CHAPTER 3 - FINAL ANALYSIS

PART I - WATER QUALITY LIMITED WATERS - 1996

Purpose and Definitions

Waterbodies assessed as having impaired uses that require more than existing technology and permit controls to achieve or maintain water quality standards are classified by this Department as "Water Quality Limited Waters.” This listing is pursuant to the Clean Water Act Section 303(d), taking into consideration comments and further information received during the four-week public review process.

Water Quality Limited Waters are already impaired by one or more stressors; therefore, entities reviewing plans for future activities in this watershed should take actions to mitigate further contributions of a listed stressor. Further, each waterbody is prioritized for completion of a Total Maximum Daily Load (TMDL) analysis.



A Water Quality Limited Water does not maintain surface water quality standards for its designated uses, and neither existing technology nor permit controls are sufficient to maintain water quality standards.

A Total Maximum Daily Load (TMDL) is the amount of pollutant that can be discharged to a waterbody and yet meet the water quality standard. A TMDL is calculted for each pollutant separately. A TMDL is the basis for allocating the load to point sources and nonpoint sources.

A waterbody is a lake or stream reach. The streams have been segmented into "reaches" by the Environmental Protection Agency (EPA) and given a unique number -- the reach number.Facilities and persons conducting activities discharging to Water Quality Limited Waters with a high or medium ranking may be asked to provide in-stream monitoring data. The accuracy of the loading capacity analysis is largely dependent on the amount of data available; therefore, a discharger may often benefit from providing monitoring data. Without that data the discharger may be erroneously assumed to be the primary contributor.

Listing Criteria

Waterbodies listed as Water Quality Limited in 1996 met these criteria:

1) A fishing, drinking, or swimming advisory has been issued for the waterbody in the past two years; OR
2) The waterbody was listed on a prior 303(d) list and insufficient information exists to delist; OR
3) The waterbody was assessed in Arizona's 1996 Water Quality Assessment Report (305(b) Report) as in "partial" or "non-support" of designated use(s) based on Arizona's numeric or narrative surface water standards; AND
There was sufficient monitoring within the waterbody to be classified as a "monitored assessment" (see assessment criteria in Appendix C).

Note that waterbodies are not listed as Water Quality Limited on the basis of: an evaluated assessment (i.e., see explanation of evaluated versus monitored assessments in Appendix C), criteria not established in rules (i.e., wildlife tissue criteria, sediment criteria, secondary maximum contaminant levels, etc.), or where enforcement of existing permit requirements can bring the waterbody into compliance. Therefore, this list is not a prioritization of all water quality problems in Arizona.
Delisting--Based on the above criteria, a previously listed waterbody can be delisted based on:

• Monitoring data that shows that the impairment has been eliminated. There must be sufficient monitoring data for a "monitored assessment.” Monitoring data and conditions within the watershed indicate that exceedances will not routinely recur; OR
• Standards are no longer exceeded because of changes in surface water quality standards; OR
• Faulty data or information resulted in a listing error.

The following four stream reaches are no longer listed because of previous listing errors:



REACH NAME AND IDENTIFICATION

REASON DELISTED



Zuni River (at New Mexico border)
15020004-004

Monitoring data published by USGS (1994) was different from draft data available for the 1994 assessment.



Kirkland Creek (in Santa Maria drainage)
15030203-016

Data error: Selenium not exceeding standards.



Sycamore Creek (in Prescott National Forest)
15060202-026

Another Sycamore Creek in this watershed was monitored. This Sycamore Creek is in full support.



Hassayampa River (Martinez-Sols Wash)
15070103-003

Mill drainage not impacting the stream. Original assessment and listing in error.


Ranking and Targeting Waterbodies for TMDLs

Ranking--In 1996, 120 waterbodies in Arizona are listed as Water Quality Limited. ADEQ has ranked and scheduled a few of these waterbodies for a loading analysis (TMDL) sometime in the next two years (Appendix H). Ranking is based on the following criteria:

• Extent of impairment (number of contaminants, number of designated uses in "non-support");
• Special status of the waterbody or watershed (designated Wilderness Area, Primitive Area, Wild and Scenic River, Unique Waters, Riparian Conservation Area);
• Fishing, swimming, or drinking advisory has been routinely issued.

Each of the 120 listed waterbodies received a score based on the above criteria; however, the final ranking depended upon the appropriateness or merits of doing the TMDL. Factors used to judge merit included:

• Risk to human health and aquatic life,
• Degree of public interest and support,
• ADEQ support available from programs and initiatives to complete this analysis, and
• Other means available to bring water into compliance (i.e., standards development, enforcement actions, or use attainability analysis).

Those waterbodies listed because of a contaminant that is apparently entirely natural received a low ranking regardless of scores. A TMDL analysis is not an appropriate tool to resolve these water quality problems. Nonetheless, these waterbodies are listed to discourage additional contributions of specified parameters until other actions can be taken (i.e., establish site specific standards or eliminate uses which cannot be supported through a use attainability analysis).

Note that new standards for arsenic (Fish Consumption use) and bacteria (Full Body Contact use - fecal coliform changed to Escherichia coli) were adopted by ADEQ in 1996 after assessments were completed. The arsenic standard will be rising from 3.1 _g/l to 1450 _g/l. The change in the bacterial standard will also bring many waters into compliance because fecal coliforms are more ubiquitous and less indicative of wastewater pollution than
Escherichia coli. Also, there is much less Escherichia coli data available for assessments. Waters impaired by only arsenic and fecal coliform remain on the list until they are reassessed; however, they were given a low ranking.

Targeting--ADEQ has established a Watershed Protection Approach for addressing water quality issues. Currently, resources for implementing that framework are directed toward two watersheds: the Verde and the San Carlos/Safford/Duncan watersheds (Upper Gila River Basin). Consequently, the water quality limited waters that are found in these watersheds have been given "high priority" rankings and have been targeted for completion of TMDLs
within the next two years.
Appendix H. 1996 Water Quality Limited Waterbodies List and Ranking

Table Format and Explanation--The list of Water Quality Limited Waters is organized by watershed, and each waterbody (lake or stream reach) has been assigned an identification number, using the Hydrologic Unit Code number (assigned by U.S. Geological Survey for the drainage area), and a Reach Number for a stream segment (assigned by the U.S. Environmental Protection Agency) or a lake number (assigned by Arizona Game and Fish Department). This unique identification number minimizes confusion caused by giving many streams the same name (e.g. Sycamore Creek). "Reach" maps are available upon request through ADEQ or EPA.

Additions to the table since the last listing are indicated with an "*." Both new waterbodies and new stressors have been added to this table.


RANK:

I. STRESSOR - 1 point per cause or stressor listed as impaired,

I. NON-SUPPORT - 1 point per use assessed in "non-support" (0 points for uses in partial support),

uses: A&W = Aquatic and Wildlife (warm water fish, coldwater fish, ephemeral, or effluent dominated waters).
FC = Fish Consumption
FBC/PBC = Full Body Contact/Partial Body Contact
AgI = Agriculture Irrigation
AgL = Agriculture Livestock Watering
DWS = Domestic Water Source


I. SPECIAL STATUS - 2 points if any (or all) of the following special status applies.

UNIQUE - waters designated or proposed as Unique Water under Arizona's surface water quality rules;
WILDER - waters within a designated Wilderness, Primitive area, or Wildlife Refuge;
W&S - waters designated or proposed as Wild and Scenic Rivers designation (W&S);
NPS - water is part of a U.S. National Park, National Monument, or National Recreational Area.
RIP - waters within a designated Riparian Protection Area;
ADVISORY - fish advisory, swimming advisory, or drinking advisory during the past two years.

I. APPROPRIATENESS OF TMDL: Scores were adjusted for appropriateness. Factors considered included: apparent risk to human health or aquatic life, degree of public interest and support, how well existing ADEQ programs and initiatives could support completion of this analysis, and other mechanisms available to bring uses into full support (i.e. standards development, enforcement actions, use attainability analysis).