Skip to main content


Buy Article:

$9.50 plus tax (Refund Policy)

Or sign up for a free trial

The Biotic Ligand Model (BLM) is a relatively new tool for explaining and predicting the effects of water quality on the bioavailability and toxicity of metals to aquatic organisms. While it is well known that metal toxicity can be affected by water quality, the existing metals criteria ignore water quality factors other than hardness. As a result, a water quality criterion for metals may be overprotective for many receiving water bodies. Sitespecific criteria can be developed from bioassay information, such as in a water effect ratio (WER) study. The BLM was developed as a regulatory tool to provide an expedient and cost-effect alternative to bioassay testing in the establishment of sitespecific metals criteria.

The BLM has been successfully applied and tested in a wide variety of settings, in waters from geographically diverse areas in North America, South America, and Europe. The Water Environment Research Federation (WERF) has funded studies for the development and testing of the model for copper, silver, and nickel. As a result of the success of these programs, the U.S. EPA is considering the use of the BLM in the upcoming revision of the ambient water quality criteria for copper. Development is ongoing for a number of metals including copper, silver, zinc, nickel, lead, and cadmium.

The BLM uses easily obtained water chemistry for input data, including pH, DOC, cation and anion concentrations. The model has been extensively tested in settings where traditional bioassay-based methods have been used to develop site-specific criteria in freshwater and marine settings. WER datasets using fish or daphnia in freshwaters, or Mytilus edulis in marine waters have been compared with model predictions and typically shows excellent agreement. As a result of the relative ease of obtaining input parameters for the model, it is often possible to investigate temporal and spatial variability at a site in much greater detail than would be possible with bioassay-based methods. For example, a WER study was conducted for San Francisco Bay in support of a TMDL for copper. The model was used to predict WER results prior to conducting the bioassay tests. After confirmation that the model was in good agreement with the test results, the model was used to predict spatial variation in the site-specific copper criterion throughout the bay.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Data/Media
No Metrics

Document Type: Research Article

Publication date: 2003-01-01

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