Accurate measurement of water levels deeper than 1,000 feet in wells requires specialized equipment. Corrections for stretch and thermal expansion of measuring tapes must be considered, and other measuring devices must be calibrated periodically. Borehole deviation corrections also must be made. Devices for recording fluctuation of fluid level usually require mechanical modification for use at these depths. A multichannel recording device utilizing pressure transducers has been constructed. This device was originally designed to record aquifer response to nearby underground nuclear explosions but can also be used for recording data from multiwell pumping tests. Bottom-hole recording devices designed for oilfield use have been utilized in a limited manner. These devices were generally found to lack the precision required, in groundwater investigations at the Nevada Test Site but may be applicable in other areas. A newly developed bottom-hole recording pressure gauge of improved accuracy has been used with satisfactory results.
Lake eutrophication is an economic, recreational, and aesthetic problem that affects every lake of the world. Eutrophication is the natural process of lake aging, and progresses irrespective of man's activities. Pollution, however, can hasten the natural rate of aging and shorten the life expectancy of a body of water. The eutrophication of a lake consists of the gradual progression from one life stage to another based on the degree of nourishment or productivity. The extinction of a lake is attributed to enrichment by nutritive materials, biological productivity, decay, and sedimentation. Presently used methods for retarding eutrophication are the abatement of cultural enrichment, treatment of eutrophic symptoms, and control of fundamental causes.
In early 1979, a retrieval was made for all phytoplankton data contained in the computerized data file of the U. S. Geological Survey. The retrieval revealed the analytical results of 17,959 samples collected and processed between October 1973 and October 1978. Of the approximately 500 genera of freshwater algae reported in the United States, the U.S. Geological Survey observed 321 genera in the phytoplankton. Fifty-two genera were considered to be commonly occurring and 42 genera were considered to be community dominants. The report lists, describes, and provides a detailed taxonomic key to the identification of 58 genera of algae considered either commonly occurring or dominant. Also included is a summary of environmental conditions under which each algal genus was observed, as well as a glossary and an extensive list of selected references. 1966). The network continued until the late 1960's as the Water Pollution Surveillance System under the purview of the Federal Water Pollution Control Administration (now the U.S. Environmental Protection Agency) (Weber, 1966). The changing emphasis toward the preservation of environmental quality during the 1960's awakened the need for a long-term data base with which changes in water quality could be determined. As a result, the U.S. Geological Survey initiated the National Stream-Quality Accounting Network (NASQAN) in 1973. NASQAN is a series of stations at which systematic and continuing measurements are made to determine the quality of the Nation's streams. Design of the network specifies measurement of a broad range of water-quality characteristics, including biological characteristics, which were selected to meet many of the information requests of groups involved
Survey introduced the first of a series of briefing papers that were designed to increase the understanding of its employees of the significance of various aspects of water quality. Numerous briefing papers have been prepared by the Quality of Water Branch. Others will be prepared as the need arises. Each paper addresses a separate topic and is written in a nontechnical, easy-to-understand manner for distribution within the organization. Because of the favorable reception that the papers have received and their apparent effectiveness in accomplishing the objectives stated above, it would appear that their wider distribution would serve a useful purpose. It is hoped that a wide range of persons, including those interested in the quality of our Nation's water resources but who have little or no technical training, will find value in reading the papers. Furthermore, it is hoped that the papers will be suitable for supplemental reading in secondary education programs and in beginning college-level courses. The U.S. Geological Survey plans to publish several U.S. Geological Survey Circulars that contain briefing papers on particular aspects of water quality. This fourth Circular contains a paper discussing infectious waterborne diseases.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.