The rule
“Introduction of any additives into the plumbing system of an FSE, grease interceptor or grease control device for the purpose of emulsifying or biologically/chemically treating FOG for grease remediation or as a supplement to interceptor maintenance is prohibited.” That sentence covers the drum a vendor leaves by the dish pit and the monthly “treatment plan” that comes with it.
Why a city writes that into law
A trap works by letting grease float and solids sink. An additive breaks the grease cap into droplets that stay in the water column and leave through the outlet. The trap looks cleaner; the grease is now in the lateral, re-congealing in the cooler pipe downstream, where it becomes the city’s blockage and your hot-spot notice. The ordinance exists because the sewer agency is required by the State Water Board to control blockages at the source. Additives move the problem from your tank to their pipe, so they are banned.
What is allowed, and works
- Drain screens on every drain in food-prep areas (required by the chapter’s BMPs)
- Scrape and dry-wipe before anything hits the sink
- Waste cooking oil into the recycling drum, never the drain (required)
- Pump on the interval the calculator gives you — full contents out, every time
If someone sells you a bottle anyway
Ask them to put in writing that the product does not emulsify or biologically treat FOG. They cannot, because that is what it is for. Then ask what percent full your interceptor was at the last service. If they do not know, the bottle was covering for a skim.