Denver — Cross giant plastic trash bags with a coal slurry pipeline and you have Aquatrain, a new way to ship coal across the country.
The method holds the potential for freshening the Colorado River as well as economically delivering clean, dry, and extremely low-sulfur coal to California or to the Pacific Ocean for export to Asia.
''Once you get over laughing at the idea of shipping coal in giant Baggies, the concept has a lot going for it,'' says Ira E. McKeever Jr., president of W. R. Grace & Co's Western Mining Operations, which came up with the novel concept only nine months ago.
In an area where traditional coal slurry pipelines create tremendous controversy, Aquatrain is already stirring considerable interest. Both the seven Colorado River Basin states and the US Bureau of Reclamation have set up committees to give the concept further study.
Coal slurry pipelines, which carry ground-up coal mixed with water, have been the focus of considerable attention since the mid-1970s because advocates claim they can carry coal more cheaply than railroads.
However, these pipelines require relatively clean water since saline water would mix with the coal powder and cause corrosion and problems when the coal is burned. This is a major problem in the semi-arid West where the pipelines would begin. Here water allocation is handled by complex legal agreements, and proposals to divert large amounts of fresh water over state lines is highly controversial.
This is where Aquatrain would be different. By bagging 3 to 4 tons of coal in thin plastic bags 15 feet long by 30 inches in diameter, W. R. Grace believes it should be possible to pump these coal-filled capsules through a 36-inch pipeline using saline water. Not only would this reduce the cost, but such a pipeline would be likely to pay for its water. That makes such a project far more politically palatable here.
To further sweeten the prospect, Mr. McKeever collaborated with Michael J. Clinton at the Bureau of Reclamation (BuRec) and came up with a way in which such a pipeline could actually improve the water quality of the Colorado River, where salinity is a major problem.
The Aquatrain pipeline would run from northwest Colorado near Axial, where Grace has coal mining operations, to Glenwood Springs, where water almost half as salty as seawater flows into the Colorado. On this first leg, the pipeline would be filled with fresh water. When it reached Glenwood Springs, this water would be dumped into the Colorado and the salty water from the local springs would be substituted in the pipeline. From there it would follow a yet-to-be-determined route to the Pacific Ocean, where the saline water could be easily disposed. The pipeline would have a capacity of 15 million tons of coal, would require 12,000 acre-feet of water, and remove 250,000 tons of salt from the Colorado annually.
''It's potentially the cheapest form of salinity control that we've identified,'' says Mr. Clinton. ''I'm really intrigued with the concept, although I can see some potholes in its future that will need to be worked out.''
The major alternative is to collect the salty spring water, pipe it to a waste area, dump it into evaporation basins, and create about 5,000 acres of artificial salt flats. BuRec estimates this plan would cost $280 million, and they have received negative reactions to the scheme's environmental impact and waste of water. In contrast, it would only cost about $80 million to collect the salt water for Aquatrain, Clinton says.
''I hope that . . . legislation pending in Congress will pass (soon) which will allow us to split the difference with Grace. This would save the taxpayers money and give them an added incentive,'' he explains. Meanwhile, BuRec is ready to help by cutting as much red tape as possible.
The biggest question mark in Aquatrain's future is financial backing. The concept is so new there are only rough estimates of what it might cost. But a 1, 200-mile pipeline wouldn't be cheap - in the range of $1.5 billion to $2 billion , perhaps 30 percent more expensive than a coal slurry pipeline because it is more complicated.
''Right now we're trying to line up some other mining companies, transport and shipping companies, and utilities,'' says McKeever. ''We've shut down our spending until we locate a customer for the coal.''
They are looking to Japan and California utilities as prime candidates. Japan's Ministry of International Trade and Industry recently allocated $500,000 to study methods for increasing Western US coal consumption in their country and hasn't yet decided where to spend it. California utilities have been interested in coal if it can be burned cleanly. But convincing them will take considerable marketing, McKeever acknowledges, because the coal delivered by Aquatrain would be different than the coal a power plant gets from a railroad car.
To keep the coal from puncturing the plastic bags, it must be ground to the texture of face powder. This allows it to be dried, and the sulfur and ash removed at the mine site. This form is a much more energy-rich fuel, McKeever says, although one potential problem is the possibility of spontaneous combustion of the fine powder.
Power plant operators would not have to grind the coal and, because of its low sulfur content, could burn it without expensive pollution-control equipment.
Grace has taken the unusual step of inviting environmentalists and other groups which may have a stake in the project to participate in the planning stages. And the response has been generally favorable.
''We're pretty positive about it. It's intriguing,'' says Don Nelson, the Rocky Mountain representative of the National Audubon Society. He and his colleagues have some questions - such as disposal of sulfur and toxic material at the mine site and the possibility that a pipeline would lead to major increases in coal mining near national parks in Utah. But he says they believe it could be a more environmentally benign way to transport coal than the alternatives.