A paint spray booth sludge recovery system, apparatus and method is provided for water washed paint spray booths. The spray booths are used with a tank or pit which can accommodate flotation for removal of spent paint. Preferably, the tank has a drop box section, a chemical treatment section, a weir box section and a booth recirculation pump section. A series of weirs are used to separate the spent paint and send a concentration thereof from the weir box to a separator or centrifuge. The water level in the system is controlled by sensing the weir box water level to keep the water crests over the weirs at the desired levels. Scavenging and agitation are provided in the tank to keep it entirely clean for prolonged periods without any accumulation, even during downtime.