Holland’s New Hope to Stop Sea--Waste

A Dutch scientist has proposed a novel idea to get rid of chemical waste and at the same time help save his country from one of its constant nightmares--the threat of inundation from the sea.

His scheme, which has drawn wide media attention and the interest of government officials, would raise the low-lying coastal areas of the Netherlands by pouring sulfuric acid chemical wastes into the limestone sub-surface.

Prof. Olaf Schuiling of Utrecht University, a geochemist, said his idea came to him in a flash when he woke up early one morning. It is based on a simple principle: Sulfuric acid mixed with limestone forms gypsum, which has twice the volume of the original limestone.

“When I first thought this up, I said to myself that I had better not talk about it, because people would think I was crazy. But when I playfully discussed it with some colleagues, they took me more seriously than I expected,” he said in an interview.

Utrecht University has applied for a patent on his idea. The Delft Soil Mechanics Research Institute has given it support in feasibility studies, and the government’s Transport and Water Ministry, responsible for the country’s dikes and coastal protection, is looking into the idea.

So far, Schuiling has done thermodynamic calculations of the reaction under all proposed conditions and made a miniature model to show that the soil expands and rises as he predicts.

The idea of raising limestone-based land surfaces using sulfuric acid might also be applicable in the Indian Ocean’s Maldive Islands, which face potential flooding because of global warming.

Schuiling has proposed that the eastern part of Ameland, an island off the northwest coast of the Netherlands, as a test site.

His idea is to bore holes about 1,500 feet into the ground--less than the depth of most oil wells--and pour in a million tons of waste sulfuric acid, which is produced by the paint and galvanizing industries.

Schuiling said that, according to his calculations, if the waste is poured in over the period of a year, it would be possible to raise by three feet an area 100 yards wide and six miles long.

The holes would reach so far down that there would be no risk of contamination to ground water or top soil, according to Schuiling.

“At the depth of 500 meters (1,500 feet), we are far away from shallow, sweet water aquifers, and there are impermeable clay layers above,” he said. “In addition, the metals in the acid would be immobilized in the limestone and would not escape upward.”

Schuiling’s idea could also be applied offshore to raise sea beds and divert water currents away from coastal areas, something that he said is virtually impossible with present engineering techniques.

Much of the Netherlands lies below sea level and is protected by dikes. Geological changes and rising sea levels from global warming are expected to force the government to spend tens of millions of dollars each year in the coming decades to reinforce its coast with fresh sand.

Schuiling’s daring alternative, however, has so far raised more questions than answers, and some officials believe it would be more expensive than simply replenishing coastal sand.

One likely problem could be cracks created in the formation of the gypsum. Schuiling believes the cracking would occur too far underground to cause any harm near the surface, but he admits that a pilot project is needed to test his theory.

Another difficulty is figuring out how the sulfuric acid would be absorbed as the limestone turned into less permeable gypsum.

Schuiling believes the cracks would partially counteract the decreasing permeability of the forming gypsum and spread the acid.

Still another issue is whether it is worth going to these lengths to get rid of sulfuric acid waste.

Environmentalists point out that new, cleaner industrial procedures are reducing sulfuric acid waste and say the emphasis in the future should be on even better processes and recycling--rather than underground dumping.