The reading suggests that new regulations on coal ash from power plants are unnecessary. However, the professor in the listening disagrees with that idea.
According to the reading, regulations already exist such as the requirement of using liner to prevent the pollution. However, the professor consider it not sufficient because liner is only required for new land. The power plants do not add liner to old sites, which may causing the contamination of groundwater.  
The reading argues that stricter regulations will discourage the recycling of the coal ash because consumers will be concerned about the safety of the products made by recycled coal ash. The professor contradicts this idea by giving the example of mercury. There are strict regulations on this material, but it has been recycled for 50 years. Customers show few concern on these products. So the recycling companies do not need to worry about that.
Finally, the reading says that new rules will result in a sharp increase in the cost of the power company, thus the price of the electricity will be increased. However, the professor thinks it is a worth deal compared to its benefits. 15 billion sounds a lot, but it only cause 1% rise of the electricity price.