Recommended maintenance activities for media filters (Sources: WMI, 1997; Pitt, 1997).
Link to this table
| Activity |
Schedule |
- If filter bed is clogged or partially clogged, manual manipulation of the surface layer of sand may be required. Remove the top few inches of media, roto-till or otherwise cultivate the surface, and replace media with like material meeting the design specifications.
- Replace any filter fabric that has become clogged.
|
As needed |
- Ensure that contributing area, facility, inlets and outlets are clear of debris.
- Ensure that the contributing area is stabilized and mowed, with clippings removed.
- Remove trash and debris.
- Check to ensure that the filter surface is not clogging (also check after storms greater than about 1”).
- Ensure that activities in the drainage area minimize oil/grease and sediment entry to the system.
- If permanent water level is present in pre-treatment chamber (e.g., perimeter sand filter), ensure that the chamber does not leak, and normal pool level is retained.
|
Monthly |
- Check to see that the filter bed is clean of sediment and the sediment chamber is not more than 6 inches of sediment. Remove sediment as necessary.
- Make sure that there is no evidence of deterioration, spalling or cracking of concrete.
- Inspect grates (perimeter sand filter).
- Inspect inlets, outlets and overflow spillway to ensure good condition and no evidence of erosion.
- Repair or replace any damaged structural parts.
- Stabilize any eroded areas.
- Ensure that flow is not bypassing the facility.
- Ensure that no noticeable odors are detected outside the facility.
|
Annually |
- Remove and replace the top 2-5 inches of media every 3 to 5 years for low sediment applications, more often for areas of high sediment yield or high oil and grease
|
3 to 5 years |
