There seems to be an ever-growing trend toward new standards and certification testing for grease interceptors. I'm referring to the proposed ASME A112.14.3 Grease Interceptor Standard and the ASME A112.14.4 Grease Removal Devices Standard; ultimately a combined effort of the American Society of Mechanical Engineers (ASME) and the Plumbing and Drainage Institute (PDI). I'm hopeful that both proposed standards will be rejected since neither complies with any current pretreatment objective.
All Standard PDI-G101 certification test procedures are performed under controlled conditions. As a result they are free from contaminants and are neither mechanically or chemically emulsified. Since the volume of water and lard used in the test is specified, a simple formula will reveal the proper efficiency ratings.