Flow chart outlining the process for selecting odour assessment tools for preparing or evaluating resource consents for proposed modifications to an existing industrial or trade activity

Text description of flow chart

1. Determine presence or absence of chronic effects. Use:

   Assessment Tool	Priority	Comments
   Complaint records	High	Complaints should be classified as validated by a council officer, or from wind-direction records, or as simply registered but not confirmed. Assess how proposed changes will reduce level of complaint.
   Industry/council experience	High	Experiences of the industry or regional council with this or other similar discharges.
   Community consultation	High	Periodic meetings with community representatives from community associations. Look for anecdotal evidence of community feeling about odour effects.
   Olfactometry and modelling of odour sources	High	Use results of complaints analysis, community consultation, and any surveys or diaries to identify the scale of problem, then use modelling to assess the effect of proposed plant changes.
   Odour annoyance survey	High	Urban and semi-urban areas. Assess against percent at-least annoyed criterion. Assess how the proposed changes will reduce level of annoyance.
   Meteorology and terrain assessment	Moderate to high	Use to assess potential for downwind adverse effects as a result of poor dispersion around terrain features or in particular meteorological conditions.
   Odour diaries	Moderate	Isolated areas with low population densities. Assess the frequency, duration, and strength of odour impact events and associated experiences over six months, or a longer time period if necessary, to encompass a specific season. Assess how the proposed changes will reduce level of annoyance.
   Review of emission control system(s)	Moderate	Look for compliance with best practicable option (BPO), or industry codes of practice.

2. Are there any chronic effects? If yes, consider further mitigation and alternative options (use the table above). If no, go to step 3.
3. Determine acute adverse effects, either already present on occasion, or with the potential to occur. Use:

   Assessment Tool	Priority	Comments
   Complaint records	High	Have any complaints been attributed to acute events? Assess how proposed changes will affect plant performance.
   Industry/council experience and records	High	As for chronic effects.
   Community consultation	High	As for chronic effects. Assess how the proposed changes will affect plant performance.
   Review of odour management plan and contingency procedures	High	What is the level of acceptable risk for uncontrolled odour discharges? Consider high-probability/low-impact events, and low-probability/high-impact events. Is BPO being utilised? Assess how the proposed changes will affect plant performance.
   Olfactometry and modelling of odour sources	Low	Not recommended as an assessment tool for occasional or periodic releases of odour.

4. Are the acute effects adequately protected against. If no, consider further mitigation and alternative options (use the table above). If yes, evaluation is complete.