COLUMN_NAME	LABEL	LEGAL_VALUES
ACID_COND	Acidity condition class	Good|Fair|Poor|Not Assessed
AG_ECO3	"NARS 3-level reporting region (2015), based on aggregating AGGR_ECO9_2015 reporting regions.  No missing values allowed."	EHIGH|PLNLOW|WMTNS|
AG_ECO3_NM	NARS 3-level reporting region Name.  No missing values allowed.	Eastern Highlands|Plains and Lowlands|West|
AG_ECO9	"NARS 9-level reporting region (2015), based on aggregated Omernik Level III ecoregions.  No missing values allowed."	CPL|NAP|NPL|SAP|SPL|TPL|UMW|WMT|XER|
AG_ECO9_NM	NARS 9-level reporting region Name.  No missing values allowed.	Coastal Plains|Northern Appalachians|Northern Plains|Southern Appalachians|Southern Plains|Temperate Plains|Upper Midwest|Western Mountains|Xeric|
ANC_MDL	Method detection limit of Acid Neutralizing Capacity (ueq/L)	NA
ANC_NARS_FLAG	"Flag assigned by NARS for Acid Neutralizing Capacity. ND = Non-detect, L = Estimated, Q = Quality-related issue, S = Shipping time exceedence, H = Holding time exceedence , NR = No lab result for analyte"	NA
ANC_RESULT	Analyte value: acid neutralizing capacity	NA
AREA_CAT6	Lake area categories (6) used in most NLA survey designs. HAND sites also assigned area category. Based on AREA_HA.  No missing values allowed.	"(0,1]| (1,4]| (4,10]|(10,20]| (20,50]|  >50|"
ATRAZINE_MDL	Method detection limit	NA
ATRAZINE_NARS_FLAG	"Flag assigned by NARS: ND = Non-detect, L = Estimated, Q = Quality-related issue, S = Shipping time exceedence, H = Holding time exceedence, NR = No lab result for analyte"	NA
ATRAZINE_RESULT	Value of associated parameter	NA
ATZ_DETECT	Atrazine Detection	Detected|Not Detected|Not Assessed
ATZ_EPA_COND_3.4	Condition based on Atrazine concentration and 3.4 ppb benchmark	At or Below Benchmark|Above Benchmark|Not Assessed
BENT_MMI_COND_2017	Condition class based on 2017 updated benthic MMI scores	Good|Fair|Poor|Not Assessed
BFXHORIZDIST_DD	horizontal distance to drawdown zone using horiz_dist_dd (mean(horiz_dist_dd))	NA
BFXVERTHEIGHT_DD	vertical height to drawdown zone using vert_height_dd (mean(vert_height_dd))	NA
CHLA_COND	"Condition for Chlorophyll a indicator, based on CHLX"	NA
CHLA_MDL	Method detection limit of chlorophyll-a	NA
CHLA_NARS_FLAG	"Flag assigned by NARS for Chlorophyll a. ND = Non-detect, L = Estimated, Q = Quality-related issue, S = Shipping time exceedence, H = Holding time exceedence , NR = No lab result for analyte"	NA
CHLA_RESULT	Analyte value: chlorophyll-a	NA
COND_MDL	Minimum detection limit of analyte for Conductivity	NA
COND_NARS_FLAG	"NARS FLAG. ND = Nondetect; H = holding time issue; S = shipping issue; L = Less than reporting limit but above MDL; Q = other quality issue. See NARS_COMMENT, NR = No lab result for analyte for Conductivity"	NA
COND_RESULT	Analyte value: conductivity	NA
CYLSPER_DETECT	Cylindrospermopsin Detection	Detected|Not Detected|Not Assessed
CYLSPER_EPA_COND	Cylindrospermopsin condition based on EPA benchmark	Above Benchmark|At or Below Benchmark|Not Assessed
CYLSPER_MDL	Method detection limit for Cylindrospermopsin (ug/L)	NA
CYLSPER_NARS_FLAG	"Flag assigned by NARS for Cylindrospermopsin. ND = Non-detect, L = Estimated, Q = Quality-related issue, S = Shipping time exceedence, H = Holding time exceedence , NR = No lab result for analyte"	NA
CYLSPER_RESULT	Result for Cylindrospermopsin (ug/L)	NA
DIS_O2_CLS	Dissolved oxygen condition class	High (>=5 Ppm)|Moderate (>3-<5 Ppm)|Low (<=3 Ppm)|Not Assessed
DOC_MDL	Method detection limit of dissolved organic carbon	NA
DOC_NARS_FLAG	"Flag assigned by NARS for Dissolved Organic Carbon. ND = Non-detect, L = Estimated, Q = Quality-related issue, S = Shipping time exceedence, H = Holding time exceedence , NR = No lab result for analyte"	NA
DOC_RESULT	Analyte value: dissolved organic carbon	NA
DO_SURF	Dissolved oxygen in top 2 m (mg/L)	NA
DRAWDOWN_COND	Lake level drawdown exposure condition	Small|Medium|Large|Not Assessed
DRAWDOWN_COND_2CAT_2017	"Drawdown condition, specifially for 2017 survey"	Not Large|Large|Not Assessed
DSGN_CYCLE	NLA survey design time period 2007 | 2012 | 2017 | etc.	2007|2012|2017
ENTEROCOCCI_NARS_FLAG	"Flag assigned by NARS: ND = Non-detect, L = Estimated, Q = Quality-related issue, S = Shipping time exceedence, H = Holding time exceedence, NR = No lab result for analyte"	NA
ENTEROCOCCI_RESULT	Value of associated parameter	NA
ENT_1X_STV_COND	"Enterococci condition category, based on comparison of  the RESULT to the NARS benchmark of 1280 CCE/100-mL statistical threshold value (STV) from the EPA 2012 Recreational Water Quality Criteria (EPA-820-F-12-058)."	Above Benchmark|At or Below Benchmark|Not Assessed
EPA_REG	EPA Region.  No missing values allowed.	Region_01|Region_02|Region_03|Region_04|Region_05|Region_06|Region_07|Region_08|Region_09|Region_10|
FED_NONFED	"Ownership divided into federal and non-federal land, based on OWN_NARS variable"	FEDERAL|NON_FEDERAL
FRAME07	Lake is included or excluded from sample frame for the NLA 2007 survey design. Blank values are not allowed or NA for missing	Exclude|Include| Not Present|
FRAME12	Lake is included or excluded from sample frame for the NLA 2012 survey design.  Blank values are not allowed or NA for missing. 	Exclude|Include| Not Present|
FRAME17	Lake is included or excluded from sample frame for the NLA 2017 survey design.   Blank values are not allowed or NA for missing.	Exclude|Include|Not Present
IND_DOMAIN	"Name of the indicator group or Domain within a study.  Standard indicator groups are: EXTENT - which includes all lakes evaluated for a study and BASE - which includes all the lakes that are sampled for the main (""core"") indicators."	EXTENT|CORE |HAND|NONE
LAKE_ORGN	"Lake origin, based on evaluation on map or in field"	MAN_MADE|NATURAL|UNCERTAIN|UNKNOWN
LAT_DD83	"Latitude (based on NAD83 datum) assigned to lake during site selection from NHD-based sample frame. Generally, but not always, represents centriod of lake polygon in NHD.   No missing values allowed."	NA
LITCVR_COND	Shallow water habitat condition class	Good|Fair|Poor|Not Assessed
LITRIPCVR_COND	Lake habitat complexity condition class	Good|Fair|Poor|Not Assessed
LON_DD83	"Longitude (based on NAD83 datum) assigned to lake during site selection from NHD-based sample frame. Generally, but not always represents centriod of lake polygon in NHD.  No missing values allowed."	NA
LitCvrQc3OE	NLA 2012 Shallow water habitat condition indicator	NA
LitRipCvrQc3OE	NLA 2012 Lake habitat complexity condition indicator	NA
MAJ_BASIN	Major USGS Hydrologic Basins derived from NHDPlus codes Text of 16 basin codes from 01 to 18 with 05_06 and 12_13 combined preceeded by letter H	H01|H02|H03|H04|H05_06|H07|H08|H09|H10|H11|H12_13|H14|H15|H16|H17|H18
MAJ_BAS_NM	Major USGS Hydrologic Basins derived from NHDPlus names Text of 16 basin names	Arkansas-White-Red Region|California Region| Great Basin Region|Great Lakes Region|Lower Colorado Region|Lower Mississippi Region|Mid Atlantic Region|Missouri Region|New England Region|Ohio-Tennessee Region|Pacific Northwest Region|Rio Grande-Texas-Gulf Region|Souris-Red-Rainy Region|South Atlantic Gulf Region|Upper Colorado Region|Upper Mississippi Region|
MICX_DETECT	Microcystin Detection	Detected|Not Detected|Not Assessed
MICX_EPA_COND	Microcystin condition based on EPA benchmark	Above Benchmark|At or Below Benchmark|Not Assessed
MICX_MDL	Method detection limit for Microcystin (ug/L)	NA
MICX_NARS_FLAG	"Flag assigned by NARS for Microcystin. ND = Non-detect, L = Estimated, Q = Quality-related issue, S = Shipping time exceedence, H = Holding time exceedence , NR = No lab result for analyte"	NA
MICX_RESULT	Result for Microcystin (ug/L)	NA
MISS_BASIN	"Within Mississippi Basin or outside, based on MAJ_BAS_NM values"	MISSISSIPPI_BASIN|NOT_MISSISSIPPI_BASIN
MIS_BASIN	The hydrologic basin code for lakes in the Mississippi Basin derived from NHDPlus codes or blank for lakes not in the Mississippi Basin Text of 7 basin codes with H10 split into H10L and H10U or blank	NA
MIS_BAS_NM	"The hydrologic basin name for lakes in the Mississippi Basin derived from NHDPlus names, or blank for lakes not in the Mississippi Basin Text of 7 basin names or blank"	NA
MMI_BENT	Benthic MMI score	NA
MMI_ZOOP_2017	Zooplankton MMI score based on 2017 revision and tow volume corrections.	NA
NTL_COND	Condition class based on total nitrogen	Good|Fair|Poor|Not Assessed
NTL_MDL	Method detection limit for Total Nitrogen (mg N/L)	NA
NTL_NARS_FLAG	"Flag assigned by NARS for Total Nitrogen. ND = Non-detect, L = Estimated, Q = Quality-related issue, S = Shipping time exceedence, H = Holding time exceedence , NR = No lab result for analyte"	NA
NTL_RESULT	Result for Total Nitrogen (mg N/L)	NA
OWN_NARS	Land ownership category used by NARS. Text of 13 land ownership category names. Similar to OWN_TYPE  in USGS PADUS dataset except that Federal_Land is separated into major federal agencies.   No missing values allowed.	BLM|DOD|USFS|FWS|Jointly Owned|Local Government|Native American|Non-Governmental Organization| NPS|Other Fed|Private|Regional Agency|State|
PSTL_CODE	"State two letter postal code for site sampled. 50 state postal codes plus AS, MP, GU, PR, VI for American Samoa, Commonwealth of Northern Marianas, Guam, Puerto Rico and Virgin Islands.  No missing values allowed."	NA
PTL_COND	Condition class based on total phosphorus	Good|Fair|Poor|Not Assessed
PTL_MDL	Method detection limit for Total Phosphorus (ug/L)	NA
PTL_NARS_FLAG	"Flag assigned by NARS for Total Phosphorus. ND = Non-detect, L = Estimated, Q = Quality-related issue, S = Shipping time exceedence, H = Holding time exceedence , NR = No lab result for analyte"	NA
PTL_RESULT	Result for Total Phosphorus (ug/L)	NA
PUBLICATION_DATE	Date the dataset was published to the NARS site	0
RDIS_COND	Lakeshore disturbance condition class	Low|Medium|High|Not Assessed
RDis_IX	NLA 2012 Lakeshore disturbance condition indicator	NA
RVEG_COND	Riparian vegetation condition class	Good|Fair|Poor|Not Assessed
RVegQc3OE	NLA 2012 Riparian vegetation condition indicator	NA
SITE_ID	"The NLA Site ID  for the study and year sampled.  Preferred form is NLAnn_MM-xxxxx  where  nn is current cycle year (07, 12, 17, etc), MM is two letter state code, and xxxxx is between 10001 and 99999. No missing values allowed."	NA
SULFATE_MDL	Method detection limit of sulfate	NA
SULFATE_NARS_FLAG	"Flag assigned by NARS for Sulfate. ND = Non-detect, L = Estimated, Q = Quality-related issue, S = Shipping time exceedence, H = Holding time exceedence , NR = No lab result for analyte"	NA
SULFATE_RESULT	Analyte value: sulfate	NA
TNT_CAT	NLA target status assigned based on lake evaluation for use in national assessments	Target|Non_Target|None
TROPHIC_STATE	Trophic state (Oligotrophic/Mesotrophic/Eutrophic/Hypereutrophic)	|OLIGOTROPHIC|MESOTROPHIC|EUTROPHIC|HYPEREUTROPHIC
UID	Unique identifier for the site/visit
UNIQUE_ID	"Unique site ID based on location that does not depend on year sampled or any other factor.  Form is NLA_ss_nnnnn  where ss state and nnnnn is number that starts at 10001.   No missing or ""blank"" values allowed."	NA
URBN_NLA07	Lake identified as an urban lake using 2007 definition of Urban. No missing or blank values allowed	Urban|Non-Urban|
URBN_NLA17	Lake identified as an urban lake using 2017 definition of Urban. No missing or blank values allowed	Urban|Non-Urban|
URBN_NLA22	"Lake identified as an urban lake using 2022 definition of Urban (HUC12 intersecting Census UAC from 2019).  No missing or ""blank"" values allowed."	Urban | Non-Urban |
WGT_TP	NLA adjusted weight for lake when want estimates to be for the Target Population. Includes weight adjustments to account for sites with unknow status and when lake status is known to be target but not sampled. Note: >0 or 0 if site is not to be used for target population estimation	NA
XCOORD	x-coordinate from US Contiguous Albers Equal Area Conic projection EXCEPT Hawaii or Alaska lakes which are calculated from Hawaii or Alaska Albers Equal Area Conic projectionNo missing values allowed.	NA
YCOORD	y-coordinate from US Contiguous Albers Equal Area Conic projection EXCEPT Hawaii or Alaska lakes which are calculated from Hawaii or Alaska Albers Equal Area Conic projection. No missing values allowed.	NA
ZOOP_MMI_COND_2017	Condition class based on 2017 updated zooplankton MMI scores (following tow volume corrections)	Good|Fair|Poor|Not Assessed
VISIT_NO	Sequential number of visit to site	|1|2