California State University, Sacramento
Week 1: Site safety, groundwater levels, groundwater gradient, field sampling and field parameters
Upon completion of this unit students should be able to:
Develop a site safety plan
Measure water levels to within 0.01 ft
Solve a 3-point problem to determine groundwater gradient
Estimate groundwater flow velocity based on groundwater gradient and sediment type
Calibrate and maintain common field meters used to measure groundwater and surface water field parameters: dissolved oxygen, pH, specific conductance, temperature and turbidity
Use a flow-through cell to measure groundwater parameters
Differentiate between water-bearing intervals using field parameters
Reading for week 1:
USGS Water Resources Division standard methods: U.S. Geological Survey, variously dated, National field manual for the collection of water-quality data: U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, chaps. A1-A9.
accessed on line at http://pubs.water.usgs.gov/twri9A/, July 2012
Ch. 9 Safety in the field
Ch. 6.1 Temperature measurement
Ch. 6.2 Dissolved oxygen measurement
Ch. 6.4 pH measurement
Ch. 6.7 Turbidity measurement
Fetter, 4th ed., pp. 107- 108 (vertical gradient)
Fetter, 4th ed., pp. 113 - 125 (hydraulic head and seepage velocity)
Measure groundwater levels in 6 monitoring wells and 2 extraction wells
Complete the worksheet that shows how to solve a 3-point problem for groundwater gradient and flow direction
Discuss average linear flow velocity, including estimates of sediment porosity
Measure the distance between wells
3-point problem worksheet (extra copy)
Calibrate D.O., E.C., pH and turbidity meters
Measure field parameters in a shallow and deep wells
Record data on field data sheets for distribution to the class
Field data sheet (extra copy)
Assignment for week 1:
Develop a site safety plan and work plan for Saturday's field exercise.
Include a cover page with your company logo. Include activities, expected hazards, site information, contact information, and important telephone numbers. The site safety plan/work plan should be 2 pages or less (cover page is extra), and parts of the plan may be in outline or list form.
Due date: Saturday, July 28
Additional Assignment for week 1:
Answer these questions in 5 pages or less (cover letter to the client and figures are extra, and may go beyond 5 pages). Please double space your report, with normal margins and standard font (times or arial). Refer to all figures in the text. Citations are optional.
Are the 50' and 200' deep wells on the CSUS campus completed in the same water-bearing interval? Use evidence from field parameters that we collected in Saturday's lab.
What is the direction and velocity of groundwater flow in the arboretum area? If the shallow and deep aquifers are different, include a brief analysis of each.
Calculate the horizontal gradient for each water-bearing interval. Use your flow map, and calculate the gradient in the direction of maximum dip.
Calculate the vertical gradient using a paired cluster of shallow and deep wells. What does this indicate?
Given a porosity of 15% and a hydraulic conductivity of 45 ft/d, what is the average linear flow velocity in the shallow water bearing interval?
Given a porosity of 25% and a hydraulic conductivity of 220 ft/d, what is the average linear flow velocity in the deeper water bearing interval?
Discuss the issue of wellhead protection, given these flow velocities. How long would it take a contaminant to travel 200 ft in each water bearing interval?
Use appropriate technical writing style, and include the following sections in your report:
Cover page (letter to the client) from your consulting company: You can pretend that CSUS is the client, and address the letter to me (Tim Horner, CSUS Geology Dept.)
Introduction and purpose
Hydrogeologic setting: geologic, hydrologic, land use, construction, hazards, etc. as appropriate.
Methods: field methods, laboratory methods, graphical methods, statistical methods as appropriate.
Results: summarize results.
Conclusions and recommendations
Due date: Saturday, Aug. 4
Field data sheets from each well will be posted below:
In class this week, Herkey the Hornet will lecture about average linear flow velocity.