Residential Fats, oils and grease

Over time, fats, oils and grease (FOG) from everyday cooking can clog the pipes in your home and in the public sewer system. FOG and food particles poured down the sink solidify in your pipes, eventually causing blockages that can send untreated wastewater backwards – out of manholes or back into your house! Overflows can create serious public health hazards, damage property, cause odor issues and often require expensive repairs.

Hot water and soap may wash fats, oils and grease out of sight, but they don’t wash them away entirely. Hot FOG will eventually cool and solidify further down your pipes, where it can still clog sewer lines and create sewage backups in your home or street.

Helpful tips to prevent FOG from entering the drain:

  • Pour cooking oils and grease into a small container with absorbent material, such as a paper towel or coffee grounds, and dispose of it in the trash.
  • Scrape food from dishes into the trash (not the garbage disposal) and wipe down greasy plates, pots and pans with a paper towel before washing.
  • Prevent food from entering your sewer by covering your kitchen sink drain with a strainer.
  • Garbage disposals only grind up the greasy, fatty foods into smaller particles, which can make it even easier for it to cling to pipes.


Restaurants play a major role in helping keep Scottsdale’s sewer system working properly. Reducing the amount of food waste that is put into the city’s sewer helps

reduce odors, avoid clogs or blockages and prevent costly repairs. Grease traps and interceptors are the best options to help keep the sewer system operating properly.

Grease traps are small devices (typically less than 100 gallon capacity) located inside the kitchen, directly plumbed to the 3-compartment sink. They help trap food debris and grease that can mistakenly be washed into the sewer.

Grease interceptors are much larger, 2- or 3-stage systems. Located underground outside of the building, they act as mini wastewater treatment systems to remove the fats, oils and grease from a restaurant’s liquid waste.

Both grease traps and interceptors must be documented that they are cleaned and maintained on a regular basis. The routine varies for each restaurant and depends on the size of the kitchen and volume of food prepared each day.

Scottsdale’s Water Quality Department is responsible for inspecting each restaurant and ensuring that all grease traps and interceptors are properly cleaned and maintained.

These PDF files are available for download:


Car washes and repair shops an important role in keeping Scottsdale’s sewer system working properly. Oil and grease released into the sewer system builds up and can eventually block the sewer pipes and equipment used to treat the wastewater.

Sand/oil interceptors are similar to a restaurant’s grease interceptor in that they are multi-stage units designed to capture dirt, debris and automotive fluids that flow into the shop’s drainage system.

Like a holding tank, the interceptor provides adequate time for the water and oil to separate so that the petroleum, oil and grease are left behind while the water is discharged into the city’s sewer system.

Automotive repair shops, auto body shops, radiator repair shops, car washes and fleet service facilities in the city are required to have their interceptor pumped and cleaned at least once a year. Depending on the amount of discharge in each facility, more pumping and cleaning may be necessary to maintain the device operates properly.

All maintenance records (including pump out documentation) must be kept on site for a minimum of three years and be available for review during routine inspections.

Contact Information

Scottsdale Water Resources
9312 N 94th St
Scottsdale, AZ 85258  
P: 480-312-5650

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Office Hours

Monday through Friday
7 a.m. to 4:30 p.m.

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