Building on karst brings Mammoth trouble!
by Paul Steward
Descent Magazine, Oct./Nov., 2001
KENTUCKY'S ten-million-year-old Mammoth Cave is facing its toughest challenge yet. On 16 February 2001 Intermodal Transportation Authority (ITA) submitted a proposal to the state of Kentucky for a 6,000 acre industrial development to be located in Oakland, only 6 miles south of Mammoth Cave National Park. The site for the so-called Kentucky TriModal Transpark (KTT) will include roads, office buildings, a rail yard, a trucking and transportation centre and an airport capable of accommodating large jets, a rail yard, and a trucking and transportation center. Two small towns will be removed to make room for the runway with construction scheduled to begin early next year.
The fatal flaw is the transpark location. Industrial parks such as this are notorious for spills and seepage including petrol, jet fuels, anti-icing fluids and other contaminants and hazardous materials, not to mention air and noise pollution. The site sits within the Graham Springs Karst Basin, where there are thousands of sinkholes and every drop of polluted run-off water flows directly into the karst system. Dye-tracing proves that groundwater exchange takes place between this region and the Mammoth Cave Basin; eighteen world-renowned karst scientists have confirmed this, yet the ITA refuses to acknowledge it. Even a small chemical spill would do irreparable damage and threaten endangered species, including bats, blind shrimp and blind crayfish. Also, never addressed by the ITA, the inevitable accumulation of low-level pollution will, without a doubt, have a considerable impact on cave life.
Furthermore, the transpark site is underlain by a 3m thick bed of chert which, although resistant to weathering, is highly brittle, prone to sudden and catastrophic collapse, and is structurally unstable--not the place to build an airport. The ITA has not studied the chert, saying that any investigation will be made after the project is underway. Noted caver and geologist Art Palmer is quoted as saying, "The concept of building an airpark on such highly cavernous ground, and in such close proximity to Mammoth Cave, is seriously flawed." A geologist from Western Kentucky University adds that he would fail any student who submitted work that bad.
Surely Mammoth Cave National Park would not permit a transpark to be built in its backyard, you say. KTT developers have been carefully skirting a formal Environment Impact Study (EIS) and, until one is published, the Park cannot legally comment on proposed developments. Citizens groups, however, can comment and KEEP (Karst Environmental Education and Protection) was formed. It and other groups are fighting the proposal but the ITA and the City of Bowling Green have obtained approval to issue $25 million in bonds to fund initial property acquisitions, yet no money has been set aside from the repayments to deal with structural karst problems.
This is one of the most studied karst areas in the world. The ITA and its environmental consultants continue to minimise or ignore karst hazards and the advice of experts: they think karst problems can be simply solved by plugging openings and filling depressions. Art Palmer points out that these sinkholes leak laterally, as well as downwards, so plugging won't work.
History has shown that building on karst land requires continual repair from collapses, which usually comes at taxpayer's expense. Why can't we learn from the mistakes of others?
What can we do?
WHAT can the caving community do?
Heads in the sand
Following receipt of this report, a major toxic spill occurred at about 2am on 30 August, upstream of Mill Hole in the Mammoth Cave catchment area. A diesel truck overturned on Interstate 65, releasing 3,800 gallons of fuel. Mammoth Cave personnel quickly became involved and immediate attempts were made to remove the contaminated soil, but virtually all the fuel had already drained through and this was already heading for the sumped upstream end of Mill Hole.
Surface surveys to locate the sump were soon underway in case a borehole could intersect the build-up of fuel and permit its pumped extraction. As it was raining, plastic sheets were spread over the contaminated area to slow down percolation, which would drive the fuel through faster. The sump, however, proved to be too deep below the surace and the plan changed: pumps would be installed in the downstream section of Mill Hole to remove the diesel fuel as it seeps out. It was reported that this might take a period of years, as during high water the fuel would be left high on passage walls awaiting another pulse to wash it through.
For cavers, the unknown passage beyond the upstream sump--believed to be a major section of river cave--will be too highly polluted to encourage exploration. Its cave life will have been destroyed; the area is known for its endangered species of cave shrimp. The event was immediately referred to as one of the worst environmental disasters to have ever occurred in the region.
It seems amazing that Mammoth Cave--the longest cave in the world, both a UNESCO World Heritage Site protected by law and a major tourist attraction--is being subjected to such environmental pressures. Accidents can and do happen--this is why we have preventative measures--but the latest incident shows how easily short-sighted planning (or lack of it) can lead to an incident. It seems sheer stupidity to build a depot which is rich in the very solutes and organic fuels that should be kept away from water, in a karst area which will enable spills to directly contaminate a vast and fragile, world-famous region.
Someone wants to make money. Someone with their hands on the reins should extract various heads from the sand in order to think about what the environment is really worth.