A sensor mounting apparatus and methods for determining level, volume, or both of contaminated cuttings in a cuttings skip includes a collar having a body having a longitudinal axis, a first end, a second end, and a sidewall connecting the first and second ends, the sidewall parallel to the axis, the sidewall having an external surface and an internal surface, the internal surface defining a longitudinal bore through the coupling configured to allow material to flow there through. The apparatus includes a sensor receiver in the sidewall that holds a TOF sensor, the sensor receiver extending from the external surface to the internal surface of the collar, the sensor receiver having an axis skewed at an angle from the sidewall of the body. Fasteners on the first and second ends allow them to be fastened to a fill hose or chute and to a fill opening for the cuttings skip.