Waste injection wells

Some injected wastes are persistent health hazards that need to be isolated from the biosphere indefinitely. For this reason, and because of the environmental and operational problems posed by loss of permeability or formation caving, well operators seek to avoid deterioration of the formation accepting the wastes and its confining layers. When wastes are injected, they are commonly far from chemical equilibrium with the minerals in the formation and, therefore, can be expected to react extensively with them (Boulding, 1990). The potential for subsurface damage by chemical reaction, nonetheless, has seldom been considered in the design of injection wells. 

Natural Gas Pipeline Co. H2S from gas stripping fi water from underground s 

Allied Chemical Corp. Byproduct of fluorocarbon manufacture, contains HC1, HF, arsenic 

US Industrial Chemicals Co. Runoff from waste gypsum, contains H2SO4 

Velsicol Chemical Corp. Wastewater from pesticide production, contains NaCl, NaOH, hex, chlordane 

According to Brower et al. (1989 Fig. 21.1), nine wells at seven industrial sites throughout the state of Illinois were in use in the late 1980s for injecting industrial wastes into deeply buried formations these wells accepted about 300 million gallons of liquid wastes per year. In this chapter, we look at difficulties stemming from reaction between waste water and rocks of the host formation at 

Industrial Chen Runoff from waste g contains H2SO4 

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FIG. 25-78 Schematic diagram of an industrial-waste injection well completed in competent sandstone. (From Vreeman, H M, Standard Handbook of Hazardous Waste Treatment and Disposal, McGraw-Hill, 1988.)... 

Geographic Distribution of Hazardous Waste Injection Wells. 786... 

The number of industrial-waste injection wells more than doubled between 1967 and 1986.3 In 1986, Class I injection wells were concentrated in two states, Texas (112 wells) and Louisiana (70 wells), which between them had a total of 69% of all wells (263 wells). Growth from 1984 to 1986 was concentrated in Texas, with a 38% increase from 81 to 112 wells. The only other states to show a significant increase from 1984 to 1986 were Indiana (13 proposed wells) and California (7 proposed wells). Nine states had had industrial-waste injection wells in the past but did not have any permitted Class I wells in 1986 (Alabama, Colorado, Iowa, Mississippi, Nevada, North Carolina, Pennsylvania, Tennessee, and Wyoming). One state (Washington) had a Class I well in 1986, but no record of industrial wastewater injection before that year. The total number of industrial-waste injection wells increased to 300 at the end of the 1990s and beginning of this century, approximately 100 Class I hazardous waste injection wells and about 200 Class I wells that hold nonhazardous waste.1-18... 

Figure 20.1 shows the number of Class I wells in the 1986 survey by state, divided into U.S. EPA regions, and also indicates the regulatory status of such wells in each state as of 1989. The map shows the heavy concentration of hazardous waste injection wells in three geologic basins Gulf Coast, Illinois Basin, and the Michigan Basin.1 3 ... 

A detailed discussion of the technical aspects of industrial-waste injection-well construction can be found in Warner and Lehr.6 U.S. EPA20 also presents a survey of well construction methods and materials used for 229 hazardous waste injection wells. Two types of injection well completions are used with hazardous waste injection wells ... 

Well head pressures increased when injection was stopped at Well No. 1 for more than 24 h, apparently caused by a combination of precipitation reactions and backflow of sand. Injecting a slug of brine after every period of interrupted flow solved this problem. Movement of the main organic constituents (n-hexylamine, butanal, butanol, and phenol) was assumed to be slowed by adsorption. This conclusion was based on laboratory adsorption experiments by involving a different geologic formation (Cottage Grove sandstone) no direct observations were made of the injected waste. For current hazardous waste injection wells in Texas, the reader can refer to Texas Environmental Profiles web site for on-line resources for the State of Texas.185... 

According to the Illinois Environmental Protection Agency (IEPA), a series of gas blowouts has occurred at two waste injection wells in the state (Brower el al., 1989). In each case, well operators were injecting concentrated hydrochloric acid into a dolomite bed. At its plant near Tuscola, the Cabot Corporation injects acid waste from the production of fumed silica into the Cambrian Eminence and Potosi Formations below 5 000 ft (1 500 m) depth. Allied Chemical Corporation injects acid into the Potosi formation below about 3 600 ft (1 100 m). The acid, which is contaminated with arsenic, is a byproduct of the manufacture of refrigerant gas. Since some of the blowouts have caused damage such as fish kills, there is environmental interest as well as operational concern in preventing such accidents. 

This book contains (Mated analysis of the sources of ground water contamination. Specific topics Include liquid waste disposal systems, industrial waste, municipal waste, oil field wastes, agricultural wastes, injection wells, underground tanks and pipelines, surface waters, and atmospheric deposition. The book also discusses contamination movement and interaction, detection, risk assessment, prevention, and management... 

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