• Sulfate (SO^) and chloride (CI) were analyzed using a Shimadzu HPLC (LC-6A pump, C- 



R3A Chromatopac processor, SCL-6A Controller); Ippm Limit of Quantitation (LOQ). 



• Nitrate (NOj) was determined using a Shimadzu HPLC (LC-6A pump, SPD-6AV UVA^is 



Detector, SCL-6A Controller); 20 ppb LOQ. 



• Carbon was analyzed using a Dohrmann DC-80 Carbon Analyzer; Total Dissolved Carbon 



(TDC), 1 ppm LOQ. 



• Selenium was quantified using a Technicon BD-40 Heating Block and Control Unit 



digester, with Technicon auto-analyzer sampling pump fitted with a glass sampling 

 probe, proportioningpump, regulated water bath, and recorder, and a Turner Flourimeter 

 Model ni with a continuous flow cuvette; Se, 1 ppb LOQ. 



Description of Field-Measured and Chemical Analysis Data 



Introduction 



A summary of results from chemical analyses of the evaporation pond water and inflow 

 samples are shown in Tables 2.3 to 2. 12. The tables include data for inflow waters as well as the 

 average values from each pair of sampling sites taken from each cell. In addition, the minimum, 

 maximum and average values for each cell are presented. Particular emphasis in this discussion 

 will be placed on the important trends and possible implications. 



Field-Measured Data 



The results of on-site analyses at Peck, Pryse and Barbizon evaporation ponds are shown 

 in Tables 2.3 to 2.6. Only salinity, as reflected by the EC, fluctuated significantly with season. 



EC values of pond waters overall ranged from 8.78 dS/m at Barbizon pond to 174 dS/m 

 at Pryse pond. Inflow waters were generally lower in salinity rangingfrom 7.73 dS/m at Barbizon 

 pond to 33.5 dS/m at Pryse pond. The conductivity was typically lowest during the Winter 

 sampling time, while maximum values have typically been found during the Summer or Fall 

 seasons. Lower ECs may be due to the dilution through addition of new drainage water. The pH 

 of inflow waters were between 7 and 8, while the pH of the pond waters were up to 2 pH units 

 above that of the inflow. The Eh measurements indicate that with only a few exceptions, the 

 waters were weakly oxidizing. Changes in Eh do not appear to be closely linked to changes in 

 dissolved oxygen concentration indicating perhaps that the dominant redox couple does not 

 involve oxygen as the electron donor/receptor which facilitates the electron transfer necessary 

 for redox reactions. There were some differences between the alkalinity of inflow and pond 

 waters which suggests, in some cases, that there was a re-equilibration between atmospheric 

 COj and soluble carbonate minerals when the water was released from the confines of the tile 

 drain system into the free surface water body. 



Chemical Analysis Data 



• Major Solutes 



The major solutes include Na% Ca^*, Mg=-, K-, HCO,", CI", SO/ and NO3-. The ternary 

 diagrams in Figure 2. 1 show the dominance of the SO^^ anion and Na* cation in inflow and pond 

 waters. Significant proportions of CI are also found at Barbizon and Pryse ponds. Only rela- 

 tively low concentrations of COj^ were found. 



Fluctuations in the concentration of the major solutes may be matched with those of EC 

 and among themselves which indicates that these changes over time are functions of the degree 

 of evapoconcentration as well as changes in the composition of inflow waters. 



In terms of average values, the dissolved organic carbon (DOC) concentrations increase 

 in the order Peck<Barbizon<Pryse. It may be possible that high values are linked to a biological 

 factor including macrophyte, algal, and microbial activities. 



• Trace Elements 



The trace elements considered in this study include As, B, Mo and Se. The concentrations 

 reported are total dissolved values for a particular element. It is important to remember that 

 these elements do not exist in appreciable quantities as singular atoms. Instead, they typically 



page 2.2 



