In order to address increased interest from scientists and regulators in quantifying environmental risks associated with release of common down-the-drain consumer products, a single-medium contaminant fate model for the lower St. Lawrence drainage basin in Southern Ontario was developed. The model was built within the pre-existing framework of the iSTREEM® in-stream environmental exposure model, which previously only contained US geographies. Data for the model were obtained from Canadian Government sources. In order to assess the model's strengths and limitations, concentrations of the chemicals triclosan and carbamazepine in surface water were compared to the predicted environmental concentrations (PECs) generated by the model for both mean and low flow scenarios. Results of the PECs and the measured surface water concentrations were comparable, with the surface water concentrations generally falling in between the mean and low flow PECs on a cumulative distribution curve.
Introduction
“Sustainable Development” is an increasingly important concept in most industries today, and one in which the water industry has been making rapid progress for over a decade. In countries around the world, including the USA, Europe, and Australia, Sustainable Urban Drainage (SUD) structures - permeable pavements, ponds, and the like - are reducing the volumes of direct urban runoff, and helping to resolve problems such as flooding and pollutant spills to rivers.
However, until recently, waste...
Recognition of the relationship between increasing phosphorus inputs to surface waters and the subsequent increase in eutrophication of water bodies gave rise to public concern during the 1970’s and 1980’s. This led to action by several countries including the USA, Japan and some EU member states, to reduce phosphorus loads, particularly from urban and industrial point sources.
The two main areas of action that have taken place, particularly in the late 1980’s and early 1990’s are:
A reduction in the amount...
End-of-life (EOL) product returns provide an opportunity for landfill diversion through remanufacturing and materials recycling. In this paper, we focus on evaluating bulk recycling processing options for a take-back center that receives large quantities of similar products through warranty returns, leasing returns, trade-in incentives and take-back programs. We develop a multicommodity flow model as a decision tool to evaluate the reprocessing options for EOL products returned to a take-back center. To illustrate...
Characterization of groundwater flow regimes in fractured bedrock aquifers on Southern Vancouver Island and the Gulf Islands of British Columbia are presently based on simple hydraulic testing methods and analytical models. Transmissivity, storativity are derived from porous media (radial flow) analytical models that do not fully represent the more complex boundary conditions inherent to fracture bedrock aquifers. Geological and horizontal loop electromagnetic (HLEM) surveys were used to characterize the lithology...
1.1 Scope and Objectives
A small number of viable options are presently available for the bleaching of wood pulp (delignification and brightening) during the manufacture of pulp and paper. The use of chlorine dioxide (ClO2) in the bleaching process has largely superceded the earlier use of Cl2, or elemental chlorine, in the majority of North American pulp mills: It was discovered over a decade ago that the previous widespread use of Cl2 contributed to the production and subsequent release to the environment of...
Overview
Environmental policy is in transition. Many observers believe that the existing regulatory system, though it has accomplished great improvements in environmental quality, is approaching the limits of its effective ness. Government regulators and policy analysts are seeking better ways to address the many issues, like non-point source pollution, that remain largely unregulated. Most corporations are seeking more cost-effective ways to meet regulatory requirements, and some leading corporations are...
Abstract
The development of numerical codes, as well as pre- and post-processors to support these codes, has made the discipline of groundwater modelling increasingly more automated and efficient. The value of such modelling is reliant on the site-specific data used to build and calibrate the models. The integration of EarthSoft`s EQuISÒ Geology and any of several popular modelling environments results in a data management and analysis system that is more complete than the modelling system alone. Water level...
Abstract
Material flows of Finnish printing papers in 1994-2000 are studied using the JTP -technique. The environmental and economic implications of two scenarios are studied. The basic scenario is built on the assumption that no major changes will take place during the study period. Predictable changes in paper consumption, recycling rate etc. are taken into account. Scenario two presents an alternative policy option with two changes to the basic model: the landfill gas is collected and incinerated and all the...
Sites where halogenated VOCs may be found include burn pits, chemical manufacturing plants or disposal areas, contaminated marine sediments, disposal wells and leach fields, electroplating/metal finishing shops, firefighting training areas, hangars/aircraft maintenance areas, landfills and burial pits, leaking collection and system sanitary lines, leaking storage tanks, radioactive/mixed waste disposal areas, oxidation ponds/lagoons, paint stripping and spray booth areas, pesticide/herbicide mixing areas, solvent...
Introduction
There is considerable public, scientific and regulatory concern over the possible adverse health effects of chronic exposure to trace levels of persistent organic pollutants. The class of compounds made up of the polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF), often collectively known as dioxins, has received widespread attention and attracted a great deal of research, following the accidental release of the most toxic of these (2,3,7,8 TCDD) at Seveso in 1976.
Diox...
Many of the Environmental Protection Agency`s (EPA`s) methods used to monitor air, water and soil for environmental contaminants prescribe step-by-step details on how the chemical analysis must be conducted and prohibit any deviations or variations. The EPA has recognized that monitoring equipment and technology have improved tremendously over the last few years; that environmental media do not always act the same way for each analysis; and that the matrix may affect the analysis and results. The EPA has been...
When determining the consequences of accidental release flow rates from pressurized gas systems, it is important to select the appropriate type of air pollution dispersion model. For released gases which are lighter than or equal to the ambient air density, Gaussian dispersion models as described in Beychok`s text1 should be used. For released gases which are heavier than air, a dense gas model such as SLAB2 or DEGADIS3 should be used.
It is also important to determine realistic flow rates for accidental release...
A new groundwater attenuation modeling tool (FATE 5) has been developed to assist users with determining site-specific natural attenuation rates for organic constituents dissolved in groundwater. FATE 5 is based on and represents an enhancement to the Domenico analytical groundwater transport model (Domenico, 1987). These enhancements include use of an optimization routine to match results from the Domenico model to actual measured site concentrations, an extensive database of chemical property data, and calculatio...
` Comparative risk assessment provides a systematic way to compare environmental problems that pose different types and degrees of health risk. It combines information on the inherent hazards of pollutants, exposure levels and population characteristics to predict the resulting health effects. Using data from available sources, rapid, inexpensive comparative risk assessments can identify the most significant health problems. Together with consideration of costs, technical feasibility and other factors, the...
Introduction
Surface and subsurface soils have different characteristics in natural attenuation. Mobile contaminants in subsurface soils diffuse into soil vapor and aqueous phase and thus are relatively easily subject to natural subsurface processes that can attenuate these contaminants. Most high-molecular-weight (persistent) organic and many inorganic contaminants will be immobilized in the subsurface soil matrix. These persistent organic contaminants often are difficult to degrade and the inorganic metals are...
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Objectives of the Review Checklist
This Review Checklist has been developed as a method for reviewing environmental information submitted by developers, to the competent authorities, as part of an EIA procedure. Its purpose is to assist reviewers in evaluating the completeness and suitability of this information from a technical and decision making viewpoint. In particular it will assist reviewers in deciding whether all relevant information is available to fulfil two main functions:...
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