OAR 340-042-0030

In addition to the definitions provided in ORS 468.005 (Definitions), 468B.005 (Definitions for water pollution control laws), OAR 340-041-0006 and 340-045-0010 (Definitions), unless otherwise required by context, the following definitions apply to OAR 340-042.


“Background Sources” include all sources of pollution or pollutants not originating from human activities. In the context of a TMDL, background sources may also include anthropogenic sources of a pollutant that the Department or another Oregon state agency does not have authority to regulate, such as pollutants emanating from another state, tribal lands or sources otherwise beyond the jurisdiction of the state.


“Designated Management Agency (DMA)” means a federal, state or local governmental agency that has legal authority over a sector or source contributing pollutants, and is identified as such by the Department of Environmental Quality in a TMDL.


“Director” means the Director of the Department of Environmental Quality or the Director’s authorized designee.


“Hydrologic Unit Code (HUC)” means a multi-scale numeric code used by the U.S. Geological Survey to classify major areas of surface drainage in the United States. The code includes fields for geographic regions, geographic subregions, major river basins and subbasins. The third field of the code generally corresponds to the major river basins named in OAR 340, division 41. The fourth field generally corresponds to the subbasins typically addressed in TMDLs.


“Local Advisory Group” means a group of people with experience and interest in a specific watershed or subbasin that is designated by the Department to provide local input during TMDL development.


“Management Strategies” means measures to control the addition of pollutants to waters of the state and includes application of pollutant control practices, technologies, processes, siting criteria, operating methods, best management practices or other alternatives.


“Performance Monitoring” means monitoring implementation of management strategies, including sector-specific and source-specific implementation plans, and resulting water quality changes.


“Pollutant” has the meaning provided in the Federal Water Pollution Control Act Section 502 (33 USC Section 1362).


“Reasonable Assurance” means a demonstration that a TMDL will be implemented by federal, state or local governments or individuals through regulatory or voluntary actions including management strategies or other controls.


“Sector” means a category or group of similar nonpoint source activities such as forestry, agriculture, recreation, urban development or mining.


“Sector-Specific Implementation Plan” or “Source-Specific Implementation Plan” in the context of a TMDL means a plan for implementing a Water Quality Management Plan for a specific sector or source not subject to permit requirements in ORS 486.050. The elements of an implementation plan are described in OAR 340-042-0080 (Implementing a Total Maximum Daily Load).


“Source” means any process, practice, activity or resulting condition that causes or may cause pollution or the introduction of pollutants to a waterbody.


“Subbasin” means the designation in the fourth field of the U.S. Geological Survey Hydrologic Unit Code.


“Surrogate Measures” means substitute methods or parameters used in a TMDL to represent pollutants.


“Total Maximum Daily Load (TMDL)” means a written quantitative plan and analysis for attaining and maintaining water quality standards and includes the elements described in OAR 340-042-0040 (Establishing Total Maximum Daily Loads (TMDLs)). These elements include a calculation of the maximum amount of a pollutant that a waterbody can receive and still meet state water quality standards, allocations of portions of that amount to the pollutant sources or sectors, and a Water Quality Management Plan to achieve water quality standards.


“Waterbody” means any surface waters of the state.


“Water Quality Management Plan (WQMP)” means the element of a TMDL describing strategies to achieve allocations identified in the TMDL to attain water quality standards. The elements of a WQMP are described in OAR 340-042-0040 (Establishing Total Maximum Daily Loads (TMDLs))(4)(l).
[Publications: Publications referenced are available from the agency.]
Last Updated

Jun. 8, 2021

Rule 340-042-0030’s source at or​.us