What is the minimum net liquid capacity required for a grease trap in an onsite wastewater system?

The minimum net liquid capacity required for a grease trap in an onsite wastewater system is 1000 gallons. This requirement is grounded in the need to effectively capture and retain grease, oils, and solids that can negatively impact the functionality of a septic system or municipal wastewater treatment. A grease trap of this capacity ensures that sufficient volume is available to allow for the separation of fats, oils, and grease from the wastewater, preventing these substances from entering the sewage system.

This capacity is typically determined based on the expected volume of wastewater generated by commercial kitchens or food service establishments, which often produce a higher load of grease. A 1000-gallon grease trap provides a buffer to manage peak flow times and contributes to maintaining the overall health and efficiency of the wastewater treatment process by minimizing the risk of blockages and system failures.

The higher capacities listed in the other options are beyond the minimum requirement; however, they may be necessary for specific applications with considerably higher grease loads or larger establishments. The regulation sets a baseline at 1000 gallons to ensure adequate treatment while also allowing for flexibility in system design based on specific needs.