EngSWMP

         Remove filter bags from the pit and wash the bags using a high pressure water
          spray. Care has to be taken to not transfer the contamination elsewhere. Waste
          water from the process should be collected of and disposed of correctly.
         Remove the filter bags from the pits and the support rings and wash the bags in an
          industrial washing machine.

The final option presented above typically results in the bags appearing like new, with no
visible stain or pore clogging within the filter mesh.




Plate 31 Slightly clogged filter bag, Plate 32 A clean used filter bag
indicated by the brown stain on in the
centre of the bag




3.5.2 Damaged Filters
Damaged filters can often be repaired, provided the damage is small. Small tears in the
fabric may occur do to several reasons, however the overall strength & structure of the
nylon fabric typically prevents small tears becoming much large. Although the bag is
unlikely to tear further care must be used when clean torn bags as not to spill the collected
material into the pit.

Small tears may repaired by either sewing the tear back together, with additional fabric to
increase the strength of the stitching, or by sewing a patch of the filter material onto the
filter bag. The filter bags may need to be replaced if large tears are present, as the filter
bag is no longer able to function as intended.

IES is able to repair bags or replace bags which have been damaged during maintenance.
Please contact IES Sydney office on 02 9907 1401 for details or a quote.

3.6   Disposal of Material
All gully pit wastes from the site are to be taken off site and disposed of at a transfer
station or similar approved disposal site. Stormwater Sediments can contain Lead,
Copper, Zinc, Mercury, hydrocarbons and PCBs, which are harmful to both humans and
the receiving environment. Appropriate sampling and laboratory analysis may be required
to classify the material as suitable for reuse, or disposal under appropriate local guidelines.