Reductive dehalogenation: A subsurface bioremediation process

Introduction and large-scale production of synthetic halogenated organic chemicals over the last fifty years has resulted in a group of contaminants that tend to persist in the environment and resist both biotic and abiotic degradation. The low solubility of these types of contaminants, along with their toxicity and tendency to accumulate in food chains, make them particularly relevant targets for remediation activities. Among the mechanisms that result in dehalogenation of some classes of organic contaminants are stimulation of metabolic sequences through introduction of electron donor and acceptor combinations; addition of nutrients to meet the needs of dehalogenating microorganisms; possible use of engineered microorganisms; and use of enzyme systems capable of catalyzing reductive dehalogenation. The current state of research and development in the area of reductive dehalogenation is discussed along with possible technological application of relevant processes and mechanisms to remediation of soil and groundwater contaminated with chlorinated organics. In addition, an overview of research needs is suggested, which might be of interest for development of in-situ systems to reduce the mass of halogenated organic contaminants in soil and groundwater.     

The object of environmental ethics

Since the term environmental ethics began to be used a generation ago, it has covered many different kinds of environmental notions, problems, ethical systems, and forms of behavior. A variety of cases are presented and examined under two terms,environmental ethics andecological morality, in an effort to illustrate different kinds of ethical objectives. In order to understand the connections between various strands of environmental ethics, personal and social values and subcultural norms of environmental ethics are examined under Christopher Stone's concept of moral pluralism. G. J. Warnock's notion of the general object of morality is proposed to integrate the variegated purposes of environmental ethics.     

THE REGULATED RIPARIAN VERSION OF THE ASCE MODEL WATER CODE: THE THIRD WAY TO ALLOCATE WATER1

ABSTRACT: Lawyers, engineers, and hydrologists are accustomed to thinking of water law as falling into one of two incompatible models: riparian rights (under which water is allocated by courts according to the relative reasonableness of the competing uses) and appropriative rights (under which water is allocated according to the temporal priority of the competing uses, largely by the action of the water users themselves but perfected by the issuance of an administrative permit). Usually unnoticed is the existence of a third approach, which I have dubbed “regulated riparianism.” Under regulated riparianism, water is allocated by water permits issued after an administrative determination of the reasonableness of the proposed use before the use is commenced. This system, now in place in about half of the states east of Kansas City (plus Hawaii), thus is fundamentally different from either the traditional ripanan rights that it replaces or the appropriative rights found in western states.     

Measuring environmental performance at niagara mohawk power

A system for measuring environmental performance is important to the success of a company's environmental excellence program. In 1991, Niagara Mohawk Power Corporation (NMPC) unveiled a new corporate policy on protection of the environment. To measure and communicate progress in achieving the goals and objectives embodied in the new policy, an environmental performance index (EPI) was developed. In this article the author shows how the EPI utilizes a weight and rating scheme to reflect environmental performance in three categories: emissions/wastes, regulatory compliance, and environmental enhancements. Performance goals have been established for the period 1992–1995, and actual performance data has been compiled for 1992 and 1993. While the EPI is designed to measure changes in NMPC's environmental performance over time, it does not provide information on how the company's performance compares to that of other electric utilities. Accordingly, NMPC is developing an environmental benchmarking program with a group of Northeast electric utilities that will allow comparisons of environmental performance between utilities.     

Metrics,decisions, and strategies: Environmental performance measurement in the electric utility industry

The twin challenges of increased competition and environmental consciousness are causing companies in the utility industry to re-examine their methods for measuring environmental performance. A new paradigm is emerging which has already appeared in other industries—treating environmental quality as a potential source of profitability and competitive advantage. This article discusses how utilities and industrial companies can develop an environmental performance measurement framework, integrate it into their strategic and operating business practices, and use it for evaluation of alternative environmental strategies.     

Work schedule flexibility and family life

This paper explores the implications of work schedule flexibility for family life. Based on data from the 1977 Quality of Employment Survey, it demonstrates that flexibility of work schedules moderates the effects of nonstandard work schedules on family life. That is, nonstandard work schedules tend to have a less negative association with the quality of family life when accompanied by a high level of schedule flexibility. The paper further demonstrates that this tendency of flexibility to act as a buffer against the negative effects of nonstandard work schedules on family life is more pronounced among working women than working men.     

WATER QUALITY MODELING OF ALTERNATIVE AGRICULTURAL SCENARIOS IN THE U.S. CORN BELT1

ABSTRACT: Simulated water quality resulting from three alternative future land‐use scenarios for two agricultural watersheds in central Iowa was compared to water quality under current and historic land use/land cover to explore both the potential water quality impact of perpetuating current trends and potential benefits of major changes in agricultural practices in the U.S. Corn Belt. The Soil Water Assessment Tool (SWAT) was applied to evaluate the effect of management practices on surface water discharge and annual loads of sediment and nitrate in these watersheds. The agricultural practices comprising Scenario 1, which assumes perpetuation of current trends (conversion to conservation tillage, increase in farm size and land in production, use of currently‐employed Best Management Practices (BMPs)) result in simulated increased export of nitrate and decreased export of sediment relative to the present. However, simulations indicate that the substantial changes in agricultural practices envisioned in Scenarios 2 and 3 (conversion to conservation tillage, strip intercropping, rotational grazing, conservation set‐asides and greatly extended use of best management practices (BMPs) such as riparian buffers, engineered wetlands, grassed waterways, filter strips and field borders) could potentially reduce current loadings of sediment by 37 to 67 percent and nutrients by 54 to 75 percent. Results from the study indicate that major improvements in water quality in these agricultural watersheds could be achieved if such environmentally‐targeted agricultural practices were employed. Traditional approaches to water quality improvement through application of traditional BMPs will result in little or no change in nutrient export and minor decreases in sediment export from Corn Belt watersheds.