Ord 1986-134 - Laserfiche WebLink

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RE(/ISEt:J Proper maintenance and use of equipment are essential for the successful acquisition of representative samples. Samples are taken at a point where the un~que chemical composition and physical state of a particular discharge is intact. The sample is therefore taken at a sampling port or control manhole downstream from the last connection to an industry's common building drain line(s). If no such sampling point exists, then the sample may be taken at a point downstream of each industrial waste source until a sampling port or control manhole is installed at the proper location. A sample's .uniqueness. must be kept intact throughout the sampling process. Thus, the proper labeling and logging in of all pertinent information concerning a particular sample are required for future reference. The industry's name and address, the sampling source (clean out, trap, manhole), the date and the type of sample taken (grab, composite, sequential, pH) are required information for labeling a sampl~. The industry's name and address, the date, the time the sample was taken, the name of the specialist doing the sampling and the reason for sampling (checking for compliance, surcharge, inspection dye testing, etc.) is required for logging in a sample. Specific identification marks or other pertinent information may be included when necessary. Also required is the proper safeguarding of a sample against contamination by the equipment or other sources. The samples must be set up according to the type of sample desired (grab, composite, pH, sequential, etc.). Control settings normally used for a twenty-four hour composite sample is 250 mls. of sample per twenty minutes. However, this setting will vary depending upon the physical conditions of the sampling source and the type of samples used. The general rule followed is to increase the volume per sample control setting and/or decrease the time interval per sample control setting as the difficulty in obtaining an adequate final sample volume increases. A final sample volume sufficient for all the laboratory tests will constitute a representative sample. Approximately 2,000 to 2,500 mise of sample will usually suffice for the standard tests which are pH, BOD, COD suspended solids and grease. Since replicate tests are run on one sample per day, at least one of the samples should be of sufficient volume to accomodate these replicate analyses. Minimum volume for a composite sample is 1,000 mise -71-