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									             Central Bay Estuarine Water Quality Monitoring Program 1988-1997


 Jane Caffrey1, Sue Shaw2, Mark Silberstein2, Andrew De Vogelaere3, Michelle White4, Kenton
                             Parker1 and Kathleen Thomasberg5



                    1
                        Elkhorn Slough National Estuarine Research Reserve
                                       1700 Elkhorn Road
                                     Watsonville, CA 95076
                                           2
                                               Elkhorn Slough Foundation
                                                     PO Box 267
                                               Moss Landing, CA 95039
                               3
                                   Monterey Bay National Marine Sanctuary
                                           299 Foam St., Suite D
                                           Monterey, CA 93940
                                     4
                                         Moss Landing Marine Laboratories
                                                  PO Box 450
                                            Moss Landing, CA 95039
                           5
                               Monterey County Water Resources Agency
                                            Salinas, CA


                                        Data Report
                     Elkhorn Slough National Estuarine Research Reserve
                                            and
                                 Elkhorn Slough Foundation

                                                   August 27, 1997




citation: Caffrey, J., S. Shaw, M. Silberstein, A. De Vogelaere, M. White, K. Parker, and K.
Thomasberg. 1997. Central Bay Estuarine Water Quality Monitoring Program 1988-1997. Data
Report. Elkhorn Slough National Estuarine Research Reserve and Elkhorn Slough Foundation.
INTRODUCTION

         Water quality monitoring is an important means to evaluate the health of a water body. In
this report, we present data from the estuarine systems in the Central Monterey Bay region from
Bennett Slough to the lower Salinas River. As data accumulates over the years, changing trends
in the constituents can indicate whether the environment is declining, improving or stable. Just
as we can monitor our health using various indicators such as body temperature and blood
pressure, we can also monitor the health of an ecosystem by measuring things like salinity,
dissolved oxygen and nutrient concentrations. This will tell us if the environment and the
creatures living in it are healthy or showing the effects of activities in the surrounding area. The
physical and chemical characteristics of the water will determine what species survive and thrive
in the water.. Salinity determines what species are found in an area; some require freshwater,
some salt water. Similarly, temperature controls species‟ distribution and the rate of growth.
Dissolved oxygen is essential for the survival of most invertebrate and all vertebrate species.
Turbidity, or the concentration of particles in water, determines how far light penetrates the water
which controls the distribution of plants such as eelgrass and phytoplankton. pH is an important
indicator of water quality in freshwater systems where acid rain or drainage can lead to
unacceptable levels. In estuarine systems, pH is less variable. Nutrients, nitrate and nitrite (NO3-
+NO2-), ammonium (NH4+), and orthophosphate (PO43-) are essential for plant growth. However,
excess nutrients can lead to much plant growth. After the plants die, bacteria break down the
dead plants using up oxygen, which can lead to hypoxia (low oxygen) or anoxia (no oxygen).
Although different species have different requirements, we have a fairly good understanding of
what constitutes “good” water quality. In addition, good water quality is essential for many of
human uses of this area such as recreational boating, sport fishing, commercial fishing, shellfish
harvesting, birdwatching and wildlife viewing. These uses, as well as agriculture, commercial
and residential development in the watershed, can affect water quality in this region.
         The Elkhorn Slough Foundation and Elkhorn Slough National Estuarine Research
Reserve began water quality monitoring in September 1988. Initially, 6 stations were sampled.
Eleven stations were added in 1989, three in 1991, three in 1992 and one in 1994. Currently, 24
stations are sampled monthly (Figure 1, Table 1). These sites were chosen to monitor critical
management areas within the slough watershed. For example, the three ponds on the Azevedo
Ranch (upper, mid and lower) will allow us to track how implementation of best management
practices on the property affect water quality. Monitoring data should be useful in evaluating
whether vegetative buffer strips reduce sediment, and nutrient inputs to the slough. The Bennett
Slough and Struve Pond sites are of particular interest because of the historic populations of the
endangered Santa Cruz long-toed salamander in Struve Pond. Because long-toed salamanders
live in freshwater wetlands, monitoring the salinity regime is critical to determine whether Struve
Pond is a suitable habitat. As management plans for Moro Cojo are implemented, particularly
restoration of riparian areas, the monitoring data will provide an important record to track
changes in the watershed. In addition, sites from the lower Salinas River, Carneros Creek,
Bennett Slough, and Moro Cojo represent areas that are tributaries to the slough. How important
are these areas in providing freshwater and nutrients to the main channel of Elkhorn Slough?
What are the links between surface water and groundwater? A long term monitoring program is
essential to address these questions.




                                                                                                  2
Table 1 Station locations and date sampling was initiated
Station                 Latitude °N              Longitude °W             initiation date
Skippers                36°48'38.32"             121° 47' 10.99"          9/20/88
Moss Landing Rd North   36° 47' 59.86"           121° 47' 3.85"           3/5/91
Moss Landing Rd South   36° 47' 58.89"           121° 47' 4.75"           3/5/91
North Potrero           36° 47' 27.01"           121° 47' 25.35"          9/23/89
South Potrero           36° 47' 25.40"           121° 47' 26.34"          9/23/89
South Marsh             36° 49' 26.47"           121° 44' 24.00"          9/23/89
Reserve Bridge          36° 49' 11.61"           121° 44' 13.48"          9/23/89
North Marsh             36° 50' 10.98"           121° 43' 56.15"          9/23/89
Kirby Park              36° 50' 23.13"           121° 44' 37.41"          9/23/89
Lower Pond              36° 50' 32.29"           121° 44' 48.86"          3/28/92
Mid Pond                36° 50' 37.95"           121° 45' 4.66"           3/28/92
Upper Pond              36° 50' 49.67"           121° 45' 16.03"          3/27/92
Hudson's Landing LP     36° 51' 23.34"           121° 45' 18.10"          9/23/89
Hudson's Landing RC     36° 51' 22.84"           121° 45' 17.58"          10/1/89
Carneros                36° 51' 36.20"           121° 44' 24.26"          9/23/89
Jetty                   36° 49' 1.52"            121° 47' 13.69"          9/21/88
Back Bennett            36° 49' 15.39"           121° 47' 27.36"          9/21/88
East Bennett            36° 49' 17.48"           121° 47' 0.36"           9/21/88
Struve Pond             36° 49' 28.91"           121° 46' 38.63"          9/21/88
Moro Cojo Slough        36° 47' 46.61"           121° 46' 59.50"          9/21/88
Monterey Dunes Way      36° 46' 18.81"           121° 47' 22.91"          12/14/91
Salinas River Lagoon    36° 44' 52.77"           121° 48' 0.60"           9/22/89
Salinas River Bridge    36° 43' 55.60"           121° 46' 50.69"          9/22/89
Tembladero Slough       36° 45' 54.42"           121° 45' 34.48"          6/13/94



FIELD INSTRUMENT CALIBRATION 1988-1995

        Between September 1988 and August 1995, salinity and temperature were measured with
a YSI model 33 SCT meter. Dissolved oxygen was measured using a YSI model 57 Dissolved
oxygen meter. An Orion model 211 pH meter was used to measure pH. Turbidity was measured
using a Monitek model 21 PE nephelometer. The calibration, operation, and maintenance
procedures are explained below for each instrument.

YSI Model 33 SCT Meter

1. Calibration:
   a) With the meter off, check that the needle rests exactly on zero. If necessary, adjust the
      meter zero by turning the black bakelite screw on the face of the meter.
   b) Turn the mode control knob to 'Red Line'. Adjust, if necessary, the 'Red Line' knob until
      the needle coincides with the red line on the meter's face. If this cannot be done, replace the
      batteries.
2. Operation
   a) Calibrate the meter just prior to each sampling round.
   b) Place the probe into the sample to be analyzed. Be sure that the sample completely covers
      both electrodes (the protrusion in each of the cylindrical boreholes in the probe.).


                                                                                                   3
     c) Turn the mode control knob to 'Temperature'. Read and record.
     d) Adjust the temperature knob to this temperature.
     e) Turn the mode control knob to Salinity. Read from the red 0-40 o/oo scale and record.
        The needle should rise smoothly and stabilize fairly rapidly (within 5-10 seconds). If the
        reading drifts when you move the probe, (being sure that the electrodes remain submerged)
        you may have a short in the probe cable. Check first to see that the probe cable is inserted
        fully into the probe jack on the right side of the instrument.
     f) Depress the 'Cell Test' button. The reading should fall less than 2% (0.667 o/oo at 33
        o/oo). If the drop is greater than this the probe is fouled and the measurement is in error.
        Clean the probe and remeasure.
3.    Meter Care
     a) Do NOT let the meter get wet. If water splashes on it, even a few drops, wipe it off
        immediately. If you are sampling on a rainy day place the meter in a plastic bag and seal it
        around the probe cable with a twist-tie or rubber band. The control knobs can still be
        operated through the bag. If water seeps under the knobs or face plate, it will corrode the
        circuitry and seriously damage the instrument.
     b) The manufacturer suggests to change the two alkaline 'D cell batteries once every six
        months to reduce the danger of corrosion due to leaky batteries. Zinc-carbon batteries may
        not be used. To replace batteries, remove the six screws from the rear plate, and carefully
        remove the rear plate. The positive (+ button) end must go on red.
4.    Probe Care
     a) The probe should be rinsed with distilled water after each use.
     b) The probe MUST be stored in distilled water (covering the electrodes) between sampling
        rounds. If stored dry, the probe will require cleaning and replatinizing after only a few
        months.
     c) Be sure the plug which plugs the probe into the meter isn't pushing up against the container
        used to transport the meter, to avoid bending the wire in the cable which can potentially
        create a short.
5.    Probe Cleaning
     a) When the 'Cell Test' drops more than the acceptable <2%, the electrodes are most likely
        dirty and must be cleaned.
     b) Cleaning can be done most conveniently using a locally available bathroom tile cleaning
        preparation such as: Dow Chemical Bathroom Cleaner, Johnson Wax 'Envy, Instant
        Cleaner', and Horizon Industries 'Rally, Tile, Porcelain and Chrome Cleaner.' Immerse the
        probe (being sure to cover the electrodes), in one of these types of cleaners for five
        minutes. For stronger cleaning, a five minute soak in a solution made of 10 parts distilled
        water, 10 parts isopropyl alcohol and 1 part HCl may be used. Always rinse the probe well
        after cleaning and before storage. If cleaning does not restore the probe performance,
        replatinizing is required.
6.    Replatinizing The Probe
     a) If the 'cell test' continues to drop the reading >2% after normal cleaning has been
        performed as described above, the probe must be replatinized. The following items are
        required: 1. Platinizing solution (YSI #3140, 2 fluid oz., 3% platinum chloride dissolved
        in a 0.025% lead acetate solution) 2. 50 ml glass beaker 3. Distilled water
     b) Clean the probe as described in section 5.


                                                                                                   4
   c) Place the probe into the 50 ml beaker. Pour in sufficient replatinizing solution to cover the
      electrodes. Do not cover the top of the probe.
   d) Plug the probe into the meter and switch the mode control knob to read x 100. An
      electrical current will then begin to flow between the two electrodes, depositing platinum
      black on each through a process called electroplating.
   e) Agitate the probe slightly to obtain the highest meter reading and record in the log book.
   f) Refer to the chart below; continue platinizing for the approximate duration listed below, as
      dictated by the meter reading in step d.
   g) Remove the probe from the beaker after the elapsed time and rinse in fresh water.
   h) Return the solution to it's original container. 2 ounces of solution should provide ~50
      replatinization treatments.
   i) Record the date of replatinization and the reading determined in step d in the instrument
      maintenance log book.

YSI Model 57 Dissolved Oxygen Meter

1. Calibration
   a) The meter must be calibrated in the position in which it will be used. Using the attached
      stand places the meter at a conveniently readable angle. Calibration can be disturbed by
      physical shock, touching the membrane, and drying out of the electrolyte.
   b) With the meter off, check to see that the needle rests exactly at zero. If not, adjust with the
      black bakelite screw on the face of the meter.
   c) Turn the mode control knob to "Red Line" and if necessary adjust the needle's position
      using the red line knob until it coincides with the red line on the meter face.
   d) Turn the mode control knob to "Zero" and, if necessary, adjust the needle's position again,
      using the zero knob, until the needle rests at zero.
   e) Remove the probe from the receptacle it has been stored in. With the moistened toweling
      still wrapped around it place the probe in a shady spot in full contact with ambient outdoor
      air. Turn the mode control knob to "Temperature" and allow to equalize until the meter is
      reading the ambient outdoor air temperature. Allow at least 5-7 minutes for this process.
   f) Set Salinity Adjustment Knob to Zero/Fresh Water.
   g) Refer to the Table of saturation oxygen values and read the calibration value appropriate to
      the temperature just recorded. Turn the mode control knob to the range (0-5, 0-10 or 0-20)
      in which the calibration value falls. Using the calibration knob, adjust the meter reading so
      that it coincides with the calibration value. If this cannot be done then the membrane and
      KCl solution need to be replaced. See below for instructions.
2. Operation
   a) Calibrate the meter as indicated above before each day of sampling.
   b) Remove the toweling from the probe and place the probe into the sample to be analyzed.
      Be sure that the membrane is fully immersed.
   c) Turn the submersible stirrer on using the knob on the face of the meter housing. The stirrer
      passes a continuous flow of water across the membrane which is critical for an accurate
      reading.
   d) Turn the mode control knob to 'Temperature' and record the reading.




                                                                                                   5
   e) Set the temperature dial on the SCT meter to this reading and read the salinity from the
      SCT meter.
   f) Set the salinity adjustment knob on the dissolved oxygen meter to the salinity reading from
      the SCT meter.
   g) Turn the mode control knob to the 0-10 range setting. If the reading is between 0 and 5
      adjust the mode control knob to the 0-5 range for a more precise reading. If the reading
      goes off the scale to the right, switch to the 0-20 scale. Occasionally the reading will be off
      of this scale also. Record the reading.
3. Meter Care
   a) The meter housing is not waterproof. Wipe off any water that contacts it immediately. If
      sampling during rain place the meter in a plastic bag and secure around the probe port with
      rubber bands. The knobs can still be operated through the plastic.
4. Probe Care
   a) The probe should be rinsed well with distilled water after each day's use. It can be stored
      between stations wrapped in moist toweling.
   b) The probe must be stored between sampling rounds in a moist air environment to prevent
      the membrane from drying out. This is most easily achieved by wrapping the probe in a
      small piece of toweling and submerging the bottom end in a reservoir of distilled water.
      As water evaporates from the toweling, replacement moisture can be wicked up from the
      reservoir. The toweling must not touch the probe head and the probe head should not be
      stored submerged in water.
5. Membrane Replacement
   a) If the probe cannot be calibrated, if readings or calibrations are erratic, if the membrane has
      developed a visible leak or if the gold cathode has become tarnished, the probe needs
      servicing.
   b) Unscrew stirrer housing.
   c) Remove 'O' ring.
   d) Drain out KCl electrolyte
   e) Rinse with distilled water
   f) Fill a glass container 1-2" deep with 3% ammonia. Place probe into ammonia and allow to
      soak overnight.
   g) Remove from ammonia, drain any residual and rinse well with distilled water.
   h) Rinse well with KCl and drain.
   i) If gold cathode (horseshoe shaped gold ring on end of probe head underneath where
      membrane covers) is tarnished or discolored rub gently 4-5 times in each spot with a clean
      ink or typewriter eraser. Excessive rubbing should be avoided in that gold is a soft metal.
      If this procedure does not remove all discoloration the probe may need to be returned to the
      manufacturer for service. Call the manufacturer's service department for suggestions on
      how to proceed.
   j) Remove a new membrane from the packet and inspect for cleanliness and absence of dust
      or flaws. Handle the membrane with care, holding it only at the ends and keeping it clean
      and free of dust.
   k) Holding the probe in your least dexterous hand, positioned so that the diaphragm is
      exposed, place one end of the membrane under your thumb.
   l) With the other hand fill the reservoir with KCl electrolyte.


                                                                                                   6
   m) Using a pencil eraser or similar soft, blunt tool pump the diaphragm. (With practice you
      can hold the probe and pump the diaphragm with the same hand.) Continue filling and
      pumping until air bubbles no longer appear. Add several more drops of electrolyte until
      the meniscus completely covers the gold cathode.
   n) Grasp the free end of the membrane with your most dexterous hand. This maneuver seems
      to work best if you grasp one corner with your thumb and fourth finger and the other corner
      with your index and third finger. In one smooth arcing motion stretch the membrane up,
      over, and down taut over the head of the probe so that no air bubbles are caught
      underneath. Secure with the index finger of the hand holding the probe. Be patient. This
      maneuver may take a number of attempts before success is achieved.
   o) Keeping the membrane taut, roll the 'O' ring over the end of the probe. There should be no
      wrinkles in the membrane and no trapped air bubbles. Small wrinkles may be pulled out
      by tugging on the membrane outside the 'O' ring.
   p) Trim off excess membrane, cutting fairly close to the 'O' ring with scissors or a sharp knife.
      Be sure that the stainless steel temperature sensor is clear of any excess membrane.
   q) Screw on stirrer.
   r) Calibrate to assure success.

MONITEK Model 21PE Nephelometer

1. Calibration
   a) Turn the nephelometer on and remove the black light cell cover.
   b) Place the 1.0 NTU Calibration Standard Vial into the light cell orifice.
   c) Replace the black light cell cover and turn the range to 0-10.
   d) Push the 'Push to Read' button on the face of the meter
   e) Use the Calibration knob to adjust the meter to read exactly 1.
   f) Remove the Calibration Standard Vial.
   g) Always keep the surface of the calibration standard clean by not handling the walls with
      fingers.
   h) Always keep the sample vials clean using a good detergent to wash off any residues.
2. Operation
   a) Agitate the sample so that any particulate matter is well distributed in the sample. Pour
      some of the sample to be analyzed into one of the optically correct cuvettes provided with
      the nephelometer. If sufficient sample water is available fill the cuvette approximately
      three quarters full. However, if insufficient sample volume exists, the nephelometer is able
      to analyze with as little as 10 ml
   b) Replace the black cover to the light cell.
   c) Push the 'Push to Read' button and record the reading.
   d) Often times the reading will fluctuate, often substantially. This is due to movement of
      particulates within the sample as the light beam is shone across it. This is to be considered
      normal and an estimated average should be taken.
3. Meter Care
   a) The meter needs approximately 12-18 hours of charge to perform a day's worth of
      sampling. The meter's batteries can be charged using the battery charger provided with the




                                                                                                  7
      meter. Be sure to plug the meter in to charge the day before a monthly round is to begin
      and the night between day samplings.
   b) The inside of the light cell can tolerate some moisture. However, to avoid corrosion, wipe
      the outside of the cuvette each time before placing inside the light cell.
   c) The meter is sturdily housed in its metal box, however, care must be taken not to drop the
      meter, as diodes and other internal mechanisms can easily break, requiring trained
      electrical repair.

Orion Model 211 pH meter

1. Calibration
   a) The pH meter can be calibrated using either a two point or a one point standardization.
      The two point is preferable if both buffers are available. If not, the one point is acceptable.
      The pH calibration is usually the most time consuming of all the meters therefore it is wise
      to begin with this calibration and move on to the others while the readings stabilize.
   b) The pH of slough and wetland waters generally fall within the range of pH 7 - 10, therefore
      these are the two buffers needed to perform the two point calibration. Obtain one pint
      bottle each of pH buffer 7 and 10.
   c) Plug the probe into the meter by matching the raised area on the port at the bottom of the
      meter with the groove in the probe connector and turn counterclockwise. Uncap the probe.
   d) Rinse the probe with distilled water and shake off excess droplets of water.
   e) Obtain an air temperature reading from the dissolved oxygen meter.
   f) Set the temperature dial on the meter to this temperature. This temperature adjustment is
      done during calibration only. It is an air temperature adjustment and therefore is unrelated
      to the varying temperatures of water samples.
   g) Refer to the temperature-pH tables on the labels of the buffer bottles, or Table 2 below and
      determine what pH each buffer should read at that air temperature.
   h) Half fill one each of the 40 ml plastic containers provided in the pH meter case with the pH
      buffer 7 and buffer 10 respectively.
   i) Turn the meter on and place the probe in the pH 7 buffer, allowing several minutes for the
      reading to become stable.
   j) Once stable, use the calibration knob to adjust the reading to the value obtained in step e.
   k) Remove the probe from the pH buffer 7, rinse with distilled water and shake off excess
      droplets of water.
   l) Place the probe into the pH buffer 10. Allow several minutes for the reading to stabilize.
   m) To the right of the probe connector on the bottom of the meter is a small screw labeled
      'SLOPE'. Once the reading has stabilized compare this with the calibration value
      determined in step f. If an adjustment is necessary use the small red handled screwdriver
      provided with the meter and turn this 'SLOPE' screw until the           reading and the
      calibration value match. This adjustment should be necessary only very infrequently.
   n) Remove the probe from the pH buffer 10, rinse with distilled water and shake off excess
      water.
   o) Return the probe to the pH buffer 7. Allow several minutes for the reading to stabilize.
   p) If an adjustment is necessary use the calibration knob to match the meter reading to the
      calibration value, as in step i.


                                                                                                    8
   q) The pH meter is now calibrated and ready for use.
2. Operation
   a) Calibrate the meter as indicated above before each day of sampling.
   b) Place the probe into the sample to be analyzed and allow the reading to stabilize. Often it
      is helpful to agitate the probe in the sample to quicken the stabilization process.
   c) Record this reading.
3. Meter Care
   a) The meter must not be allowed to get wet. If a spill or splash occurs, wipe off the meter
      immediately. If it is raining place the meter in a plastic bag to protect it.
   b) The small pH buffer containers must be emptied after use. If they are allowed to sit open
      in the case for any length of time with the meter case closed condensation or spillage can
      occur. If condensation forms inside the meter itself you will see a fog inside the display
      housing and readings will be erratic, extremely slow to stabilize and quite possibly
      inaccurate. Avoid meter contact with any water or condensation.
4. Probe Care
   a) The pH probe must be rinsed well with distilled water after each daily use.
   b) The probe must be stored in a moist environment when not in use. A small wad of cotton
      has been provided in the tip of the probe cap for this purpose. Make sure that this cotton is
      moistened before the probe is stored for any length of time. This cotton should be changed
      every several months to avoid mold development.
   c) Be sure that the point at which the cable exits the connector that attaches the probe to the
      meter is not pushed up against the box the meter is stored in. If this cable is repeatedly
      bent a short in the internal wires of the probe cable can result.


FIELD CALIBRATION 1995-PRESENT
      Starting in September 1995, a Solomat 803PS Water Quality Sonde with temperature,
conductivity, dissolved oxygen, pH and turbidity sensors was used to measure these parameters.

       Table 2 - Standard Solutions for Solomat Water Quality Sonde:

          Electrode         Low Standards            High Standards
          conductivity      NA                       15 mS/cm
          DO                6% sodium sulfite        distilled water
          pH                7.00 or 10.00 pH         4.00 pH buffer
                            buffer
          turbidity low     distilled water          100 NTU
          turbidity high    100 NTU                  400 or 1000 NTU

1. Calibration:
   Calibration of the 803PS sonde is performed in a laboratory within two days of any sample
   collection. All calibration solutions for high and low reference standards (Table 2) are used as
   received from Solomat, except for turbidity references standards. Diluted turbidity reference
   standards are made from standard stock solution available from Solomat. These diluted
   standards are made within two days of sampling and are stored in the dark.


                                                                                                  9
a) The Solomat calibration Cup is used to calibrate the 803PS sonde. Low standards are used
   first then the sensors are calibrated with the high standards. There is no calibration of the
   temperature sensor.
   i) pH: The % slope between high and low pH standards is calculated. If the reported
       value is less than 85%, the electrode is replaced.
   ii) Conductivity: After calibrating the 803PS Water Quality Sonde calculates a K-cell
       factor. If the K-factor is between 0.900 and 1.100, then the conductivity probe is
       operating correctly. If values outside this range are displayed, the probe is recalibrated to
       bring the K-factor within appropriate limits.
b) K-cell factor, % slope, and calibration constants are recorded on the Calibration Record.
   After each sampling round, post-calibration using standard solutions is performed to
   confirm earlier calibration readings. During post-calibration, additional standards are used
   as necessary to bracket sample readings outside of expected range.
c) Turbidity standards need to be made up within two days of the calibration. Try to minimize
   how much light exposure the turbidity standards get during calibration. Allow standards to
   stabilize for at least 30 minutes before calibration (so make these first when you begin your
   calibration). If measuring turbidity in samples above 5 NTU, remove the screw-on shelf
   during calibration.
   i) 100 NTU: Using a 100 ml volumetric flask, add 100 ml of distilled water to the bottle
       labeled 100 NTU. When using a volumetric flask, you want the bottom of the meniscus
       to be on the line. Remove 2.5 ml of distilled water from the bottle using the pipette.
       Shake the 4000 NTU bottle. Pipette 2.5 ml of 4000 NTU into the bottle. Shake the 100
       NTU standard that you just made. Rinse the pipette tip by sucking up distilled water and
       squirting it to waste.
   ii) 400 NTU: Using 100 ml volumetric flask, add 100 ml of distilled water to bottle labeled
       400 NTU. Remove 10 ml of distilled water. Shake the 4000 NTU bottle. Pipette 10 ml
       of 4000 NTU into the bottle. Shake the 400 NTU standard that you just made.
d) Get out the Calibration Record. Record the date for this entry. As you calibrate each
   channel, you should record on the Cal Record the reading given before you accept the new
   calibration value.
e) Remove sonde cap and the rubber caps on the dissolved oxygen and pH electrodes.
f) Rinse the sonde by dunking it in a beaker of distilled water and dry the electrodes with
   kimwipes. Rinse and dry the calibration cup.
g) Fill calibration cup to the shoulder with the following low reference solutions and put
   distilled water in the PT100 cup: DO - 6@o sodium sulfite, pH - 10 pH buffer, turbidity
   low - distilled water
h) Place the sonde in the calibration cup by lining up the PT100 skinny cup with the PT100
   probe on the sonde and slowly lower the sonde into the cup.
i) Turn the WP803 on by pressing ON (shift and OFF).
j) Press CAL (shift and TSS/NTU). At this point, you will enter the low reference
   calibrations.
k) Press YES when any of the following measurements are displayed: DO, pH, and NTU low.
   To calibrate each channel, allow the reading to stabilize. When the reading has stabilized,
   record that reading on the Calibration Record. Press YES to accept the calibration value.




                                                                                                 10
l) Press NO to skip over all of the other measurements when they are displayed (conductivity,
   NTU hi, PT100, marine depth, battery). Stop pressing NO when START HI CAL is
   displayed.
m) Leave the WP803 on and discard the low ref solutions.
n) Dunk the sonde in a beaker of distilled water and dry the electrodes. Rinse and dry the
   calibration cup.
o) Fill the calibration cup with the following hi ref solutions and fill the conductivity cup and
   PT100 cup with distilled water (be sure to shake the turbidity standard before using): DO -
   distilled water, pH - 4 pH buffer, turbidity low - 100 NTU
p) Place the sonde in the calibration cup by lining up the PT100 skinny cup with the PT100
   probe on the sonde and slowly lower the sonde into the cup.
q) At this point, you should still be in CAL mode and you are starting the high reference
   calibrations. If you are not in the high reference CAL mode, press CAL (shift and TSS /
   NTU) and press NO to skip over all of the low reference calibrations until START HI CAL
   is displayed.
r) Press YES when any of the following measurements are displayed: DO, pH, and NTU low.
   To calibrate each channel, allow the reading to stabilize. When the reading has stabilized,
   record that reading on the Calibration Record. Press YES to accept the calibration value.
s) Press NO to skip over all of the other measurements when they are displayed (conductivity,
   NTU hi, PT100, marine depth, battery). Stop pressing NO when DONE is displayed.
t) When calibrating the hi reference dissolved oxygen reading, use 9.07 mg/l as the
   calibration constant at 20°C and 1015 mbar pressure. Otherwise, correct constant for
   pressure and temperature
u) At this point the sonde should have said that you are done with calibrations and started
   scanning though the measurements again. However, you need to get back into calibration
   mode to calibrate the low reference for the NTU hi channel which is the 100 NTU solution
   that is already in the cup. Press CAL (shift and TSS/ NTU) and you should be in the low
   reference calibrations.
v) Press YES when NTU hi is displayed. Allow the reading to stabilize. When the reading has
   stabilized, record that reading on the Calibration Record. Press YES to accept the
   calibration value.
w) Press NO to skip over all of the other measurements when they are displayed (DO, pH,
   NTU low. conductivity, NTU hi, PT100, marine depth, battery). Stop pressing NO when
   DONE is displayed.
x) Leave the WP803 on and discard the low ref solutions.
y) Dunk the sonde in a beaker of distilled water and dry the electrodes.
z) Rinse and dry the calibration cup.
aa)Fill the calibration cup with following hi reference solutions and fill the PT100 cup with
   distilled water (be sure to shake the turbidity bottle before using): turbidity hi - 400 NTU,
   conductivity - 12.9 mS/ cm
bb)Place the sonde in the calibration cup by lining up the PT100 skinny cup with the PT100
   probe on the sonde and slowly lower the sonde into the cup.
cc)Press CAL (shift and TSS/NTU). At this point, you will enter the low reference
   calibrations. Press NO through all of the low reference measurements until START HI
   CAL is displayed.


                                                                                              11
   dd)Press YES when any of the following measurements are displayed: NTU hi and
       conductivity. To calibrate each channel, allow the reading to stabilize. When the reading
       has stabilized, record that reading on the Calibration Record. Press YES to accept the
       calibration value.
   ee)Press NO to skip over all of the other measurements when they are displayed (NTU low,
       DO, PT100, marine depth, battery). Stop pressing NO when DONE is displayed.
   ff) After calibrating the conductivity hi reference, the WP803 calculates a K-cell factor. The K
       factor should be between 0.900 and 1.100. Record K-cell reading on calibration record. If
       the K cell reading is within this range, press ENTER key and the display flashes OK. If
       values outside this range are displayed, reclean the probe, check for debris, and verify the
       value and integrity of the calibration solution. Recalibrate probe to bring K-factor within
       these limits. Rinse cup and electrodes.
   gg)IF you make a mistake calibrating and you want to redo a calibration for a specific channel,
       just press NO until DONE is displayed and the sonde begins scanning. Then press CAL
       (shift and TSS/NTU). Press NO until whatever measurement you want to fix is displayed
       and then press YES. Then recalibrate and continue.
2. Changing calibration points.
   a) If you have to change to a new standard for any measurement, you must change the
       calibration point that the sonde is reading. Press CAL (shift and TSS / NTU) two times.
       Use the numeric keys to select the channel of the measurement of which you want to
       change the calibration point. Press YES to select the channel. Use the numeric keys to
       enter the new calibration point. Press YES when the correct calibration point is entered.
3. Post-calibration
   a) Do not recalibrate after sampling.
   b) Place the sonde in the calibration cup with appropriate solutions and confirm earlier
       calibration readings by letting the sonde scan the measurements. If readings are very
       different, then electrode may be faulty or earlier calibration was done incorrectly.
   c) Use additional standards as necessary to bracket sample readings outside of expected
       range.
4. Changing sonde parameters.
   a) .Stirrer rate: Press FUNCS (shift and ammonium). Press  or  until STIR MODE is
       displayed and then press YES. Press NO until the appropriate stir mode is displayed and
       press YES. Press FUNCS (shift and ammonium) to return to SCAN mode.
   b) Channel setup.: Press CHANNEL SETUP (shift and store). Use numeric keys to select
       channel and press YES. Use gray keys to select the appropriate measurement. Press
       SYMBOL (shift and clear) to cycle through available measurement units (press NTU twice
       to select NTU hi). Press YES to select a unit. CHAN ON Y/N will be displayed. Press
       YES to turn channel on. Press NO to turn channel off.
   c) Dwell time. Press FUNCS (shift and ammonium). Press A or until DWELL TIME is
       displayed and then press YES. Set dwell time using numeric keys, pressing YES when
       complete. Press FUNCS (shift and ammonium) to return to scan mode.
   d) Checking the battery status.
   e) If necessary, press ON (shift and off) to switch on the WP803.
   f) With the sonde connected to the WP803, press STATUS (shift and pressure) until
       SYSTEM STATUS is displayed. Press A as necessary until BATT LIFE is displayed. Press


                                                                                                12
      YES for predicted hours of battery life and battery voltage. Press STATUS (shift and
      pressure) to return to scan mode.
5. Operation
   a) At each site, a set of water quality measurements is taken using the 803PS sonde and
      WP803 water quality monitor. The sonde is connected via a cable to an outlet on the
      WP803 monitor. Plug the free end of the sonde cable to the outlet labeled SONDE on the
      top panel of the WP803. Be sure pins in the plug are aligned correctly with the outlet
      socket. The sonde cap and electrode covers are removed. The screen shield is snapped
      into place, and the sonde is submerged into the sample water or into the bulk water sampler
      depending on the depth at the sample site. Once the monitor is turned on, electrode
      measurements using the 803PS sonde and WP803 monitor are displayed on the following
      channels:

       Channel 1- conductivity, mS/cm            Channel 2- dissolved oxygen (DO), mg/l
       Channel 3- pH                             Channel 4- turbidity low, NTU
       Channel 5- temperature, °C                Channel 6- water depth, m
       Channel 7- turbidity high, NTU                    Channel 8- battery life, v
  b)   A stirrer located in the center of the sonde is set to pulse during measurements. The sonde
       is gently shaken to dislodge any trapped air bubbles around the electrodes. Once the
       dissolved oxygen reading is stabilized in the sample water, the readings for all other
       channels are recorded onto a field data sheet or logged to a data file in the sonde. If the
       sonde cannot be completely submerged, collect a skim sample and place the sonde into the
       bulk water sampler during measurements. Mark depth as a skim sample on the data sheet.
  c)   Press ON (shift and off) to switch on the WP803. It should enter SCAN mode in which it
       cycles through all of the available measurements. If it is not cycling through the
       measurements, press HOLD. If, at any time, you would like to observe a single
       measurement, press HOLD when that measurement is displayed. If you would like to
       observe specific measurements as you are recording them, then leave SCAN mode and
       enter SINGLE mode by pressing CHAN MODE (shift and hold). This keystroke allows
       you to toggle between SCAN and SINGLE modes. In SINGLE mode, you can observe any
       measurement by pressing the gray keys labeled by the measurements. Press NTU twice to
       get turbidity hi. If you are sampling at night, you can get a backlight for 1 minute intervals
       for reading measurements by pressing shift and .
  d)   Press HOLD when the dissolved oxygen reading is displayed. When the DO reading is
       stabilized, the sonde should be in thermal equilibrium with the sample water. Press HOLD
       to return to SCAN mode. When the sonde is stabilized, the results of each electrode
       measurement can be recorded or stored to a data file (see logging data section). To turn the
       sonde off, hold the OFF key for 3 seconds.
  e)   If you are taking samples at depth, depth measurement should be rezeroed because of
       changes in barometric pressure. To re-zero the depth measurement: Press CAL (shift and
       TSS/NTU). Press NO to skip through measurements until low ref marine depth is
       displayed. Accept 0.26 m as the calibration value by pressing YES.

6. Logging Data.




                                                                                                   13
   a) Depending on the depth at each site, completely submerge the sonde in the water or place
      the sonde in the bulk water sampler.
   b) Turn the WP803 on by pressing ON (shift and OFF).
   c) Press FILE SETUP (shift and TDS / TDS).
   d) Use NO to increase file numbers or press 4 (shift and NO) to decrease files numbers. Cycle
      through file number until the correct file # is displayed.
   e) Press YES when the appropriate file number is displayed.
   f) EDIT FILE NAME is displayed. If you do not need to edit a file name, press NO. To edit a
      file name, press YES. Use NO C> or -4 (shift and NO) to cycle through letters and
      symbols. When the letter is correct, press YES to go on to the next letter.
   g) Press NO when CLEAR LAST FILE is displayed.
   h) At this point, the sonde should start scanning through the measurements. Make sure that
      the DO reading is stabilized.
   i) Press STORE to store data to the selected file.
   j) On the data sheet,, record the file # used to store data at each site. Write down the data
      from the files later using the file # listed for each site (see reviewing data files section).
   k) Repeat the instructions above at each site. Be sure to assign data at each site to a different
      file

7. Reviewing data in files.
   a) Press FILE SETUP (shift and TDS/ µS) two times.
   b) Select a file by pressing the NO t> or < (shift and NO) until the appropriate file is
      displayed.
   c) Press YES to select the file.
   d) Record each measurement in the file onto the data sheet. Press NO to move on to the next
      measurement in a file.
   e) If turbidity readings are around 100 NTU, take the average reading of both turbidity
      channels. Otherwise, use the turbidity reading that is in the correct channel range. For
      example, if turbidity low reads 44 and turbidity hi reads 35, you should record 44 for the
      turbidity measurement because 44 is in the correct range for the turbidity low channel (1-
      100 NTU), but 35 is out of the correct range for the turbidity hi channel (100-400 NTU).

8. Meter care
   a) Exposure of the 803PS sonde and WP803 monitor to excessive heat, vibration,, and shock
      is avoided in the field to prevent damage to the instruments. After each sampling round, the
      sonde is rinsed with distilled water, and any debris that has collected around the electrodes
      is clear away. The dissolved oxygen and pH electrodes are stored with protective rubber
      caps. The pH cap is filled with pH 7 storage solution. The sonde storage cap foam is kept
      wet with distilled water.

Table 3 shows the calibration records for this period for the dissolved oxygen, pH, turbidity, and
conductivity sensors. When sensors were within the manufacturers specifications for the
calibration values, the calibration was judged acceptable.

                                  Table 3 - Calibration Records


                                                                                                 14
                   DO                  pH            Turbidity                   Conductivity
1995   October:    not calibrated      acceptable    missing zero standard,      missing high
                                                     other standards -           standard, kcell
                                                     acceptable                  OK
       November    acceptable          acceptable    acceptable                  acceptable
       December    acceptable          acceptable    low standard not            acceptable
                                                     calibrating, other
                                                     standards acceptable
1996   January     high standard not   acceptable    not calibrating             acceptable
                   calibrating
       February    acceptable          acceptable    not calibrating             acceptable
       March       acceptable          acceptable    not calibrating             acceptable
       April       high standard not   acceptable    not calibrating             acceptable
                   calibrating
       May         acceptable          acceptable    high standard               acceptable
                                                     questionable
       June        acceptable          acceptable    calibrating, but not very   acceptable
                                                     stable
       July        acceptable          acceptable    acceptable                  acceptable
       August      not calibrating     not           acceptable                  acceptable
                                       calibrating
       September   acceptable          acceptable    acceptable                  acceptable
       October     acceptable          acceptable    acceptable                  acceptable
       November    acceptable          acceptable    acceptable                  acceptable
       December    acceptable          acceptable    acceptable                  acceptable
1997   January     acceptable          acceptable    calibrating, but high       acceptable
                                                     standard not stable
       February    acceptable          acceptable    acceptable                  acceptable

FIELD SAMPLE COLLECTION

1. Logistical Considerations
   a) Transportation/Sampling Vehicle: Four wheel drive is needed to access certain stations
       which require travel on agricultural roads which become impassable to 2WD vehicles
       during heavy rains and at times during irrigation.
   b) Elkhorn Slough Reserve Permit: A permit will need to be obtained from the Department
       of Fish and Game for vehicular travel on the Elkhorn Slough Reserve. Some sites require
       private property access and owner permission prior to each sampling session at those
       locations

2. Sampling Depth
    Samples are to be taken at 0.5 meters depth at any station where this can be accomplished
without disturbing the bottom sediments. In shallower settings, estimate the depth of water and
sample in the middle of the water column. In the most shallow settings (Carneros Creek for
example), where the sampling container can often not be completely submerged the sample must
be skimmed off the top. Record these depths on the data sheet. In all situations it is critical that
the bottom remain undisturbed, otherwise the turbidity will not be an accurate representation of
the suspended material in the water alone. In addition, at times certain stations may be quite
thick with Enteromorpha. Samples should be taken in an area clear of Enteromorpha if possible.
If not, push the Enteromorpha aside slowly and carefully again so as not to stir up the bottom.


                                                                                                   15
3. Obtaining Samples
        Measuring from the knuckle where your first finger joins your hand, determine a point
that can mark a 0.5 meter length on your arm. When sampling at the deeper locations you will
submerge the sampling container and your arm to this depth. The sampling container is
submerged inverted, trapping an air bubble that prevents its filling until the container is turned
upright when the marker on your arm reaches water level. In this manner a sample is obtained
from the appropriate depth. At the shallower stations the same procedure is followed except that
the depth determination is done by eye, using the tide stake as a gauge.

4. Tide Stake Reading
        Tide stakes are calibrated in 10 cm intervals. Beginning at the top, and reading down to
the water level, first count the number of whole intervals and multiply this number by ten. Then,
looking at the fraction of an interval that remains, if there is one, estimate how many units out of
the ten are exposed. Add this number to the number derived from the first calculation. Record
this final number. At sites where the tide stake is absent, a notation is recorded in the log book.

5. Meter Reading - 1988-1995
    Pay close attention to which scale you're reading from, what the difference is between the
labeled increments and what each smaller increment is therefore worth. The dissolved oxygen
meter in particular can be confusing to read in that there are three different range scales. Be sure
you are reading from the same scale that you have the mode control knob set to.
  Analysis Sequence
a. Read temperature from Dissolved Oxygen Meter.
b. Dial this temperature on to the SCT meter's temperature adjustment knob.
c. Read Salinity.
d. Dial this salinity onto the salinity adjustment knob on the dissolved oxygen meter.
e. Read the Dissolved Oxygen.
f. Read the pH.
g. Labeling Samples for turbidity analysis in the lab
    Samples should be clearly labeled using an adhesive label and a permanent marking pen with
the following data:

Station Name                         Sampler(s) Names
Date                                Elkhorn Slough Foundation

6. Meter Reading 1995-Present
        Optimal sampling depth for the Solomat Water Quality Sonde is 0.26 m, or just below the
surface.

7. Field Observations Log Book
        Any and all ecological field observations should be recorded in the log book. Label each
entry with the date, your name, the station you are at, and the time of observation. Notations
about birds, vegetation, aquatic life, weather, unusual flow patterns, instrument or calibration
irregularities and calibration temperatures can be recorded in this book.


                                                                                                  16
LABORATORY ANALYSES

         From September 1989 to November 1991, nutrient analyses (NO3- + NO2-, NO2-, NH4+,
and PO43-) were analyzed by Neil Allen of the Monterey Bay Aquarium (MBA). Samples were
frozen unfiltered after collection until they could be analyzed. Analyses were done using
standard colorimetric techniques (NO3-- Cd reduction, NH4+ - phenol hypochlorite, and PO43- -
ascorbic acid/molybdate) on a flow injection analyzer. Samples were thawed and centrifuged at
the fastest speed of the desktop centrifuge to remove sediment particles, and the supernatant was
analyzed. Standards were run every 5 samples. Nitrate concentration were linear up to 20 µM,
so samples greater than that were diluted, until they were on scale. Some high NO3- values were
recalculated using an exponential fit for the standard curve rather than a linear fit. The values in
the database reflect this correction.
         In December 1991, the Monterey County Consolidated Chemistry Laboratory began
analyzing nutrient samples (NO3- + NO2-, NH4+, and PO43-). Electrical conductivity and chloride
concentrations are also determined. All samples are analyzed using standard EPA techniques
(EPA 1983). The Consolidated Chemistry Laboratory QA/QC manual is Appendix A. The
major differences between the MBA and the county are: samples are filtered prior to NO3- + NO2-
, NH4+, and PO43- analyses, NH4+ is determined with an electrode, and NO3- samples are diluted.
Because of the complex matrix and high chloride concentration of the samples, NO3- analysis
using the Cd column is difficult, therefore, samples are diluted 10 fold prior to analysis and the
detection limit is 1 mg/l as NO3- (or 71 µM). Chloride is determined by titration with silver
nitrate to a potentiometric end point. PO43- is determined as orthophosphate using the ascorbic
acid method. The detection level is 0.03 mg/l as P. A study comparing total phosphorus with
orthophosphate indicated that the majority of phosphorus occurred in the orthophosphate form.
In 1996, the laboratory began using a DIONEX ion chromatograph for NO3- analysis. The
samples are diluted 1:10 and treated to remove chloride. The detection limit is 1 mg/l as NO3-.

PERSONNEL

       Personnel changes occur in any long-term monitoring program. Table 4 lists the
personnel in alphabetical order associated with the program, affiliation, area of responsibility,
and dates of involvement with this program. The volunteers who have assisted with the field
sampling are too numerous to list.
                                             Table 4
Name                  Affiliation                        Responsibilities        Date
Neil Allen            Monterey Bay Aquarium              nutrient analysis       Sept. „89-Dec. „91
Jane Caffrey          ES NERR                            coordination            Jan „96 - present
Andrew De Vogelaere   ES NERR                            coordination            Aug. „91-July „95
Deborah Frost         Moss Landing Marine Laboratories   field sampling          Sept. „88-Sept. „89
David Holland         Monterey Co. Consolidated          Laboratory analyses     Dec. „91 - present
                      Chemistry Laboratory
Kenton Parker         ES NERR                            field sampling          Oct. „95 present
Sue Shaw              Elkhorn Slough Foundation          field sampling          Sept. „89-present
Mark Silberstein      Elkhorn Slough Foundation          personnel management    Sept. „88-present
Kathy Thomasberg      Monterey Co. Water Resources       coordination            Dec. „91 - present



                                                                                                       17
                      Agency
Michelle White        Moss Landing Marine Laboratories   data entry              Jun. „94 - present



DATA EVALUATION
        All data have been verified against the original field or laboratory data sheets, except for
the data between September 1988 and June 1989. The original data sheets for this period have
been lost. Whenever a reading was outside the range of the meter, as specified by the
manufacturer, that reading was considered anomalous and removed from the data base. Those
cases are listed in the next section. In some cases, the data seems suspect even though it falls
within the range of expected values. In that case, the data was retained in the database, but a note
was made in the Missing or Anomalous Data Section. For example, between the December 1995
and April 1996 sampling periods, the turbidity sensor was improperly adjusted, so turbidity
readings may be incorrect. Missing data are also listed in the following section.

Measurement Units
        Salinity is reported in psu, or practical salinity units, which is the same as parts per
thousand, ppt or °/°°. Conductivity is reported in either mS/cm (millisiemens/cm), or µmhos/cm
which are equivalent. The units for dissolved oxygen are either mg/l or percent saturation (%
sat).. The standard unit for turbidity is NTU. Chloride is reported as ppm. Nutrient
concentrations are reported two ways: µM and mg/l. The following section explains how to
convert between units.

Conversion Factors

                                   mg/l NO3- = µM N *62/1000
                                   µM N = mg/l NO3- 1000/62
                                    mg/l N = µM N *14/1000
                                     µM N= mg/l N1000/14
                                    mg/l P = µM P *31/1000
                                    µM P = mg/l P *1000/31

MISSING OR ANOMALOUS DATA

1989
July: Struve Pond was not sampled because it was dry.
August: Struve Pond was not sampled because it was dry.
September: Struve Pond was not sampled because it was dry. Dissolved oxygen reading was
        higher than meter specifications at Salinas River Bridge so data point was removed.
October: No sample collection.
November: Reserve Bridge station was skipped.
December: Dissolved oxygen reading was higher than meter specifications at Salinas River
        Bridge so data point was removed.

1990



                                                                                                      18
March: Salinity meter does not appear to be accurate. Should use refractometer reading instead.
       Dissolved oxygen reading was higher than meter specifications at Salinas River Bridge so
       data point was removed.
April: Salinity meter not working. Dissolved oxygen and refractometer readings were higher
       than meter specifications at Carneros Creek so data were removed. Dissolved oxygen
       readings were higher than meter specifications at North Marsh and Moro Cojo so data
       points were removed.
May: Dissolved oxygen reading was higher than meter specifications at Salinas River Bridge so
       data point was removed.
August: No sample taken from East Bennett Slough. Dissolved oxygen reading was higher than
       meter specifications at Salinas River Bridge so data point was removed.
September: Salinity meter does not appear to be accurate, should use refractometer reading
       instead.
October: Salinity meter does not appear to be accurate, should use refractometer reading instead.
November: Salinity meter does not appear to be accurate, should use refractometer reading
       instead.
December: Data are missing.

1991
January: Salinity meter does not appear to be accurate, should use refractometer reading instead.
       Dissolved oxygen reading was higher than meter specifications at South Potrero so data
       point was removed.
February: NOT using refractometer: meter working fine.
March: NOT using refractometer for meters. Added 2 stations: Moss Landing Road North and
       South.
April: NOT using refractometer for meters.
May: Salinity reading was higher than meter specifications at North Marsh so data point was
       removed.
June: Back Bennett Slough was inaccessible.
July: Dissolved oxygen reading was higher than meter specifications at Salinas River Bridge so
       data point was removed.
September: Salinity was higher than meter specifications at Struve Pond so data point was
       removed.
October: Salinity readings were higher than meter specifications at Moss Landing Road South
       and Moro Cojo so data points were removed.
November: Added 1 additional station: Monterey Dunes Way. Dissolved oxygen reading was
       higher than meter specifications at Salinas River Lagoon so data point was removed.
December: DIP and Electrical Conductivity added to water sample analyses. Salinity reading at
       Jetty Road appears to be too low (compared to E.C. and chloride).


1992
February: Back Bennett Slough was inaccessible.
March: 3 new sites added near Kirby Park (strawberry drainage): Upper, Middle, and Lower
       Ponds. Chloride added to water sample analyses.


                                                                                               19
April: Carneros Creek and East Bennett Slough were inaccessible; No samples were taken from
       Lower Pond, Mid Pond, and Upper Pond. E.C. reading at Struve Pond appears to be too
       low (compared to chloride).
May: No sample was taken at East Bennett Slough. Dissolved oxygen reading was higher than
       meter specifications at Monterey Dunes Way so data point was removed.
June: Salinity at Lower Pond was higher than meter specification so data point was removed.
       Chloride reading at Moss Landing North appears to be too low (compared to E.C.).
July: Salinity at Lower and Mid Pond were higher than meter specification so data points were
       removed. Dissolved oxygen readings were higher than meter specifications at Salinas
       River Bridge and South Potrero Road so data points were removed.
August: Dissolved oxygen at Carneros Creek was higher than meter specifications so data point
       was removed. Salinity at Lower and Mid Pond were higher than meter specification so
       data points were removed.
September: Salinity at Lower Pond was higher than meter specification so data point was
       removed.
October: Salinity at Lower Pond was higher than meter specification so data point was removed.
November: Stirrer for dissolved oxygen meter not working constantly. Dissolved oxygen values
       are probably incorrect (too low). Salinity at Lower and Mid Pond were higher than meter
       specification so data points were removed.
December: Back Bennett Slough and Carneros Creek were inaccessible.

1993
January: Back Bennett Slough was inaccessible. Skipper salinity reading is missing.
February: Turbidity reading was higher than meter specifications at Salinas River Bridge so data
        point was removed. Salinity reading at Hudson‟s Landing LP appears to be too high
        (compared to E.C. and chloride).
March: Salinity meter not working.
May: Chloride reading at Monterey Dunes Way appears to be too high (compared to E.C.).
July: Salinity at Lower and Mid Pond were higher than meter specification so data points were
        removed.
August: Salinity at Lower and Mid Pond were higher than meter specification so data points were
        removed.
September: Salinity at Lower and Mid Pond were higher than meter specification so data points
        were removed.
October: Salinity at Lower and Mid Pond were higher than meter specification so data points
        were removed.
November: Salinity at Lower Pond was higher than meter specification so data point was
        removed. East Bennett Slough was inaccessible due to traffic.

1994
February: No data available for this month.
March: Data are missing from Upper Pond. Temperature, salinity, Dissolve Oxygen, turbidity,
       and pH readings are missing for Mid Pond and Lower Pond.
April: No data available for this month.




                                                                                             20
June: A new site was added: Tembladero Slough. Salinity meter not working. No sample taken
       at Mid Pond; spraying pesticide.
July: Salinity meter not working; use refractometer. No sample was taken at Tembladero
       Slough.
August: Salinity meter not working; use refractometer. No samples were taken at Tembladero
       Slough and Back Bennett Slough.
September: Salinity meter not accurate; use refractometer. Salinity at Moro Cojo, Lower and
       Mid Pond were higher than meter specification so data points were removed.
October: Salinity meter not accurate; use refractometer. Salinity at Lower and Mid Pond were
       higher than meter specification so data points were removed.
November: Salinity meter not accurate; use refractometer. East Bennett Slough was inaccessible
       due to traffic.
December: Salinity meter not accurate; use refractometer. Carneros Creek was inaccessible. No
       sample was taken at Hudson‟s Landing LP.

1995
January: Salinity meter not accurate; use refractometer. Nutrient data from all stations are
       missing. Carneros Creek was inaccessible.
February: Salinity meter not accurate; use refractometer. Nutrient data from all stations are
       missing. Back Bennett Slough, Carneros Creek, and Tembladero Slough were
       inaccessible.
March: Dissolved oxygen data not available. Turbidity reading was higher than meter
       specifications at Salinas River Bridge so data point was removed. Carneros Creek was
       inaccessible.
April: Carneros Creek was inaccessible. Dissolved oxygen reading was higher than meter
       specifications at Hudson‟s Landing RC, Hudson‟s Landing LP, Skippers, Jetty Road,
       Moss Landing Road North, Moss Landing Road South, Monterey Dunes Way,
       Tembladero Slough, East Bennett Slough, and Back Bennett Slough so data points were
       removed. Chloride reading at Monterey Dunes Way appears to be too high (compared to
       E.C.).
May: Carneros Creek was inaccessible. Dissolved oxygen readings were higher than meter
       specifications at North Marsh, Reserve, South Marsh, Skippers, Jetty, South Potrero,
       North Potrero, Moss Landing Road North, Moss Landing Road South, Salinas River
       Bridge, Salinas River Lagoon, Monterey Dune Way, Tembladero Slough, Struve Pond
       and East Bennett Slough so data were removed.
July: Temperature, Salinity, Dissolved Oxygen, and pH data not available.
August: Temperature, Salinity, Dissolved Oxygen, and pH data not available.
September: New Solomat Instrument used; began measuring conductivity instead of salinity.
October: Dissolved Oxygen data not available. Mid Pond water turbidity may be slightly high
       due to time to collect. Carneros Creek, Hudson‟s Landing LP, Hudson‟s Landing RC,
       and Struve Pond were inaccessible.
November: Dissolved oxygen readings were higher than meter specifications at Moro Cojo and
       Lower Pond so data points were removed. Carneros Creek, Hudson‟s Landing LP, and
       Hudson‟s Landing RC were inaccessible.
December: E.C. reading at Monterey Dunes Way appears to be too low (compared to chloride).


                                                                                           21
1996
February: Turbidity probe readings for Res. Bridge and S. Marsh readings may be off.
March: Problems with turbidity, readings may be off.
April: Turbidity probe not working. Dissolved oxygen readings were higher than meter
       specifications at North Marsh and Jetty Road so data points were removed.
June: Missing June data.
July: At some stations, Solomat wouldn't give Dissolve oxygen readings when logged.
       Dissolved oxygen readings were higher than meter specifications at Lower Pond and
       North Marsh so data points were removed. E.C. reading at Tembladero Slough appears to
       be too low (compared to chloride).
August: North Marsh was not sampled because there was only 0.25” of water on the surface.
       Dissolved oxygen reading was higher than meter specifications at Tembladero Slough so
       data point was removed.
September: East Bennett Slough was inaccessible due to traffic.
October: Dissolved oxygen reading was higher than meter specifications at Hudson‟s Landing
       RC so data point was removed.
November: Measured DO % saturation in addition to DO in ppm. Dissolved oxygen reading was
       higher than meter specifications at Tembladero Slough so data point was removed.
       Conductivity reading at Hudson‟s Landing LP appears to be too low (compared to E.C.
       and chloride). Conductivity readings at Salinas River Lagoon and Monterey Dunes Way
       appear to be too high (compared to E.C. and chloride).
December: Salinity reading at Mid Pond appears to be too low (compared to E.C. and chloride).

1997
January: Low Turbidity reading is probably incorrect, value is same as salinity at Mid Pond,
       Lower Pond and Hudson‟s Landing RC.
February: Began measuring salinity as well as conductivity.

                      Appendix A - Quality Assurance/Quality Control

                         ORGANIZATION AND RESPONSIBILITY

On October 11, 1988, the Monterey County Board of Supervisors, in Resolution No. 88-508,
authorized the Director of Health and the General Manager of Monterey County Flood Control
and Water Conservation District (MCFC&WCD) to establish a Consolidated Chemistry
Laboratory.

The Board approved a Memorandum of Agreement (MOA) that established the organizational
role the two agencies have regarding the Consolidated Chemistry Laboratory. The MOA
established a Laboratory Steering Committee consisting of six members, staffed by the Public
Health Chemist and the Water Quality Specialist:

(Health Department) Chief of Health Promotion Division
                    Director of Environmental Health


                                                                                               22
                     Director of Public Health Laboratories
(District)           Assistant General Manager
                    Principal Hydrologist
                    Water Quality Supervisor

The Laboratory Steering Committee serves the following purposes:
1. To provide for the planning, operation and future development of the analytical capability of
   the laboratory.
2. To serve as a decision and policy making body, and provide a vehicle for conflict resolution.
3. To establish and prioritize laboratory goals and objectives and set laboratory policies and
   procedures.
4. To develop a meeting schedule and milestones annually.
5. To participate in the development of a "Laboratory Master Plan" that includes cost analysis
   of alternatives and needs for future capabilities.
6. To participate in the development and preparation of the annual budget.
7. The Consolidated Chemistry Laboratory is accredited by the State Department of to perform
   tests in the following fields: 1) microbiology of drinking water and waste water; 2) inorganic
   chemistry and physical properties of drinking water; 3) analysis of toxic chemical elements in
   drinking water; 4) wastewater inorganic chemistry, nutrients and demand; and 5) toxic
   chemical elements in wastewater.

The following is a brief description of the staff support for the Consolidated Chemistry
Laboratory:
1. Director - Plans, organizes and controls laboratory operations. Coordinates laboratory
   interactions with other programs in the Health Department. Administers laboratory budget,
   billing and purchasing. Develops laboratory policy and procedures and supervises staff.
2. Chemist - Performs complex organic and inorganic chemical analysis, evaluates and
   implements laboratory procedures, develops and maintains quality assurance, reports results
   and maintains records, purchases equipment and supplies, provides technical consultation to
   Environmental Health and Water Resources Agency.
3. Microbiologist/Clinical Laboratory Technologist - Assist in the performance of blood lead
   testing. Provides medical oversight of quality assurance including patient test management
   assessment, quality control, and relationship of patient information to patient test results.
4. Laboratory Assistant - Directs preparation of culture media and reagents, assists in the
   processing of specimens where interpretation or medical judgment is not required. Performs
   water testing.
5. Laboratory Helper - Washes and sterilizes glassware and supplies. Prepares and labels
   mailing containers and specimen collection kits. Accession laboratory specimens. Sterilizes
   and disposes infectious waste. Maintains stockroom.
6. Typist-Clerk II - Enters clients and laboratory results into computer. Types premarital health
   certificates and other reports/forms. Prepares billing statements; receives and accounts for
   payments. Distributes laboratory results, and maintains laboratory files.

                      QUALITY CONTROL / QUALITY ASSURANCE




                                                                                               23
Quality Control (QC) may be defined as those measures undertaken in the laboratory to maintain
the analytical testing process within known probability limits of accuracy and precision. The
objective of quality control is to illustrate the limits of data accuracy to laboratory management.
The Quality Control Program consists of at least seven elements: certification of operator
competence, recovery of known additions, analysis of externally supplied standards, analysis of
method blanks, calibration with standards, analysis of duplicates, and maintenance of control
charts:

1.    Before an analyst is permitted to do reportable work, competence in making the analysis is to
     be demonstrated. Commonly, the analyst performs replicate analysis under the supervision of
     the chemist. General limits for acceptable work are found in Standard Methods 17th Edition,
     1989 in Table 1020 :I.
2.    Use the recovery of known additions as part of a regular analytical protocol. Use known
     additions to verify the absence of matrix effects. Spiked samples shall be analyzed with a
     minimum frequency of ten percent of the samples per matrix per batch of samples OR
3.    Analyze externally supplied standards with a minimum frequency of ten percent of the
     samples per matrix, per batch of samples. If there are less than 10 samples in a batch, at least
     one per matrix per batch must be analyzed. The concentration of the sample shall be within
     the working range of the method. Sources of these samples include but are not limited to:
     quality control samples from the EPA, commercially available sample preparations, samples
     prepared by other laboratories, or samples prepared in-house but from different sources of
     analyte.
4.    Method blanks will be analyzed with a minimum frequency of ten percent of the samples per
     matrix, per batch of samples, or if less than 10 samples in a batch, at least one per matrix, per
     batch must be analyzed. The use of method blanks provide a measurement of laboratory
     contamination.
5.    As a minimum, three different dilutions of the standard will be measured when an analysis is
     initiated. Reportable analytical results are those within the range of the standard dilutions
     used. Do not report values above the highest standard unless an initial demonstration of
     greater linear range has been made. The lowest reportable value is the Method Detection
     Limit (MDL), providing that the lowest calibration standard is less than 10 times the MDL.
6.    Replicate samples will be analyzed with a minimum frequency of ten percent of samples per
     matrix, per batch of samples. If there are less than ten samples per batch, at least one sample
     per matrix per batch must be analyzed. If the analyte is not detected, replicate matrix spike
     samples will be analyzed.
7.    Three types of control charts commonly used in the laboratory: a means chart for standards; a
     means chart for background or reagent blank and a range chart for replicate analysis.

        The means chart for standards is constructed from the average and standard deviation of
the standard. It includes upper and lower warning levels and upper and lower control levels.
Common practice is to use 2SD and 3SD for the warning and control levels.
        The range chart is constructed using the standard deviation. The standard deviation is
converted to the range so the analyst need only subtract results from replicate analysis to plot the
value on the control chart. Refer to Standard Methods for actual calculations.




                                                                                                   24
       The Quality Assurance (QA) includes all aspects of laboratory operation which affect the
accuracy and reliability of sample test results. In addition to quality control of the analytical test
process, quality assurance practices include: 1) proper sample collection, receiving and holding,
2) proper maintenance of equipment, 3) accurate data reduction validation and reporting.
       All of the quality assurance control procedures will be followed in the laboratory. All
documentation-for these checks should be available for inspection by laboratory management.

                       SAMPLE COLLECTION, HANDLING & RECEIPT

Total laboratory quality assurance includes proper labeling of samples, how to fill out the chain
of custody/analysis request form, sample acceptance criteria, how to log samples into computer,
how to preserve and store the samples, and how to dispose of the sample.

Sample Collection/Labeling
Sample collection is a coordinated effort between the client and the laboratory. The laboratory
will provide clients with appropriate sample containers and sample collection/preservation
instructions. The laboratory will also request duplicates and blanks if necessary.
        All samples submitted for testing should be appropriately labeled. Sample containers
provided by our laboratory have a suitable label which should be filled out at the time of
sampling by the sample collector. The following information must be provided with all samples:
1. Sample identification - submitters identification of sample (e.g. well number)
2. Location - an address or brief description of the place the sample taken.
3. Time and date taken.
4. Name of sample collector.
5. Any preservatives

Chain of custody/Analysis Request Form
A Chain of Custody/Analysis Request form should accompany all samples. The Chain of
custody/Analysis Request form must include the following information: submitter name and
address; sample identification; location of sample collection; date & time of collection; sample
type; analysis to be performed; signatures of persons involved in the collection and chain of
possession; and inclusive dates of possession.

Sample Receiving
Laboratory personnel receiving samples should assure that samples are properly collected,
labeled, and the Custody/Analysis Request form has been completed:
1. The laboratory assistant receiving the specimen must sign and date the Custody/Analysis
   Request form. Make sure that any special requests made by the client are recorded under the
   comments section of the form
2. Assign each sample a unique laboratory identification number. Place preprinted lab number
   on analysis request form and sample container. When a sample is collected in multiple
   containers for different analyses, each container should receive the same laboratory number
   (e.g. when a sample is collected for nitrate and coliform exams, both containers should receive
   the same number).
3. Check that the samples meet the following criteria:


                                                                                                    25
   a) Samples should be collected in a suitable container; samples collected in bottles of
      unknown origin or questionable cleanliness should be brought to the attention of the public
      health chemist.
   b) Samples should be adequately labeled
   c) Samples should be checked for proper preservative, holding time, and holding
      temperature. Refer to Sample Collection Plan
   d) Samples should be adequately sealed. Notify public health chemist if there is evidence of
      leakage. Verify that adequate sample volume exists to perform requested analysis. Refer to
      Sample Collection Plan.
      i) NOTE: Samples which are not properly identified or are otherwise unsuitable for
         testing (e.g. improperly preserved or exceeding holding/ transport time) are brought to
         the attention of the Public Health Chemist. Samples not meeting collection/preservation
         criteria may be tested only if resampling is impossible; results from such samples must
         be qualified on the laboratory report by comments describing sample deficiency.
4. When the sample meets criteria for acceptance by the laboratory, required preservatives are
   added immediately and the sample is stored until analysis (see section on sample handling and
   storage).
5. Chain of Custody/Analysis Request forms are given to the clerk to enter into the computer
   laboratory information management system. Refer to "Water Sample Entry" in Clerical
   Manual for instructions on sample log-in.

Sample Handling and Scheduling
As samples are received, screen request form for analyses with special holding/preservative
requirements:

pH - Analyze within 6 hours of collection

Microbiology, Conductivity and Alkalinity These analyses must be performed within 24 hours of
sample collection. After these analyses are completed, sample will then be routed to the
appropriate storage area.

Phosphorous (Elkhorn Slough) - These samples must be filtered and frozen at -100C until testing
(Chest freezer outside storeroom).

Nitrate - Transfer 60 ml of the sample to a Nalgene container if necessary (samples collected by
Environmental Health for nitrate testing are collected in the appropriate sample containers). Add
120 µl H2SO4 and store sample in numerical order in the chemistry room refrigerator (tray
labeled “Nitrate").

Ammonia - Transfer 250 ml of the sample to a Nalgene container.
Add 200 µl 1:1 H2SO4 and store sample in numerical order in the chemistry room refrigerator
(tray labeled "Ammonia”).




                                                                                               26
Metals (As, Se, Cu, An, Fe, Pb, Mg, Mn, Hg) - Transfer 250 ml of the sample to an acid washed
(I-Chem) container. Add 0.8 ml 1:1 HNO3 and store sample in numerical order on the bench
(area labeled "Metals").

Miscellaneous Analysis - Samples for all other chemical analysis should be stored in numerical
order on the carts.

Sample Disposal
All water samples shall be disposed of two weeks after the final report is mailed unless prior
arrangements are made with the client. Any sample known to contain hazardous waste will be
returned to the client for disposal.

                               PREVENTIVE MAINTENANCE

As part of the QA plan, the laboratory has a comprehensive preventive maintenance program.
        Balances, spectophotometers, and other instruments undergo routine maintenance and
accuracy checks by a manufacturer's representative or by laboratory personnel as described
below. All preventive maintenance performed in-house is documented on preventive
maintenance forms. Instruments which undergo routine professional maintenance have labels
affixed to indicate date of last servicing. Manufacturer's instructions, and service manuals are
readily accessible.
        Adequate spare parts are kept on hand to perform routine maintenance and minimize
downtime. The spectrophotometers have maintenance contracts that provide for immediate
servicing in the event of malfunction. Equipment records documenting preventive maintenance
and emergency servicing/repairs are kept for a minimum of three years.
1. Thermometer/temperature-reading instruments: Accuracy of thermometers or recording
    instruments are checked annually against a certified National Bureau of Standards (NBS)
    thermometer or one traceable to NBS and conforming to NBS specifications. All
    thermometers are relabeled with date calibrated and correction factor.
2. Balance: Balance accuracy is verified each month using class reference weights. Accuracy
    checks are documented on preventive maintenance chart. Balances are serviced and certified
    annually through a maintenance contract.
3. pH meter: pH meters are standardized with at least two standard buffers (pH 4.0, 7.0, or 10.0)
    and compensated for temperature before each series of tests. Date buffer solutions when
    opened and discard buffer after use.
4. Water deionization unit: Conductivity of the RO and Nanopure water is checked each month.
    A heterotrophic plate count on Nanopure water is also performed monthly. Filters are
    changed as indicated by conductivity readings and heterotrophic plate count. Records are
    maintained on preventive maintenance chart. Water is tested annually for bacteriologic
    quality and heavy metals.
5. Autoclave: Autoclave charts are used to document date, time, temperature and contents of
    each load. Chem-di indicators and heat sensitive tape are used with each load to identify
    materials that have been autoclaved; results are recorded on autoclave chart. Autoclave
    performance is checked each month with biological indicator (e.g. spore suspension).




                                                                                                 27
    Autoclaves are serviced quarterly under maintenance contract. The accuracy of autoclave
    recording thermometer is checked annually.
6. Refrigerator: Temperatures are recorded daily and units defrosted and cleaned as needed. All
    media and reagents stored in the refrigerator are labeled.
7. Freezer: Temperatures are recorded daily. Identify and date materials stored. Defrost and
    clean semiannually; discard outdated materials.
8. Ultraviolet sterilization lamps: Unit is cleaned monthly by wiping lamps with a soft cloth
    moistened with ethanol. Test lamps quarterly with UV light meter and replace if they emit
    less than 70 % of initial output or if agar spread plates containing 200 to 250
    microorganisms, exposed to the .light for 2 minutes, do not show a count reduction of 99%.
9. Water bath: Fecal coliform water bath is checked twice daily. All other water baths are
    checked each day of use.
10. Incubator: Check and record temperature twice daily (morning and afternoon) on the shelf
    areas in use. Locate incubator where room temperature is in the range of 16 to 270 C.
11. Fume hoods/Biological Safety Cabinets: Fume hoods are checked once each month using-a
    velometer; readings are recorded on preventive maintenance chart. Hoods and safety cabinets
    are certified annually through service contract.

                   DATA REDUCTION, VALIDATION AND REPORTING

The analytical chemist is responsible for describing and reporting the data in an appropriate
manner. In order to insure the accurate transcription, calculation and reporting of analytical data,
the chemist will adhere to the following quality assurance procedures.
1. Use documented procedures and record all significant experimental details in such a way that
    the measurements could be reproduced by a competent analyst at a later date.
2. Provide or make available, limits of uncertainty of all data reported including that due to
    sample and measurement variations.
3. All measurements are made so that results are representative of the matrix (soil, water, etc.)
    and conditions being measured.
4. Report data only to the number of significant figures consistent with their limits of
    uncertainty.
5. Report data with the proper units of concentration. Units should be chosen which clearly
    indicate whether the concentration is in terms of weight by weight, weight by volume or
    volume by volume. Unless otherwise specified, all data are calculated and reported in
    standard units to allow comparison with data reported by other laboratories.
6. The analytical methodology used will be cited. The raw data for each sample, along with
    reagent blanks, control, and spiked samples will be suitably identified if included in the
    report. If average values are reported, an expression of the precision, including the number of
    measurements, must be included.
7. The report should include date and place of sampling, sampling point, the name of the
    sample collector, identification as to type of sample, date of analysis, name of the analyst, and
    the result. Any conditions which may effect the interpretation of the data should be noted in
    the report.
8. All results will be validated by the public health microbiologist before a final report is
    prepared and subsequently released.


                                                                                                  28
9. Laboratory records will be retained in a permanent file for three years.
10. Retain samples for one week after issuing final report and retain data and documentary
    evidence for three years.
   NOTE: Longer retention of samples or data may be required when legal action is probable.

                     QUALITY CONTROL FOR MEASUREMENT DATA

        Measurements are made with properly tested and documented procedures. Analysts must
conduct sufficient preliminary tests using the methodology and typical samples to demonstrate
competence in the use of the measurement procedure. Procedures include use controls and
calibration steps to minimize random and systematic errors. When possible, procedures provide
the required precision, minimum artifact contamination, and the best recovery possible.
        To establish reliability of analytical measurements, data is obtained on detection limits,
accuracy, precision and recovery. Precision accuracy and detection limits for all methods used in
the laboratory is comparable to values referenced in Standard Methods 17th Edition, 1989 and
EPA Methods for Chemical Analysis of Water and Wastes, March 1983.

                      CALIBRATION PROCEDURES AND FREQUENCY

Calibration is the process for determining the correctness of the assigned values of the physical
standards used or the scales of the measuring instruments. Calibration accuracy is critically
dependent on the reliability of the standards used for the required intercomparisons. Only the
highest quality chemicals are used to provide necessary standard solutions, and due care is
exercised in their preparation. The concentrations of the calibration standards bracket the
expected concentration of the analyte in the samples. No data is reported beyond the range of
calibration of the methodology. The calibration data, when plotted graphically, is referred to as a
calibration curve. The calibration must be done under the same instrumental and chemical
conditions as those that will exist during the measurement process. The frequency of calibration
depends on the accuracy requirements of the investigation and the stability of the instrument used
for the measurements:
1. Atomic Absorption Spectrophotometers - Two approaches are used to calibrate atomic
absorption spectrophotometers. These methods are direct comparison and standard additions.
    a) Direct comparison is the simple approach, and can be used with many instruments to give
        a direct readout of the concentration of an element in an unknown sample. To obtain good
        precision (e.g., 1-2% coefficient of variation), the absorbence levels measured must be
        about 0.1 to 0.6 units. An integration interval of about 2 seconds is used. Standard and
        sample solutions should be similar in bulk matrix constituents, particularly acid and salt
        content. Interference suppressants are used in all solutions when required. A number of
        standards (usually three to five in increasing concentration) as well as a blank, are
        prepared to cover the concentration range. These solutions are run in absorbence to check
        linearity of the calibration curve. It is not sufficient to read the standard only once during
        a run. For best accuracy, one of the standards should be run at least three times over a set
        of 25 samples.
    b) The method of standard additions is used when samples contain a low concentration of
        analyte. In this case it is possible to add small amounts of conventional standard


                                                                                                   29
        solutions, in increasing amounts, to aliquots of each sample. A calibration graph can then
        be constructed. This method will often be used in work with the graphite furnace.
2. UV-VIS Spectophotomoter - The calibration procedure for the UV-VIS spectrophotometer is
similar to that for the A.A. spectrophotometers. An integration interval is not required as the
signal is very stable. It is important to use blanks and allow at least 1/2 hour warm up time.
3. pH Meters - The proper calibration of pH meters requires the use of two buffer solutions and a
thermometer. The two buffer solutions must cover the expected range of samples to be tested.
The pH meter should be calibrated each day. The temperature of the buffers must be entered into
the meter.
4. Conductivity Meter - The conductivity meter does not require frequent calibration but should
be checked against a known standard each day of use. Recalibrate when there is significant
deviation with the value of the standard.

                      ASSESSMENT OF PRECISION AND ACCURACY

        The laboratory's quality assessment techniques will be used to maintain the precision and
accuracy of all laboratory analyses within a state of statistical control.
        Precision and accuracy measurements are the best way to assess analytical performance.
Precision is the degree of reproducibility of a particular analytical procedure. Accuracy is a
measure of the agreement between an experimental determination and the true value.

PRECISION - Assess precision by replicate analysis, by repeated analysis of a stable standard, or
by analysis of known additions to samples. Precision is specified by the standard deviation of the
results. The formula for determining standard deviation (SD) is:

                                    SD = [ (xi-X) 2 /(n-1)]½

   xi is the value of the individual measurements; X is the mean of all measurements for a given
sample and n is the number of measurements.
The purpose of determining precision is to establish the typical variance of the method in the
absence of any matrix influence. In the course of determining precision, there are two cases that
indicate there is a problem with the precision data:

1. The measured values show wide variation from one to another for a given day.
2. The measured values show little variance from one to another for a given day, but the mean
and standard deviation show wide variation from one day to another.
If either of the above occurs, factors such as sample homogeneity, instrument calibration, or
analyst error should be checked, documented, and corrected. The precision measurements should
then be repeated.

ACCURACY The best method to determine accuracy is to spike an aliquot of reagent water with
a known amount of the constituent being measured and analyze the sample. The amount spiked
should be at least five to ten times greater than the analytical detection limit.




                                                                                                30
To evaluate the data accuracy, the percent recovery of the spike must be determined. The formula
for determining percent recovery is:

                                   % recovery =[(S-S1)*100]/S2

    Where S is the concentration of the spiked sample; S1 is the concentration of the unspiked
sample; S2 is the concentration of the spike added to the sample.
If the percent recovery deviates significantly from 100% and the method has not demonstrated
significant bias, the problem must be detected and corrected prior to continuing the analysis.
Sources of this problem include incorrect standard or spike solution concentration or a problem
in the procedural detection system.
CONTROL LIMITS - Once precision and accuracy data have been established, the data can be
used to determine control limits for the laboratory. The established limits are considered to be
threshold limit or limits that, if not met, indicate that the laboratories minimum precision and
accuracy performance standards are not being met.
The laboratory uses a means chart on X control chart with warning and control limits and a range
chart with upper warning and control limits.
The data should fall within the warning limits 95% of the time and within the control limits 99%
of the time. The following diagram illustrates typical control charts to be used in the laboratory.
A more in-depth analysis for the interpretation of the control charts can be found in the book,
Standard Methods For the Examination of Water and Wastewater, 17th Edition, 1989 Section
1020a.

                                     CORRECTIVE ACTION

Corrective action is required when data is outside of predetermined limits for acceptability. The
corrective actions can be triggered by the following QA activities: Control Chart analysis;
proficiency evaluation testing; and QA audits.

                                CONTROL CHART ANALYSIS:

Control Limits (CL) - An analysis is said to be out of control when data is above or below
previously established control limits (CL) usually 3 standard deviations. If one measurement
exceeds a control limit, repeat the analysis immediately. If the repeat and measurements within
the control limit, continue analysis; if it exceeds the CL, discontinue analysis and correct the
problem.
Warning Limit (WL) - The WL is defined as 2 standard deviations. If two out of three successive
points exceed a WL, analyze another sample. If the next point is less than the W-L, continue
analysis; if the next point exceed the WL, discontinue analysis and correct the problem.
Standard Deviation (SD) - If four out of five successive points exceed 1 S, or are in decreasing or
increasing order, analyze another sample. If the next point is less than 1 SD, or changes the order,
continue the analysis; otherwise, discontinue analysis and correct the problem. The above applies
when the values are either above or below the central line, but not on both sides, e.g., four of five
values must exceed either + 1 SD or -1 SD. After correcting the problem, reanalyze half the
samples analyzed between the last in-control measurement and the out of control measurement.


                                                                                                  31
Central Line - If six successive samples are above the central line, analyze another sample. If the
next point is below the central line, continue analysis; if the next point is on the same side,
discontinue analysis and correct the problem.

                          PERFORMANCE EVALUATION TESTING:

Performance evaluations will be conducted on a quarterly basis. Results of performance
evaluations for each measurement parameter will also be used as a signal for corrective action.

                               QUALITY ASSURANCE AUDIT:

The quality assurance program will be audited at least annually and any deviations from the
program will signal corrective action to be taken. Quality assurance audit will be documented in
a written report.
The Public Health Chemist will be responsible for initiating and documenting any corrective
action necessary. Corrective action will be documented on the appropriate control chart,
performance evaluation report, or QA audit report. No data shall be reported until the cause of
the problem is located and corrected or the laboratory demonstrates the cause was a random
event and no longer affects data. Although the elimination of events requiring corrective action
may not be achieved, a reduction in the repetition of these events is the objective of this program.

                           PERFORMANCE AND SYSTEM AUDITS

The Laboratory Director, Public Health Chemist and Senior Public Health Microbiologist will
meet annually to conduct a quality assurance audit. The audit would include the following:
1. Standards book kept up to date showing data on all work required by the QA program.
2. Results of proficiency sample tests.
3. Evidence of the systematic use of control samples, replicate measurements and reference
materials all in conjunction with control charts.
4. Proper labeling of reagents and samples.
5. Use of approved methods.
6. Results on blind samples.
7. Acceptable safety equipment and procedures.
8. Quality assurance reports generated on a regular basis.
9. Documentation on equipment performance and maintenance.
10. Training records.
11. All relevant files accessible and organized.
12. Laboratory personnel following good laboratory practices.
13. Laboratory personnel following good measurement practices


                 REFERENCES FOR QUALITY ASSURANCE DOCUMENT

1. Standard Method for the Examination of Water and Wastewater, 17 edition, 1989.




                                                                                                  32
2. Handbook for Analytical Quality Control in water and Wastewater Laboratories. EPA-600/4-
       79-019, March 1979, USEPA.
3. Manuals for the Certification of Laboratories Analyzing Drinking Water criteria and
       Procedures/Quality Assurance. EPA QAMS-005/80, Interim Guidelines, EPA-570/9-82-
       009, USEPA.
4. Methods for Chemical Analysis for water and Waste. EPA-600/4-79-020, March 1979.




Written by: Gerry Guibert & David Holland
         Date: May 1993

        Approved by: -
   (Laboratory Director's Signature)




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