next up previous contents
Next: Groundwater Characterization (Lab 4) Up: Water Quality Measurements (Lab Previous: Lab-3 Activities


Lab-3 Field Procedure

  1. Collect Reconaissance Sample
    1. using sample bottle, bucket, or long-handled sampler collect 200-500 ml sample
    2. place in 500 ml amber glass bottle, cap the bottle, bring to analysis table
  2. Perform the following tasks in any order (but start with bacteria, since it must sit for 20 minutes). If you find yourself waiting for a piece of equipment, try to start on one of the other tasks
    1. Prepare filtered split, to be used for nitrate measurement. Follow filtering procedure
    2. measure pH (follow pH-meter procedure)
    3. measure D.O., electrical conductivity, and salinity (follow D.O. meter procedure)
    4. Measure Turbidity, follow the turbidity measurement procedure
    5. Measure Nitrate Content, follow measurement procedure
    6. Measure basic water quality, follow measurement procedure

Lab-3 Comparative Results

Historical analyses from Prairie Creek near Plano Road (Table 4.3.1) and from the class groups (Table 4.3.1) are available for comparison. For conversion: ppm $\approx$ mg/l for low-salinity water; low-salinity water at 26 ${\rm ^\circ C }$ contains $\sim$8.1 mg/l dissolved oxygen at saturation; at 15 ${\rm ^\circ C }$ saturated D.O content is $\sim$10.1 mg/l. See also online bottled water analyses and City of Dallas tapwater analyses .

Table 4.1: Creek water chemical analyses from Prairie Creek near Plano Road (1998 data).
Component Units March April May June July August
Conductivity   600 420 510 500 460 480
pH   8.1 8.2 8.3 7.8 8.3 8.4
Turbidity NTU 3.11 3.45 2.08 2.37 2.78 1.97
D.O. mg/l 16.8 10.9 5.4 13.9 7.2 6.2
Nitrate ppm 1.82 1.21 0.95 0.7 0.34 0.14
Water Temp. $^o$F 64 58 75 80 88 82

Table 4.2: Class water chemistry results, Spring Creek at Plano Rd., Sept. 26th 1998.
Component Units A B C
Conductivity   264.8 4564.1 234.0
pH   8.21 8.17 8.07
Turbidity NTU 1.49 1.63 2.97
D.O. % sat 45.2, 50.1 52 39
Nitrate ppm 1.7 1.9 2.0
Water Temp. ${\rm ^\circ C }$ 27.2 27.2 26.7
Salinity ppt   0.2  

Table 4.3: Selected water quality parameters for local treated water.
Parameter $\rightarrow$ Hardness Alkalinity Turbidity Salinity pH
Units $\rightarrow$ ppm ppm NTU ppm -
City of Dallas water 98 53 0.3 180  
Private Swimming Pool 1000 180 0.4 1200 7.07

Lab-3 Instructions for Discussion

Discuss your own group's results, including any significant potential sources of error. Compare your results to those of the other groups, and try to explain any differences. Compare your results to the ``historical'' data and discuss why the stream chemistry changes with time (season).

Lab-3 Makeup Lab

For those who missed the field portion of this lab, do the following.

  1. write the introduction-procedures portion of you notebook entry for this lab
    1. write a procedures section. This will be difficult, since you weren't at the field lab. See the Parameters to be Measured for a description of the measurements made.
    2. Chapter 9 of the textbook (``Field Geochemical Measurements'' section describes the general approach, see also the detailed procedures sections above.
  2. Reference the Comparative Results, pretend you were a member of one of the three groups (A-C) and analyze their data for your Discussion section.
  3. Turn you lab notebook copies in at the beginning of the next lab

next up previous contents
Next: Groundwater Characterization (Lab 4) Up: Water Quality Measurements (Lab Previous: Lab-3 Activities
GEOS 3110 Professor's Notes, Summer 2007
Dr. T. Brikowski, U. Texas-Dallas. All rights reserved.