The likelihood of a monitoring well at a single or double lined landfill detecting an initial leak is very small. Lined landfills leak in very narrow plumes, whereas old, unlined landfills will produce wide plumes of leachate. This is due to the incursion of surface water in both instances. Detection by monitoring wells can also be very difficult at lined landfills. Lined landfills leak in very narrow plumes, whereas old, unlined landfills will produce wide plumes of leachate.
Ground water flows downstream, or toward nearby lakes and rivers.
This is in violation of federal law. I support the bioreactor approach if properly conducted. Most of what I see today, however, that is being practiced as landfill bioreactors falls far short of a credible approach. Based on the available literature, pumping leachate back through a landfill causes increased decomposition, and it seems logical that it would also create a super toxic leachate. In addition, it would most likely accelerate the decomposition of the liner itself, thereby allowing leachate to contaminate ground water at an increased rate.