Attachment 8 - Interim Stormwater Management Plan - TOPO · 132005.638.06

R5304: NOOSA RESOURCE RECOVERY CENTRE - STORMWATER MANAGEMENT PLAN



WT2 - The release of collected and treated stormwater to waters, from areas of the site not likely to be contaminated
with waste materials, must be in accordance with Table 2 – compliance limits for controlled releases of treated stormwater
to surface waters (reproduced herein as Table 1).

Table 1 – Surface Water Release Limits

          QUALITY
                                       RELEASE POINT             RELEASE LIMIT           LIMIT TYPE               MONITORING FREQUENCY
       CHARACTERISTICS

                   pH                                                6.5 - 9.0              Range

      Specific Conductance
                                                                       1500               Maximum           Commencement of Release then weekly
             (µS/cm)
                                                                                                              thereafter. If no release occurs, no
   Dissolved Oxygen (mg/L)                                               6                 Minimum                  sampling is required.
       Total and Dissolved
                                                                       N/A                Maximum
        Aluminium (mg/L)

                                                                                                            Commencement of Release then weekly
                                             W1                                                               thereafter for a minimum of 5 events
                                                                                                             and until a reliable TSS:NTU correlation
    Suspended Solids (mg/L)                                             50
                                                                                                             is established and agreed in writing by
                                                                                                            the administering authority. If no release
                                                                                                                 occurs, no sampling is required.

                                                                  The established       The NTU value
                                                                   correlation of      that correlates to   Commencement of Release then weekly
            Turbidity (NTU)                                     turbidity with total   50 mg/L TSS with       thereafter. If no release occurs, no
                                                                 suspended solids       a correlation R             sampling is required.
                                                                       (TSS)              value of 0.9




WT3- Monitoring of contaminant releases from release point W1 must be undertaken in accordance with the condition
WT2.

WT4 - In addition to WT2, released to waters must not:

       1.     have any other properties and content concentration causing environmental harm
       2.     produce any slick or other visible evidence of oil or grease, nor contain visible floating oil, grease, scum, litter or
              other visually objectionable matter.

1.5.             HIGH & LOW EROSION HAZARD SITES

The Guideline Stormwater and Environmentally Relevant Activities (DETSI, 2025) classifies ERA sites into two erosion
hazard categories, which determine the applicable stormwater management requirements.

1.5.1.           LOW EROSION HAZARD SITES
A site is only considered a low erosion hazard site where greater than 95 % of the site is effectively stabilised, the
unstabilised area does not exceed 2,500 m², and soil erosion is not expected to exceed 10 tonnes/hectare/year from
disturbed areas. These sites are managed under Part 2 of the guideline, which requires MUSIC modelling and a treatment
train designed to meet the load-reduction targets for Total Suspended Solids (TSS), Total Phosphorus (TP), Total Nitrogen
(TN), and gross pollutants greater than 5 mm.

1.5.2.           HIGH EROSION HAZARD SITES
All other sites are considered high erosion hazard sites. These require a full suite of erosion and sediment controls,
including sediment basins designed to retain runoff from the 24-hour, 1-in-10 year ARI storm event and to achieve a TSS
release concentration of no more than 50 mg/L. Basins must return their design capacity within 120 hours of rainfall and
include a sediment storage zone equal to 50 % of the upper settling volume.

DETSI supports the use of High Efficiency Sediment (HES) basins where it can be demonstrated that the contaminant
load released to the receiving environment over the project life is equal to or less than that of the standard design.


Environment. Engineering. Education.                                                                                                           PAGE 3