USGS Water-Year Summary 2025

450543093105306 GS1-MW4 TCAAP Site K

Sand and gravel aquifers (glaciated regions)
Glacial Surficial Sand and/or Gravel

LOCATION - Lat 45°05'42.89", long 93°10'53.56" referenced to North American Datum of 1983, Ramsey County, MN, Hydrologic Unit 07010206, The well is located in the former Twin Cities Army Ammunition Plant (TCAAP) site, 0.8 miles east of the USGS Mounds View office. The well is located approximately 0.5 miles NE of the intersection of US HWY 35W and County Rd. 10 (Mounds View Blvd).

GROUNDWATER RECORDS

WELL CHARACTERISTICS - Depth 8 ft. Upper casing diameter 2 in; top of first opening undefined, bottom of last opening undefined. Well GS1-MW4 is a groundwater observation well that was installed on 03 September 2021 with a Geoprobe 66DT to 8.00 feet. The well is constructed of a 2.00-feet-long, 2-inch-diameter, stainless steel, 0.010-inch slotted, well screen, attached with to length/s of 2-inch-diameter, stainless steel well casing. The well casing measuring point (stickup) was 1.83 feet (890.86 ft. NAVD88, +/- 0.05 ft.) above land surface when measured on 03 September 2021. The open interval of the well is between 6.00 and 8.00 feet below land surface and the total well depth is 8.00 feet below land surface. 

DATUM - Land-surface datum is 889.03 ft above North American Vertical Datum of 1988. Measuring point: Black mark on top of 1.25-inch diameter stainless steel well casing, 1.83 ft above land-surface datum, UNDEFINED BEGIN DATE to present. The measuring point is a black mark on top of the 2-inch diameter stainless steel well casing, which was 1.83 feet above land surface on 03 September 2021. Elevation of the measuring point is 890.86 plus-or-minus 0.05 feet above sea level, North American Vertical Datum of 1988, based on a differential GPS and digital levels survey completed by the U.S. Geological Survey on 16 Nov. 2021.

PERIOD OF RECORD -

Water levels were recorded periodically from 04 October 2021 to 10 June 2024. Water levels were recorded every 5-minutes from 18 October 2021 at 15:40 CDT to 10 June 2024 at 09:15 CDT, except during the following periods:

23 Feb. 2022 at 07:50-12:40 CST: due to deleting spike & equilibration data caused by QW sampling.
03 Oct. 2022 at 09:00-13:45 CDT: due to deleting spike & equilibration data caused by QW sampling.

GAGE -

Continuous water level, water temperature, and battery voltage are measured with a previously used OTT Orpheus Mini, 0-10m range, pressure transducer. These data are recorded every 5-minutes from 18 October 2021 at 15:40 CDT to 10 June 2024 at 09:15 CDT by the same OTT Orpheus Mini pressure transducer, which has a data logger built into it. The data logger is housed inside a 4-inch diameter PVC pipe attached to the side of the well casing. The pressure transducer is powered by 3 AA alkaline batteries that are inside of the data logger communications rod. Data are downloaded manually and there no telemetry at the gage.

The pressure transducer and data logger were removed from the well on 10 Jun. 2024 at 09:15 CDT. Data collection for the USGS Twin Cities Army Ammunition Plant (TCAAP) "Site K" study have concluded and all data logging equipment have been removed from the sites.

COOPERATION - This site was operated from 03 September 2021 to 10 June 2024 by the U.S. Geological Survey as a monitoring well for the USGS Twin Cities Army Ammunition Plant (TCAAP) "Site K" study. The USGS Twin Cities Army Ammunition Plant (TCAAP) "Site K" study is a collaborative study between the U.S. Geological Survey and the U.S. Army.

WATER-QUALITY RECORDS

WELL CHARACTERISTICS - Depth 8 ft. Upper casing diameter 2 in; top of first opening undefined, bottom of last opening undefined. Well GS1-MW4 is a groundwater observation well that was installed on 03 September 2021 with a Geoprobe 66DT to 8.00 feet. The well is constructed of a 2.00-feet-long, 2-inch-diameter, stainless steel, 0.010-inch slotted, well screen, attached with to length/s of 2-inch-diameter, stainless steel well casing. The well casing measuring point (stickup) was 1.83 feet (890.86 ft. NAVD88, +/- 0.05 ft.) above land surface when measured on 03 September 2021. The open interval of the well is between 6.00 and 8.00 feet below land surface and the total well depth is 8.00 feet below land surface. 

DATUM - Land-surface datum is 889.03 ft above North American Vertical Datum of 1988. Measuring point: Black mark on top of 1.25-inch diameter stainless steel well casing, 1.83 ft above land-surface datum, UNDEFINED BEGIN DATE to present. The measuring point is a black mark on top of the 2-inch diameter stainless steel well casing, which was 1.83 feet above land surface on 03 September 2021. Elevation of the measuring point is 890.86 plus-or-minus 0.05 feet above sea level, North American Vertical Datum of 1988, based on a differential GPS and digital levels survey completed by the U.S. Geological Survey on 16 Nov. 2021.

PERIOD OF RECORD -

Water quality samples have been collected periodically from 12 October 2021 to 06 May 2024.

Water temperatures were recorded every 5-minutes from 18 October 2021 at 15:40 CDT to 10 June 2024 at 09:15 CDT, except during the following periods:

11 Dec. 2023 at 10:35-15:00 CST: due to deleting spike caused by QW sampling.

COOPERATION - This site was operated from 03 September 2021 to 10 June 2024 by the U.S. Geological Survey as a monitoring well for the USGS Twin Cities Army Ammunition Plant (TCAAP) "Site K" study. The USGS Twin Cities Army Ammunition Plant (TCAAP) "Site K" study is a collaborative study between the U.S. Geological Survey and the U.S. Army.

INSTRUMENTATION - Water temperatures were measured with an OTT Orpheus Mini submersible pressure transducer thermistor sensor during 18 Oct. 2021 at 15:40 CDT to 10 June 2024 at 09:15 CDT, which were accurate to ±0.1°C. Differences in temperature are also accurate to 0.1°C.