Hydrojetting in Compton, CA

Compton runs a sewer overflow reduction program, and buried inside it is a maintenance standard that requires reading even if you have never owned an interceptor.

The rule is that a grease interceptor must be pumped at a frequency such that the combined grease and solids accumulation does not exceed 25% of the total liquid depth, and, in any case, not less than once every 6 months.

Look at the shape of that. The primary standard is a measurement of condition: a quarter full is the limit. The six-month figure is a backstop, there to make sure someone actually looks. That is a condition test with a maximum interval attached, which is a different animal from a schedule dressed up as a rule.

. A great many maintenance recommendations in this trade amount to a calendar, and a calendar is a guess made by somebody who has not looked inside your pipe. A percentage of depth is checkable. It produces one answer for a busy restaurant and another for a quiet one, and it answers differently again for the same restaurant two years apart. That is what a real standard looks like.

The same rules deal with access, and the numbers there are just as concrete. An access manhole is required over each chamber and over the sanitary tee, at least 24 inches in diameter, and each must be carried up to finished grade. Those are figures you can check with a tape before anyone arrives. The rule also requires that those manholes remain accessible, and that requirement is the one that bites: a cover buried under a new slab or an asphalt overlay makes the required inspection impossible, turning an ordinary service visit into an excavation.

Nothing here makes a residential drain a regulated thing. What it gives a homeowner is a method rather than a number: measure what is in the pipe against the pipe, and let the answer set the date.

Grease accumulates with use, and use is not uniform over time. A restaurant that changes its menu, gains a lunch trade, or installs a second fryer changes its rate of accumulation without touching its plumbing. A measurement can see that, and a standard expressed as a proportion of depth is doing arithmetic against the vessel it is written for. It asks the pipe how it is getting on and sets the next visit from the answer.

The same logic applies to a house, at a smaller scale and with the same force. A kitchen line in a house where somebody cooks daily and one where the family eats out are the same pipe with different careers, and the useful question in both cases is what is in there now. One camera pass answer it, and the answer produces an interval specific to that line. Early-stage coating on the wall usually means doing nothing yet and looking again later. A run down to half its diameter means something else entirely. This is why the refusal to sell a maintenance plan on this page is an argument and not merely a policy. A plan prices an interval in advance, which means pricing it before anyone has looked, which is the exact error the City's own standard is constructed to avoid. Booking the next visit off the last camera pass keeps the interval tied to the pipe.