Stream water

Ideally the historical record of stream water quaUty would extend back to a time when human activities in the drainage basin had no significant effects. This "pristine" condition had probably already passed in most U.S. rivers before any organized water quaUty studies were made, as concern about apparent stream pollution was commonly a motivating factor in starting such studies (see Water, pollution). 

Chemical analyses of stream water that have been pubhshed since the early years of this century generally include deterrninations for four positively charged ions (cations)—calcium (Ca ), magnesium (Mg ), sodium (Na ), and potassium (K )—and five negatively charged ions... 

Chlorine plays a less significant role in chemical weathering processes than do sulfur and carbon. Most geochemists beHeve that much, or most, of the chloride in stream water in coastal areas is derived from sea salt that is carried landward or deposited by rainfall. Farther inland, however, a major part of the chloride loads in streams is the result of human activities. 

The final composition of stream water is the product of the weathering reactions and related processes outlined above. However, the chemical processes are influenced and controlled by an intricate combination of environmental factors that are characteristic for each drainage system. Therefore, the composition of the bedrock in an area and the residual material left at the surface as soil and subsoil exert a strong influence on the chemical composition of mnoff from the area. The reactions of water with this material are the ultimate geological control and are the source of soluble weathering products. 

This reaction is relatively fast and readily reversible so that in drainage basins in carbonate-dominated terranes the stream water commonly will have near-equihbrium concentrations of hydrogen, bicarbonate, and calcium ions. At equiUbrium, the rates of forward and reverse processes represented in equation 5 are equal. 

Sulfate concentration in streams and changes over time are discussed later in this article as one of the principal indices of human influences on stream water composition. Also, it will be shown that differences and similarities ia sulfate yields help in attaining a reasonable perspective on the importance of various hydrologic and geochemical characteristics of individual drainage systems. 

Other Constituents of Stream Water. The records reported ia Refs. 21 and 22 were obtaiaed for the primary purpose of evaluating the suitabihty of surface water resources of the United States for utilization by iadustry and for irrigation of agricultural lands ia the western part of the country. These stream waters also provide pubHc water suppHes for many municipahties. Evaluations of water quaUty for the latter purpose emphasize constituents that were not given detailed consideration ia Refs. 21 and 22 summaries, although there are references ia Ref. 21 to work done ia various state health laboratories and municipal treatment plants. 

The Mississippi River drains more than 1,125,000 mi of the conterminous United States and integrates the effect on stream water quahty of a large... 

H. Stabler, Some Stream Waters of the Western Ended States with Chapters on Sediment Carried by the RJo Grande and the Industrial Application of Water Analyses, U.S. Geological Survey Water-Supply Paper 274, U.S. Geological Survey, Washington, D.C., 1911. 

R. A. Smith, R. B. Alexander, and K. J. Lanfear, "Stream Water in the Conterminous United States— Status and Trends of Selected Indicators During the 1980 s," in R. W. Paulson, E. B. Chase, J. S. WiUiams, and D. W. Moody, eds.. Compilers, National Water Summary 1990—91, U.S. Geological Survey Water-Supply Paper 2400, U.S. Geological Survey, Reston, Va., 1993, pp. 111—140. 

Condensation Scrubbing The collection efficiency of scrubbing can be increased by the simultaneous condensation of water vapor from the gas stream. Water-vapor condensation assists in particle removal by two entirely different mechanisms. One is the deposition of particles on cold-water droplets or other surfaces as the result of... 

Blum, J. D., Erel, Y., and Brown, K. (1994). Sr/ Sr ratios of Sierra Nevada stream waters Implications for relative mineral weathering rates. Geochim. Cosmochim. Acta 58,5019-5025. 

Several studies have been conducted to measure methyl parathion in streams, rivers, and lakes. A U.S. Geological Survey (USGS) of western streams detected methyl parathion in five river samples taken from four states during a 14-month period in 1970 and 1971. The amount of methyl parathion detected ranged from 0.04 to 0.23 pg/L (Schultz et al. 1973). A later and more extensive USGS study analyzed water samples from major rivers of the United States four times yearly in the period of 1975-1985. Of the 2,861 water samples, 0.1% had detectable levels of methyl parathion (Gilliom et al. 1985). In a study of Arkansas surface waters, samples of lake and river/stream water were collected and analyzed over a three-year period (Senseman et al. 1997). Of the 485 samples collected, methyl parathion was found in one river/stream sample at a maximum concentration of 3.5 pg/L. Results from an EPA study in California detected methyl parathion in 3 of 18 surface drain effluent samples at concentrations of 10-190 ng/kg. Subsurface drain effluent water had concentrations of 10-170 ng/kg in 8 of 60 samples (lARC 1983). 

Frank R, Braun HE, Van Hove Holdrinet M, et al. 1982. Agriculture and Water Quality in the Canadian Great Lakes Basin V. Pesticide use in 11 agricultural watersheds and presence in stream water, 1975-1977. J Environ Qual ll(3) 497-505. 

Hg(0), PHg, RGHg), wet deposition, throughfall, and litterfall, as discussed in the program to determine total ecosystem deposition (see Section 2.2.8). A summary of the measurements of Hg species that should be made in an intensive watershed Hg monitoring program is provided in Table 2.4. We envision that stream water measurements of total and dissolved THg and total and dissolved MeHg would also be made. 

Palmer SM, Driscoll CT, Johnson CE. 2004. Long-term trends in soil solution and stream water chemistry at the Hubbard Brook Experimental Forest relationship with landscape position. Biogeochemistry 68(l) 51-70. 

Gray JE, Theodorakos PM, Bailey EA, Turner RR. 2000. Distribution, speciation, and transport of mercury in stream-sediment, stream-water, and fish collected near abandoned mercury mines in southwestern Alaska, USA. Sci Total Environ 260 21-33. 

In contrast, during the low flow season (June-October) important nutrient loads from both point and non-point sources are relevant. Summer irrigation drives nitrate inputs to stream waters [38], The lower dilution capacity of the river causes higher concentrations of nitrate and DOC, as well as an increase in phosphate content with... 

Lassaletta L, Garcla-Gomez H, Gimeno BS, Rovira JV (2009) Agriculture-induced increase in nitrate concentrations in stream waters of a large Mediterranean catchment over 25 years (1981-2005). Sci Total Environ 407 6034-6043... 

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