Skip to main content


Buy Article:

$9.50 plus tax (Refund Policy)

Or sign up for a free trial

TMDL allocation is a required component for establishing TMDLs and its purpose is to create a technically feasible and reasonably fair division of the allowable load among various sources. Current TMDL guidance is sparse in the area of allocation development, largely because the allocation of loads is considered a policy decision on how to distribute costs among different stakeholders in order to achieve a water quality goal. Better science is needed for supporting allocation decisions and guidance on the various methods for making these decisions. Knowledge of the critical condition could help identify the feasible allocation scenarios needed to be taken to meet water quality standards. However, EPA guidelines thus far do not specify how to define the so-called design or critical conditions. When point sources and nonpoint sources are considered an “integrated” manner, the worst-case scenario is not obviously known because nonpoint sources are mostly storm-driven. Therefore, one objective of this paper is to clearly illustrate the importance of defining critical condition relating to TMDL allocation.

As a viable alternative approach to TMDL development and allocation, the event-based Critical Storm-Flow (CFS) approach explicitly addresses critical condition as a combination of stream flow, magnitude of storm event and initial watershed condition. One of the major advantages is its ability to assess the risk associated with a certain load reduction scenario and examine impacts of allocation options during TMDL development, which makes nonpoint source control more consistent with the traditional approach to point source management. Case studies in this paper emphasize TMDL allocation for nutrient and pathogen TMDLs. Key factors influencing critical condition and TMDL allocation were discussed, for example, stream flow, precipitation and antecedent condition. Ongoing research on TMDL allocation techniques was presented, such as explicit incorporation of cost function in TMDL allocation and use of decision support system in assisting the formulation of consensus-based management plan.
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: 2004-01-01

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