China
Africa
Explore chapters and articles related to this topic
Groundwater Protection
Published in William Goldfarb, Water Law, 2020
EPA regulations establish five classes of injection wells, based on purpose and degree of threat to an USDW. Each class of injection well is subject to requirements for construction, operation, monitoring and reporting, plugging and abandonment, financial responsibility, and mechanical integrity. All injection wells must be authorized by permit or regulation. If a state does not have an approved UIC program, the EPA will carry out a program for the state. Wells that inject hazardous waste directly into, above, or near an USDW (i.e., within one-fourth mile) are prohibited. Each permit applicant bears the burden of showing that his discharge will not endanger an USDW. Under the 1984 amendments to the Resource Conservation and Recovery Act (RCRA), deep well injection of certain hazardous wastes is prohibited entirely.
Underground Injection
Published in Stephen M. Testa, Geological Aspects of Hazardous Waste Management, 2020
Underground injection for the disposal of hazardous substances is based on simple hydrogeologic principles. Sedimentary basins are characterized by thousands of feet of relatively undisturbed, layered, water-bearing sedimentary rocks. Total dissolved solids (TDS) concentration in subsurface waters generally increases with depth, with the direction of groundwater flow from higher to lower TDS concentrations. Significant differences in water quality exist between deep (saline waters) and shallow fresh groundwater, and layers of relatively impermeable rocks act as a barrier to the upward movement of the saline waters. These saline water-bearing deposits are considered of nonbeneficial use and thus under certain geologic and hydrogeologic conditions may serve as receptors of hazardous and toxic waste. As such, subsurface injection is defined as the subsurface emplacement of fluid through a well or dug hole whose depth is greater than its width. Injection wells essentially serve as liquid waste disposal facilities where liquid or liquefiable wastes are pumped into confined geologic formations via gravity flow or under pressure, thus providing an alternative to surface water discharge.
Methods of Concentrate Disposal
Published in Thomas M. Missimer, Ian C. Watson, Water Supply Development for Membrane Water Treatment Facilities, 1994
Thomas M. Missimer, Ian C. Watson
There are three major aspects requiring attention prior to choosing deep well injection as the disposal method. First, the hydrogeology of the site must be adequate for an injection well system. There must be an aquifer present with sufficient hydraulic conductivity to accept the desired injection volume, and there must be confinement above the injection aquifer to prevent upward movement of the water into overlying aquifers. Second, the injection well must be permittable under the federal or state Underground Injection Control (UIC) program. The injection aquifer must be a Class IV aquifer containing water with a minimum dissolved solids concentration of 10,000 mg/l. This program is administered by the U.S. Environmental Protection Agency, which has delegated primacy to certain states for permitting (such as Florida). Some states, such as North Carolina, do not allow injection well construction. Third, the concentrate water must be chemically acceptable for injection to avoid damage to the injection well and/or receiving aquifer. For example, if the pH of the concentrate water is 4.5, then the water should be treated to increase the pH to near 7 especially if the injection zone is in a limestone or dolomite aquifer.
Optimizing submersible pump regulation of a clogging prone groundwater heat pump system in Melhus, Norway
Published in Science and Technology for the Built Environment, 2023
Lars A. Stenvik, Randi K. Ramstad, Bjørn S. Frengstad
From the presented investigations we conclude that:The monthly performance factor (SPFM) for the groundwater heat pump (GWHP) system at Lena terrasse in Melhus, Norway is higher at lower pumping rates (Q).The heat exchanger and injection well suffer from clogging. The heat exchanger clogging rate increases at Q < 6 l/s, while the suspended solids concentrations increase at Q > 12-13 l/s. The latter involves risk of mechanical clogging by sediments in the injection well. Clogging rate appears to be independent of the pumping rate in the range 6-12 l/s.Hydrochemistry does not seem to change with pumping rate, indicating that vertical redox mixing does not accelerate if the pumping rate is varied.The clogging rate of both the heat exchanger and the injection well increases with time after rehabilitation, resembling the self-catalytic effect of iron oxides on oxidation of iron. This matches previous studies which have revealed iron oxide incrustations in the same GWHP system.It is advised that the Lena terrasse GWHP system operate the submersible groundwater pump in the range 6 ≤ Q ≤ 12 l/s. The pumping rate should be minimized, but be high enough to avoid freezing the groundwater or secondary circuit fluid, meaning Q should be adjusted to the heating demand.
Development and evaluation of a mathematical model in an in situ uranium leaching technique
Published in Applied Earth Science, 2019
An injection well is a well that is intended to be used for injection of the productive formations of injected solutions through a filter that is capable of dissolving the uranium mineral content. The injection wells are used in an in situ leaching method in order to maintain reservoir pressure and regulate the mineral extraction rate. The main technological process variable, which would allow solving tasks on the high-quality ISL control to regulate the injection well level. The continuous monitoring of dynamic level in the injection wells is accomplished using a hydrostatic level gauge.