Connor P. Newman
20200715
Environmental-tracer modeling to support hydrogeochemical evaluation of the Fountain Creek Alluvial Aquifer, El Paso County, Colorado, 2018-2019
tabular digital data
https://doi.org/10.5066/P99SPQM2
Connor P. Newman
Suzanne S. Paschke
Gabrielle Keith
2020
Natural and anthropogenic geochemical tracers to investigate solute distributions, recharge sources, residence times, and groundwater-surface water interactions in an alluvial aquifer
publication
https://doi.org/10.3390/w13060871
This data release contains environmental tracer concentrations, modeled recharge conditions (water temperature, excess air), and resulting estimated groundwater residence times. This dataset supports an integrated hydrogeochemical investigation of solute sources, groundwater recharge processes, and groundwater flow in the Fountain Creek alluvial aquifer.
The data release contains five comma separated value (CSV) files. The CSV files contain the model inputs (gas and tracer concentrations) and the model outputs (simulated recharge temperature, excess air, apparent groundwater age, and mean groundwater residence time). Data were collected in cooperation with the U.S. Air Force Civil Engineering Center.
Data were collected to assist in understanding residence time distributions and potential sources of dissolved solutes in the alluvial aquifer. These data may be used to model recharge temperature and excess air, and to assess the age of groundwater at various spatial locations in the aquifer.
Environmental-tracer samples were collected and analyzed for tritium (3H), sulfur hexafluoride (SF6), and dissolved gases (oxygen [O2], nitrogen [N2], carbon dioxide [CO2], helium [He], neon [Ne], argon [Ar], krypton [Kr], and xenon [Xe]) from groundwaters in the Fountain Creek alluvial aquifer, El Paso County, Colorado. Isotopes of noble gases including helium-3 (3He) and helium-4 (4He) were also quantified. These datasets were used to estimate groundwater recharge temperature and excess air for each sampled groundwater well. Twenty-nine wells were sampled in all, with all 29 wells being sampled for 3H, 28 wells being sampled for SF6 and dissolved gases (O2, N2, Ar, and CO2), and 19 wells being sampled for noble gases (He, Ne, Ar, Kr, and Xe). Three of the 19 wells sampled for noble gases were sampled on two occasions.
Where noble gases were available concentrations were used to estimate recharge temperature, excess air, and tritiogenic helium (3He-trit) using an inverse modeling approach. At the other nine sites where noble gases were not available recharge temperature and excess air were estimated using dissolved gases, O2, N2 (corrected for excess air), Ar, and CO2. Using environmental-tracer concentrations corrected for recharge temperature and excess air, apparent groundwater ages were calculating using 3H, 3He-trit, and SF6. These results were compared to groundwater residence times estimated from lumped parameter models (LPMs) using the spreadsheet software TracerLPM.
20181001
20200301
ground condition
None planned
-104.7825
-104.6742
38.8303
38.6866
ISO 19115 Topic Category
environment
geoscientificInformation
inlandWaters
USGS Thesaurus
hydrology
noble gas elements
groundwater and surface-water interaction
groundwater flow
USGS Metadata Identifier
USGS:5eaa21dd82cefae35a21ecf5
Common geographic areas
Colorado
Colorado Springs
None
El Paso County
Fountain Creek
None. Please see 'Distribution Info' for details.
None. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations.
Connor P Newman
U.S. Geological Survey, ROCKY MOUNTAIN REGION
Hydrologist
mailing address
W 6th Ave Kipling St
Lakewood
CO
80225
US
303-236-6905
cpnewman@usgs.gov
U.S. Air Force Civil Engineering Center
Windows Operating System, version 10. Excel software using either 32-bit or 64-bit versions.
Groundwater samples are assumed to represent water within the matrix of the aquifer, as indicated by field parameters collected during sampling. Accuracy of laboratory analyses for noble gases are in the range of 1 to 3 percent of the measured value. Accuracy of dissolved major gas concentrations is typically within 5 percent of the measured value. Accuracy of 3H concentrations is typically within approximately 13 percent of replicate analyses. Accuracy of SF6 measurements ranges from 20 percent at the minimum reporting limit to 3 percent at the maximum reporting limit.
All datasets are internally consistent, do not contain duplicates, and fall within expected ranges for water that has been in recent equilibrium with the atmosphere, except for some results for SF6 which are enriched above atmospheric equilibrium. Several results are above saturation with the atmosphere, but results were confirmed by the laboratory and are representative of the environment.
The dataset is deemed complete for the purposes of estimating groundwater recharge temperature and excess air and for evaluating ranges of groundwater residence times.
No horizontal accuracy assessments were made. Positional data for groundwater wells are derived from the U.S. Geological Survey (USGS) National Water Information System database (NWIS; USGS, 2019)
No vertical accuracy assessments were made. Positional data for groundwater wells are derived from the National Water Information System database (NWIS; USGS, 2019)
Aeschbach-Hertig, W.
Peeters, F.
Beyerle, U.
Kipfer, R.
19990901
Interpretation of dissolved atmospheric noble gases in natural waters
publication
Water Resources Research
vol. 35, no.9
n/a
American Geophysical Union (AGU)
p. 2779-2792
https://doi.org/10.1029/1999WR900130
Digital and/or Hardcopy
20190501
Current
Aeschbach-Hertig and others (1999)
Methods
Jurgens, B.C.
Böhlke, J.K.
Eberts, S.M.
20120719
TracerLPM (Version 1): An Excel Workbook® for Interpreting Groundwater Age Distributions from Environmental Tracer Data
publication
Reston, VA
U.S. Geological Survey
Series Name U.S. Geological Survey Techniques and Methods Report
Issue Identification 4-F3
https://pubs.usgs.gov/tm/4-f3/
Digital and/or Hardcopy
20190501
Current
Jurgens and others (2012)
Method
Weiss, R.F.
197008
The solubility of nitrogen, oxygen and argon in water and seawater
publication
Deep Sea Research and Oceanographic Abstracts
vol. 17, no.4
n/a
Elsevier BV
p. 721-735
https://doi.org/10.1016/0011-7471(70)90037-9
Digital and/or Hardcopy
20190501
Current
Weiss (1970)
Method
Weiss, R.F.
197411
Carbon dioxide in water and seawater: the solubility of a non-ideal gas
publication
Marine Chemistry
vol. 2, no.3
n/a
Elsevier BV
p. 203-215
https://doi.org/10.1016/0304-4203(74)90015-2
Digital and/or Hardcopy
20190501
Current
Weiss (1974)
Method
Aeschbach-Hertig, W.
Solomon, D.K.
2013
Noble Gas Thermometry in Groundwater Hydrology
publication
Berlin, Heidelberg
Springer Berlin Heidelberg
In Burnard P., eds., The Noble Gases as Geochemical Tracers. Advances in Isotope Geochemistry, p. 81-122
https://doi.org/10.1007/978-3-642-28836-4_5
Digital and/or Hardcopy
20190501
Current
Aeschbach-Hertig and Solomon (2013)
Method
U.S. Geological Survey
20190501
U.S. Geological Survey National Water Information System database
tabular digital data
Reston, VA
U.S. Geological Survey
accessed May 1, 2029
http://dx.doi.org/10.5066/F7P55KJN
Digital and/or Hardcopy
20190501
Current
USGS (2019)
Locations
U.S. Geological Survey
20181001
National field manual for the collection of water-quality data
publication
http://pubs.water.usgs.gov/twri9A
Digital and/or Hardcopy
20181001
Current
USGS (variously dated)
Methods
Visser, A.
Fourré, E.
Barbecot, F.
Aquilina, L.
Labasque, T.
Vergnaud, V.
Esser, B.K.
201411
Intercomparison of tritium and noble gases analyses, 3 H/ 3 He ages and derived parameters excess air and recharge temperature
publication
Applied Geochemistry
vol. 50
n/a
Elsevier BV
p. 130-141
https://doi.org/10.1016/j.apgeochem.2014.03.005
Digital and/or Hardcopy
20190501
Current
Visser and others (2014)
Method
Busenberg, E.
Plummer, L.N.
20001001
Dating young groundwater with sulfur hexafluoride: Natural and anthropogenic sources of sulfur hexafluoride
publication
Water Resources Research
vol. 36, no.10
n/a
American Geophysical Union (AGU)
p. 3011-3030
https://doi.org/10.1029/2000WR900151
Digital and/or Hardcopy
20190501
Current
Busenberg and Plummer (2000)
Method
Suckow, A.
201411
The age of groundwater – Definitions, models and why we do not need this term
publication
Applied Geochemistry
vol. 50
n/a
Elsevier BV
p. 222-230
https://doi.org/10.1016/j.apgeochem.2014.04.016
Digital and/or Hardcopy
20190501
Current
Suckow (2014)
Method
Benson, B.B
Krause, D.
1980
The concentration and isotopic fractionation of gases dissolved in freshwater in equilibrium with the atmosphere. 1. Oxygen
publication
Limnology and Oceanography
vol. 25, no.4
n/a
Wiley
p. 662-671
https://doi.org/10.4319/lo.1980.25.4.0662
Digital and/or Hardcopy
20190501
Method
Benson and Krause (1980)
Method
Benson, B.B
Krause, D.
1984
The concentration and isotopic fractionation of oxygen dissolved in freshwater and seawater in equilibrium with the atmosphere
publication
Limnology and Oceanography
vol. 29, no.3
n/a
Wiley
p. 620-632
https://doi.org/10.4319/lo.1984.29.3.0620
Digital and/or Hardcopy
20190501
Current
Benson and Krause (1984)
Method
Collection of groundwater samples was conducted in accordance with techniques of the USGS according to the National Field Manual (USGS, variously dated). Groundwater samples were collected in copper tubes for noble gases (Aeschbach-Hertig and Solomon, 2013), in glass bottles for SF6 and dissolved gases O2, CO2, Ar, and N2 (USGS, variously dated), and in high-density polyethylene bottles for 3H (USGS, variously dated).
Twenty-nine wells were sampled, with all 29 wells being sampled for 3H, 28 wells being sampled for SF6 and dissolved gases (O2, N2, Ar, and CO2), and 19 wells being sampled for noble gases (He, Ne, Ar, Kr, and Xe). Three of the 19 wells that were sampled for noble gases were sampled on two occasions.
USGS (variously dated)
Aeschbach-Hertig and Solomon (2013)
20181001
Concentrations of dissolved gases, noble gases, tritium, and SF6 were determined in laboratories of the USGS. Analysis of dissolved gases follows Weiss (1970, 1974) and Benson and Krause (1980, 1984). Analysis of noble gases and 3H is conducted according to methods described by Visser and others (2014). Analysis of SF6 follows Busenberg and Plummer (2000).
Visser and others (2014)
Busenberg and Plummer (2000)
Weiss (1970)
Weiss (1974)
Benson and Krause (1980)
Benson and Krause (1984)
201904
Estimation of conditions during groundwater recharge (specifically water temperature and excess air) are required for attributing proportions of dissolved gases 3H, 3He-trit, and SF6, which are in turn used in LPMs calculated using the software TracerLPM (Jurgens and others, 2012) and apparent groundwater age calculations (Aeschbach-Hertig and Solomon, 2013).
In this environmental-tracer analysis the concentrations of the gases Ne, Ar, Kr, Xe, O2, and CO2 were used. Helium and N2 each may have non-atmospheric sources, and as such these gases were only used no when viable models were obtained from the subset of gases which can reliably be considered to be atmospheric in origin. Helium and N2 were used in six of the 19 models for sampled groundwater wells where noble-gas data were available.
Nine sampled groundwater wells were not sampled for noble gases. For these samples and where noble gases could not explain recharge conditions, recharge temperature and excess air were computed by the USGS Chlorofluorocarbon laboratory from concentrations of O2, N2 (corrected for excess air), Ar, and CO2 according to methods described in Weiss (1970, 1974) and Benson and Krause (1980, 1984).
For samples with noble-gas data, gas modeling utilized an inverse approach similar to those described by Aeschbach-Hertig and others (1999). Briefly, input parameters included the recharge salinity from groundwater sampling and the elevation of the land surface at the well, then an inverse-error fitting procedure was applied wherein sets of simulated gas concentrations are produced and compared to the observed values, for each of the three most commonly used models of excess air: closed-system equilibration (CE), partial re-equilibration (PR), and unfractionated air (UA), as described by Aeschbach-Hertig and Solomon (2013). The error in these sets of simulated gas concentrations is quantified using the χ2 parameter which accounts for model errors in each gas. The model returns a recharge temperature, excess air concentration, χ2 value, and probability for each of the CE, PR, and UA models. In this manner the applicability of each model may be tested.
Aeschbach-Hertig and others (1999)
Weiss (1974)
Weiss (1970)
Aeschbach-Hertig and Solomon (2013)
Jurgens and others (2012)
20200101
Calculated groundwater recharge temperature and excess air were used to apportion He, 3H, and SF6 into atmospheric equilibrium and excess components. Using the atmospheric equilibrium component, the apparent tritium-helium (3H/3He) groundwater age was calculated according to methods in Visser and others (2014) and Suckow (2014).
Also, the atmospheric equilibrium component was used to calculate the idealized piston-flow SF6 age according to methods in Busenberg and Plummer (2000) and Suckow (2014).
Finally, atmospheric the equilibrium component of gases were used to estimate a range of mean residence times using the lookup mean ages feature of TracerLPM (Jurgens and others, 2012). TracerLPM was also used to conduct visual approximations of the fit of data with respect to the piston-flow model (PFM) and dispersion model (DM).
Suckow (2014)
Visser and others (2014)
Busenberg and Plummer (2000)
Jurgens and others (2012)
20200101
Universal Transverse Mercator
13
0.9996
-105.0
0.0
500000.0
0.0
coordinate pair
0.6096
0.6096
meters
North_American_Datum_1983
GRS_1980
6378137.0
298.257222101
NamesDictionary.csv
Comma Separated Value (CSV) file containing information on the contents of each attribute (field name) in other CSV files (tables) in the data release
Producer Defined
Table Name
Names of CSV files in data release
Producer Defined
ModelingResults.csv
Results of environmental-tracer modeling
Producer defined
NobleGases.csv
File containing concentrations of noble gases in groundwater
Producer defined
DissGases.csv
File containing concentrations of dissolved gases in groundwater
Producer defined
TracerLPMLookupMeanAges.csv
Results of mean residence time estimation using the software TracerLPM
Producer defined
Field Name
Name of attribute in CSV file
Producer Defined
These values are the names of the attributes in the given CSV file
Description
Description of fields in CSV files
Producer Defined
This attribute describes the type of information contained in each field of the CSV files containing data and modeling results. Included are units and other applicable notes.
NobleGases.csv
Comma Separated Value (CSV) file containing concentrations of noble gases in groundwater.
Producer Defined
USGS Site ID
USGS site identification numbers
U.S. Geological Survey
Unique site identification number, linked to the National Water Information System database at https://doi.org/10.5066/F7P55KJN
Sample Date
Date of collection (MM/DD/YYYY)
Producer Defined
11/19/2018
3/20/2019
He
Helium concentration in water, in cubic centimeters per gram of water at standard temperature and pressure (ccSTP/gH2O)
Producer Defined
3.70e-08
8.36e-08
errHe
Error in He concentration, in cubic centimeters per gram of water at standard temperature and pressure (ccSTP/gH2O)
Producer Defined
3.93e-10
8.88e-10
Ne
Neon concentration in water, in cubic centimeters per gram of water at standard temperature and pressure (ccSTP/gH2O)
Producer Defined
1.52e-07
2.32e-07
errNe
Error in Ne concentration, in cubic centimeters per gram of water at standard temperature and pressure (ccSTP/gH2O)
Producer Defined
3.04e-09
4.62e-09
Ar
Argon concentration in water, in cubic centimeters per gram of water at standard temperature and pressure (ccSTP/gH2O)
Producer Defined
2.86e-04
3.71e-04
errAr
Error in Ar concentration, in cubic centimeters per gram of water at standard temperature and pressure (ccSTP/gH2O)
Producer Defined
5.72e-06
7.43e-06
Kr
Krypton concentration in water, in cubic centimeters per gram of water at standard temperature and pressure (ccSTP/gH2O)
Producer Defined
6.28e-08
8.43e-08
errKr
Error in Kr concentration, in cubic centimeters per gram of water at standard temperature and pressure (ccSTP/gH2O)
Producer Defined
1.88e-09
2.53e-09
Xe
Xenon concentration in water, in cubic centimeters per gram of water at standard temperature and pressure (ccSTP/gH2O)
Producer Defined
8.45e-09
1.20e-08
errXe
Error in Xe concentration, in cubic centimeters per gram of water at standard temperature and pressure (ccSTP/gH2O)
Producer Defined
2.53e-10
3.60e-10
N2
Nitrogen (N2) concentration in water, in cubic centimeters per gram of water at standard temperature and pressure (ccSTP/gH2O), CO2inf indicates an interference in the analysis from carbon dioxide
Producer Defined
CO2inf
Interference from CO2 in analysis
Producer defined
1.21E-02
1.74E-02
errN2
Error in nitrogen (N2) concentration, in cubic centimeters per gram of water at standard temperature and pressure (ccSTP/gH2O)
Producer Defined
<< empty cell >>
Values are left blank where CO2 interference was present in the analysis
Producer defined
6.10e-04
8.70e-04
3He/4He
Ratio of 3He/4He, unitless
Producer Defined
1.03e-06
1.41e-06
3He/4He error
Error in ratio of 3He/4He, unitless
Producer Defined
1.43e-08
1.96e-08
DissGases.csv
Comma Separated Value (CSV) file containing concentrations of dissolved gases in groundwater. Two sample records are presented for each well because the samples are analyzed in duplicate.
Producer Defined
USGS Site ID
USGS site identification numbers
U.S. Geological Survey
Unique site identification number, linked to the National Water Information System database at https://doi.org/10.5066/F7P55KJN
date_collected
Date of collection (MM/DD/YYYY)
Producer Defined
11/19/2018
3/20/2019
time_collected
Time of collection, coordinated universal time (UTC)
Producer Defined
1015
1630
field_temp_C
Water temperature during field collection, in degrees Celsius
Producer Defined
9.2
16.0
bottle_num
Unique identifier of sample bottle
Producer Defined
18Y4032
18Y4345
excess_N
Excess nitrogen (N2), in milligrams per liter (mg/L)
Producer Defined
<< empty cell >>
No excess N2 was indicated by the analysis
Producer defined
1.0
3.0
Ar_mg/L
Argon concentration in water, in milligrams per liter (mg/L)
Producer Defined
0.4805
0.6185
N2_mg/L
Nitrogen (N2) concentration in water, in milligrams per liter (mg/L)
Producer Defined
13.0447
19.6704
O2_mg/L
Oxygen (O2) concentration in water, in milligrams per liter (mg/L)
Producer Defined
0.1826
0.2575
CO2_mg/L
Carbon dioxide (CO2) concentration in water, in milligrams per liter (mg/L)
Producer Defined
2.6646
81.401
ModelingResults.csv
Comma Separated Value (CSV) file containing results of environmental-tracer modeling. Results for the well with only tritium data (but no other applicable data types) are not presented.
Producer Defined
USGS Site ID
USGS site identification numbers
U.S. Geological Survey
Unique site identification number, linked to the National Water Information System database at https://doi.org/10.5066/F7P55KJN
Site Alias
Short site alias name for identification
Producer Defined
Short site alias for identification
date_collected
Date of collection (MM/DD/YYYY)
Producer Defined
11/19/2018
3/20/2019
FieldTemp
Water temperature during field collection, in degrees Celsius
Producer Defined
9.2
16.0
RechTemp_DG
Recharge temperature as determined by dissolved gases O2, CO2, N2 (accounting for excess air), and Ar, in degrees Celsius
Producer Defined
9.0
17.9
EA_DG
Excess air as determined by dissolved gases O2, CO2, N2 (accounting for excess air) and Ar, in cubic centimeters per liter at standard temperature and pressure (ccSTP/L)
Producer Defined
0.48
5.06
DG_Used
List of dissolved gases used in calculation of recharge temperature and excess air
Producer Defined
List of dissolved gases used in calculation of recharge temperature and excess air
NobleGasData
Indicator if noble-gas data are available for site, yes or no
Producer Defined
Yes
Noble-gas data are available for this site
Producer defined
No
No noble-gas data are available for this site
Producer defined
RechTemp_NG
Recharge temperature as determined by noble gases, in degrees Celsius
Producer Defined
<< empty cell >>
No noble-gas data were collected, and as such no recharge temperature was computed.
Producer defined
4.3
13.2
EA_NG
Excess air as determined by noble gases, in cubic centimeters per kilogram at standard temperature and pressure (ccSTP/kg)
Producer Defined
<< empty cell >>
No noble-gas data were collected, and as such no excess air was computed.
Producer defined
4.96E-05
8.73E+00
NG_Used
List of noble gases used in calculation of recharge temperature and excess air
Producer Defined
List of noble gases used in calculation of recharge temperature and excess air
Model
Type of excess-air model used
Producer Defined
<< empty cell >>
No Data
Producer defined
Partial re-equilibration (PR)
Partial re-equilibration (PR) model
Producer defined
Closed-system equilibration (CE)
Closed-system equilibration (CE) model
Producer defined
Chi_Square
Coefficient of model fit, unitless
Producer Defined
<< empty cell >>
No noble-gas data were collected, and as such no chi-square was computed.
Producer defined
7.39e-26
3.53
Probability
Likelihood of model, fractional
Producer Defined
<< empty cell >>
No noble-gas data were collected, and as such no probability was computed.
Producer defined
0.06
1.0
3H
Tritium (3H) concentration in water, in tritium units (TU)
Producer Defined
3.11
19.87
3He-trit
Tritiogenic helium (3He-trit) concentration in water corrected for excess air and recharge temperature, in tritium units (TU)
Producer Defined
<< empty cell >>
No noble-gas data were collected, and as such no 3He-trit was able to be computed.
Producer defined
0.0
12.33
3H_3He_age
Apparent 3H/3He age, in years
Producer Defined
<< empty cell >>
No noble-gas data were collected, and as such no apparent age was able to be computed.
Producer defined
0.0
21.48
SF6_conc
Sulfur hexafluoride (SF6) concentration in water, in femtomoles per kilogram (fmol/kg)
Producer Defined
2.28
369.71
SF6_atm_mix
Sulfur hexafluoride (SF6) atmospheric mixing ratio in water at estimated temperature and excess air concentration, in parts per trillion volume (pptv)
Producer Defined
5.58
714.58
SF6_age
Idealized piston-flow age based on SF6 mixing ratio, in years
Producer Defined
MF
Model fails for this concentration because the atmospheric mixing ratios is greater than what is explainable by equilibration.
Producer defined
1.93
14.4
TracerLPMLookupMeanAges.csv
Comma Separated Value (CSV) file containing results of mean residence time estimation using the software TracerLPM
Producer Defined
USGS Site ID
USGS site identification numbers
U.S. Geological Survey
Unique site identification number, linked to the National Water Information System database at https://doi.org/10.5066/F7P55KJN
Site Alias
Short site alias name for identification
Producer Defined
Short site alias name for identification
Model
Type of lumped parameter model used based on visual fit, choice of piston-flow model (PFM) or dispersion model (DM)
Producer Defined
DM
Dispersion model
Producer defined
PFM
Piston-flow model
Producer defined
age_type
Tracer age estimate is based on 3H, 3He-trit, or SF6
Producer Defined
3H
Tritium
Producer defined
SF6
Sulfur hexafluoride
Producer defined
3He-trit
Tritiogenic helium
Producer defined
lookup_mean_age
Age estimate, in years
Producer Defined
1.00
62.5
error_pct
Uncertainty in age estimate, in percentage of age estimate
Producer Defined
0.0
4.2
This data release contains environmental tracer concentrations, modeled recharge conditions (water temperature, excess air), and resulting estimated residence times. This data release supports an integrated hydrogeochemical investigation of solute sources, groundwater recharge processes, and groundwater flow in the Fountain Creek alluvial aquifer, described fully in Newman and others (in preparation).
Newman, C.P., 2020, Environmental-tracer modeling to support hydrogeochemical evaluation of the Fountain Creek Alluvial Aquifer, El Paso County, Colorado: U.S. Geological Survey data delease, https://doi.org/10.5066/P99SPQM2.
GS ScienceBase
U.S. Geological Survey
mailing address
Denver Federal Center, Building 810, Mail Stop 302
Denver
CO
80225
United States
1-888-275-8747
sciencebase@usgs.gov
Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Digital Data
https://doi.org/10.5066/P99SPQM2
None
20200814
Connor P Newman
U.S. Geological Survey, ROCKY MOUNTAIN REGION
Hydrologist
mailing address
W 6th Ave Kipling St
Lakewood
CO
80225
US
303-236-6905
cpnewman@usgs.gov
FGDC Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998