1. FIELD METHODS IN ENVIRONMENTAL GEOLOGY GEOS 3110

2. WATER QUALITY MEASUREMENTS

3. Water quality measurements - Introduction - Parameters to be measured - Methodology

4. Introduction - determine the chemical states of natural waters - understand how waters will react with minerals, gases and fluids of the Earth ’ s crust and hydrosphere - define relationships between drainage basins - water managers and regulators commonly make these types of measurements to determine the flux of contaminants into drinking water supplies.

5. Water quality measurements - Introduction - Parameters to be measured - Methodology

6. Parameters - Temperature

7. Temperature - controlling variable: once it begins to change, so do other parameters - variable of interest : - tracking a warm plume - differentiating two carst systems - delineating recharge and discharge areas Measuring devices: - thermometer - during other parameters determination which require temperature calibration

8. Parameters - Temperature - pH

9. pH H 2 O can act as both a proton donor and acceptor for itself. A proton can be transferred from one water molecule to another, resulting in the formation of one hyroxide ion (OH - ) and one hydronium ion (H 3 O + ). 2H 2 O(l) H 3 O + (aq) + OH-(aq) This is called the autoionization or dissociation of water. This equilibrium can also be expressed as: H 2 O(l) H + (aq) + OH-(aq)

10. The pH scale DEFINITION: The negative logarithm of the hydrogen ion activity in water is called the pH of the water. pH = - log [H + ] From this it is obvious that at 25 C: pH < 7 solution is acidic pH = 7 solution is neutral pH > 7 solution is basic

11. The pH scale

13. Parameters - Temperature - pH - Turbidity

14. Turbidity DEFINITION: Turbidity is a measure of the lack of clarity of the water sample. High turbidity makes it difficult to treat water for microbial contaminants, and therefore is regulated in drinking water supplies by the EPA. Measuring devices: - portable turbidimeter (Hach 2100 P)

15. Parameters - Temperature - pH - Turbidity - Dissolved gases

16. Dissolved Gases May affect important characteristics such as its corrosivity, taste, toxicity, potability, solubility of other components in contact with the sample. Dissolved gases may include : - oxygen - carbon dioxide - hydrogen sulfide - methane, etc. Dissolved oxygen (D.O.) is importantfor determining the solubility of metals and for the viability of fish and other organisms. Measuring devices: - YSI-85 DO meter

17. Parameters - Temperature - pH - Turbidity - Dissolved gases - Electrical conductivity

18. Electrical Conductivity DEFINITION: Electrical conductivity (conductance) is a measure of the ability of a water to conduct electricity. In general, the higher the concentration of dissolved salts in the water, the easier it is for electicity to pass through the water. Measuring devices: - YSI-85 DO meter

19. Parameters - Temperature - pH - Turbidity - Dissolved gases - Electrical conductivity - Nitrates

20. Nitrates Nitrate concentration is one of the principal contaminants in urban surface water. The maximum concentration allowed in drinking water is 10 ppm. In general, nitrates represent a remnant of fertilizer application. Measuring devices: - spectrophotometer (colorimeter)

21. Water quality measurements - Introduction - Parameters to be measured - Methodology

22. pH Methodology 1. CALIBRATION 2. TAKING THE MEASUREMENT

23. pH Calibration 1. Press MODE key until the pH mode indicator is displayed 2. Place the electrode(s) into the 4.0 buffer. 3. Press CAL key. CALIBRATE will be displayed above the main field. After the calibration slope is displayed, P1 will be displayed in the lower field. P1 indicates that the meter is ready to accept the first buffer point. 4. When the electrode is stable, the meter will beep and READY will be displayed along with the temperature corrected value for the buffer (flashing). Press YES key to accept this point. 5. The display will remain fixed momentarily, then P2 will be displayed in the lower field. The meter is now ready for the second buffer (7.0).

24. pH Calibration 6. Rinse the electrode(s) and place them in the second buffer (7.0). Wait for a stable pH reading (the meter will beep) and for READY to be displayed. Press the YES key to accept the second point. The electrode slope will be displayed in pH units. SLP will appears in the lower field. The advances to the measure mode and MEASURE appears above the main display. The meter is now ready to take pH measurements. The EC10 retains this calibration until a new calibration is entered or until power is disconnected from the instrument. NOTE: To view the current slope value at any time, press CAL key. Press the MODE key to return to measure mode without changing the current calibration. Always use buffer solutions that have a pH in the same range of measurements expected.

25. pH Measurement 1. Take the reading directly in the field or immediately after sampling. 2. Use the MODE button to switch between different types of readings (pH, mV, T) 3. Record the values in your field notebook. NOTE: The pH measurement should be accompanied by a temperature measurement. EC10 pH meter records a pH already temperature compansated.

26. Turbidity Methodology 1. CALIBRATION 2. TAKING THE MEASUREMENT

27. Turbidity Methodology CALIBRATION The 2100P Portable Turbidimeter was been calibrated at the factory and does not require recalibration before use. TAKEING THE MEASUREMENTS 1. Collect a representative sample in a clean container. Fill a sample to the line (about 15 mL), taking care to handle the sample cell by the top. Cap the cell. 2. Wipe the cell with a soft, lint-free cloth to remove water spots and fingerprints. 3. Press I/O - the instrument will turn on. Place the instrument on a flat surface. Do not hold the instrument while making readings.

28. 4. Put the sample cell in the instrument cell compartment so the diamond or orientation aligns with the raised orientation mark in front of the cell compartment. Close the cover. 5. Automantic range by pressing the RANGE key. The display will show “ AUTO RNG ” when the instrument is in automatic range selection. 6. Press READ - the display will show “ ----NTU ” then the turbidity in NTU ( Nephelometric Turbidity Units, a standard measurement). Record the turbidity after the lamp symbol turns off. NOTE: Always wipe any fingerprints, spots, etc. from the outside of the vial, and be sure to close the vial-compartment lid when taking a measurement. Turbidity Methodology

29. D.O. & Conductivity Methodology 1. CALIBRATION 2. TAKING THE MEASUREMENT

30. D.O. Calibration To accurately calibrate the YSI Model 85 you will need to know the approximate altitude of the region in which you are located. 1. Ensure that the sponge inside the instrument ’ s callibration chamber is wet. Insert the probe into the calibration chamber. 2. Turn the instrument on by pressing the ON/OFF button on the front of the instrument. Press the MODE button until dissolved oxygen is displayed in mg/l or %. Wait for the dissolved oxygen and temperature readings to stabilized (usually 15 minutes is required). 3. Use two fingers to press and release both the UP ARROW and DOWN ARROW buttons at the same time. 4. The LCD will prompt you to enter the local altitude in hundreds of feet. Use the arrow keys to increase or decrease the altitude. When the proper altitude appears on the LCD, press the ENTER button once.

31. D.O. Calibration 5. The Model 85 should now display CAL in the lower left of the display, the calibration value should be displayed in the lower right of the display and the current % reading (large display) is stable, then press ENTER button. The display should read SAVE then should return to the Normal Operation Mode. NOTE: Each time the Model 85 is turned off, it may be necessary to re-calibrate before taking measurements. All calibration should be completed at a temperature which is as close as possible to the sample temperature. Dissolved oxygen readings are only as good as the calibration.

32. Conductivity Calibration System calibration is rarely required because of the factory calibration of the Model 85. However, from time to time it is wise to check the system calibration and make adjustments when necessary.

33. D.O & Conductivity Measurements 1. Press the ON/OFF button to turn on the machine. The instrument will activate all segments of the display for a few seconds, which will be followed by a self-test procedure and will last for several more seconds. The Model 85 will display the cell constant of the conductivity probe when the self-test is complete. The Model 85 is designed to provide six distinct measurements: - Dissolved Oxygen % - a measurement of oxygen in percent of saturation - Dissolved Oxygen mg/L - a measurement of oxygen in mg/L - Conductivity - a measurement of the conductive material in the liquid sample without regard to temperature - Specific Conductance - also known as compensated conductivity which automatically ajusts the reading to a calculated value which would have been read if the sample had been at 25 C. - Temperature - which is always displayed - Salinity - a calculation done by the instrument electronics, based upon the conductivity and temperature readings.

34. D.O & Conductivity Measurements 2. To choose one of the measurement modes above, simply press and release the MODE button. Carefully observe the small legends at the far right side of the LCD. If the instrument is reading Specific Conductance the large numbers on the display will be followed by either a uS or an mS (micro Siemens). flashing on and off. If the instrument is reading Conductivity (not temperature compensated) the large numbers on the display will be followed by either a uS or an mS. Additionally the small portion of the display will show the C (temperature) NOT flashing. If the instrument is reading Salinity the large numbers on the display will be followed by a ppt (parts per thousand).

35. Nitrates Methodoloy The spectophotometer uses indicator compounts to determine the concentration of the desired species. Use of the Hach Test kit involves mixing a pre-measured amount (a “ pillow ” ) of the indicator compound with a measured amount of sample water, then measruring the absorption of light of a particular wavelength. After mixing and delay of reaction, a color will appear (for nitrates it is amber color), the darkness of which is measured in the spectophotometer. The sample is introduced to the spectophotometer via a pour-through-cell aparatus, to minimize interferece ’ s from sample handling. The CALIBRATION is working in the same way as the actual reading, but have to be done on samples with known concentration in nitrates. Two such kind of samples will be used, and the real values will be obtained by a linear interpolation between the standard samples.

36. Nitrates Measurement 1. Enter the stored program number for high range nitrate nitrogen (NO 3 - -N). Press 355 ENTER. The display will show Dial nm to 500. 2. Rotate the wavelength dial until the small display shows: 500 nm. When the correct wavelength is dialed in, the display will quickly show : Zero Sample, then mg/L NO 3- -N HR. 3. Fill a sample cell with 25 mL of sample. 4. Add the contents of one NitraVer 5 Nitrate Reagent Powder Pillow to the cell (the prepared samples). Stoppper. 5. Press SHIFT TIMER. Shake the cell vigorously until the timer beeps in one minute. 6. When the timer beeps, press SHIFT TIMER A five minute reaction period will begin.

37. Nitrates Measurement 7. Fill another sample cell with 25 mL of sample (the blank). 8. When the timer beeps, the display will show mg/L NO 3- -N HR. Place the blank into the cell holder. Close the light shield. 9. Press ZERO. The display will show: Zeroing … then, 0.0 mg/L N O 3 - -N HR. 10. Remove the stopper. Place the prepared sample into the cell holder.Close the light shield. 11. Press READ The display will show: Reading … then the result in mg/L nitrate nitrogen (NO 3 - -N) will be displayed. 12. Press SHIFT STORE to store the result. Type in the sample number and record the value in your notebook.

38. 1. Collect Sample (a) using sample bottle, bucket, or long-handled sampler collect 200-500 ml sample (b) place in 500 ml amber glass bottle, cap the bottle, bring to analysis table 2. Measure Chemical State: as soon as possible measure the following in the sample (a) temperature (by thermometer or meter) (b) pH (follow pH-meter procedure) (c) dissolved oxygen content (equivalent to Eh) 3. Prepare Filtered Split (a) obtain a filter funnel and filter paper (fold this in 1/4, spread and place in funnel) (b) fill filter cone 2/3's full (c) repeat (once) 4. Measure Turbidity (a) fill turbidity sample vial to bottom of white line (vial has white line around top with upside-down triangle on it, avoid touching sides!) (b) follow the turbidity measurement procedure 5. Measure Nitrate Content (a) pour 25 ml of filtered sample into clear, glass-stoppered bottle (25 ml is marked on bottle side) (b) follow colorimetry procedure 6. Measure Electrical Conductivity (can be done at any point during lab, in stream or in sample) (a) use the YSI-85 DO meter: (b) press ``MODE'' button until display shows units of micro-Siemens (S) (c) be sure probe is fully immersed in unfiltered sample or stream (or display will show zero) (d) record reading when it becomes stable Field Procedures