Guidance from the U.S. Environmental Protection Agency for the
Texas Water Quality Inventory and 303(d) List requires that all
water bodies be placed into one of five categories. Each assessed
area, or assessment unit (AU), must be categorized by how it meets
its designated uses.
Description of Categories
One of five categories is assigned to each parameter and water
body to provide information about water quality status and
management activities. When a water body has parameters in multiple
subcategories, its overall category is the highest category.
Category 1—Attaining the water quality standard and
no use is threatened.
Category 2—Attaining some of the designated uses; no
use is threatened; and insufficient (or no data) are available to
determine if the remaining uses are attained or threatened.
Category 3—Insufficient data (or no data) to
determine if any designated use is attained.
Category
4—The standard is not supported or is threatened for one
or more designated uses but does not require the development of a
Total Maximum Daily Load (TMDL).
- Category 4a—A TMDL has been completed and approved
by the EPA.
- Category 4b—Other pollution control requirements
are reasonably expected to result in the attainment of the water
quality standard in the near future.
- Category 4c—Nonsupport of the water quality
standard is not caused by a pollutant.
Category
5—The water body does not meet applicable water quality
standards or is threatened for one or more designated uses by one
or more pollutants.
- Category 5a—A TMDL is under way or scheduled, or
will be scheduled.
- Category 5b—A review of the water quality standards
will be conducted before a TMDL is scheduled.
- Category 5c—Additional information will be
collected before a TMDL is scheduled.
For a more detailed explanation of the categories, see
2002 Strategy for a Comprehensive Assessment and Categorization of
Waters in Texas (PDF, October 1, 2002). (Help with PDF.)
Category Reports
These files are in Portable Document Format (PDF). (Help with PDF.)
- Summary of the 2002 Texas Water Quality Inventory (Categories
1-5),
Full document (449 pages, ~930KB).
