Water from California streams has been analyzed for concentrations of selected chemical constituents since the early 1950's. This summary includes about 1,200 water years of data from 88 sampling sites on 66 streams. Results of this summary show that about 80 percent of the sites had a mean dissolved-solids concentration of 400 milligrams per litre or less. All the sites that had mean concentrations ranging from 601 to 800 milligrams per litre were in either the South Coastal or Central Coastal subregions. Results of regression analysis between specific conductance and calcium, magnesium, sodium, bicarbonate, dissolved solids, and hardness usually indicated a high percentage of explained variance. Other constituents, such as potassium, sulfate, chloride, and particularly nitrate, were not as frequently highly associated with specific conductance. At sites where the water discharge was highly regulated, the variation in specific conductance that was explained as a function of discharge ranged from 0 to more than 90 percent. Whereas at the unregulated sites, the explained variance ranged from 50 to more than 90 percent. HISTORY OF THE CHEMICAL-QUALITY BASIC-DATA PROGRAM Most of the data that are included in this report were obtained through a cooperative effort between the Geological Survey and the California Department of Water Resources. Other State, county, and public-utility organizations also participated, but to a lesser degree. The collection of chemical-quality basic data began in California on a more or less routine basis in April 1951 (J. L. Welsh, 1974, written commun.). The California Department of Water Resources designed the sampling network and collected the water samples. The water samples collected in northern and central California were transported to the Geological Survey laboratory, initially in Davis and later in Sacramento, for subsequent analysis. This program routine continued until about 1966. At that time, most of the analytical service work was transferred to the California Department of Water Resources laboratory in Bryte. Samples collected in southern California (sites shown in fig. 1 south of lat. 35 N.) were analyzed by the California Department of Water Resources laboratory in San Bernardino. Since 1966, almost all the chemical-quality data included in this summary have been furnished by the State of California. The sampling frequency at most of the sites was usually once monthly or less. However, some sampling in the Sacramento and San Joaquin Rivers was done on a once-daily basis, at least for part of the sampling period. One common sampling frequency was to collect a water sample during May and September for a "complete" analysis. This analysis usually included determinations for silica, calcium, magnesium, sodium, potassium, bicarbonate, sulfate, chloride, nitrate, boron, dissolved-solids residue, hardness, and specific conductance. May and September were selected in the attempt to obtain water samples that represented both high-and low-discharge periods. During other months, sam...
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Results of a 1983-84 reconnaissance of 15 municipal wastewater treatment plants in Florida indicated that effluent from most of the plants contains trace concentrations of volatile organic compounds. Chloroform was detected in the effluent at 11 of the 15 plants and its common occurrence was likely the result of chlorination. The maximum concentration of chloroform detected in the effluent sampled was 120 micrograms per liter. Detectable concentrations of selected organophosphorus insecticides were also common. For example, diazinon was detected in the effluent at 12 of the 15 plants with a maximum concentration of 1.5 micrograms per liter. Organochlorine insecticides, primarily lindane, were detected in the effluent at 8 of the 15 plants with a maximum concentration of 1.0 micrograms per liter. Volatile compounds, primarily chloroform, were detected in water from monitor wells at four plants and organophosphorus insecticides, primarily diazinon, were present in the ground water at three treatment plants. Organochlorine insecticides were not detected in any samples from monitor wells. Based on the limited data available, this cursory reconnaissance suggests that the organic contaminants commonly occurring in the effluent of many of the treatment plants are not transported into the local ground water.
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