Meeting papers

                                                                                      Burgess Creek
                                                 Receiving Environment Monitoring Program
                                                                                 Annual Review 2022
sedimentary geology, such as Weyba Creek and Noosa River. The Burgess Creek catchment
is more similar to the barrier islands in Moreton Bay and Hervey Bay, where extensive
monitoring has shown that groundwater levels respond rapidly to climate changes and
vegetation disturbances such as logging and bushfires (Armstrong and Cox, 2002). Although
there are no records of groundwater monitoring in the Burgess Creek catchment, extensive
monitoring of Bribie Island has shown that nitrogen, particularly ammonia concentrations, are
at least an order of magnitude higher than the background levels considered in the Burgess
Creek.

Wet weather, particularly La Nina conditions and intensified rainfall, has a substantial impact
on the treatment and transport of sewage in the Noosa Sewage Treatment Plant (STP) and
associated sewer catchment. The primary mechanisms for increased sewage flows that
require transportation and treatment are inflow directly into the sewer network and infiltration
through the soil into the sewerage infrastructure. Numerous pump stations are located
throughout the Noosa and northern Sunshine Coast Regional Council areas, including some
within the Burgess Creek Catchment, which could be a potential source of elevated total
nitrogen concentrations during wet weather events when sewage flows exceed pump station
capacity. A critical review of pump stations that may affect water quality within the catchment
should be identified and considered in future assessments of water quality data within Burgess
Creek. Although releases from the Noosa STP have remained stable over the past few years,
with total nitrogen mass load calculations prescribing flow by median total nitrogen
concentration, minor fluctuations around the 15,000 kg of nitrogen released per year are
calculated weekly. Total nitrogen concentrations have decreased in 2021 after reaching a
peak in 2019. However, the increasing trend within Burgess Creek is not supported by
compliance data measured at the Noosa STP. To increase monitoring transparency, future
assessments should include the monitoring of flows of treated wastewater released from the
Noosa STP. The observed increase in total nitrogen levels could be due to a combination of
these factors or other factors, and further investigation and analysis are necessary to identify
the underlying causes of the trend.

The discharge of treated wastewater from the STP outfall is a dominant impact on key water
quality parameters such as pH, dissolved oxygen, and conductivity. These parameters show
an increase at or just downstream of the outfall point, followed by a slight decrease or stable
levels further downstream. The low pH and dissolved oxygen levels at monitoring site B8
represents conditions that are experienced within the ephemeral catchment above the Noosa
STP. The primary cause is the presence of dominant health lands and acidic soils. which


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