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PART A <br />SURFACE WATER SAMPLING PROCEDURES <br />FOR NPDES DISCHARGES <br />Permit Section 4.8.5.1 presents Trapper's surface water monitoring program. Table 4.8 -11 lists the sur- <br />face water monitoring schedule while Table 4.8 -12 lists the parameters to be monitored. The following <br />discussion provides the guidelines to be followed for obtaining required surface water information. <br />Flow Measurements <br />A. All discharge sites are monitored with Parshall Flumes with throat widths of one foot. <br />Instantaneous readings are obtained by reading water level heights off the staff gauges. <br />Water level readings are converted to cubic feet per second (CFS) from the appropriate <br />discharge tables. The CFS value is converted to gallons per minute by multiplying by <br />448.8. <br />B. Stevens Graph Recorders may be installed on those sites showing continuous dis- <br />charges. These recorders graph flows versus time over the sampling period. Graphs are <br />changed or reset weekly. During the cold weather months, the distilling wells of the <br />Parshall flumes freeze requiring removal of the recorders. <br />Monitoring <br />A. In -situ measurements. Temperature, pH and specific conductance (SPCO) are taken on <br />site in the outfall flow or flowing water sections of the discharge. Since these measure- <br />ments are taken in place, there is no holding time for sample analysis. <br />B. Visual Measurements. Visual inspections are made of the outfall for oil and grease con- <br />tamination. If a sheen or floating material is observed, then a grab sample is taken for <br />analysis at the laboratory. <br />C. Grab Samples. After in -situ measurements are taken, grab samples are taken from the <br />discharge. These samples are obtained for lab analysis of parameters outlined on permit <br />Table 4.8 -12. <br />Samples are refrigerated until shipment to the lab. During shipment, samples are "iced" <br />and shipped in coolers. To meet recommended EPA holding times, the lab must receive <br />samples within 24 hours of the time the samples were taken. <br />Guidelines as outlined by the lab are followed as to the number of bottles to be filled, <br />samples to be preserved, storage, etc. Chain of Custody forms provided by the lab are <br />filled out and handling instructions followed. <br />D. WET Tests. WET (Whole Effluent Toxicity) tests are conducted on a yearly basis on <br />those drainages designated by the NPDES permit. Acute, two species tests are <br />conducted. <br />Samples are collected with bottles provided by the lab. Samples are kept chilled or <br />refrigerated prior to shipping. Handling procedures and shipping instructions provided by <br />the lab are followed to insure samples reach the lab in good condition and at the required <br />temperature. The Chain of Custody form is completed and shipped with the sample. <br />Samples need to be received by the lab within 36 hours of being collected. <br />III. Monitoring Equipment <br />A. A single combination meter and or dedicated meters may be used for the following <br />observations. <br />B. pH meter. pH is taken at each discharge with a portable pH meter. The meter is usually <br />calibrated monthly or when repairs to the meter are made or when the batteries are <br />� �ll <br />