Pat, what would help is ...

Pat, what would help is required is the characterization of the original disposal waste to determine the original moisture content and carbon content. Dependent where you are in the world the waste will degrade at steady rate, this may be influenced by the water content in the peat and the natural drainage. The leachate is likely to be produced solely from the degrading organic matter. This requires water to initiate the process, usually rainwater (as the site is sealed with an impermeable layer this may slow down the process. Typically if you are in wet temperate climate the rate of organic degradation will be about 15% per year, if the conditions are dryer (Dry temperate conditions then this could reduce to less than 5% a year. Regards Paul