[Code of Federal Regulations]
[Title 40, Volume 19]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR130.2]

[Page 354-355]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 130--WATER QUALITY PLANNING AND MANAGEMENT--Table of Contents
 
Sec. 130.2  Definitions.

    (a) The Act. The Clean Water Act, as amended, 33 U.S.C. 1251 et seq.
    (b) Indian Tribe. Any Indian Tribe, band, group, or community 
recognized by the Secretary of the Interior and exercising governmental 
authority over a Federal Indian reservation.
    (c) Pollution. The man-made or man-induced alteration of the 
chemical, physical, biological, and radiological integrity of water.
    (d) Water quality standards (WQS). Provisions of State or Federal 
law which consist of a designated use or uses for the waters of the 
United States and water quality criteria for such waters based upon such 
uses. Water quality standards are to protect the public health or 
welfare, enhance the quality of water and serve the purposes of the Act.
    (e) Load or loading. An amount of matter or thermal energy that is 
introduced into a receiving water; to introduce matter or thermal energy 
into a receiving water. Loading may be either man-caused (pollutant 
loading) or natural (natural background loading).
    (f) Loading capacity. The greatest amount of loading that a water 
can receive without violating water quality standards.
    (g) Load allocation (LA). The portion of a receiving water's loading 
capacity that is attributed either to one of its existing or future 
nonpoint sources of pollution or to natural background sources. Load 
allocations are best estimates of the loading, which may range from 
reasonably accurate estimates to gross allotments, depending on the 
availability of data and appropriate techniques for predicting the 
loading. Wherever possible, natural and nonpoint source loads should be 
distinguished.
    (h) Wasteload allocation (WLA). The portion of a receiving water's 
loading capacity that is allocated to one of its existing or future 
point sources of pollution. WLAs constitute a type of

[[Page 355]]

water quality-based effluent limitation.
    (i) Total maximum daily load (TMDL). The sum of the individual WLAs 
for point sources and LAs for nonpoint sources and natural background. 
If a receiving water has only one point source discharger, the TMDL is 
the sum of that point source WLA plus the LAs for any nonpoint sources 
of pollution and natural background sources, tributaries, or adjacent 
segments. TMDLs can be expressed in terms of either mass per time, 
toxicity, or other appropriate measure. If Best Management Practices 
(BMPs) or other nonpoint source pollution controls make more stringent 
load allocations practicable, then wasteload allocations can be made 
less stringent. Thus, the TMDL process provides for nonpoint source 
control tradeoffs.
    (j) Water quality limited segment. Any segment where it is known 
that water quality does not meet applicable water quality standards, 
and/or is not expected to meet applicable water quality standards, even 
after the application of the technology-based effluent limitations 
required by sections 301(b) and 306 of the Act.
    (k) Water quality management (WQM) plan. A State or areawide waste 
treatment management plan developed and updated in accordance with the 
provisions of sections 205(j), 208 and 303 of the Act and this 
regulation.
    (l) Areawide agency. An agency designated under section 208 of the 
Act, which has responsibilities for WQM planning within a specified area 
of a State.
    (m) Best Management Practice (BMP). Methods, measures or practices 
selected by an agency to meet its nonpoint source control needs. BMPs 
include but are not limited to structural and nonstructural controls and 
operation and maintenance procedures. BMPs can be applied before, during 
and after pollution-producing activities to reduce or eliminate the 
introduction of pollutants into receiving waters.
    (n) Designated management agency (DMA). An agency identified by a 
WQM plan and designated by the Governor to implement specific control 
recommendations.

[50 FR 1779, Jan. 11, 1985, as amended at 54 FR 14359, Apr. 11, 1989]