INDUSTRIAL WATER DEMAND WITH WATER REUSE1

ABSTRACT: This work establishes an industrial water demand (IWD) model for a short term estimate, which considers water reuse technologies and discharge regulations, for the integrated circuit (IC) industry in northern Taiwan. Based on the optimization of an industrial water cost system, a computerized system dynamics model (SD model) is developed to generate individual firm IWD using data from year 2000. A market IWD is further constructed for 25 1C firms in the study area and is approximated by an inverse logistic curve. Analytical results demonstrate that price elasticity varies with water price in cases involving water reuse.     

COMPROMISE PROGRAMMING METHODOLOGY FOR DETERMINING INSTREAM FLOW UNDER MULTIOBJECTIVE WATER ALLOCATION CRITERIA1

ABSTRACT: This paper presents a quantitative assessment framework for determining the instream flow under multiobjective water allocation criteria. The Range of Variability Approach (RVA) is employed to evaluate the hydrologic alterations caused by flow diversions, and the resulting degrees of alteration for the 32 Indicators of Hydrologic Alteration (IHAs) are integrated as an overall degree of hydrologic alteration. By including this index in the objective function, it is possible to optimize the water allocation scheme using compromise programming to minimize the hydrologic alteration and water supply shortages. The proposed methodology is applied to a case study of the Kaoping diversion weir in Taiwan. The results indicate that the current release of 9.5 m³/s as a minimum instream flow does not effectively mitigate the highly altered hydrologic regime. Increasing the instream flow would reduce the overall degree of hydrologic alteration; however, this is achieved at the cost of increasing the water supply shortages. The effects on the optimal instream flow of the weighting factors assigned to water supplies and natural flow variations are also investigated. With equal weighting assigned to the multiple objectives, the optimal instream flow of 26 m³/s leads to a less severely altered hydrologic regime, especially for those low‐flow characteristics, thereby providing a better protection of the riverine environment.     

Nanotechnology and groundwater remediation: A step forward in technology understanding

Nanotechnology application to contaminated site remediation, and especially the use of nanoscale zero‐valent iron particles to treat volatile organic compound (VOC)‐impacted groundwater, is now recognized as a promising solution for cost‐effective in situ treatment. Results obtained during numerous pilot tests undertaken by Golder Associates between 2003 and 2005 in North America (United States and Canada) and Europe have been used to present a synthetic cross‐comparison of technology dynamics. The importance of a comprehensive understanding of the site‐specific geological, hydrogeological, and geochemical conditions, the selection of appropriate nanoscale particles, the importance of monitoring geochemical parameters during technology application, and the potential of nanoparticle impact on microbial activity are discussed in this article. The variable technology dynamics obtained during six pilot tests (selected among numerous other tests) are then presented and discussed. © 2006 Wiley Periodicals, Inc.     

WATER COLUMN LIGHT ATTENUATION IN DANSHUEI RIVER ESTUARY,TAIWAN1

ABSTRACT: The penetration of sunlight into the water column plays a critical role in the aquatic ecosystem. This study investigates light attenuation through the water column of the Danshuei River estuary and explores the models for quantifying it. The measurement of photosynthetically active radiation (PAR) indicates that the conventional exponential attenuation of light with depth is a very good model. A light attenuation coefficient may be derived from the PAR measurements at each location. The simpler measurements of Secchi depth (SD) provide an approximate estimate of the attenuation coefficients through an inverse linear relationship. The results also reveal that the amount and kinds of materials, which are either dissolved or suspended in the water, control light attenuation through the water column. However, the linear regression with such a model results in very poor correlation, and a relatively large constant term for the Danshuei River estuary. The regression with salinity yields a good correlation, indicating that the fraction of sea water might be a good parameter for estimating light attenuation coefficient for practical application in the Danshuei River estuary.     

SCREENING THE RELOCATION STRATEGIES OF WATER QUALITY MONITORING STATIONS BY COMPROMISE PROGRAMMING1

Water quality monitoring network designs historically have tended to use experience, intuition, and subjective judgment in siting monitoring stations only sporadically. Better design procedures for optimizing monitoring systems with respect to multiple criteria decision analysis had rarely been put into practice up front when the needs for intensive monitoring became critical. This paper describes a systematic relocation strategy that is organized to identify several significant planning objectives and consider a series of inherent constraints simultaneously. The planning objectives considered in this analysis are designed to enhance the detection possibility for lower compliance areas, reflect the emphasis for different attainable water uses at different locations, promote the potential detection for the lower degradation areas of pollutants, increase the protection degree of those areas with higher population density in the proximity of the river system, and strengthen the pre‐warning capability of water quality for water intakes. The constraint set contains the limitations of budget, the equity implication, and the detection sensitivity in the water environment. A case study in the Kao‐Ping River Basin, South Taiwan, demonstrates the application potential of this methodology based on a seamless integration between the optimization and the simulation models. It enables identification of the optimal locational pattern stepwise using the embedded screening and sequencing capacity in a compromise programming model. However, a well calibrated and verified water quality model is an indispensable tool in support of this multiobjective evaluation. Extra sampling procedures become necessary for the sites with sparse environmental information. Comparison of planning outcomes of compromise programming is made against previously achieved analyses by using weighted programming and fuzzy programming.     

WATER SHORTAGES,DEVELOPMENT, AND DROUGHT IN ROCKLAND COUNTY,NEW YORK1

Knowledge of the historical variability of regional climate is an essential element of successful water resource planning. Lacking such perspective, planners and managers can be deceived as to the severity of a recent climate extreme, such as drought, and place a disproportionate blame on the climate, not the integrity of the supply system should water restrictions become necessary to avoid shortages. Presented here is a vivid example of how development, a lack of adequate planning, and climate variability have converged to produce three water emergencies in Rockland County, New York, since 1995. An examination of climate data over the past century indicates that the severity of the recent droughts was well within the range of past variability. Rather than climate alone, the recent water emergencies have highlighted a significant mismatch between supply and demand that has been developing in Rockland County over the past three decades. Substantial development, largely in the form of single‐family homes, has not been matched with a corresponding enhancement of the county's water system. Realistic plans for meeting current water demand will require cooperation among all stakeholders, beginning with an acknowledgement that climate variations are inevitable, not the sole source of blame when water shortages arise.     

Indications of limited altered gene expression in Pinus sylvestris trees from the Chernobyl region

To evaluate the consequences of irradiation on the vegetation of the Chernobyl region, gene expression was compared in morphologically normal and dwarf needles from the same Pinus sylvestris trees in a region where the absorbed dose was 3-5 Gy. To compare the levels of gene expression, arrays consisting of 373 Pinus taeda cDNAs were hybridized with labeled cDNA derived from normal and dwarf needles of P. sylvestris. Twelve genes were significantly (P<0.01) up- or down-regulated between normal and dwarf needles for all five trees taken together. Five of these, related to stress or development, were up- or down-regulated 1.25-1.7-fold in the dwarf needles. There were no significant differences in (137)Cs content in the normal and dwarf needles, or in elongation growth rate of seedlings raised under controlled conditions from seed derived from trees in the region that had received a radiation dose over the range 2-12 Gy.     

New Criteria for Sustainable Water Quality Management1

Abstract: New criteria, pollutant load of unit area (PLUA), are developed for sustainable water quality management, which not only avoids degrading water quality but also considers the equity of development between different generations. A simulation‐optimization model is established to determine PLUA, in which uses the QUAL2E model to simulate pollutant transport and formulates a linear programming model to optimize the objective of maximal loads (carrying capacity). Two watersheds, the Touchen creek and the Keya creek, both in Taiwan, are taken as case studies. The PLUA criterion is applied to several existing projects which have passed environmental impact assessment (EIA). The results show that if the Hsinchu Science‐Based Industrial Park discharges wastewater to the Touchen creek, the total pollutant discharge of 85.6 kg/day exceeds the allocated load. Consequently, a waste reduction of at least 23.4% is required. Although these existing projects have passed EIA, most of them violate the criterion of PLUA and thus contribute to continued degradation of water quality. This study suggests developing PLUA as a part of the process of strategic environmental assessment (SEA) for watershed management plans and then applying it to EIA as a criterion for new project assessment. Furthermore, if carrying capacities of all pollutant discharges and resource uses can be translated into loads per unit of area, an integrated sustainable watershed management plan can be developed.