16-001014-02A (Ultimate SCMMP)

    Maintenance overview                                        Super-critical HumeGard® (HG12 & HG15)


    To ensure ongoing long-term environmental protection        The super critical Humegard® consists of an internal
    HumeGard® needs to be maintained (generally annually).      broad crested weir and holding chamber.
    The actual on-going maintenance frequency
    requirements will be determined through quarterly           A specially designed patented broad crested weir diverts
    inspections undertaken during the first year. However,      material entrained in the flow into the adjacent holding
    only an annual maintenance period is anticipated            chamber. This consists of the holding sump and another
    for most HumeGard® units installed within drainage          baffle/weir/channel arrangement designed to retain
    infrastructure.                                             floating material while guiding flow through to the
                                                                outlet.
    Inspection can be performed by anyone, and procedures
    for inspection are provided in this document.               • Low/Treatment flow operation
                                                                  During low to moderate flows, the weir diverts all flows
    Generally, comprehensive maintenance is performed             into the sump area where pollutants are captured and
    from the surface via vacuum truck. Companies capable of       retained. The velocity in this sump is controlled and
    performing this maintenance can be found in the Yellow        never exceeds a maximum average velocity of 0.2m/s.
    Pages or online by searching sewer cleaning or liquid       • High/Bypass flow operation
    waste removal.                                                During high flows, the weir diverts up to the treatable
                                                                  flowrate into the sump and any excess flow is able to
    Additionally large litter items may also be removed           flow over the hump and through to the outlet. This
    utilizing the optional stainless steel basket arrangement     ensures that the previously caught pollutants are not
    within the HumeGard®. Alternatively the litter can be         disturbed, resuspended and diverted out of the outlet
    removed during eduction/vacuum clean out, which will          pipe.
    be required in order to remove the sediment component
    of the stormwater pollution.
                                                                Figure 1 – Super-critical HumeGard® GPT




    HumeGard® operation

    The HumeGard® GPT utilises the processes of physical
    screening and floatation/sedimentation to separate the
    litter and coarse sediment from stormwater runoff. It
    incorporates an upper bypass chamber with a floating
    boom (or broad-crested weir for small units) that diverts
    treatable flows into a lower treatment chamber for
    settling and capturing coarse pollutants from the flow.
    There are two types of HumeGard® - the super-critical
    version, which incorporates a broad-crested weir
    approach for treatment flow diversion, and a larger,
    standard version, which incorporates a floating boom
    arrangement to divert treatable flows.




3   HumeGard® GPT