A control system for a water treatment system having at least one treatment tank (10, 12) that requires periodic regeneration, the control system including a control valve assembly having a multi-level valve housing (590a, 637, 638, 397, 398, 399), and further including a servo control system enclosed in the housing that includes: a stationary port disc located in a sealed chamber located in said valve housing, said port disc defining signal ports; a regeneration control disc rotatable in a rotational plane atop said port disc such that rotation of said regeneration control disc selectively communicates said signal ports with pressurized water or an ambient drain, said rotatable regeneration control disc biased into sealing engagement with said port disc; a water usage turbine (116', 702) for monitoring the quantity of water treated by said water treatment system, the control valve assembly characterized by: a) an encoder wheel operatively coupled to said regeneration control disc, said encoder wheel monitoring a rotation and position of said regeneration control disc; b) a sensor for monitoring movement in said encoder wheel; c) an electric drive motor operatively coupled to said regeneration control disc so that energization of said electric drive motor produces attendant rotation in said regeneration control disc, wherein said electric drive motor is disposed within a dry chamber, said dry chamber located in the valve housing below a rotational plane defined by said regeneration control disc; d) a sensor for monitoring rotation of said water usage turbine and operative to produce signals in response to rotation of said water usage turbine (116', 702); and, e) a regeneration controller electronically coupled to said electric drive motor and operative to receive signals from said water usage turbine sensor and using said signals from said water usage turbine sensor to determine when regeneration of a tank forming part of said water treatment system requires regeneration and further operative to control energization of said electric drive motor to cause rotation of said regeneration control disc in order to effect a regeneration cycle. a stationary port disc located in a sealed chamber located in said valve housing, said port disc defining signal ports; a regeneration control disc rotatable in a rotational plane atop said port disc such that rotation of said regeneration control disc selectively communicates said signal ports with pressurized water or an ambient drain, said rotatable regeneration control disc biased into sealing engagement with said port disc; a water usage turbine (116', 702) for monitoring the quantity of water treated by said water treatment system, the control valve assembly characterized by: a) an encoder wheel operatively coupled to said regeneration control disc, said encoder wheel monitoring a rotation and position of said regeneration control disc; b) a sensor for monitoring movement in said encoder wheel; c) an electric drive motor operatively coupled to said regeneration control disc so that energization of said electric drive motor produces attendant rotation in said regeneration control disc, wherein said electric drive motor is disposed within a dry chamber, said dry chamber located in the valve housing below a rotational plane defined by said regeneration control disc; d) a sensor for monitoring rotation of said water usage turbine and a) an encoder wheel operatively coupled to said regeneration control disc, said encoder wheel monitoring a rotation and position of said regeneration control disc; b) a sensor for monitoring movement in said encoder wheel; c) an electric drive motor operatively coupled to said regeneration control disc so that energization of said electric drive motor produces attendant rotation in said regeneration control disc, wherein said electric drive motor is disposed within a dry chamber, said dry chamber located in the valve housing below a rotational plane defined by said regeneration control disc; d) a sensor for monitoring rotation of said water usage turbine and operative to produce signals in response to rotation of said water usage turbine (116', 702); and, e) a regeneration controller electronically coupled to said electric drive motor and operative to receive signals from said water usage turbine sensor and using said signals from said water usage turbine sensor to determine when regeneration of a tank forming part of said water treatment system requires regeneration and further operative to control energization of said electric drive motor to cause rotation of said regeneration control disc in order to effect a regeneration cycle.