Sizing indoor hydromechanical grease interceptors (HGI) vs. exterior gravity interceptors (GGI). Texas Commission on Environmental Quality (TCEQ) rules and municipal pumping schedules.
Grease interceptor compliance is strictly enforced by municipal utility districts and health inspectors across Texas. Improper sizing delays certificate of occupancy permits.
Engineers calculate fixture unit (DFU) loading and peak gallon flow rates from 3-compartment pot sinks, prep sinks, floor drains, and mop basins to select certified PDI G-101 interceptor units.
Full-service restaurants with commercial fryers and dishwashers typically require a 1,000 to 1,500-gallon exterior precast concrete gravity interceptor. Small cafes or bakeries may be permitted with point-of-use 50 to 100 GPM indoor hydromechanical units.
Under the Texas "25% Rule", interceptors must be pumped out completely whenever the total depth of floating fats, oils, grease, and settled solids exceeds 25% of the liquid depth, or at least every 90 days.
No. High-temperature commercial dishwasher discharge (140°F+) melts grease, allowing it to bypass indoor point-of-use traps and congeal further down the line. Dishwasher lines must route to exterior gravity interceptors.