Change Of Plan

I recently changed my plan to convert my garage into a full fledged kitchen, it came to my knowledge that under the garage area is my house' sewage system. I have to find a sewage pump at least to clean it before I do the conversion which is more expensive and costly than keeping my kitchen stay inside the house by installing much smaller oven for my baking needs. I have to have a plan B or C at least.

Universe, guide me!