Car oil contaminating Carlsbad Caverns

CARLSBAD CAVERNS, N.M. (KRQE) - Researchers found high levels of heavy metal in various pools in Carlsbad Caverns. After some investigating, scientists determined the contamination was coming from a parking lot built 750 feet above the natural wonder.

Cars have parked on top of the caverns for about a century. Originally, no one knew there would be consequences for doing so. A parking lot, built in the 1940s, is now taking its toll on the caves.

After testing the cave water, they found high levels of heavy metals. They realized the source was from oil and antifreeze from cars seeping down, through the soil, into the caves for decades.

"Cars, as you see around you will leak off various fluids, and those eventually can get washed off in rain water down into the drains, and therefore into the groundwater," said Paul Burger a hydrologist with the Carlsbad Caverns National Park. "If you think about it, especially if you have an older car that sits on the driveway, you get that little puddle of fluids on your driveway. Multiply that, times thousands of visitors of year, and the parking lots sits right on top of Carlsbad Caverns. Things like zinc, aluminum, other metals can actually discolor the cave formations."

It takes about six weeks for the contaminants to travel through 60 feet of rock. The levels found are not a danger to drinking water, but they are affecting the cave formations and the microbiotic life.

The chemicals are also killing microbes, which could throw off the entire ecosystem. Researchers also found increased nitrates and phosphates in the caves. After exploring that discovery, they learned that sewage lines, built in the 1920s, were also leaking. So, the national park made some changes.

"We didn't understand those things then, [but] we do now, so now is when we're taking action to make things better," said Paula Bauer of Carlsbad Caverns.

In 2010, Carlsbad started the "Carlsbad Cavern Resource Protection Implementation Plan." Crews repaved the parking lot. They also installed a tank underground that separates the oil and grit from the rain water. The leaking sewer lines were also repaired. Those improvements combined with paving the road to the caverns amounted to $7 million. Decades will pass before all the previous contaminants will stop trickling down into Carlsbad Caverns.