Ground water requirements

Factors that affect the costs for excavation include the depth of contamination, depth of ground-water (requiring dewatering), and extent of underground infrastructure and/or nearby structures that require shoring. The cost for excavation tends to be higher for areas with deeper contamination, shallower groundwater, and more infrastructures and nearby structures. 

Sampling ground water requires expert selection of procedures and techniques to avoid significant analytical errors. 

In practice, answers to questions about the extent to which given minerals influence the chemistry of specified ground waters require expert judgment. In addition to the simple test of mineral presence or absence used in the prototype saturation index module, a realistic evaluation would include such criteria as reaction rates, stability relative to other minerals of the same or closely similar composition, uncertainty in mineral stability constants due to compositional variation, temperature and its effect on... 

Water Quality. AH commercial oil shale operations require substantial quantities of water. AH product water is treated for use and operations are permitted as zero-discharge facHities. In the Unocal operation, no accidental releases of surface water have occurred during the last four years of sustained operations from 1986 to 1990. The Unocal Parachute Creek Project compliance monitoring program of ground water, surface water, and process water streams have indicated no adverse water quaHty impacts and no violations of the Colorado Department of Health standards (62). 

Pretreatment of aqueous streams may be required prior to using ion exchange. Suspended soHds that can plug an ion-exchange unit should be reduced to the 10 p.m level. Organics that can foul resins can be removed by carbon adsorption. Iron [7439-89-6] and manganese [7439-96-5], commonly present in ground waters, should be removed because they precipitate on the resin. 

Is the toller site being required to remediate soil or ground water under federal or state supervision ... 

EPA s surface water treatment rules require systems using surface water or ground water under the direct influence of surface water to (1) disinfect their water, and (2) filter their water or meet criteria for avoiding filtration so that the following contaminants are controlled at the following levels ... 

Pozzolan. Diatomaceous earth is a type of pozzolan. Pozzolan refers to a finely ground pumice or fly ash that is marketed as a cement additive under that name. The specific gravity of pozzolans is slightly less than the specific gravity of cement. The water requirements for this additive are about the same as for cements. Only a slight reduction in specific weight of a slurry can be realized by using these additives. The cost of pozzolans is very low. 

The supply of water is usually limited and requires the use of a cooling tower. Other possibilities are worth investigation for example, in the food industries, large quantities of water are used for processing the product, and this could be passed first through the condensers if precautions are taken to avoid contamination. Also, where ground water is present, it could be taken from a borehole and afterwards returned to the ground at some distance from the suction. In both... 

In mining and, more recently, the construction of underground storage tanks for liquefied natural gas, it is often necessary to sink a shaft through water-logged ground. The requirement is to form a temporary cofferdam to permit excavation and the building of a permanent liner. 

Because of the low rainfall and high evaporation rate, other water sources which might carry contamination Into the ground water were Investigated. The Company was required to check the Industrial water settling basin and all existing storm and sanitary sewers In the potllner area for leaks. 

These annexes set out the requirements for the dossier to be submitted by applicants either for inclusion of an a.i. in Annex I or for authorization of a plant protection product. Active ingredients are listed in Annex I if their use and their residues, resulting from applications consistent with good plant protection practice [or Good Agricultural Practice (GAP)] do not have harmful effects on human and animal health, or on ground water or any unacceptable influence on the environment (Article 5 of the Directive). 

Significant and active microbial populations are usually found in the subsurface soil and ground-water. However, if there is a lack of required microorganisms, then bacteria can be injected in situ. An optimum food/microorganisms (F/M) ratio should be maintained for effective removal of organic contaminants. 

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