Skip to main content
padlock icon - secure page this page is secure


The full text article is not available for purchase.

The publisher only permits individual articles to be downloaded by subscribers.

Industrial refrigeration systems produce significant amount of hot wastewater that is usually discharged into rivers, lakes or oceans. A thermal waste has adverse effects on the receiving water bodies causing a potential threat to the existing ecological community. The risk posed by the thermal discharges to a lake or ocean environment depends on, among other factors, the size of the thermal discharge, its temperature at the outfall, the extent of the exposure and response of the receptors. The quantification of the risk to the aquatic community is rendered uncertain due to variability in the responses of the receptors as well as uncertainties in the extent of their exposure. An assessment of the exposure of the aquatic life to such affected environment is rendered further uncertain by various factors such as bio-availability and/or the duration of the exposure. In spite of the uncertain nature of the input parameters and the associated estimation methods, the quantification of the risk has been traditionally done based on deterministic approaches thus leaving the risk managers with an unknown degree of uncertainty in the implementation of their management strategies.

Using a probabilistic approach, this paper demonstrates a USEPA-based methodology for characterizing the ecological risk. An example of the stepwise application of the method to characterize the risk posed by the thermal discharges to the aquatic life in a lake environment is presented. The temperature distribution in the lake water due to the dispersion of heat from the thermal outfall is probabilistically estimated by using a centerline temperature decay model available in the literature. The uncertainties in the thermal responses of assessment endpoints and their exposure are estimated using an approach based on two-dimensional Monte Carlo simulation.

The results from the case studied show that the deterministic approaches of risk assessment may fail to identify the inherent threat to the aquatic community for a given management goal. However, using the probabilistic method, the uncertainty associated with the input parameters is clearly manifested in the increased risk! Risk management and communication aspects, including the limitations of the study are also discussed in the paper.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
No Metrics

Document Type: Research Article

Publication date: 01 January 2004

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Learn about the many other WEF member benefits and join today
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more