USGS Water-Year Summary 2024

450542093105506 GS2-MW4 TCAAP Site

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

LOCATION - Lat 45°05'42.41", long 93°10'54.61" 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 6.20 ft. Upper casing diameter 2 in; top of first opening undefined, bottom of last opening undefined. Well GS2-MW4 is a groundwater observation well that was installed on 03 September 2021 with a Geoprobe 66DT to 6.20 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 0.86 feet (890.09 ft. NAVD88, +/- 0.05 ft.) above land surface when measured on 03 September 2021. The open interval of the well is between 4.20 and 6.20 feet below land surface and the total well depth is 6.20 feet below land surface. 

DATUM - Land-surface datum is 889.23 ft above North American Vertical Datum of 1988. Measuring point: Black mark on top of 1.25-inch diameter stainless steel well casing, 0.86 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 0.86 feet above land surface on 03 September 2021. Elevation of the measuring point is 890.09 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 29 May 2024. Water levels were recorded every 5-minutes from 18 October 2021 at 17:40 CDT to 16 November 2022 at 08:55 CST, except during the following periods:

07 Oct. 2022 at 06:30 CDT - 16 Nov. 2022 at 08:55 CST: due to water level dropping below transducer and hanging in air.

GAGE -

Continuous water level, water temperature, specific conductance, and battery voltage were measured with a previously-used OTT CTD pressure transducer with a built-in specific conductance sensor. These data were recorded every 5-minutes from 19 November 2021 at 13:25 CST to 16 November 2022 at 09:00 CST by the same OTT CTD pressure transducer, which had a data logger built into it. The data logger was housed inside a 4-inch diameter PVC pipe attached to the side of the well casing. The pressure transducer was powered by 3 AA alkaline batteries that were inside of the data logger communications rod. Data were downloaded manually and no telemetry at the gage.

The OTT CTD pressure transducer was removed from the well on 16 November 2022 at 09:00 CST.

COOPERATION - This site was operated from 03 September 2021 to 29 May 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 6.20 ft. Upper casing diameter 2 in; top of first opening undefined, bottom of last opening undefined. Well GS2-MW4 is a groundwater observation well that was installed on 03 September 2021 with a Geoprobe 66DT to 6.20 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 0.86 feet (890.09 ft. NAVD88, +/- 0.05 ft.) above land surface when measured on 03 September 2021. The open interval of the well is between 4.20 and 6.20 feet below land surface and the total well depth is 6.20 feet below land surface. 

DATUM - Land-surface datum is 889.23 ft above North American Vertical Datum of 1988. Measuring point: Black mark on top of 1.25-inch diameter stainless steel well casing, 0.86 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 0.86 feet above land surface on 03 September 2021. Elevation of the measuring point is 890.09 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 13 October 2021 to 08 May 2024.

Water temperature (6.2 ft. BLS):

Water temperature was recorded every 5-minutes from 19 November 2021 at 13:25 CST to 16 November 2022 at 09:00 CST, except during the following periods:

18 Oct. 2021 at 17:40-18:00 CDT: due to thermistor equilibrating to GW temperature after deployment.
26 Oct. 2021 at 10:50-10:55 CDT: due to deleting spike & equilibration data caused by QW sampling.
02 Nov. 2021 at 09:40-10:15 CDT: due to deleting spike & equilibration data caused by QW sampling.
08 Nov. 2021 at 12:30-12:55 CST: due to deleting spike & equilibration data caused by QW sampling.
15 Nov. 2021 at 14:05 CST - 16 Nov. 2021 at 11:00 CST: due to deleting spike & equilibration data caused by QW sampling.
19 Nov. 2021 at 12:50-16:45 CST: due to replacing thermistor and equilibrating to GW temperature after deployment.
30 Nov. 2021 at 09:05-20:45 CST: due to deleting spike & equilibration data caused by QW sampling.
14 Dec. 2021 at 12:35 CST - 17 Dec. 2021 at 10:45 CST: due to deleting spike & equilibration data caused by QW sampling.
24 Jan. 2022 at 10:05-11:30 CST: due to removing a spike during a site visit.
16 Feb. 2022 at 10:30-12:15 CST: due to deleting spike & equilibration data caused by QW sampling.
17 Feb. 2022 at 10:45-16:00 CST: due to removing thermistor from well during a sensor inspection.
23 Feb. 2022 at 13:30-14:30 CST: due to removing a spike during a site visit.
05 May 2022 at 09:05-11:05 CDT: due to deleting spike & equilibration data caused by QW sampling.
18 May 2022 at 10:25-12:05 CDT: due to removing thermistor from well during a sensor inspection.
14 Jun. 2022 at 09:50-10:45 CDT: due to deleting spike & equilibration data caused by QW sampling.
18 Jul. 2022 at 09:40-12:35 CDT: due to deleting spike & equilibration data caused by QW sampling.
09 Aug. 2022 at 10:10-13:20 CDT: due to deleting spike & equilibration data caused by QW sampling.
10 Aug. 2022 at 09:15-13:50 CDT: due to removing thermistor from well during a sensor inspection.
06 Sept. 2022 at 09:50-12:20 CDT: due to deleting spike & equilibration data caused by QW sampling.
04 Oct. 2022 at 09:15-10:10 CDT: due to deleting spike & equilibration data caused by QW sampling.
06 Oct. 2022 at 01:45 CDT - 16 Nov. 2022 at 09:00 CST: due to water level dropping below thermistor and hanging in air.

Specific Conductance, uS/cm, (6.2 ft. BLS):

Specific conductance was recorded every 5-minutes from 19 November 2021 at 13:25 CST to 16 November 2022 at 09:00 CST, except during the following periods:

19 Nov. 2021 at 13:25-19:15 CST: due to sensor equilibrating to static conditions after deployment.
30 Nov. 2021 at 09:20-10:35 CST: due to deleting spike caused by QW sampling.
14 Dec. 2021 at 12:50-13:20 CST: due to deleting spike caused by QW sampling.
16 Feb. 2022 at 10:30-11:45 CST: due to deleting spike caused by QW sampling.
17 Feb. 2022 at 10:45-11:35 CST: due to removing sensor from well during a sensor inspection.
05 May 2022 at 09:25-11:00 CST: due to deleting spike caused by QW sampling.
14 May 2022 at 23:55 CDT to 15 May 2022 at 01:15 CDT: due to low battery voltage causing noisy and inaccurate data values.
15 May 2022 at 03:05-07:35 CDT: due to low battery voltage causing noisy and inaccurate data values.
15 May 2022 at 22:25 CDT to 16 May 2022 at 08:00 CDT: due to low battery voltage causing noisy and inaccurate data values.
16 May 2022 at 22:05 CDT to 17 May 2022 at 10:20 CDT: due to low battery voltage causing noisy and inaccurate data values.
17 May 2022 at 21:15 CDT to 18 May 2022 at 11:15 CDT: due to low battery voltage causing noisy and inaccurate data values.
18 May 2022 at 11:15-12:05 CDT: due to removing sensor from well during a sensor inspection.
18 Jul. 2022 at 09:40-12:05 CDT: due to deleting spike caused by QW sampling.
06 Aug. 2022 at 07:15-08:50 CDT: due to water level dropping below sensor. Sensor was hanging in air.
06 Aug. 2022 at 17:45 CDT - 08 Aug. 2022 at 10:15 CDT: due to water level dropping below sensor. Sensor was hanging in air.
09 Aug. 2022 at 10:10-13:05 CDT: due to deleting spike caused by QW sampling.
10 Aug. 2022 at 09:10-09:55 CDT: due to removing sensor from well during a sensor inspection.
06 Sept. 2022 at 09:50-10:50 CDT: due to deleting spike caused by QW sampling.
26 Sept. 2022 at 06:50 CDT - 16 Nov. 2022 at 09:00 CST: due to water level dropping below sensor. Sensor was hanging in air.

COOPERATION - This site was operated from 03 September 2021 to 29 May 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 temperature and specific conductance were measured with an OTT CTD submersible pressure transducer and specific conductance sensor. Water temperature data are accurate to ±0.1°C. Differences in water temperature are also accurate to 0.1°C. Specific conductance data are accurate to ±1.5% of measurement value; (min ±10 uS/cm). Specific conductance differences are accurate to 10 uS/cm.