THE VIRGINIAN-PILOT
Copyright (c) 1994, Landmark Communications, Inc.
DATE: Friday, September 23, 1994 TAG: 9409230547
SECTION: LOCAL PAGE: B3 EDITION: FINAL
SOURCE: BY JAMES SCHULTZ, STAFF WRITER
DATELINE: NORFOLK LENGTH: Medium: 97 lines
Piling easily off the conveyor belt, the dirt looks like a gardener's dream: moist, fluffy, ready for good growing. No casual observer would suspect that the Norfolk State University soil was once laced with gallons of gasoline, diesel fuel and heating oil.
Give credit to the latest in environmentally friendly cleanup. A Richmond-based engineering firm contracted by Norfolk State is using a technique called bioremediation to purify the dirty dirt. All that's required is air, hungry microbes, heavy-duty filtering and a little fertilizer.
``The soil, when it's finished, is very fertile and ready to support vegetation,'' said Michael D. Schleinkofer, environmental manager for the company, RECO Industries Inc. ``It's recycling in the best sense of the word. And it's inexpensive.''
Five years ago, NSU officials were shocked to find severe contamination of a several-acre site the university had bought to use for dormitories and playing fields. A Trailways bus station and maintenance garage occupied part of the land, once known as Liberty Park, bordered by Middle Towne Crescent and Ballentine Boulevard.
While project supervisors were aware that the area contained several underground fuel tanks, they weren't prepared for the discovery of 21 tanks uncovered by crews prepping for construction in 1989.
``We really didn't know the number of tanks in the ground,'' said Norfolk State engineer Howard D. Mast. ``We were surprised. We didn't expect that much contamination. We didn't anticipate any leaks.''
Gasoline, diesel fuel and heating oil that had spilled from buses and underground tanks contaminated about an acre of land, spreading slowly underground.
The university was forced to dig up 14,000 tons of soil, an amount that if spread four inches deep would cover 15 acres. Testing revealed 12,000 parts per million of petroleum contaminants; 50 or fewer parts per million is considered safe.
The university tried bioremediation unsuccessfully several years ago, when the technique was still in its infancy. Since then, the technology has dramatically improved, RECO's Schleinkofer said. Last month, RECO began its cleanup work, which both the university and the company say should be complete in a couple of weeks.
As part of the purification, RECO is using a specialized machine that vaguely resembles a concrete mixing truck. A bulldozer dumps dirt into a screened, rotating barrel that then spits out concrete chunks, rocks, bricks, bits of metal, roots, even an errant bus part or two onto a conveyor belt that dumps the debris on the ground. Filtered dirt is separated from larger objects.
Specialized petroleum-munching microbes in solution (related, but not identical, to those used in ocean oil spills) are sprayed onto the filtered dirt, which is aerated and fertilized. The hungry microbes then multiply and chow down.
The only byproducts are small amounts of carbon dioxide and water. Once the pollutants are gone, so too are the microbes, which die and are naturally reabsorbed into the soil.
``There doesn't seem to be a down side to this. Basically, I think it's a sound process,'' said John Novak, a bioremediation expert and professor of civil engineering at Virginia Tech in Blacksburg. ``A lot of people are using bioremediation. It seems fairly effective for petroleum products, especially if you've dug up the dirt.''
RECO officials say pollutant levels in the NSU soil have dropped to 200 to 300 parts per million. Within the next week or two the company wants to get the levels to 50 parts per million or lower.
``It's this close to being finished,'' said Schleinkofer, holding his index finger and thumb a fraction of an inch apart. ``All the data looks excellent. But it ain't finished yet.''
Norfolk State is also eager to finish up the soil cleaning.
``RECO knows that, until the site is remediated, there is no paycheck,'' said Rex Aaron Gay, director of the NSU physical plant. ``As far as I can tell, things are on track. We're happy with it.''
By project's completion, officials say the university will have spent $800,000. Part or all of that amount could be returned to Norfolk State under the provisions of a state fund designed to help with environmental cleanup.
NSU will use the cleansed dirt as topsoil for seven acres next to the original contamination site. Current plans call for creating intramural playing fields for sports such as soccer and flag football. Three dormitories have since been built in the area from which the tainted earth was removed. ILLUSTRATION: Photo
BILL TIERNAN/Staff
The dirt-filtering machinery will solve a major problem for engineer
Howard D. Mast, left, and architect Jerry L. Jones at NSU.
Graphic
JOHN EARLE/Staff
HOW ``BIOREMEDIATION'' WORKS
SOURCE: Norfolk State University, RECO Industries Inc.
[For complete graphic, please see microfilm]
by CNB