USGS Water-Year Summary 2025

433527092265701 NPR-4 North Drain Site Perimeter

Sand and gravel aquifers (glaciated regions)
Pleistocene Series

LOCATION - Lat 43°35'27.46", long 92°26'56.70" referenced to North American Datum of 1983, in SW 1/4 SW 1/4 sec.31, T.102 N., R.13 W., Fillmore County, MN, Hydrologic Unit 07060002, The piezometer is located approximately 1.75 miles SW of Ostrander, MN. The piezometer is located along the perimeter/edge of an agricultural field. The piezometer is located approximately 0.3 miles NE of the intersection of 160 street and Mower/Fillmore County Line Road.

GROUNDWATER RECORDS

WELL CHARACTERISTICS - Depth 15.89 ft. Upper casing diameter 1.57 in; top of first opening 3.36 ft, bottom of last opening 12.82 ft. Piezometer NPR-4 was installed using several sections of 3.25-inch-diameter Geoprobe rods to a depth of 16.0 feet. The piezometer is constructed of a 9.46-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 1.66 feet (1335.81 ft. NAVD88, +/- 0.05 ft.) above land surface when measured on 14 June 2016. The open interval of the piezometer is between 3.36 and 12.82 feet below land surface and the total well depth is 15.89 feet below land surface.

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

DATUM - Land-surface datum is 1,334.15 ft above North American Vertical Datum of 1988. Measuring point: Black mark on top of PVC well casing, 1.66 ft above land-surface datum, Jun. 14, 2016 to present. The measuring point is a black mark on the top of the white PVC 1.5-inch diameter well casing, which was 1.66 feet above land surface on 14 June 2016. Elevation of the measuring point is 1335.81 plus-or-minus 0.05 feet above sea level, North American Vertical Datum of 1988, based on differential GPS survey on 20 August 2016.

PERIOD OF RECORD -

Water levels were recorded periodically from 16 June 2016 to 29 October 2018. Water levels were recorded hourly from 17 June 2016 at 10:00 CDT to 13 September 2016 at 14:00 CDT. Water levels were recorded quarter-hourly from 14 September 2016 at 15:15 CDT to 29 October 2018 at 14:30 CDT, except during the following periods:

23 Aug. 2016 at 21:15 CDT to 14 Sept. 2016 at 15:30 CDT: due to damaged transducer due to high water at the site.

29 Apr. 2018 at 10:00-18:30 CDT: due to deleting inaccurate WL behavior during this period.

GAGE - Continuous water level and water temperature were measured with a new Solinst Model 3001 Levelogger Edge non-vented pressure transducer during 14 September 2016 at 15:30 CDT to 29 October 2018 at 14:30 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 was installed at nearby piezometer NTR2-3A. 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 is wired into the gage.

Continuous water level, water temperature, and battery voltage were measured with a previously-used OTT Orpheus Mini 0-10m pressure transducer during 17 June 2016 at 10:00 CDT to 13 September 2016 at 14:00 CDT. These data were recorded hourly by the same OTT Orpheus Mini pressure transducer, which had a data logger built into it. The data logger was housed inside the 1.5-inch PVC well casing and inside an attached 4-inch PVC shelter. Both the piezometer and shelter had a slip-on PVC cap and no pad lock. The gage was powered by 3 AA alkaline batteries that were inside of the data logger communications rod. Data was downloaded manually and no telemetry or phone line is wired into the gage.

The pressure transducer and data logger were removed from the well on 29 Oct. 2018 at 14:30 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 immediately after installation on 13 June 2016. 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 during 14 September 2016 to 29 October 2018 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 NTR2-3A. 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 14 September 2016 to 29 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 water-level record during 14 September 2016 to 29 October 2018 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 0.05 feet based on a differential GPS survey on 20 August 2016.  Water elevation accuracy is the sum of the water level (below land-surface datum) and land-surface elevation accuracy, or about ±0.15 feet.

Water levels below land surface are accurate to 0.01 feet during 17 June 2016 - 13 September 2016. Water-level differences are accurate to within 0.01 feet. Water levels above North American Vertical Datum of 1988 (sea level) are calculated by subtracting recorded water levels from the land surface elevation, which is accurate to plus-or-minus 0.05 feet based on location of a differential GPS Survey on 20 August 2016. Continuous water levels are measured with a barometric pressure compensated (vented) pressure transducer. Water level record is calibrated twice per year (Spring & Fall), to check/correct the accuracy of the transducer water level, against HIF calibrated water level measurement equipment, ie) e-tapes, steel tapes, etc.

WATER-QUALITY RECORDS

WELL CHARACTERISTICS - Depth 15.89 ft. Upper casing diameter 1.57 in; top of first opening 3.36 ft, bottom of last opening 12.82 ft. Piezometer NPR-4 was installed using several sections of 3.25-inch-diameter Geoprobe rods to a depth of 16.0 feet. The piezometer is constructed of a 9.46-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 1.66 feet (1335.81 ft. NAVD88, +/- 0.05 ft.) above land surface when measured on 14 June 2016. The open interval of the piezometer is between 3.36 and 12.82 feet below land surface and the total well depth is 15.89 feet below land surface.

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

DATUM - Land-surface datum is 1,334.15 ft above North American Vertical Datum of 1988. Measuring point: Black mark on top of PVC well casing, 1.66 ft above land-surface datum, Jun. 14, 2016 to present. The measuring point is a black mark on the top of the white PVC 1.5-inch diameter well casing, which was 1.66 feet above land surface on 14 June 2016. Elevation of the measuring point is 1335.81 plus-or-minus 0.05 feet above sea level, North American Vertical Datum of 1988, based on differential GPS survey on 20 August 2016.

PERIOD OF RECORD - Water temperatures were recorded hourly from 17 June 2016 at 10:00 CDT to 29 October 2018 at 14:30 CDT, except during the following periods:

13 Sept. 2016 at 15:00 CDT to 14 Sept. 2016 at 15:30 CDT: No transducer in piezometer; transducer replacement period.

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 immediately after installation on 13 June 2016. 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 temperatures were measured with a Solinst Levelogger 3001 submersible pressure transducer during 14 September 2016 at 15:45 CDT to 29 October 2018 at 14:30 CDT, which are accurate to plus-or-minus 0.1°C. Differences in temperature are also accurate to 0.1°C.

Water temperature were measured with an OTT Orpheus Mini submersible pressure transducer during 16 June. 2016 at 10:00 CDT to 13 Sept. 2016 at 14:00 CDT, which were accurate to plus-or-minus 0.3°C. Differences in temperature are accurate to 0.1°C.