Disposal of liquid wastes by injection underground--Neither myth nor millennium

Abstract

Injecting liquid wastes deep underground is an attractive but not necessarily practical means for disposing of them. For decades, impressive volumes of unwanted oil-field brine have been injected, currently about 10,000 acre-feet yearly. Recently, liquid industrial wastes are being injected in ever-increasing quantity. Dimensions of industrial injection wells range widely but the approximate medians are: depth, 2,660 feet; thickness of injection zone, 185 feet; injection rate, 135 gallons per minute; wellhead injection pressure, 185 pounds per square inch. Effects of deep injection are complex and not all are understood clearly. In a responsible society, injection cannot be allowed to put wastes out of mind. Injection is no more than storage--for all time in the case of the most intractable wastes--in underground space of which little is attainable in some areas and which is exhaustible in most areas. Liquid wastes range widely in character and concentration-some are incompatible one with another or with materials of the prospective injection zone; some which are reactive or chemically unstable would require pretreatment or could not be injected. Standards by which to categorize the wastes are urgently desirable. To the end that injection may be planned effectively and administered in orderly fashion, there is proposed an immediate and comprehensive canvass of all the United States to outline injection provinces and zones according to their capacities to accept waste. Much of the information needed to this end is at hand. Such a canvass would consider (1) natural zone, of groundwater circulation, from rapid to stagnant, (2) regional hydrodynamics, (3) safe injection pressures, and (4) geochemical aspects. In regard to safe pressure, definitive criteria would be sought by which to avoid recurrence of earthquake swarms such as seem to have been triggered by injection at the Rocky Mountain Arsenal well near Denver, Colo. Three of the 50 States--Missouri, .Ohio, and Texas-have statutes specifically to regulate injection of industrial wastes. Other States impose widely diverse constraints under unlike administrative authorities. Few, if any, State agencies currently have the staff skills, centralized authority, and financial resources to assure rights of the general public to be spared harm from, and to reap the benefit of accrued experience with, deep injection. Some new, fully competent institutional arrangement appears to be essential, under a unified policy. As required, such an institution might have en echelon components, respectively having nationwide, single State or major province, subprovince, or local jurisdiction.