11.   Another issue being debated is whether it is practical to require property owners to bring contaminated sites to preindustrial conditions regardless of their future use.

12.   -- A disagreement about whether the Resource Conservation and Recovery Act allows individual federal lawsuits to recover the cost of cleaning up a contaminated site.

13.   Business leaders want legislation that would allow owners to base any cleanup on both the risk to public health and the proposed use of the contaminated site.

14.   Business leaders want to allow owners to consider the realistic health risks and the proposed uses of contaminated sites when cleaning them up.

15.   But the risks of radiation releases during and after wildfires at contaminated nuclear sites are still not thoroughly understood by scientists, let alone the public.

16.   But the risks of radiation releases during and after wildfires at contaminated nuclear sites are still not very well understood by scientists, let alone the public.

17.   But there are thousands of less severely contaminated sites, or brownfields, many in poor communities, that lie fallow.

18.   Do contaminated sites need to be thoroughly cleaned even when they will be put to industrial use?

19.   Electricity in the ground, not the atmosphere, may have an effect on the chemistry of contaminated industrial sites, helping to clean up them up.

20.   Hanford, which made plutonium for nuclear weapons for four decades, remains the most contaminated nuclear site in the nation.