Water tank monitoring and pump control mechanism.

I am prototyping a water tank monitoring and pump control mechanism. but there is a problem i am facing is how to read the transistor status with arduino .

I am using BC547 transistors for sensing water level of my water tank. It reads out perfectly with LED. but i want to read the status with my Arduino Uno board.
Attaching The schematic of electronic sensing module . Please help me out with arduino codes.

circuit.jpg

Can't help at all while you are reading -( negative) voltages. Reverse that and perhaps you have a chance.

Paul