City of Arlington, Texas AWS
City of Arlington, Texas Interceptor Sizing Calculator How to Use This Calculator: Step One: Count the number and size of plumbing fixtures in any food preparation, serving, handling, or clean up area. Bathroom fixtures and rooftop condensate drains should not be plumbed to the grease interceptor or counted for grease interceptor sizing. Step Two : Input the quantity of each fixture size into the formula below. Step Three: Each fixture size has an assigned Drainage Fixture Units (DFU). The total DFU will give a rough estimate of flow through the interceptor at any given time, per minute. Multiply the total DFU by 30 minutes to see what size interceptor you will need. Step Four: Use the "Minimum Required Capacity (Gallons)" value below to select a standard grease interceptor size that is larger than the minimum required capacity. For example, if the minimum required capacity is 584 gallons, a grease interceptor with a capacity of 750 gallons or larger would be acceptable.
Fixture Inlet Size 1¼" 1½" 2" 2½" 3" 4"
Quantity 0 0 1 0 2 0
Drainage Fixture Units (DFUS) 1 2 3 4 5 6 Total Potential Flow=
Potential Flow (GPM) 0 0 3 0 10 0 13
Formula Description: Total Potential Flow X 30 Minute Retention Time = Minimum Required Capacity (Gallons)
Minimum Required Capacity (Gallons) =
390 minimum size not to be less than 500 gallons, unless approved by Authority
Minimum required capacity is for guidance only. Water Resource Services recommends against grossly oversizing grease interceptors; however, users who are likely to produce wastewater with atypical strength may be required to install a larger interceptor. Hydromechanical grease interceptors are generally not permitted within City of Arlington. Water Resource Services is the final approving Authority. For assistance completing this form or questions, please contact Water Resource Services at 817-459-5902 and ask to be connected with the Analyst who does plan reviews. Revised 11-28-2017
Fixture Inlet Size 1¼" 1½" 2" 2½" 3" 4"
Quantity 0 0 1 0 2 0
Drainage Fixture Units (DFUS) 1 2 3 4 5 6 Total Potential Flow=
Potential Flow (GPM) 0 0 3 0 10 0 13
Formula Description: Total Potential Flow X 30 Minute Retention Time = Minimum Required Capacity (Gallons)
Minimum Required Capacity (Gallons) =
390 minimum size not to be less than 500 gallons, unless approved by Authority
Minimum required capacity is for guidance only. Water Resource Services recommends against grossly oversizing grease interceptors; however, users who are likely to produce wastewater with atypical strength may be required to install a larger interceptor. Hydromechanical grease interceptors are generally not permitted within City of Arlington. Water Resource Services is the final approving Authority. For assistance completing this form or questions, please contact Water Resource Services at 817-459-5902 and ask to be connected with the Analyst who does plan reviews. Revised 11-28-2017
