Leachate cost savings
The Council was spending a considerable amount of money tankering leachate off site for treatment and disposal. It was decided to carry out a review to see if we could realise any savings whilst not affecting gas production or flare run time. As a result of the initial consideration, over a number of weeks the 19 leachate pumps were turned off and then turned back on if required. To track the effects of these changes the frequency of monitoring of leachate levels and landfill gas was increased; the results led to a decision to raise some pump levels significantly above the bottom of the wells. We saw no adverse effects on gas migration or flare run time, which allowed monitoring to be returned to its original frequency. As a result of the project, we achieved a 50% reduction in the cost of leachate tankering, treatment and disposal.
Historically, dilute leachate had been discharged directly into the sewer system with a number of discharge conditions set by Severn Trent. It was discovered on a routine sampling visit that we were exceeding the limits set for dissolved methane. This needed rectifying as dissolved methane coming out of solution had potential to create an explosive atmosphere within the sewage pipework. Worcestershire County Council wanted a low cost, environmental and sustainable option to treat the problem. We researched various treatment options available and it was decided to install a reed bed. After the initial build costs, running costs are minimal and maintenance of the bed is negligible so it proved to be an ideal choice. Since installation we've not breached the consent limits for dissolved methane.