Exercise: Water Wells & Lithology

1. With generous support from: Exercise: Water Wells & Lithology Exercise created by Niah Venable, Amanda Walega and Susan Grammer with web content by Niah Venable A special thanks to 8th grade teacher Becky Dalecki, Portage North Middle School and to the 8th grade science teachers and students at Mattawan Middle School. Brought to you by Core Kids, WMU-MGRRE Geosciences K-12 Outreach Program

2. This exercise can be adapted for: • High school students wishing to do an independent project using real data from their local area. • Middle school students whose teachers can lead them through accessing data and constructing stratigraphic columns as a class according to the instructions on this website. • Later elementary students who can use this exercise to visualize what is underground in their area.

3. Exercise Steps 1. Choose an area of interest (e.g. Charlotte, MI) 2. Find the corresponding topographic map 3. Find water well data from the area of interest 4. Interpret water well driller’s logs 5. Create lithologic columns 6. Calculate the Well Elevation 7. Create stratigraphic columns 8. Create cross-sections for comparison

4. 1. Pick an Area of Interest • For this example we will look at water wells around Charlotte, MI. • Charlotte is located in Eaton County. • First we need to get a topographic map of the area near Charlotte. This map will give us political and landform information such as section numbers and elevation contours for use in this project.

5. Browse to the State of Michigan, Department of Natural Resources homepage: www.michigan.gov/dnr From there browse to Publications and Maps, then Online Maps. Go to Topographic Quadrangles by Location. Use the dropdown list to find the county, in this case it is Eaton. A quick link to this page is: www.michigan.gov/dnr/1,1607,7-153-10371_14793-31264--,00.html Click Download. 2. Find a Topo Map

6. The next screen shows a green and yellow version of a political map with the locations of cities and towns with a blue grid overlay of the quadrangle names. Click on the quad labeled “Charlotte” in Eaton and Carmel townships. 2. Find a Topo Map cont.

7. A pdf of the Charlotte quadrangle will open in Adobe Acrobat. We can save this and use as-is or copy and zoom to a portion of the map using MS Word or image handling software. 2. Find a Topo Map cont.

8. Browse to the State of Michigan, Department of Environmental Quality homepage: www.michigan.gov/deq From there click Water, then browse to Drinking Water, to Water Well Construction, then click on Scanned Water Well Record Retrieval System. A quick link to this page is: www.deq.state.mi.us/well-logs/ 3. Find Water Well Data

9. The information used to find the topo and the map itself provide the county, township and section data we need to search the well retrieval database. We are interested in Eaton County so two searches need to be done by township, one for Eaton in sections 6, 18 and 19; and one for Carmel in sections 12, 13, and 24. We will omit section 7 of Eaton township, due to an absence of usable logs. 3. Find Water Well Data cont.

10. After selecting the county, township(s) and section(s) of interest, we will be able to review a pdf file containing the scanned images of driller’s reports from each area. The pdf driller’s reports or logs will look like this. The number of logs available for each section varies. 3. Find Water Well Data cont.

11. The driller’s log header contains well location information and often a hand-drawn map with street names, which may prove useful if the quarter-quarter location information is not recorded, or recorded incorrectly. 4. Interpreting Driller’s Logs

12. The driller’s log lithology information is listed by type of material, thickness of each unit, and total depth. The formation descriptions are more likely to be generic than scientific. The total drilled depth of this well is 100 feet below the surface. 4. Interpreting Driller’s Logs cont.

13. Other information provided by the driller’s log is the owner of the well, the depth, the completion date and how the well was completed. It will also list possible sources of contamination, pump type, and who drilled the well. The static water level is equal to the depth to the water table, in this case it was encountered 36 feet below the surface. 4. Interpreting Driller’s Logs cont.

14. Lithologic or stratigraphic columns can be created from driller’s logs using the formation descriptions provided by the driller and the depths to and the thicknesses of each unit. 5. Creating Lithologic Columns • From 0-12 feet below the surface the driller encountered clay. • From 12 to 16 feet below the surface they found sand. • From 16 to 54 feet below the surface they found clay. • From 54 to 60 feet below was gravel. • From 60 to 100 feet below the surface they found “sandrock”, most likely the sandstones of the Saginaw Aquifer.

15. 5. Creating Lithologic Columns cont. • A basic form created in Excel is useful for plotting lithogy and other well information for viewing as a lithologic or stratigraphic column. • The lithologic key can be modified depending on the type of earth material encountered in the wells.

16. 5. Creating Lithologic Columns cont. • Using the driller’s log depths below the surface as a guide, we plot the lithologic types on the column with the lithologic key patterns and colors as fill. • Next, we mark the water level on the column using the symbol from the key. Hammond

17. To calculate the well elevation values in feet above sea level and to convert the lithogic column to a stratigraphic column, we must first determine the well surface elevation. This is done using a topographic map since most of the driller’s reports do not provide well elevations. 6. Calculate the Well Elevation

18. Using the topo map of Charlotte and the location information provided in the driller’s report we find that the example well is located here. Contour lines in this area range between 910 feet and 920 feet above sea level. Interpolating the location between the two contours gives us a value of 918 feet above sea level. 6. Calculate the Well Elevation cont.

19. 6. Calculate the Well Elevation cont. • We record the well elevation in the blank to the right. And then place the value on the top line of the scale on the right side of the lithology column. • Next we subtract the depths in ten foot increments from the elevation value until the bottom of the well is reached.

20. 7. Create Multiple Strat Columns • To compare the hydrogeology from several wells around the Charlotte area we must create more stratigraphic columns. • Repeat steps 3 through 6 to create these columns. • For this example we will use driller’s logs from Eaton township, sections 18 and 19, and Carmel township, sections 12, 13, and 24. • We will mark the locations of all the wells on the topo map for reference.

21. All of the wells are now marked on the topographic map for reference. Well elevation values have been picked from the map and used to convert the lithologic columns to stratigraphic columns. Burt City Hammond Mishler Porter Archer 7. Multiple Strat Columns cont.

22. 7. Multiple Strat Columns cont. • Well Name and Elevation Range: Hammond: 918-818 ft. Burt: 890-790 ft. City: 912-872 ft. Archer: 895-775 ft. Porter: 900-800 ft. Mischler: 945-835 ft. • The depth datum should be 880 feet above sea level since all wells intersect that depth. • Once the stratigraphic columns are created, a depth datum is picked. • The depth datum is used to compare the lithology and water levels in all wells at corresponding depths.

23. 8. Cross-Section Creation B • The geographic area covered by the wells can be divided into two cross-sectional lines running approximately North to South • They are labeled A to A’ and B to B’. A A’ B’

24. 8. Cross–Section Creation cont. • The wells in each cross-section can be compared by lining them up on the datum value. 880 ft. A A’ ~ 1.5 mi. ~ 1 mi.

25. 8. Cross–Section Creation cont. • It is important to remember the distances between wells when making cross-sectional comparisons. 880 ft. B B’ ~ 2 mi. ~ 1.75 mi.

26. 9. Interpretation • The cross-sections combined with the well locations on the topo map give a spatial comparison of the earth materials encountered at depth and how those materials vary over a distance between wells. • The wells are about 1 to 2 miles apart and the relief between the highest and lowest wells is 55 feet. Static water levels range between a max elevation just under 900 ft. to just over 875 ft.

27. 9. Interpretation cont. • The glacial sediments found above the sandstone and shale bedrock in this area show variation in type and thickness from well to well, which is typical of these kinds of materials. • Generally though, the glacial deposits in the A-A’ wells consist of clay and gravels, while the deposits in the B-B’ wells are mainly sand and clay.

28. 9. Interpretation cont. • The Charlotte wells show no significant variation in static water levels. Dramatic variations in static water levels could be due to draw down effects in heavy-use areas. • The sandstone and shale bedrock elevations vary by 60 ft for all wells, but for each cross section, the variation is between 25-45 feet.

29. 10. Summary • Topographic maps and water well driller’s logs can be used to examine the near-surface geology of Michigan. • The driller’s logs are also useful for determining depth to the water table, potential nearby contamination hazards, and other information. • The data needed for these exercises is readily available on the internet from State of Michigan sources.