OCR Text |
Show 30 Water Quality in the Great Salt Lake Basins, Utah, Idaho, and Wyoming, 1998- 2001 polychlorinated biphenyls, and some solvents containing chlorine. Organochlorine insecticide- A class of organic insecticides containing a high percentage of chlorine. Includes dichlorodi- phenylethanes ( such as DDT), chlorinated cyclodienes ( such as chlordane), and chlorinated benzenes ( such as lindane). Most organochlorine insecticides were banned because of their carcinogenicity, tendency to bioaccumulate, and toxicity to wildlife. Pesticide- A chemical applied to crops, rights of way, lawns, or residences to control weeds, insects, fungi, nematodes, rodents or other " pests." Picocurie ( pCi)- One trillionth ( 10- 12) of the amount of radioactivity represented by a curie ( Ci). A curie is the amount of radioactivity that yields 3.7 • 1010 radioactive disintegrations per second ( dps). A picocurie yields 2.22 disintegrations per minute ( dpm) or 0.037 dps. Polychlorinated biphenyls ( PCBs)- A mixture of chlorinated derivatives of biphenyl, marketed under the trade name Aro- clor with a number designating the chlorine content ( such as Aroclor 1260). PCBs were used in transformers and capacitors for insulating purposes and in gas pipeline systems as a lubricant. Further sale for new use was banned by law in 1979. Point source- A source at a discrete location such as a discharge pipe, drainage ditch, tunnel, well, concentrated livestock operation, or floating craft. Recharge- Water that infiltrates the ground and reaches the saturated zone. Riparian- Areas adjacent to rivers and streams with a high density, diversity, and productivity of plant and animal species relative to nearby uplands. Runoff- Excess rainwater or snowmelt that is transported to streams by overland flow, tile drains, or ground water. Sorption- General term for the interaction ( binding or association) of a solute ion or molecule with a solid. Species- Population of organisms that may interbreed and produce fertile offspring having similar structure, habits, and functions. Specific conductance- A measure of the ability of a liquid to conduct an electrical current. Study Unit- A major hydrologic system of the United States in which NAWQA studies are focused. Study Units are geographically defined by a combination of ground- and surface- water features and generally encompass more than 4,000 square miles of land area. Suspended sediment- Particles of rock, sand, soil, and organic detritus carried in suspension in the water column, in contrast to sediment that moves on or near the streambed. Taxon ( plural taxa)- Any identifiable group of taxonomically related organisms. Tolerant species- Those species that are adaptable to ( tolerant of) human alterations to the environment and often increase in number when human alterations occur. Trace element- An element found in only minor amounts ( concentrations less than 1.0 milligram per liter) in water or sediment; includes arsenic, cadmium, chromium, copper, lead, mercury, nickel, and zinc. Volatile organic compounds ( VOCs)- Organic chemicals that have a high vapor pressure relative to their water solubility. VOCs include components of gasoline, fuel oils, and lubricants, as well as organic solvents, fumigants, some inert ingredients in pesticides, and some byproducts of chlorine disinfection. |