Data Type Name Description Category Notes Column Header Type Population estimate groups National|Lake_Origin|Major_River_Basin|Misissippi_River_Basin|EPA_Region|Aggregated_Ecoregion_3 | Aggregated_Ecoregion_9 See 'Population estimate group' descriptions below Column Header Subpopulation Subpopulation estimate groups (subsets of the Type) Arkansas-White-Red Region | California Region | CPL | EHIGH | Great Basin Region | Great Lakes Region | Lower Mississippi Region | MAN_MADE | Mid Atlantic Region | MISSISSIPPI_BASIN | Missouri Region | NAP | National | NATURAL | New England Region | NOT_MISSISSIPPI_BASIN | NPL | Ohio-Tennessee Region | Pacific Northwest Region | PLNLOW | Region_01 | Region_02 | Region_03 | Region_04 | Region_05 | Region_06 | Region_07 | Region_08 | Region_09 | Region_10 | Rio Grande-Texas-Gulf Region | SAP | Souris-Red-Rainy Region | South Atlantic Gulf Region | SPL | TPL | UMW | Upper Colorado-Lower Colorado Region | Upper Mississippi Region | WMT | WMTNS | XER Column Header Indicator Indicator assessed ACID_COND | DIS_O2_CLS | PTL_COND | NTL_COND | CHLA_COND | TROPHIC_STATE |ATZ_EPA_COND_3.4 | ATZ_DETECT | CYLSPER_EPA_COND|CYLSPER_DETECT | MICX_EPA_COND | MICX_DETECT | ECOLI_EPA_COND | ECOLI_DETECT | BENT_MMI_COND_2017 | ZOOP_MMI_COND_2017 | DRAWDOWN_COND_2CAT_2017 | LITRIPCVR_COND|LITCVR_COND | RVEG_COND | RDIS_COND | NLA_SCI_STATUS| See 'Indicator' descritpions below Column Header Category "Condition category (e.g., good, fair, poor)" Above Benchmark | At or Below Benchmark |Detected | Eutrophic | Fair | Good | High (>= 5 ppm) | Hypereutrophic | Large | Least Disturbed | Low (<= 3 ppm) | Mesotrophic | Moderate (> 3 - < 5 ppm) | Moderately Disturbed | Most Disturbed | Not Assessed | Not Detected | Not Large | Oligotrophic | Poor See NLA 2017 Technical Support Document for more details Column Header NResp "Number of ""responses""/sites in the category from the National Lakes Assessment 2017" NA Column Header Estimate.P "National Lakes Assessment 2017 population estimate - proportion of lakes (e.g., percent), includes all lakes 1 ha and larger" NA Column Header StdError.P Standard error for the population estimate based on percentages. Multiply by 1.968 to develop upper and lower confidence limits. NA Column Header LCB95Pct.P Error Bar for condition assessment based on percentages-- Lower confidence bound at 95% NA Column Header UCB95Pct.P Error Bar for condition assessment based on percentages--Upper confidence bound at 95% NA Column Header Estimate.U "Population Estimate, based on number of lakes for National Lakes Assessment 2017 data, includes all lakes 1 ha and larger" NA Column Header StdError.U Standard error for the population estimate based on number of lakes NA Column Header LCB95Pct.U Error Bar for condition assessment based on based on number of lakes -- Lower confidence bound at 95% NA Column Header UCB95Pct.U Error Bar for condition assessment based on based on number of lakes --Upper confidence bound at 95% NA Indicator ACID_COND Acidity condition class NA Indicator ATZ_DETECT Atrazine Detection NA Indicator ATZ_EPA_COND_3.4 Condition based on Atrazine concentration and 3.4 ppb benchmark NA Indicator BENT_MMI_COND_2017 Condition class based on 2017 updated benthic MMI scores NA Indicator CHLA_COND "Condition for Chlorophyll a indicator, based on CHLX" NA Indicator CYLSPER_DETECT Cylindrospermopsin Detection NA Indicator CYLSPER_EPA_COND Cylindrospermopsin condition based on EPA benchmark NA Indicator DIS_O2_CLS Dissolved oxygen condition class NA Indicator DRAWDOWN_COND_2CAT_2017 "Drawdown condition, specifially for 2017 survey" NA Indicator ECOLI_DETECT E. coli Detection NA Indicator ECOLI_EPA_COND E. coli condition based on EPA benchmark NA Indicator LITCVR_COND Shallow water habitat condition class NA Indicator LITRIPCVR_COND Lake habitat complexity condition class NA Indicator MICX_DETECT Microcystin Detection NA Indicator MICX_EPA_COND Microcystin condition based on EPA benchmark NA Indicator NLA_SCI_STATUS "Sediment Contaminant Index condition assignment for NLA 2017 based on sediment contaminant thresholds of Mean_PEC_Q <=0.1 is Least Disturbed, Mean_PEC_Q > 0.1 and Mean_PEC_Q < 0.6 is Moderately Disturbed, and Mean_PEC_Q >=0.6 is Most Disturbed. " NA Indicator NTL_COND Condition class based on total nitrogen NA Indicator PTL_COND Condition class based on total phosphorus NA Indicator RDIS_COND Lakeshore disturbance condition class NA Indicator RVEG_COND Riparian vegetation condition class NA Indicator TROPHIC_STATE Trophic state (Oligotrophic/Mesotrophic/Eutrophic/Hypereutrophic) NA Indicator ZOOP_MMI_COND_2017 Condition class based on 2017 updated zooplankton MMI scores (following tow volume corrections) NA Population estimate groups Aggregated_Ecoregion_3 "NARS 3-level reporting region (2015), based on aggregating AGGR_ECO9_2015 reporting regions. No missing values allowed." EHIGH|PLNLOW|WMTNS| Population estimate groups Aggregated_Ecoregion_9 "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| Population estimate groups EPA_Region 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| Population estimate groups Lake_Origin "Lake origin, based on evaluation on map or in field" MAN_MADE|NATURAL|UNCERTAIN|UNKNOWN Population estimate groups Major_River_Basin 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| Population estimate groups Misissippi_River_Basin "Within Mississippi Basin or outside, based on MAJ_BAS_NM values" MISSISSIPPI_BASIN|NOT_MISSISSIPPI_BASIN Population estimate groups National Conterminous United States NA