The rule of thumb
Clean when the sump is 25 to 30% full or annually, whichever comes first. Florida's stormwater rules use the same threshold. A basin more than one-third full is functionally reduced and out of compliance with most ERP O&M expectations.
By property type
- HOA / residential community: annual full clean, plus a post-storm sweep after named events.
- Office park: annual, with a mid-year check on tree-canopy sections.
- Retail / big-box center: twice yearly, quarterly on restaurant pads.
- Restaurant / grocery pad: quarterly at minimum for FOG-heavy inlets.
- Industrial / warehouse: quarterly, monthly for MSGP-permitted operations.
- Automotive (body shops, dealers): quarterly with oil-water separator service.
Signals to shorten the cycle
Standing water 30+ minutes after normal rain. Sediment fanning out from a grate. Odor at an inlet (FOG or organics). Post-storm ponding that didn't exist last year. Any of those and you're due, regardless of the calendar.
What monthly vs quarterly actually costs
Per-visit pricing scales down when you commit to a recurring cadence. A quarterly program typically prices 20 to 30% below the per-basin one-off rate. See catch basin cleaning cost and our full catch basin cleaning service.
