Los Angeles County Public Works - Industrial Waste
Environmental Programs public counter located on the 3rd floor of the Annex building in Alhambra is open to the public. In order to maintain facility capacity we have implemented an online appointment system. Masks are highly recommended at all times for all visitors and staff. Click here to schedule an in person appointment or call (626) 458-3517 for questions or assistance.

For Industrial Waste questions or submissions, email us at iw@pw.lacounty.gov. You can also mail submissions to:

Los Angeles County Public Works
Environmental Programs Division
900 S. Fremont Ave
Alhambra, CA 91803

If you have any questions, contact the Environmental Programs Public Counter at (626) 458-3517, Monday to Thursday, 8 am to 4 pm.


Pretreatment means the reduction of the amounts of pollutants, the elimination of pollutants, or the alteration of the nature of pollutant properties in wastewater to a less harmful state prior to or in lieu of discharging or otherwise introducing such pollutants into a Publicly Owned Treatment Works (POTW) or other disposal facility. The reduction or alteration can be obtained by physical, chemical, or biological processes or process changes by use of an industrial waste treatment facility or other means, except as prohibited by 40 CFR Section 403.6(d) (LACC, Division 2, Section 20.20.264). The most commonly used County Standard pretreatment drawings are available below:

  • Grease Interceptor (PDF, 220 KB)
  • Sand and Grease Interceptor (Clarifier) (PDF, 241 KB)
  • Sample Box (PDF, 177 KB)
  • Rain Water Diversion System (PDF, 286 KB)

  • Restaurants and other food service facilities may significantly impact the public sewer line causing blockages. Grease pretreatment devices are required for most of these installations.

    Managed by the Los Angeles County Public Works, Environmental Programs Division
    Toll Free Phone Number: 1(888) CLEAN LA
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