Wet Fume Scrubber Cleaning & Packing Replacement
A 2-Year Maintenance Must for Semiconductor Fabs
Why Scrubber Maintenance Matters
Wet fume scrubbers are essential in semiconductor manufacturing. These systems remove hazardous gases like HF, HCl, and sulfuric acid mist from process exhaust. To meet Bay Area Air Quality Management District (BAAQMD) requirements, scrubbers must operate at 95–99%+ efficiency, 24/7.
But over time, these systems degrade. Without routine cleaning and replacement of packing material every 2 years, they become energy hogs, performance deteriorates, and compliance risk skyrockets.
How Wet Scrubbers Work in Semiconductor Fabs
Most fabs use packed bed scrubbers:
- Contaminated gas enters a vertical tower
- Liquid (water + neutralizer) trickles over plastic Pall rings or similar packing
- Pollutants dissolve into the liquid film coating the media
- Cleaned air exits through a mist eliminator
Over time, the internal packing media fouls with:
- Mineral scale (e.g., calcium, sodium salts)
- Silicon dust or photoresist mist
- Sludge and neutralization byproducts
Fouling increases pressure drop and decreases removal efficiency.
Why Repacking Every 2 Years Is Best Practice
Preserve Removal Efficiency
- Fouled packing loses surface area and causes poor gas-liquid contact
- Can reduce removal efficiency well below permit requirements
- Unclean scrubbers risk violating BAAQMD air permits
Stay Compliant with BAAQMD
- BAAQMD expects pollution control devices to operate as designed
- Facilities are required to monitor pressure drop, liquid flow, and maintenance logs
- Failing to do so can lead to fines, inspections, or forced shutdowns
Local Example:
In 2022, United Airlines was fined $382,500 by BAAQMD for failing to maintain their scrubber. Despite low pressure readings, the system was not serviced for over 8 months. Violations included:
- Non-functioning pollution control system
- Refusal to conduct a required source test
- Recurrence of violations after a previous warning
Source: BAAQMD Press Release
Reduce Energy Costs
- Fouled packing increases fan power requirements
- Every 0.1” of added pressure drop can cost $200+ annually in extra fan energy (per system)
- Clean media = low pressure drop and optimal airflow
Avoid Emergency Downtime
- Scrubber fouling can cause full system shutdown
- Emergency response, overtime labor, and lost production are far more costly than scheduled service
- Biennial service ensures peace of mind and budget stability
Typical Costs & ROI
Service & Estimated Cost
Professional Cleaning & Repack
$5,000 – $20,000
Downtime (with planning)
1–2 days
Energy cost savings (annual)
$1,000 – $3,000
Emergency repair or outage
$10,000+ to $100k+ loss
Replacing packing every 2 years is often a 1-year ROI or better, especially when factoring in energy, downtime, and compliance risk.
BAAQMD Expectations & Local Fit
BAAQMD permits typically require:
- Routine inspection of spray nozzles, pressure drop, and mist eliminators
- Documentation of operating parameters and repairs
- System performance to remain consistent with Best Available Control Technology (BACT)
Additional regional factors:
- PG&E’s high commercial electricity rates make fouled scrubbers costly to run
- Bay Area sustainability programs increasingly push for energy and water efficiency
- Permit renewals and source tests expect verifiable maintenance logs
Summary: 2-Year Scrubber Maintenance Is a Smart Investment
For semiconductor fabs in Northern California, repacking and cleaning scrubbers every 2 years helps you:
- Avoid unplanned shutdowns and emergency repairs
- Stay within BAAQMD permit and emission limits
- Reduce energy usage and fan load
- Extend equipment life
- Support corporate ESG goals and sustainability reporting
Need Help?
WaterSystems Cleaning provides expert fume scrubber maintenance and packing replacement across the Bay Area. We service all major scrubber makes and models and offer rapid turnaround during fab maintenance windows.
- Serving: Bay Area, San Jose, Fremont, Santa Clara, Livermore, and beyond
- www.wscnc.com
- (408) 320-6880
Sources
- U.S. EPA: Packed Tower Scrubber Principles
- BAAQMD Press Release (United Airlines fine):
- Torch-Air: Wet Scrubber Media Maintenance
- Monroe Environmental: Wet Scrubber Rebuild vs Replacemen
- Honeywell: Fan Power vs Pressure Drop in HVAC
- Michigan DEQ Example: Chrome Scrubber O&M Plan
- KCH Services: Annual Cleaning Case Study
