I think you just missed commenting out one more reference to the EEPROM in line 144:
EEPROM_read(KVALUEADDR, Kvalue); //1.0 means no change to raw readings. Just commenting or deleting that line should fix the compiler error. I would also suggest you delete lines 38-43 so you’re not even trying to include the unused EEPROM library.
If you wanted to, you could use the “extVoltage” sensor in ModularSensors with >1 reading to simplify all your code for reading the analog values. You would still need to create a calculated variable for the pH, conductivity, and eTape calculated from the voltage. There’s nothing wrong, though, with reading the value and doing the calculations just as you are.