Cave water pollution a long, puzzling story

Cave water pollution a long, puzzling story

July 14th, 2013 in Opinion Times

Everything has a consequence, and for every action there is a reaction. Consider a dangerous herbicide, banned in the United States in 1985, but found recently in cave water in Lookout Valley between Aetna and Raccoon mountains.

The herbicide is 2,4,5-TP -- more commonly known as Silvex or fenoprop. It was banned by the U.S. Environmental Protection Agency because it is a long-lived chemical which, in drinking water, was found to cause liver and kidney damage over time.

Only 3.6 parts per billion are considered safe in tap water, but 470 parts per billion were found in a June 1 sample of the cave water here. How the contaminant got there is also a long story.

The EPA says the greatest use of the chemical was to prevent the sprouting and growing of woody plants and broadleaf weeds. It could be used to clear ground in rangeland improvement projects or lawns, including golf courses. It also was used aquatically to control weeds in ditches and riverbanks, and on reservoirs, streams, and along Southern waterways, according to EPA. It could also have been used beneath power transmission lines.

Atop the long crown of Aetna Mountain is a string of massive Tennessee Valley Authority transmission towers that carry high-voltage power lines. Atop Raccoon Mountain are more power transmission lines that run to and from the Raccoon Mountain Pumped Storage Plant. TVA for decades has sprayed herbicides on the power transmission lines to keep trees and brush clear beneath them because electrical arcs from vegetation that grows too tall can cause massive power outages.

TVA officials acknowledge the use of herbicides, but this week said they cannot know without more research whether they have ever used Silvex.

Wherever and however it was used here, it would -- by virtue of its very makeup -- still be around. Like dioxin and DDT and many other banned pesticides, herbicides and chemicals, 2,4,5-TP is slow to break down. In fact, it hangs around for decades and decades.

So from a mountain peak or a riverbank or a golf course or a farm field, it will stick in the dirt until it gets washed from place to place to place whenever there is a hard rain or land disturbance.

If you put those two events together, you get real movement, as freshly bared soil can easily become a silty mudwash under the kinds of rains we've had this year.

The question for the cave owners, Jeff and Steven Perlaky, is what does it mean for their property, Raccoon Mountain Caverns and Raccoon Mountain campgrounds. They say they believe bulldozing to move earth for the posh Black Creek development, along with failed or deficient stormwater runoff fences, has swept the contaminated soils and storm water into their cave.

In water sampling at the cave last year -- before the Black Creek development swung into high gear -- the chemical wasn't found. With at least 10 inches of rain in the Lookout Valley region in the past two weeks, silt-laden water poured off the construction sites, and angry neighbors charged that lax pollution controls made a bad situation worse.

Developer Doug Stein, who also is chairman of the Chattanooga City Stormwater Regulation Board, said vandals had disrupted his silt fences.

Ironically, the development's stormwater trouble is reminiscent of another silting event off Aetna Mountain into Lookout Valley in recent years. A favorite pastime in the area is four-wheeling along the power line right-of-way, which also disturbs lots of dirt that no doubt holds some herbicide chemicals. It was Stein and other Black Creek developers who complained about the silt and stormwater pollution caused by the all-terrain vehicle playground atop Aetna Mountain in 2011.

That year, another massive weather event -- the torrent of rain that accompanied tornadoes here, sent mud swirlling from what four-wheelers called the Peanut Butter hole down an Aetna Mountain creek until it plopped into the middle of U.S. Highway 41 and eventually oozed into the Tennessee River, creating a sandy delta.

The bad blood among the developers, longtime residents like the Perlakys, and the four-wheelers will now likely escalate.

But there are other reactions and consequences environmentally.

The Perlakys' cave, originally known as "The Crystal Cave" during commercial tours in the 1960s, is home to several endangered species including the Indiana gray bat and the blind cave spider, which is known only to exist there.

So, what should we make of an action that theoretically ended in 1985 having a reaction today with the discovery of a banned pollutant in a previously pristine cave?

We all want to turn on lights when we get home. So our utilities build power plants and transmission lines, and then must keep them clear. We all want our patios and boat docks clean and pretty and free of weeds without back-breaking sweat. Of course, we all want healthy kidneys and livers, too, so we must balance consequences: Some that we can't even know to question.

The world we live in is complicated and fragile. What's billed as a panacea today may be a curse in 50 years.

Long live the blind cave spider.