2016-07-12 - Item 14 - Att 1 - Effluent Disposal Planning Study

In light of the above, the previous Planning Study concluded a conservative approach towards
development in unsewered locations is justified until further information emerges. The information
gaps identified in 1997 are still largely present today. Additional water quality testing has occurred
but there is still no more certain understanding of the likely environmental effects of on-site
wastewater treatment systems in Noosa Shire along with other regions. Our countryside is varied
with differing slopes, geology and soil characteristics. The movement of sediment and pollutants
across ground can be estimated but in the absence of extensive local monitoring, predictions are
best guesses at this time. The situation is similar for sub-surface movement but estimation is an
even less certain process. It is therefore difficult to accurately quantify the effects of sediment and
pollutants on the environment within a broad catchment. The amount of pollutants and sediment
present in waterways can be tested but as to estimating how and what caused it is a much more
difficult matter. There have been recommendations for more research to be supported in the
documents supporting this planning study.

Technology and the options for on-site wastewater treatment systems have progressed
significantly since 1997. A wide range of secondary treatment systems have emerged and been
brought to the market. Due to the improved outcomes anticipated, these systems have been
popular. However widespread shortcomings have evolved with the ongoing operation of the
systems. The Queensland government is currently investigating measures to improve on the
operational aspects of secondary treatment systems. Tertiary systems have a better reputation but
due to their extraordinary costs currently, very few are installed in Noosa Shire.

Improvements in the technology are acknowledged but the shortcomings around maintenance do
not yet convincingly offer any degree of confidence that secondary treatment systems can be
safely employed in marginal locations.

The following specific policy positions are recommended for endorsement by Council: –

       1. Catchment wide environmental effects of on-site wastewater treatment systems are not
          well understood. Further research into these effects is supported in principle in
          conjunction with a water quality monitoring framework.
       2. Secondary level on-site wastewater treatment systems have the capability to work well
          locally. However there is widespread failure associated with the maintenance of the
          systems. Positive action including audits and community engagement, is necessary for
          improving the outcomes for secondary systems. These measures to be considered
          when the current plumbing legislation is reviewed.
       3. In respect to future development in unsewered localities, a precautionary approach be
          adopted.
       4. Notwithstanding 3 above, development in unsewered localities that complies with the
          intent of the applicable zone of The Noosa Plan is assessed in the normal manner, but
          with greater consideration to the operation of the approved on-site wastewater
          treatment plant.
       5. For Cooran the 2000 m2 minimum allotment size remains apropriate, noting that
          sewerage is not planned to be provided.




On-Site Effluent Disposal in Noosa Shire 2016                                                  Page 23