Appendix 3 - Stormwater quality management plan

Operational Management and Maintenance Manual for Stormwater Quality Improvement Devices      CC-3668



3. GROSS POLLUTANT TRAPS
3.1.      Background
Gross pollutant capture devices serve as primary stormwater treatment devices in a stormwater
treatment train as they target litter, coarse sediments and other large particles (larger than 5mm).
This pre-treatment of stormwater flows can help to reduce the risk of secondary or tertiary treatment
devices, located downstream, from being smothered, affecting the treatment performance and
effective service life.

3.2.      Inspection and Maintenance
Gross pollutant traps will be installed to the top of all inlet pits within the development. Regular
inspection and maintenance is required to ensure the traps do not become blocked from sediment,
debris or litter. The storage capacity of the gross pollutant trap has been sized to ensure that the
maintenance (cleanout) frequency is not greater than once every 3 months.

Inspection and maintenance of the gross pollutant traps should be undertaken as per the manufacturer’s
recommendations and guidelines. At a minimum, at least three inspections should occur in the period
between October and May each year. Inspections should not be made less than 24 hours and not
more than 72 hours after the cessation of rainfall if the total rainfall on any day exceeds 30mm.
Litter, debris and sediment should be removed from the gross pollutant traps approximately every 3
months.




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