Seattle kitchens in neighborhoods like Ballard and Fremont often sit in buildings from the 1920s through 1960s where cast-iron laterals run under sidewalks or through crawl spaces that stay damp most of the year. Grease solidifies faster here once winter rains drop ground temperatures, so quarterly service is common for restaurants near Pike Place Market and monthly checks for homes in Queen Anne that still use older 3- or 4-inch lines. We pump, scrape baffles, and flush with hot water to break residual layers without pushing material downstream into the King County system.
Discovery Park and West Seattle properties frequently have outdoor traps exposed to salt air and constant moisture, which accelerates corrosion on steel lids and lets roots from nearby trees enter through hairline cracks. In Belltown high-rises the traps sit in tight utility rooms where access requires coordination with building staff and often needs low-odor enzyme follow-up so residents do not smell the work for days. University District student housing adds another layer: shared kitchens generate heavy fryer waste that can overwhelm a trap in under three weeks during finals week.
Tacoma and Bellevue customers call when their line crosses into Seattle because King County rules treat any grease discharge the same regardless of city line. We document trap condition with photos and leave a written report noting baffle condition, FOG depth, and recommended interval so operators stay ahead of the next wet season when flows slow and blockages surface first at the lowest cleanout.
Technician insight
In Seattle the thing that catches most people out with grease trap cleaning is how quickly fats re-solidify once the mild winter rains cool the ground and slow flow through older 3-inch lines common in Capitol Hill and Ballard brick buildings.
Fremont Restaurant Line Backup
A Fremont café reported slow drains after two weeks of heavy rain. We found the 50-gallon trap half full of cooled grease that had migrated into the 4-inch lateral under the sidewalk. After pumping and scraping we flushed the line and confirmed clear flow to the main; the owner scheduled quarterly service before the next dry-summer slowdown.
Grease Trap Cleaning Services We Offer
✓Restaurant Grease Trap Pumping
Full evacuation and baffle cleaning for commercial kitchens in Capitol Hill and Belltown that must meet King County health inspection intervals.
✓Residential Grease Trap Service
Homeowner trap cleaning in older Queen Anne and Fremont houses where kitchen lines tie into 1920s cast-iron laterals that trap animal fats quickly.
✓Outdoor Grease Interceptor Cleaning
Service for buried concrete interceptors common in West Seattle and Discovery Park properties exposed to constant moisture and root intrusion.
✓Enzyme Maintenance Program
Monthly low-odor enzyme dosing after mechanical cleaning to keep traps in University District rentals from re-accumulating between scheduled visits.
✓Emergency Grease Blockage Response
Same-day clearing when a trap overflows into floor drains during peak dinner service in Fremont or near the Space Needle.
Grease Trap Cleaning Cost in WA
| Service | Typical Range | What Affects It |
|---|---|---|
| Standard residential trap | $225–$375 | Size, depth, and whether roots are present move the price. |
| Restaurant under-sink trap | $275–$450 | Frequency of service and volume of fryer waste affect cost. |
| Outdoor concrete interceptor | $450–$850 | Lid condition, water table, and pump-truck access change pricing. |
| Emergency after-hours call | $150–$300 added | Applies outside Mon–Fri 8–6 and Sat 9–2 window. |
Ranges are typical for WA and confirmed with an exact written quote before any work starts.
How it works
- 1
Site Assessment
We locate the trap, measure access, and note pipe material and surrounding soil conditions typical of Seattle’s wet winters.
- 2
Pumping and Scraping
Contents are removed, baffles scraped, and interior walls flushed to remove embedded grease layers without damaging older cast iron.
- 3
Line Flush and Camera Check
Downstream lines are flushed and scoped to confirm flow reaches the main without pushing material into neighboring properties.
- 4
Report and Schedule
Photos and written notes are left with the next recommended service date based on observed FOG accumulation and local rainfall patterns.
Pricing
Most residential traps fall in the mid-hundreds; commercial jobs vary with size and access.