Can you tell me the price difference between electric and pneumatic pumps?

The price difference is going to depend pretty heavily on the depth that you have to pump from and the flow rate that you need. But as an example, if your wells were 75 to 100 feet deep and you had a flow rate requirement of about 10 gallons per minute, an air-powered pump for that application would cost about $2,800 to 3,500 depending on your option choices; an electric submersible pump for that application would cost in the range of $1,200 to 2,000 depending on options selected there. Remember, these are examples based on the air-powered pump being designed specifically for leachate, and the electric submersible pump being a standard off-shelf type of pump. If you go to the companies that make specific electric pumps for leachate applications, then the cost differential is lower. The $2,800 to 3,500 for the air-powered pump is now matched at roughly the same price (a range of $2,500 to maybe $3,200) for the electric pump. The off-shelf electric pumps are a little less expensive, but they do not have the same reliability, and often do not carry a warranty if the pump fails in a leachate application.