Frac sand mining in WisconsinFocus on groundwater…

Madeline Gotkowitz, Mike Parsen

• Wisconsin Geological & Natural History Survey

• Groundwater, wells and streams

• Industrial sand mining and groundwater

Topics

Wisconsin Geological Survey

Where does groundwater come from?

Recharge occurs everywhere on the landscape, not just the uplands…

Pumping lowers the water table

The well causes a cone of depression and reduces discharge somewhere…

Pumping can sometimes change the direction of groundwater flow

Source: Alley, Reilly, and Franke, USGS Circular 1186 (1999)

The water table responds to the weather

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1949 1958 1968 1978 1988 1998

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OU-326Slope of line is 3 feet per year

Over‐pumping can lower the water table

Fox River Valley (3 ft/yr)

300

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1940 1949 1959 1969 1979 1989 1999

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Racine County

Kenosha CountySlope of line is 7 feet /year

Milwaukee County

Waukesha County

Southeast Wisconsin (7 ft/yr)

USGS Circular 1139 (1998)

Groundwater discharge is easy to see in Wisconsin

Aquifers can be stacked on top of each other, and may be “confined” or “unconfined”

Sand mining process1.Removal of cover (vegetation, soil, undesirable rock)

Chippewa County, WI

Are mining operations above or below the groundwater table?

Sand mining process2. Extraction of sand (excavation, dredging)

Groundwater and recycled water are used to move sand at this site

Crusher

Washer

Sand mining process3. Sand crushed and rough screened

Photo: Chippewa Co.

Sand mining process4. Sand washed to remove fines (may use flocculants)

- Infiltration of water (recharge)- Some sites recycle water

better than others- Water for fugitive dust control

Sand mining process5. Processed sand is stored in piles

Sand mining process6. Drying of sand and further screening7. Sand transported to end user (train, truck, barge)

Photo: Google Maps

Photo: Chippewa Valley Newspapers

Sand mining process8. Reclamation of mine (may continue 30 years from now)

- Long-term impacts to recharge?- Future water users (irrigation,

development?)

Photo: WI DNR

• 2,000 – 3,000 gpm needed to wash sand (closed loop system) *

• 150 gpm of groundwater pumped to make up for water loss *– Evaporation– Infiltration– Trucked away with sand

Wash / sedimentation tanks

* Estimate based on 100,000 tons of sand production / month, from Chippewa County

Photo:Chippewa Co.

Hydrologic considerations

• A well in Wisconsin is “high-capacity if pumping > 70 gpm

• Typical municipal, industrial, or agriculture supply wells pump 100 - 1500 gpm

Hydrologic considerations

MunicipalityLocal Well #

WI. Unique Well #

Aquifer Type

2000 Average

Pump Rate (gpm)

Pump Capacity

(gpm)

Modeled Pump

Rates for Calibration

(gpm)

Modeled Pump Rates for ZOC

determinations (gpm)

Baraboo 7 AR322 Unlithif ied 523 1300 523 650Baraboo 2 BG928 Sandstone 229 650 229 325Baraboo 4 BG929 Sandstone 403 1100 403 550Baraboo 6 BG931 Sandstone 413 1000 413 500Baraboo 8 RX387 Sandstone not in use 1000 0 799

North Freedom 2 BG936 Sandstone 30 300 30 150Rock Springs 1 BG946 Sandstone 0.03 150 0.03 75

Ironton 1 EP387 Sandstone 13 550 13 275LaValle 1 BG932 Sandstone 26 182 26 91

Lake Delton 1 BG951 Sandstone 58 340 58 170Lake Delton 2 EJ765 Sandstone 114 450 114 225Lake Delton 3 EJ766 Sandstone 305 750 305 375Lake Delton 4 EJ767 Sandstone 132 600 132 300

Photos: WI DNR

• Surface water impacts– Overflow to neighboring

creeks and wetlands

– Water quality

Large overflow to wetlandsOverflow erosion

Photos: WI DNR

• Recharge– Infiltration ponds

– Reclamation conditions• Topography• Land use• Soil type

• Groundwater withdrawals– Impacts to neighboring wells

– Impacts to baseflow of creeks

Large overflow to wetlandsOverflow erosion

Infiltration ponds receive: Storm water and process water

• Wisconsin DNR regulates:– High capacity wells

– Surface water impacts

– Stormwater discharge

– Process water discharge– Reclamation plans

(County administered)

• Regulatory concerns:– Adverse impacts to sw

and gw quantity & quality– Contamination from

flocculants - acrylamides(used regularly in waste water treatment)

On-site washing facilityPhoto: Chippewa Co.

Sand pile with water infiltrationPhoto: Chippewa Co.

Hydrologic considerations

Source: The Groundwater Forum