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<br />COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT <br />W ATER QUALITY CONTRO L DI V [S ION <br />VJATERQUALITY PROTECTION SECTION <br />GROUND-~VA.TER PSRMfT GUIDANCE <br />SUGGESTED MONiTORiNG WELL SAMPLING PROTOCOL <br />S. CzRCEL72vTIl-WATER SAMPLE CQLLECTION <br />6. FIELD SAMPLE COLLECTION AvB TESTING <br />is area[er than 11 and sodium concentration is more than 10 moles per liter Measurement of pH is <br />temperature is temperature sensitive, so the standazd buffers should be within -/- I°C of the sample solution <br />for precise determinations. Calibrate [he.equipment in strict accordance with the manufacturer's instructions. <br />If the sampling continues from one day to the next, the pH field testing equipment is to be calibrated each day <br />of its use. The correct buffer solution is to be determined based upon };.nowledge of the ground water in the <br />area. Typically the ground water is going to be around 7.0 s. u. The buffer solutions of 7.00 and 10.0 aze to <br />be used to calibrate the off equipment. The pH is [o be recorded to the neazest hundredth. Ensure that the <br />buffer solutions are stored properly and acprozimately at the [emperatu:e o: the ground water. If the <br />temperature or` the Ground water is not lmown, then a temperaure near 45 °F would sur7ce. It is suggested <br />that two probes be available for use. The probe in use should be kept wet in deionized water or according to <br />the manufacture:'; instructions. <br />'9 Specific Conductance <br />Specific conductance is to be measured for each monitoring well during the purging process. the meter is to <br />be calibrated m strict adherence to the manufacturer's instructons. The meter is to be calibrated on each day <br />that sampling is to occur. Calibration is made by using the 0.00702 N standazd solution at the ambient <br />temperature. The temperature conuol s see at 2~°C, and the ambient temperature of the srandard KCl <br />solution is recorded A value of specifc conductance is obtained and compared with values given in a graph <br />of Specific conductance at 3~°C and specitc conductance of a 0.00702 N KCI solution at various <br />temperatures. The meter is to be within five (~) percent of the grzoh. Specitc conductance meters used in <br />the feld should be banerv opera[ed, equipped with temperature comceasator and read directly in <br />micromhos/cm at 2~ °C. Tire direr*, reading meter is recerunended to save time in converting resistance <br />i <br />values co specific conductance and to msurz that the value rs read in the fie]d. <br />Temperature <br />Measurement of g-round-water temeerature is most accurate when the ambient temperature is within 20°C of <br />the ground-water temeerature. New or little-used wells may develop new producing zones during ptunpvng, <br />thereby varying die propottiou of water enre:ins ;he well from different deaths and causins either an <br />instantaneous change or con[inual drift ir, the temperature measuremen[s. Drawdown may czuse <br />