Further Council Report MCU21-0110.pdf

               In review of report prepared by Unitywater’s consultant Council’s consulting odour expert advises
               the operation of the sewage treatment plan is regulated by an Environmental Authority, issued by
               Department of Environment and Science, which requires that the onus is on the operation to not
               cause nuisance/harm from odour emissions. This applies at all times whether it be normal
               operating conditions or the upset conditions, being the unintended and unavoidable odour relates
               events which Unitywater’s consultant refers to. Furthermore, Council’s consulting expert notes that
               existing residential uses at Noosa Springs, situated west of the STP are within proximity of the
               2.5OU line whilst the existing outdoor recreation areas of the resort, including the existing tennis
               courts, would experience odour concentrations above 2.5 OU. Thus, existing approved and
               developed areas are already a constraint on the STP operation. It is also noted that Unity Water
               have advised that they have no record of odour complaints from these current uses.
               In terms of the comments by Unitywater’s consultant regarding the suitability of methodology used
               by the applicant’s odour expert Council’s consulting expert states:
                      The use of modelling of odour from STP is an accepted practice for both development
                      assessment at the Local Government level and in the Planning and Environment Court.
                      Typically, the assessment is based upon normal worst case emissions not Upset conditions
                      (unintended or unavoidable odour emission conditions).
                      Whilst there are uncertainties in any form of assessment and modelling, it is a tool for




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                      assessment purposes which informs the assessment manager of potential impacts.
                      In respect to independent ground truth verification – I assume the author is identifying the




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                      use of field odour surveys which are manned inspections by persons with a laboratory verified
                      sense of smell that are used to characterize odour ie in terms of intensity and offensiveness.
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                      The use of field odour surveys can inform and provide validation points for modelling.
                      In this instance there are existing residential uses and the Noosa Springs facility and outdoor
                      uses which are currently occupied and used and there does not appear to be a complaint
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                      history in respect to odour which supports the modelling outcomes. Even if field odour testing
                      was conducted it does not guarantee any improved odour prediction/assessment outcome
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                      in my opinion.
                      I have been involved in matters where modelling of upset conditions has been undertaken in
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                      respect of STP operation. However, the reliance upon odour from upset conditions in
                      informing development assessment against the 2.5 OU 99.5%ile 1 hour criterion is in my
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                      opinion very limited. This is because the 99.5%ile allows for periods of higher odour to occur
                      ie it is not absolute and the Environmental Authority requirement to not cause odour
                      nuisance/harm is in play at all times.
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                      I understand the STP operator desire to maintain buffer separations, but this must be
                      considered on the basis of existing land uses and proximity of existing sensitive uses to the
                      STP which, as per above, already exist.
                      Further, it is my opinion that a short stay resort development has far less reverse amenity
                      constraint potential than standard residential uses.
               In terms of the proposed additional mitigation measures proposed by Unitywater’s consultant:
               •      Legal advice has been obtained and it has been determined that an encumbrance or
                      similar that transfers all responsibility of STP-related odour complaints from Unitywater to
                      the proponent is too uncertain and potentially against public policy resulting in a deed of
                      agreement that is void, unenforceable and ineffective.
               •      Agreed that activated carbon filters to fresh air makeup locations can be required to further
                      protect indoor air quality.
               •      A major redesign of the development is not warranted.
               The applicant’s odour expert also reviewed the Unitywater’s consultant’s comments and forms a
               similar view to Council’s consulting expert, however, opposes the recommendation that activated
               carbon filters be installed. The opposition to the carbon filters is on the basis that the applicant’s
               proposal for fresh air makeup to the air conditioning systems must be drawn from roof level



Document Set ID: 22048375
Version: 34,
         32, Version Date: 24/10/2023
                           05/07/2023