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Frank Eldridge Clarke

Publications and source records attributed to Frank Eldridge Clarke.

7 recordsLinked to original sources
USGS1979

The corrosive well waters of Egypt's western desert

The discovery that ground waters of Egypt's Western Desert are highly corrosive is lost in antiquity. Inhabitants of the oases have been aware of the troublesome property for many decades and early investigators mention it in their reports concerning the area. Introduction of modern well-drilling techniques and replacements of native wood casing with steel during the 20th century increased corrosion problems and, in what is called the New Valley Project, led to an intense search for causes and corrective treatments. This revealed that extreme corrosiveness results from combined effects of relatively acidic waters with significant concentrations of destructive sulfide ion; unfavorable ratios of sulfate and chloride to less aggressive ions; mineral equilibria and electrode potential which hinder formation of protective films; relative high chemical reaction rates because of abnormal temperatures, and high surface velocities related to well design. There is general agreement among investigators that conventional corrosion control methods such as coating metal surfaces, chemical treatment of the water, and electrolytic protection with impressed current and sacrificial electrodes are ineffective or impracticable for wells in the Western Desert's New Valley. Thus, control must be sought through the use of materials more resistant to corrosion than plain carbon steel wherever well screens and casings are necessary. Of the alternatives considered, stainless steel appears to. be the most promising where high strength and long-term services are required and the alloy's relatively high cost is acceptable. Epoxy resin-bonded fiberglass and wood appear to be practicable, relatively inexpensive alternatives for installations which do. not exceed their strength limitations. Other materials such as high strength aluminum and Monel Metal have shown sufficient promise to. merit their consideration in particular locations and uses. The limited experience with pumping in these desert wells leaves uncertainties concerning the durability of conventional pump designs. Egypt's New Valley Project provides an excellent opportunity for continuing study of the corrosion problems that concern ground-water developers in many parts of the world.

Water Supply Paper↗
USGS1973

The Great Tunisian Flood

In the autumn of 1969, unusual meteorological conditions over Europe and northern Africa caused an enormous persistent desert storm in Tunisia and eastern Algeria. Poorly developed drainage patterns and gypsum-encrusted surfaces of these desert regions intensified effects of the storm and contributed to the heavy loss of life and property. Destruction of Roman bridges suggests that such storms may have recurrence probabilities of several thousands of years. The event also suggests that, although desert storms are less frequent than those of temperate regions, they can be similar in magnitude.

Journal of Research of the U.S. Geological Survey↗
USGS1972

Significance of ground-water chemistry in performance of North Sahara Tube wells in Algeria and Tunisia

Nine ground-water samples from the principal shallow and deep North Sahara aquifers of Algeria and Tunisia were examined to determine the relation of their chemical composition to corrosion and mineral encrustation thought to be contributing to observed decline in well capacities within a UNESCO/UNDP Special Fund Project area. Although the shallow and deep waters differ significantly in certain quality factors, all are sulfochloride types with corrosion potentials ranging from moderate to extreme. None appear to be sufficiently supersaturated with troublesome mineral species to cause rapid or severe encrustation of filter pipes or other well parts. However, calcium carbonate encrustation of deep-well cooling towers and related irrigation pipes can be expected because of loss of carbon dioxide and water during evaporative cooling. Corrosion products, particularly iron sulfide, can be expected to deposit in wells producing waters from the deep aquifers. This could reduce filterpipe openings and increase casing roughness sufficiently to cause significant reduction in well capacity. It seems likely, however, that normal pressure reduction due to exploitation of the artesian systems is a more important control of well performance. If troublesome corrosion and related encrustation are confirmed by downhole inspection, use of corrosion-resisting materials, such as fiber-glass casing and saw-slotted filter pipe (shallow wells only), or stainless-steel screen, will minimize the effects of the waters represented by these samples. A combination of corrosion-resisting stainless steel filter pipe electrically insulated from the casing with a nonconductive spacer and cathodic protection will minimize external corrosion of steel casing, if this is found to be a problem. However, such installations are difficult to make in very deep wells and difficult to control in remote areas. Both the shallow waters and the deep waters examined in this study will tend to cause soil salinization because their salt contents are relatively high, and both have sodium absorption ratios which are unfavorable to sodium-sensitive soils and vegetation. Proper drainage and soil treatment are the only means of overcoming these problems during irrigation.

Water Supply Paper↗
USGS1971

A procedure for evaluating environmental impact

In a recent article in "Science" discussing the Environmental Policy Act of 1969, Gillette (1971) states "The law's instructions for preparing an impact report apparently are not specific enough to insure that an agency will fully, or even usefully, examine the environmental effects of the projects it plans." This report contains a procedure that may assist in developing uniform environmental impact statements. The Department of the Interior and the Council on Environmental Quality will appreciate comments on the procedure here proposed. The heart of the system is a matrix which is general enough to be used as a reference checklist or a reminder of the full range of actions and impacts on the environment that may relate to proposed actions. The marked matrix also serves as an abstract of the text of the environmental assessment to enable the many reviewers of impact reports to determine quickly what are considered to be the significant impacts and their relative importance as evaluated by the originator of the impact report. Many exhaustive studies of the use of matrices for environmental studies are now being undertaken. (See Sorensen, 1971.) This comparatively simple system is intended as a guide for the many people who are faced with the evaluation and preparation of environmental impact reports before the results of these studies have been completed. It should be borne in mind that there is presently no uniformity in approach or agreement upon objectives in an impact analysis and this generalized matrix is a step in that direction. The procedure does not limit the development of detail in any specific aspect of the environment; a separate expanded matrix for any environmental aspect can easily be developed within the framework provided.

Circular↗
USGS1969

Chemical properties of ground water and their corrosion and encrustation effects on wells

Well waters in Egypt, Nigeria, and West Pakistan were studied for their chemical properties and corrosive or encrusting behavior. From the chemical composition of the waters, reaction states with reference to equilibrium were tested for 29 possible coexisting oxides, carbonates, sulfides, and elements. Of the 29 solids considered, only calcite, CaCO 3 , and ferric hydroxide, Fe(OH) 3 , showed any correlation with the corrosiveness of the waters to mild steel (iron metal). All 39 of the waters tested were out of equilibrium with iron metal, but those waters in equilibrium or supersaturated with both calcite and ferric hydroxide were the least corrosive. Supersaturation with other solid phases apparently was unrelated to corrosion. A number of solids may form surface deposits in wells and lead to decreased yields by fouling well intakes (screens and gravel packs) or increasing friction losses in casings. Calcite, CaCO 3 ; ferric hydroxide, Fe(OH) 3 ; magnetite, Fe 3 O 4 ; siderite, FeCO 3 ; hausmannite, Mn 3 0 4 (tetragonal); manganese spinel, Mn 3 O 4 (isometric); three iron sulfides mackinawite, FeS (tetragonal); greigite, Fe 3 S 4 (isometric); and smythite, Fe 3 S 4 (rhombohedral)-copper hydroxide, Co(OH) 2 ; and manganese hydroxide, Mn(OH) 2 , were all at least tentatively identified in the deposits sampled. Of geochemical interest is the demonstration that simple stable equilibrium models fail in nearly every case to predict compositions of water yielded by the wells studied. Only one stable phase (calcite) was found to exhibit behavior approximately predictable from stable equilibrium considerations. No other stable phase was found to behave as would be predicted from equilibrium considerations. All the solids found to precipitate (except calcite) are metastable in that they are not the least soluble phases possible in the systems studied. In terms of metastable equilibrium, siderite and ferric hydroxide behave approximately as would be predicted from equilibrium considerations, but both are metastable and the presence of neither would be anticipated if only the most stable phases were considered. The behaviors of none of the other solids would be predictable from either stable or metastable equilibrium considerations. An unanswered problem raised by the study reported here is how, or by what paths, truly stable phases form if first precipitates are generally metastable. The utility of the findings in well design and operation is in no way impaired by the general lack of equilibrium. Conditions leading to either corrosion (which is related to lack of supersaturation with protective phases), or encrustation (supersaturation with phases that were found to precipitate), or both, apparently can be identified. The application of the methods described can be of great importance in developing unexploited ground-water resources in that certain practical problems can be identified before extensive well construction and unnecessary well failure.

Professional Paper↗
USGS1969

Evaluation and control of corrosion and encrustation in tube wells of the Indus Plains, West Pakistan

Seepage from rivers and irrigation canals has contributed to waterlogging and soil salinization problems in much of the Indus Plains of West Pakistan. These problems are being overcome in part by tube-well dewatering and deep leaching of salinized soils. The ground waters described here are anaerobic and some are supersaturated with troublesome minerals such as calcium carbonate (calcite) and iron carbonate (siderite). These waters are moderately corrosive to steel. Some wells contain sulfate-reducing bacteria, which catalyze corrosion, and pH-electrode potential relationships favorable to the solution of iron also are rather common. Corrosion is concentrated in the relatively active (anodic) saw slots of water-well filter pipes (screens), where metal loss is least tolerable. Local changes in chemical properties of the water, because of corrosion, apparently cause deposition of calcium carbonate, iron carbonate, and other minerals which clog the filter pipes. In some places well capacities are seriously reduced in very short periods of time. There appears to be no practicable preventive treatment for corrosion and encrustation in these wells. Even chemical sterilization for bacterial control has yielded poor results. Periodic rehabilitation by down-hole blasting or by other effective mechanical or chemical cleaning methods will prolong well life. It may be possible to repair severely damaged well screens by inserting perforated sleeves of plastic or other inert material. The most promising approach to future, well-field development is to use filter pipes of epoxy-resin-bonded fiber glass, stainless steel, or other inert material which minimizes both corrosion and corrosion-catalyzed encrustation. Fiberglass plastic pipe appears to be the most economically practicable construction material at this time and already is being used with promising results.

Water Supply Paper↗