NASHVILLE, Tenn. -- In the past week, 175 more people have filed lawsuits against the Tennessee Valley Authority after December's coal ash spill in east Tennessee.

Video: Concerns Grow Over TVA Ash Spill

There may be even more reason to be concerned about the spill here at home.

What happens when more than a billion gallons of toxic sludge seeps into Roane County neighborhoods?

In the past three days, 170 people affected by the spill joined others from the area in lawsuits against TVA.

These people filed their suits with May and Ryan PLC of Nashville. The firm is affiliated with a larger group from New York, who works with famed environmentalist Erin Brockovich. Brockovich toured the spill site earlier this year.

Subtract the cost of the suits filed against TVA, and the cleanup alone is estimated to cost upward of $500 million.

John McFadden, a member of the Tennessee Environment Council, said the cleanup will be costly to the entire public.

"We're going to end up paying for this disaster," said McFadden.

So, how does this affect drinking water?

"There's the potential for the hazardous materials that's in this waste to get into our water supply. And no doubt at some level, it has gotten into our water supply," said McFadden.

Without wanting to sound like an alarmist, McFadden said the air we all breath is also in question.

"One of the problems was that the material as it dried out becoming airborne and people getting exposed to it that way," said McFadden. "Middle Tennessee really ought to be concerned about our air quality now. That's the big concern."

The TVA is asking a judge to throw out all of the lawsuits over the Kingston coal ash spill.