Marlborough Sounds Resource Management Plan Base Threshold The Base Threshold (B) is dependent on the substances intrinsic hazardous properties. The Base Threshold is expressed as the weight (tonnes), or volume for compressed gases (m at 101.3kPA and 20C), of each substance stored or used on site. Base Thresholds 3 for Effect Group Levels are given in Table C2: Base Thresholds for all Effect Groups and Hazard Levels. Adjustment Factor Adjustment Factors provide for circumstances that influence the severity of an effect reflected by the risk or consequences of release. Adjustment Factors consider: • physical state of the substance • pressure and temperature required for storage and usage • type of storage • type of activity or use • separation distance to site boundary • environmental sensitivity of the site and location However, not all considerations are relevant to each Effect Group. Within each Effect Group, the Adjustment Factor is calculated by multiplying individual consideration values to produce a single value. Table C3: Adjustment Factors, presents consideration values for calculation of the Adjustment Factor. FF, FH, and FF are adjustment Factors for the Fire/Explosion, Health, and Ecological Effect Groups, respectively. Adjusted Threshold The Adjusted Threshold (T) is calculated for each Effect Group by multiplying the Base Threshold by the relevant Adjustment Factor. For example: B x FF = T Adjusted Threshold for a substance in the Fire/Explosion Effect Group B x FH = T Adjusted Threshold for a substance in the Health Effect Group B x FE = T Adjusted Threshold for a substance in the Ecological Effect Group The Adjusted Threshold defines the amount of a substance generating no significant off-site effects when released, after taking account of site and substance consideration. Effects Ratio The Effects Ratio (R) represents the proposed quantity of hazardous substance divided by the Adjusted Threshold. Effects Ratios fulfil two important purposes. First, they define the hazardous facility threshold and determine the activities status within the Plan. The status is set by the highest value for R in any of the Effect Groups. Second, they assess the cumulative effects that may be created by several hazardous substances on the same site. By using a ratio it is possible to aggregate the assessment of effects from multiple substances on the same site. App C - 2