EngSWMP

3     Operations

This section details the specific activities required to clean the Enviropod units. Please
note it has been written for use by someone who has never encountered a stormwater pit
or an Enviropod unit, providing a step by step process for each of the cleaning stages.


3.1    Maintenance & Monitoring of Enviropod filters

The maintenance frequency is dependant on several variables, such as catchment area,
surrounding land use, vegetation type, traffic loading and rainfall patterns. IES
recommends that during the first year of operation the units should be monitored monthly,
with maintenance as required.

The ensure that the unit performs optimally, the material collected by the filter bag should
be emptied when the level of material is no more than approximately half to two thirds of
the total bag depth or when there is evidence of material overflow. Although the bag has
greater storage area, it is recommended that it is not left to fill completely prior to empting,
for the following reasons; the bags are capable of retaining a heavy mass of material (in
excess of 50kg); material near the top of the bag can be resuspended during high to
extreme rainfall events; and blockage of the overflow sections can occur, when material is
allowed to build up above the filter bag.

Maintenance frequency should be adjusted to accommodate variable rainfall patterns.
Regions east of the Great Dividing Range typically are dominated by greater rainfall during
summer and Autumn Months, as such more maintenance is typically required during these
periods. It is recommended that biannual inspections be carried out in November and
April, while quarterly inspections should be conducted in February, April, July and
November.

It is also recommended that additional monitoring should be conducted following moderate
to extreme rainfall events, in particular, when preceding months have had little to no
rainfall. This monitoring is considered necessary to accommodate for higher volumes of
runoff generated during major rainfall events, an anticipated greater accumulation of
surface contamination during low rainfall periods and to ensure that the units have not
been damaged due to high pipe velocities.

Attached in Appendix A & B is an example of an Enviropod Service Receipt and Generic
Monitoring Form which is to be completed by the Cleaning Contractor when servicing any
Filters. Relevant information is recorded and forwarded to the client following each
maintenance clean.

                     Table 1: FREQUENCY OF MAINTENANCE ACTIVITY
                                INSPECTION/MINOR                       MAJOR
                            MAINTENANCE (TIMES/YEAR)                MAINTENANCE
                                                                    (TIMES/YEAR)
       Enviropod              12 (and after major storms)       2-6 (except in case of a
                                                                         spill)