US Environmental Protection Agency NHEERL-Atlantic Ecology Division 2007 Narragansett, RI U.S. EPA Office of Research & Development (ORD) - National Health and Environmental Effects Research Laboratory (NHEERL) http://www.epa.gov/aed/lakesecoservices The Water Quality data set reports physical water quality parameters measured in the field and concentrations of nutrients measured from samples collected from lakes in the National Lake Assessment program during the summer of 2007. Water samples reflect lake conditions from an 'index site' located at the deepest point of a lake (</=50 meters, and near the center if sampling a reservoir). Data reported include dissolved oxygen at 2 m or less, depth, conductivity, acid neutralizing capacity, turbidity, total organic carbon, dissolved organic carbon, total ammonium, nitrate + nitrite, total nitrogen, total potassium, color, chloride, nitrate, sulfate, calcium, magnesium, sodium, silica, chlorophyll a, Secchi depth (mean), and phosphorus. Dissolved oxygen was measured with a probe on a vertical profiler. Secchi depth was recorded from a Secchi disk, while nutrients were measured from samples taken from the upper 2 m of the water column with a depth integrated water sampler. The U.S. Environmental Protection Agency (EPA), in partnership with state and tribal organizations, has designed the Survey of the Nation's Lakes to periodically assess the condition of the Nation's surface waters. The National Lake Assessment is a statistical assessment of the condition of our Nation's lakes, ponds, and reservoirs. The survey is designed to: 1) Assess the condition of the Nation's Lakes; 2) Establish a baseline to compare future surveys for trends assessment and evaluate trends since the 1970's National Eutrophication Survey Study and 3) Help build State and Tribal capacity for monitoring and assessment and promote collaboration across jurisdictional boundaries. EPA Produced 20070508 20071018 Publication date Complete As needed -79.2277 -67.6993 47.1778 36.8415 ISO 19115 Topic Category environment inlandWaters EPA GIS Keyword Thesaurus Ecosystem Environment Monitoring Quality Surface Water NLA acid neutralizing capacity calcium chloride chlorophyll a color conductivity dissolved organic carbon dissolved oxygen Lakes Ecosystem Services magnesium National Lakes Assessment nitrate nitrate + nitrite nutrient concentrations phosphorus physical measurements Secchi depth silica sodium sulfate total ammonium total nitrogen total organic carbon total potassium turbidity None Connecticut Delaware Maine Maryland Massachusetts New Hampshire New Jersey New York Pennsylvania Rhode Island United States Vermont Virginia Washington DC West Virginia None. None. Download data as comma delimited (csv) files at URL under Online Linkage. U.S. Environmental Protection Agency, NHEERL-Atlantic Ecology Division Jeff Hollister Principal Investigator mailing and physical address

27 Tarzwell Drive

Narragansett RI 02882 (401) 782-9655 hollister.jeff@epa.gov hollister.jeff@epa.gov FIPS Pub 199 No Confidentiality Standard Technical Controls Test of Valid Values Complete Data were collected using methods that are accurate to within 26-100 meters (EPA National Geospatial Data Policy [NGDP] Accuracy Tier 4). For more information, please see EPA's NGDP at http://epa.gov/geospatial/policies.html) 0.000001 Calibration of GPS unit and availability of back-up GPS unit. Data underwent Quality Assurance checks and were loaded into Oracle. 20101231 0.000001 0.000001 Decimal degrees North American Datum of 1983 Geodetic Reference System 1980 6378137.000000 298.257222 Water Quality Water Quality Data: Physical measurements and Nutrient concentrations NA WB ID Unique Waterbody ID NA NA NA DISSOLVED OXYGEN @2M OR LESS Mean Dissolved oxygen concentration (mg/L) in upper 2 m (or upper 50% if depth < 4 m) NA 1.35 16.20 CONDUCTIVITY Conductivity (uS/cm @ 25 C) NA 15.73 746.20 TURBIDITY Turbidity (NTU) NA 0.33 35.60 TOTAL ORGANIC CARBON Total Organic Carbon (mg/L) NA 0.79 16.66 ACID NEUTRALIZING CAPACITY Gran acid neutralizing capacity (ueq/L) NA -40.89 3274.10 DISSOLVED ORGANIC CARBON Dissolved Organic Carbon (mg/L) NA 1.18 14.01 AMMONIUM Ammonium (mg N/L) NA 0.01 0.28 NITRATE+NITRITE Nitrate + Nitrite (mg N/L) NA 0.01 3.43 TOTAL NITROGEN Total Nitrogen (ug/L) NA 63.00 4222.00 TOTAL PHOSPHORUS Total Phosphorus (ug/L) NA 1.00 315.00 CHLORIDE Chloride (mg/L) NA 0.18 135.59 NITRATE Nitrate (mg N/L) NA 0.01 3.17 SULFATE Sulfate (mg/L) NA 1.04 35.54 CALCIUM Calcium (mg/L) NA 0.31 44.87 MAGNESIUM Magnesium (mg/L) NA 0.17 22.89 SODIUM Sodium (mg/L) NA 0.52 87.19 POTASSIUM Potassium (mg/L) NA 0.10 8.22 COLOR Color (PCU) NA 0.00 140.00 SILICA Silica (mg/L SiO2) NA 0.03 20.59 CHLOROPHYLL A Chlorophyll a concentration (µg/L) NA 0.69 216.00 SECCHI (MEAN) Secchi transparency (m); avg. disk disappearance/reappearance depths NA 0.25 9.60 CLEAR TO BOTTOM 'Y' indicates disk visible at bottom of lake NA NA NA NLA ID National Lake Assessment study lake ID NA NA NA NLA LAKE NAME National Lake Assessment lake name NA NA NA EPA REGION EPA Region NA 1 3 STATE CODE State assigned by US EPA-AED within which the greater percentage of lake area falls NA NA NA COUNTY County assigned by US EPA-AED within which the greater percentage of lake area falls NA NA NA LATITUDE Latitude (decimal degrees) NA 36.8415 47.1778 LONGITUDE Longitude (decimal degrees) NA -79.2277 -67.6993 SAMPLING YEAR Sampling year NA 2007 2007 VISIT NUMBER Sequential visit number within year NA 1 2 The Water Quality data were collected in 2007 from Northeast region lakes from the states of Maine to Connecticut. Samples reflect lake conditions from an 'index site' located at the deepest point of a lake (</=50 meters, and near the center if sampling a reservoir). Water quality parameters included dissolved oxygen at 2 m or less, depth, conductivity, acid neutralizing capacity, turbidity, total organic carbon, dissolved organic carbon, total ammonium, nitrate + nitrite, total nitrogen, total potassium, color, chloride, nitrate, sulfate, calcium, magnesium, sodium, silica, chlorophyll a, Secchi depth (mean), and phosphorus. Lakes are classified according to their trophic state. Trophic means nutrition or growth. A eutrophic (well-nourished) lake has high nutrients and high plant growth. An oligotrophic lake has low nutrient concentrations and low plant growth. Mesotrophic lakes fall somewhere in between eutrophic and oligotrophic lakes. Three variables, chlorophyll, Secchi disk depth, and total phosphorus, are most often used to estimate biomass and define trophic state of a lake. Other variables are measured in conjunction with the trophic state variables to supplement and enhance understanding of lake processes that affect primary productivity. Depth profiles for dissolved oxygen were taken with a calibrated water quality probe meter or multi-probe sonde from the index station in each lake. This information was used to determine the extent of stratification and the level of dissolved oxygen necessary to support aquatic life. A Secchi disk, a black and white patterned disk, was used to measure the clarity of water in visibility distance. The Secchi disk measurement helps make an estimate of the euphotic zone depth in the field. Water chemistry measurements were used to determine the acidic conditions, trophic state and nutrient enrichment, and classification of water chemistry type. The measurement of Chlorophyll a is used to determine algal biomass in the water and estimate trophic status. USEPA. 2007. Survey of the Nation's Lakes. Field Operations Manual. EPA 841-B-07-004. US Environmental Protection Agency, Washington, DC. U.S. Environmental Protection Agency, NHEERL-Atlantic Ecology Division Jeff Hollister Principal Investigator mailing and physical address

27 Tarzwell Drive

Narragansett RI 02882 (401) 782-9655 hollister.jeff@epa.gov hollister.jeff@epa.gov Downloadable Data "Although these data have been processed successfully on a computer system at the Environmental Protection Agency, no warranty expressed or implied is made regarding the accuracy 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. It is also strongly recommended that careful attention be paid to the contents of the metadata file associated with these data to evaluate data set limitations, restrictions or intended use. The U.S. Environmental Protection Agency shall not be held liable for improper or incorrect use of the data described and/or contained herein." 20110223 20150223 U.S. Environmental Protection Agency, NHEERL-Atlantic Ecology Division Jeff Hollister Principal Investigator mailing and physical address

27 Tarzwell Drive

Narragansett RI 02882 (401) 782-9655 hollister.jeff@epa.gov hollister.jeff@epa.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998