USGS Water-Year Summary 2023

360252090173202 Cardwell McNairy Formation

Mississippi embayment aquifer system
McNairy Formation

LOCATION - Lat 36°02'56.4", long 90°17'32.2" referenced to North American Datum of 1983, in SW 1/4 SW 1/4 SE 1/4 sec.03, T.16 N., R.7 E., Dunklin County, MO, Hydrologic Unit 08020203,

REVISIONS HISTORY -
Revisions: Land-surface datum was updated to 249.49 ft NAVD88 on May 22, 2023, as determined by a GNSS survey by Missouri DNR. Land-surface datum was previously published as 248 ft NAVD88 from topographic map. Discrete water-level measurements prior to May 22, 2023, are referenced to the original datum.

The record from 12/11/2007 to 08/31/2009 was temporarily set to 'APPROVED' for a period of 5 days (July 16, 2010 to July 21, 2010). The data was previously approved without the measuring point height correction (-2.6 ft) being applied to the data. This correction references water levels to land surface instead of the measuring point. The record was corrected on 07/21/2010.

GROUNDWATER RECORDS

DATUM - Land-surface datum is 249.49 ft above North American Vertical Datum of 1988. Measuring point: unknown, 2.6 ft above land-surface datum, Aug. 21, 1962 to Aug. 9, 2011; This is height of pressure transducer above land surface, 2.85 ft above land-surface datum, Aug. 9, 2011 to present.  

PERIOD OF RECORD - December 11, 2007 to present. Gage installed on November 28, 2007.

GAGE - November 28, 2007 to present, the water level measuring device is a vented, submersible pressure transducer connected to a hydrant that is connected to the flow pipe coming from the turbine pump. The water level recorder is a DCP with telemetry capability sitting in a metal gage house inside the well house. Unit values begin on December 11, 2007.

COOPERATION - Data furnished by Missouri Department of Natural Resources (MDNR). The record is processed by USGS and MDNR.

REMARKS -

Data from 12/11/2007 to 08/31/2009 has been processed by the USGS with no independent field water level measurements to verify the pressure transducer readings. Seven site visits occurred during the period to verify the recorder and water level measuring devices were operating correctly. This record cannot be rated since there are no independent water level measurements performed. Nine site visits were made during the period 09/01/2009 to 08/09/2011 to service the gage. There was no independent water level measuring device at the site, prior to 08/09/2011, other than the transducer used to send the data to the data recorder. Therefore, there was no way to rate the data. However, when an independent pressure gage was installed on August 9, 2011, the pressure gage and the pressure transducer were in agreement within +/- 0.05 ft. The pressure gage now provides an method for checking the accuracy of the pressure transducer. An oil filled pressure gage was installed in-line and 0.25 ft higher than the pressure transducer on August 9, 2011. At the time the pressure gage was installed, the pressure gage and the pressure transducer were in agreement within +/- 0.05 ft. The pressure gage is now the reference point from which water levels are measured and provides a method for checking the accuracy of the pressure transducer. The record from 08/09/2011 to 09/11/2012 is good based on 4 water level measurements made during the period and is accurate to +/- 0.1 ft. The record from 09/11/2012 to 08/19/2013 is good based on 5 water level measurements made during the period and is accurate to +/- 0.1 ft. The record from 08/20/2013 to 08/11/2014 is good based on 3 water level measurements made during the period and is accurate to +/- 0.3 ft. The record from 08/12/2014 to 05/09/2016 is good based on 4 water level measurements made during the period and is accurate to +/- 0.3 ft. The record from 05/10/2016 to 02/28/2017 is good based on 2 water level measurements made during the period and is accurate to +/- 0.3 ft. The data from 03/01/2017 to 09/05/2017 is fair based on 1 water level measurement made during the period to verify the recorded data and is accurate to +/- 1.50 ft. This measurement was made after installing a new DCP after the previous one lost communication. Although no measurements were taken while the DCP was operating properly, the equipment had been consistently performing well and previous check measurements showed water level comparisons within +/- 0.10 ft. The record from 09/06/2017 to 04/10/2018 is good based on 2 water level measurements made during the period and is accurate to +/- 0.3 ft. The record from 04/11/2018 to 08/21/2018 is good based on 1 water level measurement made during the period and is accurate to +/- 0.4 ft. The record from 08/22/2018 to 04/15/2019 is good based on 1 water level measurement made during the period and is accurate to +/- 0.40 ft. The record from 04/16/2019 to 05/21/2019 is good based on 1 water level measurement made during the period and is accurate to +/- 0.05 ft. The record from 05/22/2019 to 10/02/2019 is good based on 1 water level measurement made during the period and is accurate to +/- 0.3 ft.

All later remarks can be found in RMS as of 10/03/2019.