Groundwater and springs

Table 3.13 Areas with elevated arsenic (>10iigL ) concentrations in groundwater and spring water... 

Leachate in landfills. Leachate may be defined as hquid that has percolated through sohd waste and has extracted dissolved or suspended materials from it. In most landfills, the liqiiid portion of the leachate is composed of the liquid produced from the decomposition of the wastes and liquid that has entered the landfill from external sources, such as surface drainage, rainfall, groundwater, and water form underground springs. Representative data on chemical characteristics of leachate are reported in Table 25-72. 

Water supplies should never be assumed to be chemically pure. Groundwater from wells and springs contains dissolved impurities. Its properties depend... 

Wang, L.K. and Wang, M.H.S., Decontamination of groundwater and hazardous industrial effluents by high-rate air flotation process, Proc. Great Lakes 1990 Conference, Hazardous Materials Control Research Institute, Silver Springs, MD, September 1990. 

Sulfide (S ) is a bivalent monoanion produced from the decomposition of metal sulfide salts. It occurs in groundwaters, hot springs, and wastewaters. It is also formed from the bacterial reduction of sulfate. Sulfide salts in solid wastes in contact with an acid can produce hydrogen sulfide. H2S, which is highly toxic. In an aqueous sample, sulfide may be present as dissolved H2S and HS , dissolved metallic sulfide, and acid-soluble metallic sulfide contained in suspended particles. All these soluble and insoluble sulfides and dissolved H2S and HS together are termed as total sulfide. The sulfide remaining after the removal of suspended solids is termed the dissolved sulfide. Copper and silver sulfides are insoluble even under acidic conditions. Therefore, these two sulfides are not determined in the following tests. 

Many stages of the water cycle are described by specific information implanted into surface water and groundwater. Yet, field hydrochemists have limited access to the water, being able to measure and sample it only at single points—wells and springs. Their task is to reconstruct the complete water history. A list of pertinent topics is given below. 

Surface water is that contained in streams, rivers, ponds, lakes, swamps, marshes, and springs. Approximately 0.014% of the water on Earth is found on continental land, while the rest is contained in the oceans and ice caps, glaciers, permanent snow, groundwater, and as water vapor in the atmosphere. 

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