Sunday, October 22, 2006

Odd Environmental News: Treated Sewage to be Used to Build a "Natural Buffer" Near New Orleans

A couple of years ago a talented Tufts University PHD student named Kayo Tajima wrote her thesis on the market for "night soil" in Japan long ago. Urbanites would sell their waste to farmers who used it as a nitrate input in growing agricultural products. Now that was a closed loop general equilibrium! Ecological economists always talk about reducing waste by turning this "output" into another "input" in another production process.

This article on yahoo today tells a similar story. I must reveal my ignorance here. Will these new buffers smell bad? What is the downside of treated sewage? This article makes it sound like a cheap "wall". Is this true? Is treated sewage, when turned into a wall, a potential public health disaster?

Treated sewage to restore New Orleans swamps

by Russell McCulley Sun Oct 22, 2:42 PM ET

Louisiana is planning to use millions of gallons of treated sewage to restore swamps surrounding New Orleans to help protect the city from disasters like last year's Hurricane Katrina.

Ecologists say the treated waste will help stimulate the growth of the region's vanishing cypress swamps, which provide a natural buffer for deadly Gulf of Mexico hurricanes.

"It sounds way out there, but a number of these sites exist across the coast," said Jerry Duszynski, assistant secretary of the Louisiana Department of Natural Resources.

"It's not a new idea, but it hasn't been done on this scale before."

The 40 million dollar project will divert treated wastewater from New Orleans and St. Bernard Parish to an area east of New Orleans, where saltwater intrusion has destroyed what was once an expansive cypress forest. The project targets restoring 10,000 acres (4,000 hectares) of eroding wetlands in the area.

The treated sewage will help push out the salt water that was swept into the swamps and ensure the right balance of nutrients and fresh water, said John Day, professor of oceanography and coastal sciences at Louisiana State University.

The effluent will also stimulate the growth of new cypress trees which could reach a height of 30 feet (nine meters) in a decade.

"If that cypress swamp had still been in place, we wouldn't have had the damage we had in St. Bernard Parish," Day said.

Hurricane Katrina swept ashore in the early morning of August 29, 2005, killing more than 1,500 people along the US Gulf Coast and flooding 80 percent of New Orleans.

The plan to use sewage to rebuild the coastal swamps is one of many proposals designed to address the state's rapidly diminishing coastline, where wildlife-rich estuaries and marshlands on the gulf and near the mouth of the Mississippi River have been sinking at a rate of some 15,320 acres (6,200 hectares) per year since the 1930s.

Last year's twin punishing hurricanes, Katrina and Rita, accelerated the trend, gobbling up 138,875 acres (56,200 hectares) of Louisiana's coast in less than a month, according to a recent report by the US Geological Survey's National Wetlands Research Center.

Intense oil and gas exploration, logging, levees built to constrain the Mississippi's natural flooding and an extensive network of navigation canals have contributed to decades of coastal erosion.

Scientists and environmental activists say wetland loss exacerbated the damage caused by last year's storms, and that coastal restoration must be a key element in making the area safer from hurricanes.

Federal legislation approved before the 2005 hurricanes allocated 530 million dollars over four years to help Louisiana ameliorate coastal erosion.

A restoration plan that includes waste water assimilation, river diversion projects, barrier island protection and marsh restoration using piped-in sediment deposits is expected to be unveiled by the end of 2006, Duszynski said.

The state has also sued the federal Minerals Management Service that oversees oil and gas exploration in the Gulf of Mexico for allegedly using outdated coastal erosion data when it put vast tracts of offshore exploration leases up for bid earlier this year.

Louisiana wants a greater share of the seven billion dollars in royalties from those leases to fund coastal restoration.

Eighty percent of the United States' domestic oil and gas production comes ashore in Louisiana, said Sidney Coffee, chair of the Louisiana Coastal Protection and Restoration Authority.

"Those pipelines all touch our shore, those holding units are on our shore. Everything that happens to get that product to the rest of the nation happens on our shore," Coffee said. "What happens offshore in Louisiana is extremely critical for the rest of the nation."

But federal government money needed for restoration is still not flowing, activists say.

"All of the billions of dollars committed after Katrina largely went to patching the holes in the levee system," said Mark Davis, executive director of the Coalition to Restore Coastal Louisiana, a 20-year-old consortium of environmental groups, businesses and local government agencies. "But none went toward securing a brighter future."

Davis said last year's alarming loss of coastline should serve as a warning to the businesses and shipping interests who have long fought efforts to close some navigation canals.

Some of those canals, like the Mississippi River Gulf Outlet, are said to have contributed to the catastrophic flooding in St. Bernard Parish and Eastern New Orleans during Katrina.

"You have to get them to understand that if we don't do something about the coastline, there's no future here," he said.