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• PART A SURFACE WATER SAMPLING PROCEDURES FOR NPDES DISCHARGES Permit Section 4.8.5.1a presents the surface water monitoring program for 1993-1997. Table 4.8-11a lists the surtace water monitoring schedule while Table 4.8-12a lists the parameters to be monitored. The following discussion provides the guidelines to be followed for obtaining required surtace water information. Flow Measurements A. All discharge sites are monitored with Parshall Flumes with throat widths of one foot, Instantaneous readings are obtained by reading water level heights off the staff gauges. Water level readings are converted to cubic feet per second (CFS) from the appropriate discharge tables. The CFS value is converted to gallons per minute by multiplying by 448.8. B. Stevens Graph Recorders may be installed on those sites showing continuous dis- charges. These recorders graph flows versus time over the sampling period. Graphs are changed or reset weekly. During the cold weather months, the distilling wells of the par- shall flumes freeze requiring removal of the recorders. II. Monitoring A. In-situ measurements. Temperature, pH and specific conductance (SPCO) are taken on site in the ouffall flow or flowing water sections of the discharge. Since these measure- ments are taken in place, there is no holding time for sample analysis. • B. usual Measurements. Ysual inspections are made of the outfall for oil and grease con- tamination. If a sheen or floating material is observed, then a grab sample is taken far analysis at the laboratory. C. Grab Samples. After in-situ measurements are taken, grab samples are taken from the discharge. These samples are obtained far lab analysis of parameters outlined on permit Table 4.8-12a. Samples are refrigerated until shipment to the lab. During shipment, samples are ' iced° and shipped in coolers. To meet recommended EPA holding times, samples must be received by the lab within 48 hours of the time the samples were taken. Guidelines as outlined by the lab are followed as to the number of bottles to be filled, samples to be preserved, storage, etc. Chain of Custody fortes provided by the lab are filled out and handling instructions followed. D. WET Tests. WET (Whole Effluent Toxicity) tests are conducted on a quarterly basis on those drainages designated by the NPDES permit. Acute, two species tests are con- ducted. An exception is NPDES Site 002 (NoName Drainage) which has WET tests con- ducted on asemi-annual basis and single species evaluations. Samples are collected with bottles provided by the lab. Samples ar8 kept chilled or refrigerated prior to shipping. Handling procedures and shipping instructions provided by the lab are followed to insure samples reach the lab in good condition and at the required temperature. The Chain of Custody forth is completed and shipped with the sample. • Samples need to be received by the lab within 36 hours of being collected. III. Monitoring Equipment A. pH meter. pH is taken at each discharge with the portable pH meter. The meter is usu- ally calibrated the first week of the month or when repairs to the meter are made or when -(R-76 ~~ 14 ~ 7 8