Ground waters

In a normally pressured reservoir, the pressure is transmitted through a continuous column of water from the surface down to the reservoir. At the datum level at surface the pressure is one atmosphere. The datum level for an offshore location is the mean sea level (msl), and for a onshore location, the ground water level. 

D. M. Nielsen, ed.. Practical Handbook of Ground-Water Monitoring, Lewis Pubhshers, Inc., Chelsea, Mich., 1991. 

M. Barcelona, A. Wehrmann, J. Kelly, and W. Pettyjohn, Contamination of Ground Water Prevention, Assessment, Restoration, Pollution Technology Review No. 184, Noyes Data Corporation, Park Ridge, N.J., 1990. 

Ref. 295 unless otherwise noted. SW = surface water GW = ground water. Positive results/number of tests. 

D. W. Nelson and R. H. Dowdy, eds.. Methodsfor Ground Water Quality Studies, University of Nebraska, Lincoln, 1988. 

U.S. EPA, Method SCI-Determination of Nitrogen- and Phosphorus Containing Pesticides in Ground Water hy GCj NPD, draft, Apr. 15, 1988 available from U.S. EPA Environmental Monitoring and Support Laboratory, Cincinnati, Ohio, 1988. 

Environmental Business Journal Global Environmental Change Report Golob s Oil Pollution Bulletin Greenhouse Effect Report Ground Water Monitor Industrial Environment Industrial Health Ha2ards Update (IH HU)... 

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). 

LLDPE can be disposed of by landfill or incineration. In landfill, the material is completely inert, degrades very slowly, does not produce gas, and does not leach any pollutants into ground water. When incinerated in commercial or municipal faciHties, LLDPE produces a large amount of heat (the same as heating fuel) and should constitute less than 10% of the total trash. 

Biodegradation results from the pH drop such a detergent polymer experiences as it leaves the alkaline laundry environment (pH ca 10) and enters the sewage or ground water environment (pH close to neutral) the polymer (now a polyacid rather than a salt) is unstable and hydrolyzes to monomer which rapidly biodegrades. The chemistry has been reported ia many patents (186) and several pubHcations (187,188). 

J. S. Briskin, Mechanisms of Pesticide Movement into Ground Water, Lewis Pubhshers, Boca Raton, Ela., 1994, pp. 143. 

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. 

Aeration basins can be constmcted as concrete or steel tanks or earthen impoundments, although tanks are more common in the United States now because of ground water problems with leakage from impoundments and stringent regulation of impoundments for the treatment of hazardous waste. 

They may be favored over in situ treatment where they will reduce cleanup times, their operation and capabiHties are considered more reHable or better understood, or they can achieve lower cleanup levels. Both in situ and ex situ treatment for soil and ground water rely on a combination of unit processes, which often include biological degradation of organics. 

Nonaqueous phase Hquids (NAPLs) present special problems for soil and ground water cleanup. Contaminant transport through ground water depends in part on the water solubiHty of the compound. Because NAPLs cling to subsurface particles and are slow to dissolve in ground water, they hinder cleanups and prolong cleanup times. Dense nonaqueous phase Hquids (DNAPLs) migrate downward in the aquifer and can coUect in pools or pockets of the substmcture. Examples of DNAPLs are the common solvents tetrachloroethylene (PCE) and trichloroethylene (TCE) which were used extensively at many faciHties before the extent of subsurface contamination problems was realized. 

On the downside, various studies (23—25) have shown that hydrogen peroxide decomposes rapidly after soil contact, it is cytotoxic at a 3% solution and unless stabilized, oxygen bubbles can escape prematurely through the unsaturated zone before they have a chance to disperse well in the ground water. 

---