USGS Water-Year Summary 2025

433245092254904 SUTR1-4 South Undrained Site Transect 1

Sand and gravel aquifers (glaciated regions)
Pleistocene Series

LOCATION - Lat 43°32'45.32", long 92°25'49.67" referenced to North American Datum of 1983, in SE 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).

REVISIONS HISTORY - On 07 Mar. 2019, it was discovered that all discrete and continuous water level data during 27 Feb. 2017 - 30 Oct. 2017 were inaccurate due to the first "non-dry" static water level being measured at this piezometer on 14 May 2018. This static water level was then used to prorate a correction during 16 Mar. 2017 to 14 May 2018 based on the "non-dry" static water level measurement on 14 May 2018. This correction was then continued until the end of the water level record, since no other "non-dry" static water level was measured during 15 May 2018 to 30 Oct. 2018. There are not enough "non-dry" static water level measurements during the entire water level period-of-record to accurately apply biannual instrument-drift corrections, as usual. This is the most accurate way of correcting this water level dataset, since the piezometer often goes dry. This water level correction method will satisfy the data quality for the Impact on Drainage Recharge study during this period.

GROUNDWATER RECORDS

WELL CHARACTERISTICS - Depth 9.31 ft. Upper casing diameter 1.59 in; top of first opening 4.4 ft, bottom of last opening 8.88 ft.

Piezometer SUTR1-4 was installed using several sections of 3.25-inch-diameter Geoprobe rods to a depth of 9.31 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 2.24 feet (1290.22 ft. NAVD 88, +/- 0.03 ft.) above land surface when measured on 02 November 2016. The open interval of the piezometer is between 4.40 and 8.88 feet below land surface and the total well depth is 9.31 feet below land surface.

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

This piezometer frequently goes dry due to being so shallow (bottom of well screen at 8.88 ft. BLS). This piezometer is also installed in an undrained agricultural field that has a loess unit, which is highly porous. Water levels are periodically recorded in this piezometer during snow melt, wet Spring conditions, or during heavy rainfall events.

DATUM - Land-surface datum is 1,287.98 ft above North American Vertical Datum of 1988. Measuring point: Black mark on top of 1.59-inch diameter PVC well casing, 2.24 ft above land-surface datum, Nov. 15, 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 2.24 feet above land surface on 15 November 2016. Elevation of the measuring point is 1290.22 plus-or-minus 0.03 feet above sea level, North American Vertical Datum of 1988, based on differential GPS survey on 16 March 2017.

PERIOD OF RECORD -

Water levels were recorded periodically from 27 February 2017 to 30 October 2018. Water levels were recorded quarter-hourly from 16 March 2017 at 10:00 CDT to 30 October 2018 at 12:30 CDT, except during the following periods:

11 Jan. 2018 at 03:30 CST - 13 Jan. 2018 at 11:00 CST: due to transducer recording inaccurate data, which was deleted from record.

22 Jan. 2018 at 05:45 CST - 26 Jan. 2018 at 05:15 CST: due to transducer recording inaccurate data, which was deleted from record.

20 Feb. 2018 at 06:00-20:45 CST: due to transducer recording inaccurate data, which was deleted from record.

23 Jan. 2018 at 00:15 CST - 24 Feb. 2018 at 13:45 CST: due to transducer recording inaccurate data, which was deleted from record.

GAGE - Continuous water level and water temperature were measured with a new Solinst Model 3001 Levelogger non-vented pressure transducer from 16 Mar. 2017 at 10:00 CDT to 30 Oct. 2018 at 12:30 CDT. These data were recorded quarter-hourly by the Solinst Model 3001 Levelogger pressure transducer, which had an internal data logger built into it. The data logger was 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 were used to post-process/correct the non-vented pressure transducer data. Data were downloaded manually and no telemetry or phone line were wired into the gage.

The pressure transducer and data logger were removed from the well on 30 Oct. 2018 at 12:30 CDT. Data collection for the Impacts on Drainage Recharge study have concluded and all data logging equipment have been removed from the site.

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 15 Nov. 2016 to 30 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 16 March 2017 to 30 October 2018 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 0.03 feet based on a differential GPS survey on 16 March 2017.  Water elevation accuracy is the sum of the water level (below land-surface datum) and land-surface elevation accuracy, or about ±0.13 feet.

This piezometer frequently goes dry due to being so shallow (bottom of well screen at 8.88 ft. BLS). This piezometer is also installed in an undrained agricultural field that has a loess unit, which is highly porous. Water levels are periodically recorded in this piezometer during snow melt, wet Spring conditions, or during heavy rainfall events.

Since this piezometer is usually dry during entire period-of-record, a manual calibration water level has not yet been able be measured to correct the recorded water level record against. Therefore, water level record has only be corrected by shifting all recorded water levels to be 'dry' (deleted) after they reach the bottom of a well screen elevation. Currently, the over-all accuracy of this entire water level period-of-record is assumed to be be ±0.2 feet.

WATER-QUALITY RECORDS

WELL CHARACTERISTICS - Depth 9.31 ft. Upper casing diameter 1.59 in; top of first opening 4.4 ft, bottom of last opening 8.88 ft.

Piezometer SUTR1-4 was installed using several sections of 3.25-inch-diameter Geoprobe rods to a depth of 9.31 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 2.24 feet (1290.22 ft. NAVD 88, +/- 0.03 ft.) above land surface when measured on 02 November 2016. The open interval of the piezometer is between 4.40 and 8.88 feet below land surface and the total well depth is 9.31 feet below land surface.

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

This piezometer frequently goes dry due to being so shallow (bottom of well screen at 8.88 ft. BLS). This piezometer is also installed in an undrained agricultural field that has a loess unit, which is highly porous. Water levels are periodically recorded in this piezometer during snow melt, wet Spring conditions, or during heavy rainfall events.

DATUM - Land-surface datum is 1,287.98 ft above North American Vertical Datum of 1988. Measuring point: Black mark on top of 1.59-inch diameter PVC well casing, 2.24 ft above land-surface datum, Nov. 15, 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 2.24 feet above land surface on 15 November 2016. Elevation of the measuring point is 1290.22 plus-or-minus 0.03 feet above sea level, North American Vertical Datum of 1988, based on differential GPS survey on 16 March 2017.

PERIOD OF RECORD -

Water temperatures were recorded quarter-hourly from 16 March 2017 at 10:00 CDT to 30 October 2018 at 12:30 CDT.

16 Mar. 2017 at 10:00 CDT - 19 Apr. 2017 at 23:30 CDT: WL below bottom of well screen and/or piezometer went dry.

22 Apr. 2017 at 11:45 CDT - 21 Jul. 2017 at 11:15 CDT: WL below bottom of well screen and/or piezometer went dry.

24 Jul. 2017 at 03:45 CDT - 07 Oct. 2017 at 11:15 CDT: WL below bottom of well screen and/or piezometer went dry.

09 Oct. 2017 at 04:30 CDT - 23 Apr. 2018 at 15:30 CDT: WL below bottom of well screen and/or piezometer went dry.

26 Apr. 2018 at 06:45 CDT - 04 May 2018 at 03:30 CDT: WL below bottom of well screen and/or piezometer went dry.

18 May 2018 at 09:45 CDT - 08 Jun. 2018 at 22:15 CDT: WL below bottom of well screen and/or piezometer went dry.

17 Jun. 2018 at 19:30 CDT - 20 Sept. 2018 at 08:00 CDT: WL below bottom of well screen and/or piezometer went dry.

26 Sept. 2018 at 08:30 CDT - 09 Oct. 2018 at 07:30 CDT: WL below bottom of well screen and/or piezometer went dry.

14 Oct. 2018 at 06:30 CDT - 30 Oct. 2018 at 12:30 CDT: WL below bottom of well screen and/or piezometer went dry.

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 15 Nov. 2016 to 30 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.

REMARKS - This piezometer frequently goes dry due to being so shallow (bottom of well screen at 8.88 ft. BLS). This piezometer is also installed in an undrained agricultural field that has a loess unit, which is highly porous. Water temperatures (and water levels) are periodically recorded in this piezometer during snow melt, wet Spring conditions, or during heavy rainfall events.