National Water Information System (NWIS) Water-Quality Web Services

USGS domains of WQX-Outbound data elements

Domains are not enforced on data elements by the WQX-Outbound schema. However, the expected domains are listed here to assist others in conforming to a consistent nomenclature. A "domain-values" web service can be queried to determine the USGS-supplied values of the domains used for retrievals.

CharacteristicName: is confined by the USEPA Substance Registry System (SRS), with a small number of exceptions also implemented by the USEPA WQX system.

USGS identifies measurements using parameter codes. The association of parameter codes to SRS names is evolving as parameters and SRS names are added and modified. This list will be updated periodically. A relatively small number of USGS results (<3% of non-taxonomic measurements) are not provided through the water-quality web services. Measurements are not included for one of these reasons: (1) No Substance Registry System (SRS) name has been assigned, (2) measurement describes counts of algae or benthic invertebrate taxonomic groups, or (3) measurement describes surrogate recovery for a compound added at the laboratory prior to analysis. These data may be obtained from NWIS Web.

The following names are employed but are not in the SRS.

Aluminum, Organic + Inorganic Monomeric (reactive aluminum)
Aluminum, Organic Monomeric (reactive aluminum)
Hydrophilic fraction of organic carbon
Hydrophobic fraction of organic carbon
Transphilic fraction of organic carbon

NWIS Parameter Code to SRS Crosswalk

The association of USGS parameter codes with WQX-Outbound data elements is available in html or Excel formats. The following column names are used.

• parm_cd - USGS parameter code
• description - USGS parameter description
• epa_equivalence - Comparison of USGS usage with USEPA of this parameter code
• characteristicname - WQX-Outbound characteristic name
• measureunitcode - WQX-Outbound measurement units
• resultsamplefraction - WQX-Outbound sample fraction
• resulttemperaturebasis - WQX-Outbound temperature basis
• resultstatisticalbasis - WQX-Outbound statistical basis
• resulttimebasis - WQX-Outbound time basis
• resultweightbasis - WQX-Outbound weight basis
• resultparticlesizebasis - WQX-Outbound particle-size basis

ResultSampleFractionText:

Fraction	Comment
Bed Sediment	- Added by USGS
Bedload	- Added by USGS
Comb Available
Dissolved
Free Available
Non-filterable
Non-settleable
Recoverable
Settleable
Suspended
Total
Total Residual

 

MeasureUnitCode:

Units	Comment
#/m3	Number per cubic meter
#/ml	Number per milliliter
%	Percent
% by wt	Percent by weight
% saturatn	Percent of saturation - added by USGS
100xA/cm/c	100 times the absorbance per centimeter per milligram per liter of hydrophobic acid - added by USGS
AU	Light, detection angle 180 degrees to incident light, attenuation units - added by USGS
AU/cm	Light absorbance units per centimeter - added by USGS
BU	Light, detection angle 0 degrees to incident light, backscatter units - added by USGS
Bcol/day	Billions of colonies per day - added by USGS
Deg	Direction or angle, degrees
FAU	Light detection angle 180 degrees to incident light, attenuation units - added by USGS
FBU	Light detection angle 0 degrees to incident light, backscatter units - added by USGS
FNMU	Light multiple beam, detectors at multiple angles including 90 degrees, - added by USGS
FNRU	Light multiple beam, detectors at multiple angless including 90 degrees, ratiometric correction - added by USGS
FNU	formazin nephelometric units - added by USGS
IVFU	in vivo fluorescence units - added by USGS
JTU	Turbidity, Jackson Turbidity Units
Kac-ft	thousand acre feet - added by USGS
L/mgDOC*m	Liter per (milligram of dissolved organic carbon * meter) - added by USGS
MPN	Most Probable Number
MPN/100 ml	Most Probable Number per 100 milliliters
MPN/100L	most probable number per 100 liters - added by USGS
MPN/gram	most probable number per gram - added by USGS
Mft3	million cubic feet - added by USGS
Mgal	million gallons - added by USGS
NTMU	Light multiple beam, detectors at multiple angles including 90 degrees, - added by USGS
NTRU	Light detectors at multiple angles including 90 +/-30 degrees, ratiometric correction, nephelometric - added by USGS
NTU	Turbidity, Nephelometric Turbidity Units
None	None
PCU	Platinum Cobalt Units (color)
PSS	Practical Salinity Scale
PrsAbs	presence or absence - added by USGS
PrsAbs/50L	presence or absence in 50 liters - added by USGS
PrsAbs0.1L	presence or absence per 100 milliliters - added by USGS
RFU	Relative fluorescence units - added by USGS
T.U.	Tritium Unit
TON	Threshold Odor Number
ac-ft	Acre-feet
bq/g	becquerels per gram - added by USGS
cal/cm2/d	calories per square centimeter per day - added by USGS
cells/mm2	number of cells per square millimeter - added by USGS
cfs	Cubic feet per second
cfs-days	cubic feet per second-days - added by USGS
cfu/100ml	Colony Forming Units per 100 Milliliters
cm3/g @STP	Cubic centimeters per gram at standard temperature and pressure - added by USGS
cm3/g STP	cubic centimeters per gram at standard temperature and pressure - added by USGS
code	code - added by USGS
col/gram	colonies per gram - added by USGS
col/mL	colonies per milliliter - added by USGS
counts/sec	Counts per second - added by USGS
cysts/100L	cysts per 100 liters - added by USGS
cysts/10L	cysts per 10 liters - added by USGS
days	Days
deg C	Degrees Celsius (Centigrade)
deg F	Degrees Fahrenheit
dpm/g	disintegrations per minute per gram - added by USGS
dpm/l	Disintegrations per minute per liter - added by USGS
fg/kg	femtograms per kilogram - added by USGS
ft	feet
ft abv MSL	feet above mean sea level - added by USGS
ft/sec	Feet per second
g H2O/g	grams of water per gram of dry solids - added by USGS
g/day	Grams per day
g/kg	grams per kilogram
g/m2	grams per square meter
g/m2/day	grams per square meter per day
g/m3	grams per cubic meter
g/mL @ 20C	grams per milliliter at 20 degrees Celsius - added by USGS
gal/batch	gallons per batch - added by USGS
gal/min	Gallons per minute
in	inches
in/H2O	Pressure, inches of water
in/Hg	Pressure, inches of mercury
inches/day	inches per day - added by USGS
kPa	kilopascals - added by USGS
l	Liters
lb/d as N	pounds per day as nitrogen - added by USGS
lb/day	Pounds per day
m	meters
m/sec	Meters per second
m2/g	square meters per gram - added by USGS
mL/L/hr	milliliters per liter per hour - added by USGS
mV	Millivolts
meq/100g	milliequivalents per 100 grams - added by USGS
meq/L	Milli-equivalents per Liter
mg 02/m2/d	milligrams oxygen per square meter per day - added by USGS
mg 02/m3/d	milligrams oxygen per cubic meter per day - added by USGS
mg/g	milligrams per gram
mg/kg	milligrams per kilogram
mg/kg NH4	milligrams per kilogram as NH4 - added by USGS
mg/kg PO4	milligrams per kilogram as phosphate - added by USGS
mg/kg as N	milligrams per kilogram as nitrogen - added by USGS
mg/kg as P	milligrams per kilogram as phosphorus - added by USGS
mg/l	milligrams per liter
mg/l CaCO3	Milligrams per liter calcium carbonate
mg/l NH4	milligrams per liter as NH4 - added by USGS
mg/l NO3	milligrams per liter as nitrate - added by USGS
mg/l PO4	milligrams per liter as phosphate - added by USGS
mg/l SiO2	milligrams per liter as silicon dioxide - added by USGS
mg/l as H	milligrams per liter as hydrogen ion - added by USGS
mg/l as N	milligrams per liter as nitrogen - added by USGS
mg/l as Na	milligrams per liter as sodium - added by USGS
mg/l as P	milligrams per liter as phosphorus - added by USGS
mg/l as S	milligrams per liter as sulfur - added by USGS
mg/m2	milligrams per square meter
mg/m2 NH4	milligrams per square meter as NH4 - added by USGS
mg/m2 NO3	milligrams per square meter as nitrate - added by USGS
mg/m2 as N	milligrams per square meter as nitrogen - added by USGS
mg/m2 as P	milligrams per square meter as phosphorus - added by USGS
mg/m2 as S	milligrams per square meter as sulfur - added by USGS
mg/mL @25C	Milligrams per liter at 25-degrees Celsius - added by USGS
mgC3H6O2/L	milligrams per liter as propionic acid - added by USGS
mgal/mnth	Millions of gallons per month
mgd	Millions of gallons per day
millibars	millibars - added by USGS
minutes	Minutes
ml/l	Milliliters per liter
mm	millimeters
mm/Hg	Pressure, millimeters of mercury
mosm/kg	milliosmoles per kilogram - added by USGS
ng/POCIS	nanograms per polar organic chemical integrative sampler (POCIS) - added by USGS
ng/SPMD	nanograms per semi-permeable membrane device - added by USGS
ng/g	nanograms per gram
ng/l	nanograms per liter
ng/m2/hr	nanograms per square meter per hour - added by USGS
ng/m2/wk	nanograms per square meter per week - added by USGS
ng/m3	nanograms per cubic meter
nmol/L	nanomoles per liter - added by USGS
nu	number or gage
ocyst/100L	oocysts per 100 liters - added by USGS
oocyst/10L	oocysts per 10 liters - added by USGS
pCi/L	pico-Curies per Liter
pCi/g	pico-Curies per gram
pCi/ml	pico-Curies per milliliter
pct modern	percent modern - added by USGS
per mil	per mil - added by USGS
pg/g	picograms per gram
pg/kg	picograms per kilogram
pg/l	picograms per liter
pg/m3	picograms per cubic meter
pg/mL	picograms per milliliter - added by USGS
ppth	parts per thousand
std units	standard units - added by USGS
ton/d as N	tons per day as nitrogen - added by USGS
ton/d/ft	tons per day per foot of width - added by USGS
tons/ac ft	Tons per acre feet
tons/day	Tons per day
uS/cm	Micro-Siemens per Centimeter
uS/cm @25C	Microsiemens per centimeter at 25 degrees Celsius - added by USGS
ueq/L	Micro-equivalents per Liter
ug/L U3O8	micrograms per liter as uranium(V,VI) oxide (U3O8) - added by USGS
ug/L as As	micrograms per liter as arsenic - added by USGS
ug/L as Cl	micrograms per liter as chloride - added by USGS
ug/L as N	micrograms per liter as nitrogen - added by USGS
ug/L as P	micrograms per liter as phosphorus - added by USGS
ug/g	micrograms per gram
ug/g as Cl	micrograms per gram as Chloride - added by USGS
ug/g as N	micrograms per gram as Nitrogen - added by USGS
ug/kg	micrograms per kilogram
ug/l	micrograms per liter
ug/m2	micrograms per square meter
ug/mg	micrograms per milligram - added by USGS
ugAtrazn/L	micrograms per liter as Atrazine - added by USGS
ugAtrzn/kg	ug of Atrazine per kilogram - added by USGS
umol/l	micromoles per liter - added by USGS
umol/m2/s	micro moles per square meter per second
units/cm	Units per centimeter, for UV absorbance
watts/m2	watts per square meter - added by USGS

 

ResultWeightBasisText:

Weight Basis	Comment
Ash Weight	Added by USGS
Ash-Free Dry
Dry
Wet

 

ResultTemperatureBasisText:

Temperature Basis	Comment
105 deg C
110 deg C
180 deg C
20 deg C
25 deg C
35 deg C
37 deg C
42 deg C
43 deg C
44.5 deg C
60 deg C
Heated

 

ResultStatisticalBasisText:

Statistical Basis	Comment
1-Sigma CSU	Combined standard uncertainty, 1 standard deviation - Added by USGS
2-Sigma CSU	Combined standard uncertainty, 2 * standard deviation - Added by USGS
Counting Error	Added by USGS
Maximum
Mean
Standard Deviation

 

DetectionQuantitationLimitType:

Quantitation Limit Type	Comment
Elevated detection limit	Added by USGS
Historical lower reporting limit	Added by USGS
Interim reporting level	Added by USGS
Laboratory reporting level	Added by USGS
Long term method detection level
Lower quantitation limit
Minimum reporting level	Added by USGS
Method detection limit
Sample-specific min detect concentration	Added by USGS
Sample-specific critical level	Added by USGS
Upper reporting limit

 

ResultDetectionConditionText:

Detection Condition	Comment
Not Detected
Systematic Contamination	Added by USGS
Detected Not Quantified
Present Above Quantification Limit

 

ResultStatusIdentifier:

Result Status Type	Comment
Preliminary
Historical	Added by USGS
Accepted