Solutions to This Puzzle Are Clear as Mud

Off Southern California’s shore, purity is an illusion that lies only a few feet deep.

The trouble’s not with the water; it’s with what lies beneath it.

From Santa Catalina Island to New York Harbor, the mud and silt that line the bottom of rivers, bays and lakes contain chemicals deemed potent enough to kill aquatic animals and endanger the health of people who consume marine life. Dangerous compounds such as mercury, arsenic, lead, PCBs and DDT--the residue of years of pollution--are hidden below the surface.

Among the local hot spots are coveted coastal playgrounds including Catalina, Malibu, Santa Monica, the Palos Verdes Peninsula, Newport Beach, Dana Point and Coronado--most of Southern California’s offshore waters.

The underwater legacy of sediment contamination is one of the country’s most extensive and intractable--yet overlooked--pollution problems.

“For the last 20 years, we’ve focused on the water, and there are appreciable changes for the better,” said Jim Keating, who is heading up an unprecedented study of the problem for the U.S. Environmental Protection Agency. “But there has not been a lot of focus on the sediment. And sediments are the ultimate sink for water pollutants.”

Nearly 5,200 bodies of water--three out of every four targeted for testing--contain sediment likely to injure marine life or human health, according to the EPA’s National Sediment Quality Survey. People who eat fish, mussels or other aquatic life from 2,300 sites face a significantly heightened chance of cancer or birth defects, the EPA data show.

Individual problem areas have long been recognized, such as Puget Sound, Cape Cod and Chesapeake Bay. But the sheer number discovered to pose a high risk has astonished the EPA research team.

There is so much “hot sediment” in so many places that there is little hope of a quick or easy cure.

In the meantime, the buildup of silt is also wreaking economic havoc. Where sediment is contaminated, routine dredging often is halted, creating “mud lock” that blocks ships at many of the nation’s busiest ports and marinas, including New York, Oakland and Marina del Rey.

Soft, muddy sediments are like sponges that slowly soak up the world’s most dangerous and persistent chemicals, including some now banned because of their toxicity.

Poisons are spread throughout the food web from fish to bird to mammal, starting with the variety of creatures that feed and spawn in the silt and sand.

Particles embedded in the mud are ingested by small burrowing animals such as worms and crabs. Crustaceans and other organisms can die from poisoning, and fish can grow cancerous tumors and cataracts. Once-thriving shellfish harvests have been shut down on both coasts, including much of the Gulf of Mexico and Chesapeake Bay. If a creature survives, its body can build up a toxic load over its lifetime that passes to whatever consumes it.

While never touching the sediment itself, fish-eating birds such as eagles and pelicans can perish from poisoning, or produce unhatchable eggs or chicks with deadly birth defects. Seals, dolphins and other water-reliant animals may grow tumors or lose their ability to fight off disease.

People are not immune. In the water itself, the pollution is often barely detectable, so swimming above the sediment is safe. But eating the tainted fish can cause cancer or birth defects.

Some places are so severely damaged by sediment that they are virtually void of life.

“There’s no question that some systems are highly stressed by toxics,” said Raymond Alden, director of the Applied Marine Research Laboratory at Old Dominion University in Virginia, who has studied sediment along the Eastern Seaboard for almost 20 years. “We see certain species disappearing, and eventually everything starts disappearing. Diversity goes down, and that’s a good measure of how healthy a community is.”

Still, scientists in the relatively new field of sediment toxicology question how serious the ecological risk is in the thousands of places where the injury to animals is less obvious. If a type of worm, or brittle star, is killed in one spot, what, if anything, does that mean to a marine ecosystem as a whole? No one at this point has an answer.

For decades, sediment has been a case of out of sight, out of mind.

Some of the contamination dates to the chemical boom just after World War II. Until the late 1960s, disposal offshore was deemed safe because the chemical doses were too low to be considered poisonous. It came as a harsh surprise when many of the compounds, insoluble in water, worsened over the years by accumulating in animals’ bodies.

The worst compounds--especially PCBs, or polychlorinated biphenyls, employed mostly as insulation in electrical transformers--have not been used since the 1970s, but they simply refuse to go away. They can remain toxic for decades, perhaps centuries, before degrading to harmless levels.

Today, much of the waste dumping has stopped under laws protecting water quality. However, toxic chemicals still flow from modern sewage plants, urban streets, farm fields and industrial sites. Some, such as mercury spewed by coal-burning power plants, fall from the air.

Some sites are getting worse, some better, but the vast majority have stayed the same despite an array of pollution laws, the National Oceanic and Atmospheric Administration recently concluded.

In a report to be unveiled Thursday, a committee of the National Academy of Sciences will identify sediment contamination as an immense problem that warrants more attention. The panel of experts will recommend policies aimed at finding effective yet reasonable solutions.

Getting rid of tainted sediments--or at least ensuring that they are entombed--poses a monumental engineering challenge.

Does digging them up make matters worse by stirring them up? And once removed, what do you do with tons of contaminated material? Where, especially in congested urban areas, is there room on land to dump hundreds of truckloads? And when left in offshore waters, do tomb-like pits covered with sand really keep the material sealed permanently?

Most sediments are not bad enough to be declared hazardous waste. Instead, they are half-jokingly called “chemically challenged”--although perilous in waters as they build up in animals, they are fairly safe on land.

At New York Harbor, sediment has touched off a crisis.

Every year, millions of cubic yards of chemical-tainted mud accumulate on the harbor floor. Until recently, the U.S. Army Corps of Engineers dredged and dumped it off New Jersey. But in 1995, the EPA deemed it too contaminated for ocean dumping, and an impasse among local authorities has left mud clogging much of the harbor.

Meanwhile, barges and tankers are switching to other ports or transferring cargo to smaller vessels, threatening the harbor’s billions of dollars in annual revenue and raising the cost of fuel and other goods.

At the Port of Oakland, ships used to line up, awaiting high tide to avoid running aground on silt. After a heated debate over drawing the line between clean and dirty sediment, the EPA recently approved a novel solution--the California Coastal Conservancy used large amounts of the least tainted material to construct new wetlands at San Francisco Bay.

Still, more than 1 million cubic yards contain so much ship-building waste and coal tar that the port had to spend $15 million to create a special landfill and haul the sediment there over the past three years, said Jim McGrath, the port’s environmental manager.

In the Los Angeles area, recreational boaters at Marina del Rey have navigated around sediment hazards for 15 years. Choked with polluted silt washing down Ballona Creek, the channels are periodically shut down. Fed up with the recurring hunt for disposal sites, county supervisors and the Corps of Engineers last month launched a $2.7-million search for new solutions.

Trouble is also brewing at the ports of Los Angeles and Long Beach. The California Coastal Commission warned in January that it will no longer allow disposal of contaminated sediment in marine waters because of heavy metals and other toxic compounds.

That leaves port officials and the Corps of Engineers with few options. They had been excavating silt from the harbor and moving it to waters near shore, creating special pits covered with sand. But the coastal commissioners question whether this is a safe and justifiable use of California’s ocean resources. A task force has just been formed to head off a disposal crisis.

Compounding the fears, the EPA is drafting more rigorous national guidelines. Now, a small amount of silt is tested in a laboratory aquarium before disposal to see whether it kills small aquatic creatures. But if new testing criteria are applied rigidly--so that sediment either “passes” or “fails”--the Corps worries that it would stymie more navigation projects.

“What I foresee is a potential for whole mud lock,” said James Raives, a program analyst at the Coastal Commission. “These problems will happen more and more, and we will eventually get to a point where there will be no dredging of any contaminated sediments at all.”

To end the paralysis, John Farrington, a geochemist at Woods Hole Oceanographic Institution, said the parties involved should be willing to try some controversial disposal techniques on a small scale.

“People say it is experimenting with the environment, but by leaving the stuff in place, we are experimenting too,” Farrington said. “In some instances, it’s not going to make it any worse and it could make it better. But some groups want an answer that’s going to survive for eternity and, of course, science can’t give that answer right now.”

Although most biologists and chemists agree that toxic sediment threatens underwater life, some question whether the EPA used too stringent criteria in highlighting 5,200 sites.

Robert Risebrough, who discovered in the 1960s that DDT-tainted sediment off California was inflicting severe ecological damage, says most of today’s lingering problems are nowhere near as serious as they were 30 years ago. At most sites today, he says, there is no proof of serious injury to birds and mammals, so expensive cleanups are unwarranted.

“I don’t believe there is any hazard to most of these sediments in the real world,” said Risebrough, a researcher at the nonprofit Bodega Bay Institute in Berkeley. In the laboratory, “you put a tiny amphipod in the mud, and if it doesn’t like it, then the sediments are considered toxic. You can’t predict anything from those laboratory tests.”

In the 1960s and ‘70s, injuries from sediment were obvious.

Brown pelicans nearly became extinct along the West Coast because they ate anchovies and other fish contaminated by DDT that flowed into waters off Palos Verdes from a pesticide plant near Torrance. Even today, those wounds have not healed. Bald eagles on Catalina Island still cannot produce young because their eggs contain too much of the old DDT. Dolphins and seals off Los Angeles County also remain highly contaminated, although no one knows whether it has led to disease or deaths.

But the Palos Verdes site is an extreme case. At most locations with tainted sediment, the damage is more subtle--perhaps reflected in fewer chicks, or a disappearance of tiny sea organisms.

EPA officials acknowledge that many questions remain, and testing of many waterways remains sparse or outdated. Such uncertainty is one reason why they have not ordered cleanups, or told anglers to avoid eating fish at most of the thousands of sites identified as a risk to humans. Only a few are posted with health warnings--including the Palos Verdes area and parts of the Great Lakes. The EPA’s Keating said the goal of the new analysis is to highlight troublesome areas that warrant more thorough looks by local authorities.

Alden said the uncertainty comes in “quantifying how bad is bad” when it comes to the threat chemicals pose to underwater life and the people who feed on it.

“It’s a political issue as much as a scientific one,” Alden said. “Do you try to get a more realistic answer about certain chemicals or do you err on the side of protecting the environment and human beings?”

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From the Bottom Up

From the sand-dwelling red tube worm to human beings, polluted sediment can poison every strand of the food web. Fish that feed on bottom-dwelling organisms become contaminated over time through a process called bioaccumulation. This buildup of chemicals can cause death or mutation in contaminated organisms, or be passed along to fish, mammals and humans that eat them.

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Toxic 10

From more than 21,000 sampling stations nationwide, 15,922 were found to have levels of chemical pollutants in sediments that pose a high or intermediate danger to human and/or animal life. A look at the top 10 chemicals found in the silt:

Substance: Locations

Copper: 7,172

Nickel: 6,284

Lead: 5,681

PCBs: 5,454

Arsenic: 5,392

Cadmium: 4,808

Mercury: 4,333

Zinc: 3,468

DDT: 3,422

Chromium: 3,070

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California’s 10 Worst Sites

1. San Francisco Bay

2. Coyote Creek

3. Tulare-Buena Vista lakes

4. Los Angeles River Basin

5. Santa Monica Bay

6. Seal Beach-Huntington Beach

7. San Pedro Channel Islands

8. Newport Bay

9. Aliso Creek-San Onofre area

10. San Diego Bay

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Poisonous Side Effects

Benthic (bottom-dwelling) organisms can be exposed to sediment contamination through direct contact, ingestion of particles or intake of dissolved contaminants in the water.

* Eating fish is the most significant route of aquatic exposure of humans to many heavy metals and organic compounds implicated in health problems from birth defects to cancer.

* Fin rot and tumors have been found in fish living above sediments contaminated by polycyclic aromatic hydrocarbons (PAHs), common compounds in urban runoff.

* Skin lesions are more likely to occur in fish from sites with higher concentrations of chemical contaminants in sediments.

* Some aquatic species can be wiped out by contamination, decreasing the diversity of life in a waterway.

* Above the water, contamination can cause reproductive failure or birth defects in birds such as eagles, bringing them close to extinction. The chemicals may also contribute to death or disease of marine mammals such as seals.

* Various toxic contaminants found only in barely detectable amounts in water can accumulate at much higher levels in sediments.

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Above the water

Surface dwellers--brown pelicans and other birds, sea mammals and humans--face health risks from eating aquatic life contaminated by toxic chemicals.

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Below the water

Poisons spread throughout the food web, starting with creatures that feed and spawn in the silt and sand.

Red tube worm: Uses gills to collect plankton

Clam: Uses siphons like vacuum cleaner to suck minute particles, plankton and algae off ocean floor

Bay ghost shrimp: Burrows in loose sandy mud; eats plankton, small fish

Daisy brittle star: Scavenges food particles, algae, plankton under tide pool rocks

White croaker: Swims in schools over sandy bottoms in shallow water eating smaller fishes and crustaceans

California halibut: Eats smaller fishes and crustaceans

Contamination: Soft, muddy sediments slowly soak up dangerous chemicals, including some now banned because of their toxicity.

Sources: U.S. Environmental Protection Agency, California Dept. of Fish and Game, Orange County Marine Institute, National Toxicology Program, “Pacific Coast,” “Fishes of the Pacific Coast” and World Book Encyclopedia

Researched by MARLA CONE and APRIL JACKSON / Los Angeles Times