The South Florida Water Management District, the U.S. Environmental Protection Agency, and the USGS South Florida Ecosystems Initiative have organized an intensive study of surface water chemistry in Southern Florida. In 1994, several onsite-research locations were selected in the Water Conservation Areas of the South Florida Water Management District in conjunction with this multidisciplinary, multiagency research project. Surface water and marsh porewater water samples were collected and analyzed. Details of the onsite and laboratory procedures used in this investigation are described in other reports (Aiken, 1992 ; Fishman and Friedman, 1985 ; Garbarino and Taylor, 1979 and 1980 ; Reddy and others, 1989 ; Skougstad and others, 1979 ; Wood, 1976). Sample preparation, analytical procedures, and laboratory quality-control protocols used by the U.S. Geological Survey laboratory are described by Cotlove and others (1958) , Fishman and Friedman (1985) , Garbarino and Taylor (1979; 1980) and Schroder and others (1980) . Field procedures and equipment were adapted from a trace metal protocol developmed by the U.S. Geological Survey National Research Program (Taylor and others 1995).

This work has been done as part of the U.S. Geological Survey South Florida Ecosystems Initiative and was funded in part by the U.S. Environmental Protection Agency (through Grant IAG #DW14936802-01-0). The purpose of this report is to make available to the South Florida Ecosystem Research Community the results of our investigation of DOC concentration, nature, and distribution in a prompt and widely available manner. Further additions will be made to the data file as sample collection continues, and as laboratory analyses are completed.

The data file contains sample description, DOC concentration, and specific UV absorbance. Additional analytical data for samples collected at several sites in the Water Conservation Areas, the Everglades, South Florida, intended to be used by this project for chemical species modeling, are included.

This report presents results of chemical analysis for samples collected during March 1995 as part of a study to quantify the interaction of aquatic organic material (referred to here as dissolved organic carbon (DOC)) with dissolved metal ions. The work was done in conjunction with the South Florida Water Management District, the U.S. Environmental Protection Agency, the USGS South Florida Ecosystems Initiative, and the South Florida National Water Quality Assessment Study Unit. Samples were collected from surface canals and from marsh sites. Results are based on onsite and laboratory measurements for 27 samples collected at 10 locations. The data file contains sample description, DOC concentration and specific UV absorbance, and additional analytical data for samples collected at several sites in the Water Conservation Areas, the Everglades, South Florida.

Photo 1 - U3 sampling site in the South Florida Water Management District Water Conservation Area 2A (click on image for larger photograph - photo by M.M. Reddy).

Data are available for samples collected in March 1995 and analyzed shortly thereafter. Surface water samples were collected at a single depth from 7 locations and at two depths at 3 locations. Photograph 1 illustrates a representative water sample collection at site U3 in Water Conservation Area 2A, Everglades Florida. Marsh pore-water samples were collected at several depths below the sediment water interface at 4 locations. Surface water samples were collected at each pore-water sampling location. Photograph 2 illustrates selected Everglades Study Site Locations superimposed on a composite map based on the Threshold Study Site Locations map of the South Florida Water Management District and a color satellite photograph taken during the spring of 1993. A replicate sample was collected to evaluate onsite-sampling variability. Distilled-water blank samples and standard reference water samples (SRWS) were submitted to the laboratory with the onsite samples and were analyzed concomitantly with them. Reference samples were processed using the same procedures as the onsite samples. For further information about the availability, call Michael M. Reddy (303) 541-3012 mmreddy@usgs.gov.

The data file consists of 34 variables. Variable names and codes established for sample description and identification are listed in table 1. Variable names for parameters measured onsite and in the laboratory are listed in table 2. Summary statistics for standard reference water samples and distilled-water blank samples are given in table 3.

Samples that had analytical results less than the detection limits of the selected methods are indicated in the data set by the less than symbol. The detection limits of quantification are listed in table 4. The full data set is given in table 5.

(SRWS = Standard Reference Water Samples are prepared and used by the U.S. Geological Survey's quality assurance program to ensure that the laboratory is producing analytical data for inorganic constituents that are of acceptable reliability (Schroder and others, 1980).)

1. Variable names and codes for sample description and identification
2. Variable names for onsite and laboratory measured parameters
3. Summary statistics for standard reference water samples (SRWS) and distilled-water blank samples (SBL)
4. Detection limits for laboratory and onsite analyses
5. Analyses of surface water and marsh porewater from the South Florida Water Management Districts Water Conservation Areas, the Everglades, South Florida, March 1995.
   • 5.A
   • 5.B
   • 5.C
   • 5.D

1. A sampling site in the South Florida Water Management District Water Conservation Area 2A., December 1995, Photo by M. M. Reddy
2. Everglades study site locations, by Jason Tregellas

A total of 27 samples from 10 locations from South Florida Water Management District Water Conservation Areas have been analyzed using a protocol designed to minimize errors associated with sample handling procedures, laboratory analyses, and data-entry operations.

A listing of references is available.

For more information contact:

Chief, Branch of Regional Research
U.S. Geological Survey
Box 25046, Mail Stop 418
Denver, CO 80225-0046

Related information:

SOFIA Project: Interactions of Mercury with Dissolved Organic Carbon in the Florida Everglades

U.S. Department of the Interior, U.S. Geological Survey
This page is: http://sofia.usgs.gov/publications/reports/merc_carbon/print.html
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Last updated: 23 December, 2004 @ 12:41 PM (KP)