This page contains information about mixing zones and the hydrodynamics of the mixing process. Examples of mixing zones and CORMIX application are presented. In addition, related issues where CORMIX analysis is possible is given, along with information about areas in which additional model development is necessary.
Bernhard H. Schmid (Bernhard H. Schmid) in Wien, Germany, has presented a paper on using CORMIX for evaluation of the Donaustadt diffuser, which has been accepted for presentation at the 2007 IAHR Congress held in Venice.
The National Institute of Air and Water Research (NIWA) in Hamilton, New Zealand, uses CORMIX for mixing zone simulation in Waimakariri District Ocean Outfall Option, an outfall diffuser siting study for a coastal wastewater discharge.
Water authorities apply a diversity of models and input data to set water quality-based emission limits in discharge permits. To illustrate the consequences of model and data selection, A. M. J. Ragas and R. S. E. W. Leuven compare results from two complete mixing models and four mixing zone models used in Germany, the United Kingdom (UK), the Netherlands and the United States of America (USA) were applied to various discharges of cadmium in "Modelling of water quality-Based Emission Limits for Industrial Discharges in Rivers", in Water Science Technology Vol. 39, No.4 pp.185-192 1999.
This consultant uses CORMIX for initial mixing modeling.
Ever since Charles Darwin developed his theory of evolution, the Galapagos Archipelago has been known for its unique ecosystem and biodiversity. Today the islands are a center of ecological conservation and international scientific research. Here is a description on how CORMIX was applied for environmental impact assessment of wastewater effluent plumes.
E. B. Marecellino and J. P. Ortiz demonstrate the use of CORMIX to determine the performance of marine outfalls in "Systematization of Submarine Sewers Operated By Basic Sanitation Company of Sao Paulo State-SABESP and Performance Evaluation Carried Out by the CORMIX Expert System Application" in Proceeding XXIX IAHR Congress, Beijing China, September 16-21 2001.
Cornell University applied CORMIX in environmental impact assessment on Lake Cayuga for its new Lake Source Cooling Project. Lake Source Cooling technology utilizes the thermal storage capacity from large deep lakes to provide chilled water for air conditioning demand. This report details the application of CORMIX for environmental impact assessment.
A well known engineering consulting firm reports how CORMIX is applied for regulatory compliance of thermal discharges. In this particular application, the impacts on a sensitive species of freshwater mussel from a cooling water discharge under various design conditions is analyzed with CORMIX3.
In the Pacific Northwest, the several species of Salmon have been placed under the jurisdiction of the Endangered Species Act. Salmon migrate to and hold in mixing zones characterized by cool thermal refugia habitat to survive in freshwater during warm months. Refugia habitat has been associated with cool tributary source mixing and groundwater recharge areas. Physical mixing zone thermal refugia characteristics may be predicted by CORMIX models.
Downstream migration of juvenile salmon experience high mortality rates when smolts pass through turbines rather than fish passage structures. Introduction of turbulence can provide an attraction flow to fish passage diversion structures in dam forebays to bypass turbine intakes. This paper by C.C. Coutant (see also Oak Ridge National Laboratory Report Number ORNL/TM-13608) outlines how the CORMIX model could be used to design turbulent jets to help guide young fish around damns in down river migration.
The California Coastal Commission recently published a report on potential environmental impacts of desalination facility discharge. As freshwater resources for water supply become more scarce, many coastal communities may begin to consider seawater desalination as a source of supply. CORMIX1 and CORMIX2 can be directly applied to many of these discharges.
In the paper by Jody A. Berry and Peter G. Wells, "Integrated Fate Modeling for Exposure Assessment of Produced Water on the Sable Island Bank", Environmental Toxicology and Chemistry, 2004, Vol. 23, No. 10, pp. 2483–2493, the authors use CORMIX for initial dilution modeling for exposure assesment from produced water discharges in Nova Scotia.
The cruise ship industry has experienced rapid growth in recent years. Passengers are drawn to cruising by the beauty of the cruise locales. In order to protect the water quality of scenic coastal waters, Alaska's
Department of Environmental Conservation has commissioned a
report which reviews CORMIX estimates dilution of wastewater discharged from cruise ships.
Fossil fuel combustion releases "Greenhouses Gases" such as CO2, SO2, and HCL into the atmosphere and has been identified as a forcing factor in acid rain, global warming, and climate change. One possible solution is to use the oceans as a sink by capture and disposal of dissolved flue gases directly into the coastal environment. Dissolved CO2 discharges produce dense effluents which transport the dissolved gas quickly towards the bottom. In a paper titled "Alternative Models for the Disposal of Flue Gases in Deep Sea" P.N. Tandon and P. Ramalingam uses CORMIX models to investigate the transport and mixing behavior of dissolved gas discharges into the ocean and present analysis of the likely ecological impact. (Reference: Environmental Coastal Regions, C.A Brebbia ed., 2nd International Conference on Environmental Coastal Regions, Computational Mechanics, Inc. 1998, pp.185-194).
Submarine Pipeline Construction
Underwater construction of pipeline generally requires excavation of trench. This report by the US Army Corps of Engineers Cold Regions Research Laboratory outlines how CORMIX was used to predicted environmental impacts from trench excavation for a proposed project to bring Canadian natural gas to the United States crossing Lake Erie.
The Exploration and Geological Services Division of the Indian and Northern Affairs Canada, prepared a report titled "Use of Diffuser Systems for Dispersion of Placer Mining Effluent" in open file report 1996-2(T) in which CORMIX2 was used to evaluate different discharge designs to dispose of mine wash water.