Maintenance - Underground


Catch basin, drywell, manhole, and vaults

Maintenance is needed if you see these signs
• The facility drains slowly after a rain storm.
• Leaves, trash and other debris slow or stop outflow or filtration.
• There is more than ¼ - ½ inch of sediment on the cartridges.

Confined space warning for underground facilities


Due to potential dangers, only trained and certified persons should enter confined spaces. These are defined as:
• Large enough that an individual could fully enter the space and work. 
• Having limited or restricted entry or exit.
• Not primarily designed for human occupancy. 
For more information visit Washington State Labor & Industries confined spaces rule.

Checklists for maintenance and recognizing and fixing problems (PDF files)
• Catch basin
• Drywell
• Manhole
• Vault - stormwater filter
• Vault - vortex sedimentation
• Vault - closed detention system

Facility Elements

• Field inlet
• Flow control structure/flow restrictor
• Access road
• Fence, gates, signs

Problem with Catch Basin
This catch basin has a lot of sediment buildup.
Problem with Drywell
Trash has collected inside this drywell.
Problem Vault Filter
This stormwater filter vault has a lot of sediment buildup, indicating that the filter needs to be replaced by professionals.