Frank L. Parker

Physical and engineering aspects of thermal pollution

The rate of growth of cooling water requirements with particular reference to central electricity generating stations, the possibilities of improved efficiencies in electricity production, the limited availability of cooling water and the mechanisms and means of heat dissipation are detailed. Also described are the effects of heated discharges upon the biota and the hydrodynamics of the receiving waters.

CAD comparisons for wastewater treatment facilities

Abstract A comparison was made between two computer aided design (CAD) models for wastewater treatment facilities, CAPDET and EXEC/OP, which are widely used in the U.S.A. The purpose of both programs is to optimize preliminary designs and to determine costs for municipal wastewater treatment plants, however, their size, capabilities, and computational procedures are vastly different. CAPDET is a much larger program than EXEC/OP that provides a larger selection of unit operations and has a more refined costing scheme. CAPDET was found to be user‐friendlier, once installed on a main frame computer system. Testing of their operational and design capabilities against a consultants designs has shown that, despite their flaws, both programs can fulfill their purpose satisfactorily.

Letter to the Editor on A National Strategy for Vadose Zone Science and Technology

We would like to make your readers aware of the recently completed Department of Energys (DOEs) National Roadmap for Vadose Zone Science and Technology, DOE/ID10871. This Roadmap was published in August 2001 at ([U.S. Department of Energy, 2001][1]). Together with

Reliability analysis for hazardous waste treatment processes

The reliability of a treatment process is addressed in terms of achieving a regulatory effluent concentration standard and the design safety factors associated with the treatment process. This methodology was then applied to two aqueous hazardous waste treatment processes: packed tower aeration and activated sludge (aerobic) biological treatment. The designs achieving 95 percent reliability were compared with those designs based on conventional practice to determine their patterns of conservatism. Scoping-level treatment costs were also related to reliability levels for these treatment processes. The results indicate that the reliability levels for the physical/chemical treatment process (packed tower aeration) based on the deterministic safety factors range from 80 percent to over 99 percent, whereas those for the biological treatment process range from near 0 percent to over 99 percent, depending on the compound evaluated. Increases in reliability per unit increase in treatment costs are most pronounced at lower reliability levels (less than about 80 percent) than at the higher reliability levels (greater than 90 percent, indicating a point of diminishing returns. Additional research focused on process parameters that presently contain large uncertainties may reduce those uncertainties, with attending increases in the reliability levels of the treatment processes.

Fate of Heptachlor

Abstract Since field ecosystems are so complex, a dynamic laboratory riverine microcosm was set up to observe the persistence and fate of heptachlor. The microcosm included aqueous, biotic, and sediment compartments capable of physical, chemical, and biological processes. Heptachlor, nutrients, and water were added to the system at a constant rate of 18.4 1/day while the dynamic processes of the system were studied. To extend this analysis to the prototype, a model is necessary. The fate of heptachlor in the microcosm is compared to the fate in the prototype as computed by the model, Exposure Analysis Modeling System (EXAMS), developed by the Environmental Protection Agency Research Laboratory in Athens, Georgia. EXAMS is a compartmentalized model based on differential equations of the partitioning of five ionic species of heptachlor in waters, sediment, and biotic compartments, taking into account the dominant physical, chemical, and biological processes. The input parameters for EXAMS are obtained from and the literature compared with the laboratory microcosm. The results of this study show differences between fate predictions of the theoretical and laboratory modeling systems.

Significant issues in water resources policy

Abstract The difficulties in resolving water resource policy questions are analogous in many ways to the difficulties in resolving energy policy questions — technical, legal, institutional and social. Federal involvement in water resources began in 1809 and continues to the present time. The most recent comprehensive study was the Second National Water Assessment by the U.S. Water Resources Council in 1979. Conclusions reached were that water quality and quantity and surface and ground water are artificial distinctions, that water policies should reflect national needs and priorities, that flood control must be accelerated and drinking water quality protected and that more decisions should be made at a local level while integrated into national planning and development. Though the study disaggregated the U.S. into 106 subregions, its projections of a single future rather than a range of futures gives an erroneous sense of predictability to the work. To help resolve the major problems, inadequate supply and contamination and flooding and erosion, ultrasophisticated mathematical models are widely utilized without sufficient verification. A more tractable approach for policy studies would be to use simplified semi-empirical models rather than first principle models. Possibly more important, policy resolution awaits social value resolution which means that the policies adopted must be flexible, incremental, and non-divisive.