and phosphorus levels within their borders. According to the web site, Louisiana has not done so, and has provided EPA with no information on plans to do so through 2016.