Autor:D. Owen
J. Cromwell
S. Rajachandran
Stuart Krasner
Zaid Chowdhury
Data wydania:2004
Utilities must decide whether to modify their existing treatment practices to achieve compliance with the D/DBP regulations. A regulatory impact analysis predicted that up to 70% of large surface-water systems would need to make some treatment modifications. Meeting multiple water-quality objectives plays an important role in the decision-making process of water utilities. Utilities must meet other regulatory requirements and secondary drinking-water standards. In addition, there are operational, financial, and engineering issues that affect the selection of treatment technologies. Because of the uncertainty of how stringent certain regulations will be and the high costs of advanced treatment technologies, many utilities have implemented treatment modifications in
Autor:Christopher Crockett
Jeffrey Rosen
Jose Sobrinho
Kristyn Stevens
etc.
Data wydania:2004
This research project aims to identify, list, and characterize chemical occurrence databases and data sets that can be used by states and utilities to perform source water assessments. The data sets were inventoried and reviewed based on a variety of descriptors (metadata). Amendments to the Safe Drinking Water Act (SDWA) require all US states to establish Source Water Assessment Programs (SWAPs). This includes the submission of a plan to the USEPA detailing how the states will delineate source water assessment areas, inventory significant contaminants in these areas, and determine the susceptibility of each public water supply to contamination. The collection of existing data on chemical occurrence is one tool to help determine potential contaminants and perform
Autor:C. Chauret
C. Volk
G. Gagnon
K. O'Leary
R Andrews
T. Dykstra
Data wydania:2005
Interest in UV disinfection has increased significantly in recent years, due its ability to inactivate Cryptosporidium parvum. Although UV disinfection shows significant promise for inactivation of Cryptosporidium, very few investigations have examined the impact of UV disinfection on biological stability in distribution systems. Biologically stable water is defined as drinking water that does not promote the growth of microorganisms and is typically achieved either through the removal of substrate and/or by providing a secondary disinfectant. At present there is little information concerning potential synergies between UV treatment and secondary disinfectants for improving biological stability. The overall objective of the research was to evaluate the effect that UV
Autor:B. Barbeau
B. Marinas
C. Mysore
Debra Huffman
Gary Amy
J. Leparc
M. Hernandez
M. Prevost
S. Dow
Data wydania:2004
The results from this research affirmed the fact that inactivation of microorganisms by chemical disinfectants is influenced by disinfection, microbial, and water quality factors and the various interactions between these factors. The results showed that for all disinfectants, temperature is a key parameter that influences disinfection efficiency. The effect of turbidity was generally of less importance than pH and temperature. The safety factors (1.5 to 2.0) that are applied in the USEPA Ct tables should be satisfactory to account for these effects, not to mention the additional safety factors that are employed during Ct calculations (Cresidual and t10). Research Partner: USEPA Originally published by AwwaRF for its subscribers in 2003
Autor:E. Von Sacken
K. Stone
L. Jentgen
R. Riddle
S. Conrad
S. Ranade
W. Grayman
etc.
Data wydania:2004
The operating environment for water utilities is changing. New information and control systems and operating procedures are required to manage water utility operations. Operations and maintenance managers must pursue improved planning and scheduling methods to reduce costs. Electric deregulation presents an opportunity and a challenge for energy cost reduction. Water quality and supply issues must be managed to maximize system performance and minimize costs. EWQMS systems enable water utilities to better utilize limited resources to provide optimal service to their customers. By planning and scheduling operations processes and integrating the use of data from automated systems, an EWQMS enables utilities to do more with less?just what is needed in the changing business
Narrative water quality criteria are an integral component of States water quality standards but they pose special problems when incorporated into the TMDL process. The TMDL process is typically a quantitative activity, defining numeric allowable loads necessary to meet a numeric water quality objective. Narrative criteria confound development of quantitative TMDLs, due to the absence of these numeric criteria. The objective of this research was to improve the methods for addressing narrative water quality criteria in the TMDL process. The problems associated with narrative criteria in the TMDL process are known in general terms but, prior to this research, there has not been a thorough review of the use of narrative criteria in TMDLs nor broad guidance on how to
The main objective of this project is to demonstrate that the technology of on line monitoring of waterborne metals by X-ray Fluorescence (XRF) at part per billion (ppb) and sub-ppb levels, which has been successfully applied in the power industry for several years, can be applied to water and wastewater treatment plants. A specially designed on line XRF monitor was assembled, tested in the laboratory, and used at the City of Alliance, Ohio Wastewater and Water Treatment Plants from July 2002 until March 2004. At various times through this project, the metals monitored included iron, copper, chromium, nickel, zinc, manganese, arsenic, cadmium, mercury and lead. The results indicate that XRF on line monitoring of waterborne metals at trace levels is feasible for the
Integrated water resource management has been discussed since at least the Civil War; yet, there is still no integrated framework for sustainably managing water. Recognizing this need, the Water Environment Research Foundation (WERF) funded a research project to develop an integrated, conceptual framework for sustainable water resources management. Through WERF funding, this framework was developed over the past four years. Development of the framework was guided by the U.N. Agenda 21, Global Water Partnership, the Enlibra Principles, and Panarchy Theory. The conceptual framework for Sustainable Water Resources Management considers water as a renewable, but finite resource with global and regional constraints. It integrates ecological, economic, and social
