USGS Water-Year Summary 2025

433243092260602 STR2-2 South Drained Site Transect 2

Sand and gravel aquifers (glaciated regions)
Pleistocene Series

LOCATION - Lat 43°32'43.38", long 92°26'06.04" referenced to North American Datum of 1983, in SW 1/4 SE 1/4 sec.18, T.101 N., R.13 W., Fillmore County, MN, Hydrologic Unit 07060002, The piezometer is located approximately 4.25 miles NE of LeRoy, MN. The piezometer is located approximately 0.4 miles northwest of the intersection of 130th street and County Rd. 109 (111th Ave).

GROUNDWATER RECORDS

WELL CHARACTERISTICS - Depth 9.95 ft. Upper casing diameter 1.59 in; top of first opening 4.9 ft, bottom of last opening 9.38 ft. Piezometer STR2-2 was installed using several sections of 3.25-inch-diameter Geoprobe rods to a depth of 10.0 feet. The piezometer is constructed of a 4.48-feet-long, 1.5-inch-diameter, schedule-40 PVC, 0.010-inch slotted Hole Products Inc. well screen, flush threaded to length/s of 5.00 feet of 1.5-inch-diameter, schedule-40 PVC well casing. The piezometer casing measuring point (stickup) was 2.10 feet (1286.85 ft. NAVD88, +/- 0.02 ft.) above land surface when measured on 17 November 2016. The open interval of the piezometer is between 4.90 and 9.38 feet below land surface and the total well depth is 9.95 feet below land surface.

This piezometer is screened in glacial till/clay sediment, which is overlies bedrock.

DATUM - Land-surface datum is 1,284.75 ft above North American Vertical Datum of 1988. Measuring point: Black mark on top of 1.59-inch diameter PVC well casing, 2.10 ft above land-surface datum, Nov. 17, 2016 to present. The measuring point is a black mark on the top of the white PVC 1.59-inch diameter well casing, which was 2.10 feet above land surface on 17 November 2016. Elevation of the measuring point is 1286.85 plus-or-minus 0.02 feet above sea level, North American Vertical Datum of 1988, based on differential GPS survey on 27 March 2017.

PERIOD OF RECORD - Water levels were recorded periodically from 27 February 2017 to 31 October 2018. Water levels were recorded quarter-hourly from 02 March 2017 at 12:45 CST to 01 November 2017 at 08:15 CDT.

GAGE -

Continuous water level and water temperature are currently measured with a new Solinst Model 3001 Levelogger non-vented pressure transducer from 02 March 2017 at 12:45 CST to 09 April 2018 at 15:45 CDT. These data are recorded quarter-hourly by the Solinst Model 3001 Levelogger pressure transducer, which has an internal data logger built into it. The data logger is housed inside the 1.5-inch PVC well casing. The piezometer has a slip-on PVC cap and no pad lock. The gage was powered by an internal pressure transducer battery. A Solinst Model 3001 Barologger Edge atmospheric barometer is also installed (hanging) in nearby piezometer STR2-3A. These barometric pressure data are used to post-process/correct the non-vented pressure transducer data. Data are downloaded manually and no telemetry or phone line is wired into the gage.

Continuous water level and water temperature data measured during 01 November 2018 at 08:30 CDT to 09 April 2018 at 15:45 CDT were discontinued and not published for the purpose of this study.

COOPERATION - This site was operated (2016-2018) by the U.S. Geological Survey as a monitoring piezometer for the Southeast Minnesota Subsurface Drainage Impacts on Groundwater Recharge study. The piezometer began to be used as part of the Southeast Minnesota Subsurface Drainage Impacts on Groundwater Recharge study during 17 Nov. 2016 to 31 Oct. 2018. The GW Drainage Recharge study is a collaborative effort between the Environment and Natural Resources Trust Fund (via Legislative-Citizen Commission on Minnesota Resources (LCCMR)) and the U.S. Geological Survey.

REMARKS - Continuous water levels are measured with a sealed (non-vented) pressure transducer. Transducer water-levels are compensated for barometric-pressure variations the record of a nearby barometric-pressure sensor located at site STR2-3A. The water-level record is linearly corrected to calibration water levels twice per year (Spring & Fall). Calibration water levels are measured with electric or steel tapes that are themselves calibrated about every 3 years.

Water levels below land surface appear accurate to about ±0.10 feet during 02 March 2017 to 01 November 2017 based on short-term water-level variability and calibration corrections of the water level record. Sequential water-level differences are accurate to ±0.01 feet based on manufacture specifications. However, the entire water-level record contains cyclic artifacts of the barometric pressure that remain after raw water levels from the unvented pressure transducer are corrected with the barometric pressure record.  These artifacts, which are not real water level changes, are circum-daily in period and have an amplitude of about 0.02 to 0.05 feet.  Additionally, the water-level record is biased depending on where in the barometric-artifact cycle calibration corrections are made.  The direction of this bias is unknown, but the amount is less than or equal to the amplitude that of the artifact cycle.

Water elevation above North American Vertical Datum of 1988 (sea level) is calculated by subtracting water level (below land-surface datum) from land-surface elevation. Land-surface elevation is accurate to plus-or-minus 0.02 feet based on a differential GPS survey on 27 March 2017.  Water elevation accuracy is the sum of the water level (below land-surface datum) and land-surface elevation accuracy, or about ±0.12 feet.

WATER-QUALITY RECORDS

WELL CHARACTERISTICS - Depth 9.95 ft. Upper casing diameter 1.59 in; top of first opening 4.9 ft, bottom of last opening 9.38 ft. Piezometer STR2-2 was installed using several sections of 3.25-inch-diameter Geoprobe rods to a depth of 10.0 feet. The piezometer is constructed of a 4.48-feet-long, 1.5-inch-diameter, schedule-40 PVC, 0.010-inch slotted Hole Products Inc. well screen, flush threaded to length/s of 5.00 feet of 1.5-inch-diameter, schedule-40 PVC well casing. The piezometer casing measuring point (stickup) was 2.10 feet (1286.85 ft. NAVD88, +/- 0.02 ft.) above land surface when measured on 17 November 2016. The open interval of the piezometer is between 4.90 and 9.38 feet below land surface and the total well depth is 9.95 feet below land surface.

This piezometer is screened in glacial till/clay sediment, which is overlies bedrock.

DATUM - Land-surface datum is 1,284.75 ft above North American Vertical Datum of 1988. Measuring point: Black mark on top of 1.59-inch diameter PVC well casing, 2.10 ft above land-surface datum, Nov. 17, 2016 to present. The measuring point is a black mark on the top of the white PVC 1.59-inch diameter well casing, which was 2.10 feet above land surface on 17 November 2016. Elevation of the measuring point is 1286.85 plus-or-minus 0.02 feet above sea level, North American Vertical Datum of 1988, based on differential GPS survey on 27 March 2017.

PERIOD OF RECORD - Water temperatures were recorded quarter-hourly from 02 March 2017 at 12:45 CST to 01 November 2017 at 08:15 CDT.

COOPERATION - This site was operated (2016-2018) by the U.S. Geological Survey as a monitoring piezometer for the Southeast Minnesota Subsurface Drainage Impacts on Groundwater Recharge study. The piezometer began to be used as part of the Southeast Minnesota Subsurface Drainage Impacts on Groundwater Recharge study during 17 Nov. 2016 to 31 Oct. 2018. The GW Drainage Recharge study is a collaborative effort between the Environment and Natural Resources Trust Fund (via Legislative-Citizen Commission on Minnesota Resources (LCCMR)) and the U.S. Geological Survey.

INSTRUMENTATION - Water temperature are measured with an Solinst Levelogger 3001 submersible pressure transducer accurate to +/- 0.1°C. Temperature differences are accurate to 0.1°C.