a container for receiving and holding effluent water containing oil / grease to be removed has sectional covers . a main sectional cover supports a partially immersed rotatable disk ; a drive on the main sectional cover rotates the disk ; a trough on the main sectional cover straddles the disk ; and a blade on the trough scrapes a side of the disk , to direct oil and grease from the disk along the scraper blade along the trough for collection in a storage container . efficiencies of construction of the sectional covers , disk and a sensor probe are disclosed .