8^th Grade Groundwater Study

8^th grade earth science students the Breck School are currently engaged in two long-term projects: 1) Monitoring well-water levels in the observation well through the school year to look at long-term trends. 2) Students participate in two pumping tests each year. This work has become a long-term study in which all 8^th grade students participate each year (Figure 1).

As a result of receiving a NSTA Toyota Tapestry Grant, we installed two observation wells (shallow well is 19 ft deep into the glacial aquifer and the deep observation well and water-supply well are about 400 feet deep into the a bed-rock Jordan aquifer). We also installed ten piezometers at 1-15 feet depths and retrofitted an existing pumping well on school grounds to monitor water levels.

Figure 1 Installation of two observation wells on campus

Throughout the school year, students monitoring well-water levels in the observation well through the school year to look for long-term trends (Table 1).

Table 1. One year of student-derived measurements from the static water levels for the Breck School observation wells.

OBS-1 = shallow well, 19 feet deep, screened in the glacial aquifer.

OBS-2 = deep well, 390 feet deep, open hole in the Jordan sandstone aquifer

Date	OBS -	1 Obs - 2
Oct. 1	14.1	34.75
Oct. 11	13.75	31.8
oct. 15	13.6	29.3
oct. 22	13.5	29.5
oct. 29	13.3	29.6
nov. 15	13.21	28.5
nov. 18	13.4	24.35
dec. 3	14.6	31.6
apr. 7	13.32	29.56
apr. 8	13.35	30.44
apr. 9	13.31	30.9
apr. 10	13.29	31.3
apr. 14	13.32	32.8
apr. 15	13.4	33
apr. 16	13.8	33.6
apr. 17	13.15	31.9
apr. 21	13.15	26.85
apr. 22	13.25	30.5
apr. 23	13.9	32.3
apr. 24	13.2	30.9
apr. 25	13.15	31.2
apr. 28	13.25	33.2
apr. 29	13.3	34.4
apr. 30	13.3	34.3
may. 1	13.3	34.3
may. 5	13.35	34.6
may. 6	13.4	32.32
may. 7	13.4	34
may. 8	13.5	34.9

Figure 2. Students participating the in groundwater project

Figure 2a. This is the pumping well. It was installed with the school was first constructed in the 1960s. It is between 370-400 feet deep.	Figure 2b. The students are at the deep well, which is 390 feet deep. The shallow well had no drawdown. The deep well had over 21 feet of drawdown in 24 hours.
Figure 2c. Students are determining the pumping rate at the discharge site.	Figure 2d. The students are taking a water-level reading with a solinist and recording the reading. The boy in the back is watching the clock telling the others when to take the readings.

Students access well logs from the 1950s from the Minnesota Geological Survey, which they use to determine elevation, static water level, and depth of wells around our school. Students then use USGS quadrangle maps to plot location of the wells using the legal description pf the township range section down to four quarter sections (Figure 3).

Figure 3. One student’s plot of the well locations in our township range

Students study core samples from the drilling into our shallow and deep-water aquifers, and they use MN Geological Survey well logs within a two-mile radius of school to create a cross-sectional model over a two miles slice though our school’s area (Figure 4). Students then locate Breck’s well on their maps to determine the geology of our campus and make their own well logs (Figure 5).

Figure 4. One student-created geologic cross-section

Figure 5. One student’s well log

Students then compare their well logs to the well logs that the drillers made when they put in our wells (Figure 6). Students use the logs to determine the aquifer from which water is obtained and talk about well construction. We then pump one well for 24 hours at 60 gallons/minute and monitor water levels in the two observations wells that are 50 feet from the pumping well.

Figure 6. Student-developed comparison to driller’s well log

Students collect water-level measurements and plot drawdown versus time and water-level recovery measurements (Figure 7).

Figure 7. Student graphs of drawdown and water-level recovery

The pumping tests have enabled students to determine how much water will have to be pumped out of the aquifer to lower the water table. And, the current recommendation for our surface-water problem is to pump the surficial aquifer. While this solution may make our make our athletic fields drier, this solution could impact the deep aquifer that is used by local communities for drinking water. With continual monitoring, students will be able to collaborate with school engineers as they make decisions on water-elimination.

Beyond the surface-water problem that the students are addressing, discussions that the project generates are a key component for the environmental focus in our curriculum. Because we are pumping 60 gal/min, students are worried that we are wasting so much crystal-clear water during pumping tests. So, students discuss how cities pumping 600 gal/min per well with many wells pumping, identifying critical uses of water by cities versus non-critical uses, such as water lawns, golf courses, pools, fountains. The students also get into water distribution, investigating how water gets from the well to the tap. They are fascinated by how the water moves through the pipes from the water tower to household tap by gravity. They also have looked at water treatment plants and ethics of adding chemicals to water.