2017-09-18 General Committee Agenda

GENERAL COMMITTEE MEETING AGENDA                                            18 SEPTEMBER 2017


From a practical perspective, maximum values are very useful to inform release criteria for point
source polluters. However, maximum values may not be useful for tracking the health of an
ecosystem where the chemical ecology has adapted to, and requires seasonal variations, i.e.
during winter where there is less sunlight, the processing of chemicals has different chemical
uptakes or outputs compared to longer summer days. Climatic cycles such as El Nino and La
Nina also have impacts of ecological processes. Seasonal or climatic variation is suggested to be
accommodated via provision of %ile based criteria, or seasonal or climatic criteria.
Now that long term data is available for Moderately Disturbed waters, it is unclear why the criteria
for moderately disturbed waters is not being proposed to be changed to 20th-50th-90th%ile
values as is the situation for High Ecological Value (HEV) waters.
In terms of using criteria to identify where harm is happening, for data sets that do not have
baseline data prior to human impact, the DSITI guidelines for preparing a Receiving Environment
Monitoring Program recommends to compare monitoring results to use standard deviations away
from the long term median value to identify whether any change from the general ambient
conditions is a shock or stress to the system. The standard deviation of water quality away from a
median value is generally used to trigger an alert to further investigate the cause of sudden
changes to water chemistry. Changes of 2 standard deviations can generally indicate a stress
shock to the system that may cause environmental harm (i.e. in a similar way humans living at
sea level get altitude sickness if they do not have time to adapt to changing oxygen
concentrations in the atmosphere).
In summary, a change to water quality objectives to accurately reflect the ecological needs of the
catchments is supported, but the proposed revision of the water quality criteria to the 50th%ile of
the past 10 years of data is not supported due to inadequate information. Setting a singular
maximum or minimum value that cannot be breached is not supported for natural environments
as it does not account for seasonal variation and facilitates for the system to operate under
maximum pressure. It is requested for DSITI to reissue consultation documentation to:
   Articulate the rational of how the proposal to lower protection will protect and enhance
     ecological process necessary to sustain life, as per the objective of the Act; or
   Reconsider or explain why the 50th%ile values have been chosen to be used; or
   Be consistent in the method for applying water quality criteria for all waters and include
     tightening the criteria for waters that are more pristine than the existing criteria expects,
     and long term data shows the criteria is always met.
   Include the results of the e-source scenario modelling that has been commissioned by
     Healthy Land and Water to confirm proposed water quality objectives are achievable, or
     whether better water quality is achievable, and identify the expected type of socio-
     economic investment necessary to achieve them; or
   Consider using 20th, 50th, 80th percentile objectives for Moderately Disturbed waters, or
     use 20th 50th 80th %ile data from e-source modelling under best land management practice
     scenario, now long term data is available for Moderately Disturbed catchment; and
   Demonstrate that the 10 years data set adequately incorporates the impact of EL Nino,La
     Nina climate cycles.
Do you have any comments on the environmental values shown in EPP Water mapping
(e.g. locations of aquatic ecosystem, recreation, industry use, cultural and spiritual values
stock watering, recreation)?
Weyba catchment still contains rural and rural settlement zones properties with onsite farm
dams. Keeping stock on these properties is permitted under the Noosa planning scheme and as
such the Environmental Values for stock watering is requested to be returned to the mapping in
the Weyba Catchment.




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