Weeks after millions of gallons of highly acidic chemicals flowed into one of the Gulf Coast’s most productive estuaries, a wide river of rusty brown trees and dead marsh grass slices through the summer green of Mississippi’s Bangs Lake, near Grand Bay on the Alabama border.

Portions of the shallow waters at the upper end of the brackish lake, once hopping with redfish and mullet and home to some of Mississippi’s healthiest oyster beds, appear lifeless, except for the fluorescent lime glow of algae, still spreading in dense, sticky mats where the sudden burst of phosphate pollution fuels its growth. Such algal mats tie up the water’s oxygen as they collapse and decay, scientists say.

Mississippi environmental regulators say they can’t be sure the worst effects of the April 14 spill at Mississippi Phosphates Corp. are over for Bangs Lake. The 1-mile-long lake is part of an arc of marshes and shallow waters in the Grand Bay National Reserve, a federally protected ecosystem described as one of the northern Gulf Coast’s least disturbed stretches of coastline.
Estimating the damage:

Mississippi regulators said last week that they were still trying to determine what impact a soup of contaminants — ranging from heavy metals like mercury, cadmium and lead to radioactive uranium and radium — could have on the long-term health of the oyster beds and fish nurseries. They also said they were reassessing the measures that the state had taken to protect the estuary from the mountains of phosphate waste surrounding it.

Mississippi Phosphates was required “to do everything possible to protect Bang’s Lake,” said Phil Bass, director of Mississippi’s Office of Pollution Control, who described the area as “the most pristine part” of Mississippi’s coast.

Bass said that while the investigation was far from complete, he expected “some kind of enforcement action … some kind of recapture of the environmental damage.” He said that he planned to work closely with the Jackson, Miss.-based company to prevent future spills.

After speaking with Mobile Register reporters Thursday and Friday morning about the spill, a spokeswoman for Mississippi Phosphates called back Friday afternoon to say that senior management had decided that the company “didn’t want to be quoted, and refused to participate because of the grave concern over the accuracy” of the reporting.

In the earlier conversations, spokeswoman Melinda Hood blamed the spill on unusually heavy rains, and said that the company expected such an event would never happen again. The Register, however, was unable to find evidence of unusually heavy rains in the days just before the spill.

In 1998, the company also reported a spill that Hood said was even larger than the one that occurred this year.

Hood offered various estimates of the size of the April spill, at first estimating about 50,000 gallons. On Friday, Hood left a message saying the spill was in the range of 17 million gallons.

The Register was unable to determine the exact concentrations of acids, heavy metals and uranium in the mix, or the residual concentrations in Bangs Lake.

Mounds of contamination:

Mounds of phosphate waste, approaching 100 feet high and stretching for hundreds of yards along Industrial Road, have been a Pascagoula landmark since the 1950s, when the original Mississippi Chemical Corp. first began producing phosphate fertilizers here.

Phosphate, in moderate quantities, is needed by green plants for growth. But the production of useable phosphate from phosphate ores leaves a large volume of waste — 5 tons of waste for every ton of product. Florida, which is naturally rich in phosphate ores and is a center for the phosphate industry, produces 30 million tons of waste each year.

The bulk of the waste is composed of gypsum, a combination of sodium and calcium that in itself is largely benign, and has some uses as an agricultural supplement for compacted soils.

But the U.S. Environmental Protection Agency prohibits phosphate producers from selling the gypsum wastes because of the spectrum of contaminants also present. Phosphate ore deposits often contain significant quantities of other minerals — fluoride, selenium, chromium, copper, cadmium, nickel, aluminum and even uranium — which can be toxic in sufficient doses. In some parts of the world, including Morocco, where Mississippi Phosphates now buys its ores, concentrations of radioactive uranium in the phosphate deposits are sometimes so high that they’re extracted for nuclear production.

As a result, massive gray hills of phosphate waste — often called “gyp stacks” –are fixtures at phosphate processing facilities.

Scientists who have researched phosphate facilities say that the most immediate dangers posed by such stacks are the liquid wastes poured into large settling ponds carved into the tops of piles.

Mississippi regulators likened the gypsum stacks and their hazardous waste ponds to a large heap of mashed potatoes, with a crater-like depression in the top to hold the gravy. The “gravy” in this case contains large quantities of phosphoric acid, which many believe to be responsible for the rapid killing of much of the marsh vegetation and aquatic life in Bangs Lake, making the water and soil so acidic most life can’t exist.

Explosions of algae:

The liquid also contains high concentrations of phosphates and nitrogen compounds. When these chemicals get into natural water bodies, according to scientists, they fertilize explosions of opportunistic algae, which strangle other life as they compete for light and oxygen, until they essentially grow themselves to death.

The sudden collapse of the algae ties up most of the oxygen in the water, suffocating many of the fish and other creatures living there.

These effects are already apparent over much of the northern end of Bangs Lake. Mississippi regulators said they’re still trying to understand how widespread the impacts have been on the lake’s oyster beds, though Ed Cake, an environmental consultant in Mississippi, said he heard from some observers that many beds over a wide area in the lake may have been killed.

Ironically, Bass said, Mississippi had planned to use Bangs Lake oysters as examples of what “clean” oysters should look like, as regulators compared effects from contamination in various areas along the Mississippi coast.

Even after life in Bangs Lake recovers from the immediate toxicity of the phosphate spill, other contaminants could persist for decades to come. The liquids from gyp stacks typically contain relatively high concentrations of other contaminants — the heavy metals and the radioactive materials — that are found in phosphate ore.

The Mississippi regulators said they were still uncertain how severe that contamination might be, but they would be monitoring the oysters and other life in Bangs Lake in the months to come.

‘The gyp stack failed’:

In other news accounts, and in Register interviews, Mississippi Phosphate’s Hood has blamed the spill on unusually heavy rainfall — conditions that she said were not likely to occur again.

“Back in April, we had a tremendous amount of rain,” Hood said Thursday. “Because of the heavy rainfall, and the water level being as high as it was in one of the ponds, the gyp stack failed.”

The company’s permits from the Mississippi Department of Environmental Quality specify that the waste ponds must be designed to withstand a maximum 25-year, 24-hour rainfall — a storm producing about 11 inches in a 24-hour period, according to the standard calculations produced by the National Oceanic and Atmospheric Administration for this part of the Gulf Coast.

Weather information from the Southern Climate Data Center indicates that there was no rainfall in Pascagoula on April 13 or 14, when the spill occurred. Weather service radar and Southern Climate Data Center reports indicate that two weeks before the spill, on April 1, an area along the Mississippi/Alabama border may have received about 8 inches of rain, the largest rainfall the Climate Data Center reported for that month. NOAA records indicate a storm of that intensity could be expected about once every five years along the Mississippi coast.

Officials with the Mississippi Department of Environmental Quality said their preliminary investigation indicates that the failure of the waste pond was not ultimately the result of excessive rainfall, but rather because the company was trying to increase the capacity of the pond at a faster rate than normal.

“As they built it, they had a failure, they just lost part of the dam,” Bass said.

Bass said that a bigger issue itself may be that the levees around the gyp stacks weren’t sufficient to catch the pond spill before it poured into the marsh. The gyp stacks are ringed by a moat-like ditch-and-berm system, which environmental permits say should be designed to capture such spills.

Reporters who accessed the marsh area by boat saw swaths of dying vegetation that spread out toward Bangs Lake from two low points in the levees.

Florida regulators have been dealing with the impacts of phosphate spills for decades, and have reassessed the safeguards placed on maintenance of gyp stacks. A 1997 spill of more than 50 million gallons in Florida’s Alafia River was reported to have killed 1 million fish, according to local news accounts.

Dumped into the Gulf:

In Tampa in 2004, dangerously full gypsum stack ponds at a phosphate factory were drained in an emergency action approved by the EPA. In the controversial action, hundreds of millions of gallons of the liquid were barged out and dumped into the Gulf of Mexico. State officials said it was the only way of saving Tampa Bay and averting what they described as “one of the biggest environmental threats in Florida history.”

Florida experienced two hurricane-related breaks at phosphate facilities last year. In June of this year, regulators overhauled design specifications for the phosphate ponds and levees because they weren’t believed to be sufficient to handle the Gulf’s heavy rainfalls and hurricanes, which can dump 20 to 30 inches of rain.

“Our regulations are being updated right now because we had spills during hurricanes last year,” said Mary Ellen Murphy, with the Florida Institute of Phosphate Research. “Every time there is a spill, we get new regulations.”

Hood said that Hurricane Georges in 1998 precipitated another, and much larger spill, at the Mississippi Phosphates plant. She speculated that it didn’t attract much notice because attention was focused on an oil spill at the Chevron refinery next door to her plant.

Bass said he would be looking at the latest regulations from Florida on phosphate facilities, and said he hadn’t excluded the possibility of updating Mississippi’s rules. “We’re certainly going to use this incident to look back at everything we regulate to make sure that everything is protected as it should be,” Bass said.