Schedule Three - Measurement and Sampling of the Characteristics of a Tradewaste Discharge 1. Sampling of a Tradewaste 1.1 An Instantaneous Sample Three grab samples of the discharge shall be taken at intervals of not less than 1 minute or more than 5 minutes. The three grab samples must be combined using equal volumes of all three samples to obtain the instantaneous sample. 1.2 A Four Hour Average Sample (a) No less than 12 grab samples shall be taken from the discharge over a continuous four hour period. The samples shall be taken at reasonably even intervals over the whole period. The intervals between the samples must not be less than five minutes nor more than 20 minutes. The samples shall be mixed using equal volumes of all samples to obtain the four hour average sample. (b) The four hour flow period used when taking a four hour average sample shall be a continuous period of four hours during which the discharge is occurring and: (i) shall as far as practical be representative of the discharge occurring on a typical working day; and (ii) shall exclude periods of decreased discharge prior to or after the day’s operations. 1.3 A Twenty Four Hour Flow Proportionate Sample (a) No less than 18 grab samples shall be taken from the discharge over a continuous twenty four hour period. The samples shall be taken at reasonably even intervals over the whole period. The intervals between the samples must not be less than 15 minutes nor more than 60 minutes. Whenever more than one sample is taken within a 60 minute period the samples must be of equal quantity and may be stored with other samples taken during that 60 minute period in a common container. (b) The twenty four hour flow proportionate sample is then obtained by taking a part of the contents of each container and mixing all such samples together. The size of the part of each container sample that is used shall be in direct proportion to the volume of discharge that occurred from the time a sample was first placed in the particular container to the time a sample was first placed in the next container. 2. Use of Independent Analysts An independent analyst shall: (a) Take samples and make measurements at times and in the manner specified in the occupiers consent; (b) Analyse samples in accordance with clause 14 and clause 5 of this schedule; and (c) Deliver the results of any such analysis in accordance with this schedule. 2.1 Requirements of an Independent Analyst (a) An inspection undertaken in accordance with this bylaw may be undertaken during a period of 5 working days. Prior to such inspection period, the Council shall give not less than five working days notice to an independent analyst of the commencement date of the inspection period. (b) During any inspection period, the independent analyst shall take such samples, recordings and measurements at such time as may be directed by the Council prior to the commencement of the inspection period. Page 23