Lake Wales Ridge Groundwater

^a Lower values are currently under consideration as MCL's ("administrative stay of effective date") by the USEPA [2004 Edition of the Drinking Water Standards and Health Advisories: http://www.epa.gov/waterscience/drinking/standards/dwstandards.pdf]: 3 µg/L for aldicarb and aldicarb sulfone, 4 µg/L for aldicarb sulfoxide, and 7 µg/L for the sum of any 2 or more of these compounds.

^b U.S.Geological Survey, 2004, data base from NAWQA data warehouse web site. Includes data collected between 1991 and September 20, 2002. [http://infotrek.er.usgs.gov/servlet/page?_pageid=543&_dad=portal30&_schema=PORTAL30, accessed 2/2/2004]. Sources of agricultural region data summaries were http://ca.water.usgs.gov/pnsp/pestgw/Pest-GW_2001_Text.html, and http://water.usgs.gov/nawqa/nutrients/datasets/nutconc2000/.

^c Excluding DIA.

^d GC of 3 ug/L corresponds to parent compound atrazine, as specified by FDEP.

^e Concentration is also an MCL (Maximum Contaminant Level, which is a USEPA primary drinking-water standard).

^f Subunit of the NAWQA Southern Florida Study Area, focused on citrus land use in Collier and Hendry Counties [see: http://fl.water.usgs.gov/Sofl/gw/gwintro.html], where soils and hydrogeology differ from Lake Wales Ridge; nitrate concentration in 22 of the 31 samples was <1 mg/L.

^g NO₃ concentrations are in mg/L.

^h Percentiles indicate specific non-exceedance probabilities; for example, the 95% percentile values are unlikely to be exceeded 95% of the time, based on the data collected in this study.

ⁱ For laboratory detection limits, refer to http://fisc.er.usgs.gov/Lake_Wales_Ridge/html/table_3.html