EPA 832-R-05-006
December 2005
Development of Water Quality Analyses for the
Shared Waters of the United States and Mexico
*K53£
Prepared for:
United States Environmental Protection Agency
Office of Wastewater Management
Washington DC, 20460
Prepared by:
RTI International
3040 Cornwallis Road
P.O. Box 12194
Research Triangle Park, NC 27709-2194
BRTI
INTERNATIONAL
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Development of Water Quality Analyses for the
Shared Waters of the United States and Mexico
Prepared for:
United States Environmental Protection Agency
Office of Wastewater Management
Washington DC, 20460
Prepared by:
RTI International1
3040 Cornwallis Road
P.O. Box 12194
Research Triangle Park, NC 27709-2194
1 RTI International is a trade name of Research Triangle Institute.
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Development of U.S.-Mexico Water Quality Analyses
Acknowledgments
The U.S.-Mexico Shared Waters project represents a unique effort to bring together
organizations and individuals from both sides of the U.S.-Mexico border to help with the design
and creation of the first prototype version of the U.S.-Mexico Border Waters Repository and the
Mexico Border Reach File (MBRF). This effort has developed a baseline of what water quality
information is available on both sides of the U.S.-Mexico border, generated useful products
based on this information, and identified ways to build up on what has been done so far towards
developing a binational water quality dataset that can be used to establish baseline border water
quality conditions and measure future progress towards improving water quality conditions for
this important resource.
One of the most important accomplishments of this project has been to identify current and
future key players involved with U.S.-Mexico border environmental issues and to gain their
cooperation towards establishing a baseline data set. Many of these organizations have been
working for years on important environmental problems in the region and have vast experience
dealing with water resources and water quality issues along the U.S.-Mexico border. The
following organizations contributed data, comments, and recommendations to this project; their
expertise and guidance on border issues was fundamental to completing this report:
« U.S. Environmental Protection Agency (EPA) Region 6 and Region 9
Comision Nacional del Agua (CNA), Mexico Distrito Federal, Mexico
Comision Internacional de Lfmites y Aguas (CILA), Juarez, Mexico
International Boundary and Water Commission (IBWC), El Paso, TX
Southwest Consortium for Environmental Research and Policy (SCERP), San Diego,
CA
» University of Texas at Austin (UTA)
U.S. Geological Survey (USGS), Austin, TX.
Future cooperation and coordination with these entities must be included in planning for
subsequent phases of this project and will be critical towards the continuing success of the border
water data collection efforts.
*
In addition, this report builds upon earlier work on this project conducted by Parsons
Engineering Science, Inc. (A Unit of Parsons Infrastructure & Technology Group Inc.). In
particular, that work contributed significantly to the description of the study area in Section 2 and
Appendix A of this report.
This work was led and directed by Alfonso Blanco, Office of Wastewater Management, U.S.
EPA Office of Water. The work was done under task order contract by RTI International. Eric
Solano was the RTI technical lead and Robert Truesdale was the RTI task order leader.
111
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Development of U.S.-Mexico Water Quality Analyses
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IV
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Development ofU.S.-Mexico Water Quality Analyses
Table of Contents
Acknowledgments ,,..iii
Table of Contents v
List of Figures vi
List of Tables vi
List of Acronyms and Abbreviations..; vii
1.0 Introduction 1
1.1 Background 1
1.2 Stakeholder Workgroup 3
1.3 Document Content and Organization 4
2.0 Study Area .... 6
2.1 Pacific/Salton Sea Transboundary Basins 8
2.2 Colorado River/Sea of Cortez Transboundary Basins 9
2.3 Central Desert/Closed Transboundary Basins 10
2.4 Upper Rio Grande Transboundary Basins 11
2.5 Lower Rio Grande Transboundary Basin 12
3.0 U.S.-Mexico Border Waters Data Repository 13
3.1 Methodology 13
3.2 Findings and Recommendations 19
4.0 Developing Water Quality Indicators for the U.S.-Mexico Border 26
5.0 Mexico Border Reach File 30
5.1 Methodology 30
5.2 Findings and Recommendations 31
6.0 Future Work..; 31
6.1 Maintaining and Enhancing the Repository 32
6.2 Water Quality Analysis 33
6.3 Mexico Border Reach File 34
7.0 References; 34
Appendices
A Study Area Descriptions
B U.S.-Mexico Border Waters Repository
C Water Quality Indicators Included in the U.S.-Mexico Border Waters Repository
D Water Quality Comparisons Against Benchmarks
E Water Quality Trends Scenarios
F Summary of 303(d), 305(b), and Fish Advisory Information for the U.S. Part of
the Border
G Temporal Data Gaps
H Mexico Border Reach File
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Development of U.S.-Mexico Water Quality Analyses
List of Figures
1 U.S.-Mexico border study area 6
2 Pacific/Salton Sea Basins 8
3 Colorado River/Sea of Cortez Basins 9
4 Central Desert/Closed Basins 10
5 Upper Rio Grande Basins 11
6 Lower Rio Grande Basin 12
7 Process for developing water quality indicators within the Border 2012 conceptual
framework 27
List of Tables
1 Transboundary Basin Characteristics , 7
2 Number of Stations Sampling, Generating, or Reporting Data, by State 20
3 Number of Stations Sampling, Generating, or Reporting Data, by Transboundary
Region 20
4 Number of Stations Sampling, Generating, or Reporting Data on a Water Quality
Parameter, by Country 21
5 Number of Stations Sampling, Generating, or Reporting Data on a Water Quality
Parameter, by Transboundary Region 21
6 Repository Parameters Related to Aquatic Life or Public Health Uses and
Typical Applicability as Ambient Water Standards or for Use in Permitting 28
VI
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Development of U.S.-Mexico Water Quality Analyses
List of Acronyms and Abbreviations
BASINS Better Assessment Science Integrating Point and Nonpoint Sources
BECC Border Environment Cooperation Commission
BFCC U.S.-Mexico Border Field Coordinating Committee
BITF Border Indicators Task Force
BOD biological oxygen demand
CILA Comision Internacional de Limites y Aguas
CNA Comision Nacional del Agua
COD chemical oxygen demand
CU cataloging unit
DO dissolved oxygen
DOI U.S. Department of the Interior
DPSIR driving forces-pressure-state-impact-response
EPA U.S. Environmental Protection Agency
ESAR Environmental Sampling, Analysis, and Results
GIS geographic information systems
GNEB ' Good Neighbor Environmental Board
GNIS Geographic Names Information System
GPS global positioning system
IB WC International Boundary and Water Commission
ITFM Interagency Task Force on Monitoring
MBRF " Mexico Border Reach File
NAD National Assessment Database
NADB North American Development Bank
NAFTA . North American Free Trade Agreement
NHD National Hydrography Dataset
NWIS National Water Information System
OMB Office of Management and Budget
PSR pressure-state-response
QA/QC Quality Assurance/Quality Control
RIT Reach Indexing Tool
RTI RTI International
SCERP Southwest Consortium for Environmental Research and Policy
SEMARNAT Secretariat of Environment and Natural Resources
SNICA Sistema Nacional de Informaci6n de la Calidad del Agua
SQL structured query language
STORET EPA's STOrage and RETrieval data repository
TCEQ Texas Commission on Environmental Quality
TDS total dissolved solids
TN total nitrogen
TSS total suspended solids
U.S. United States
USGS U.S. Geological Survey
UTA University of Texas at Austin
VII
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Development of U.S.-Mexico Water Quality Analyses
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vni
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Development of U.S.-Mexico Water Quality Analyses
1.0 Introduction
The U.S. Environmental Protection Agency's (EPA's) Office of Wastewater Management
initiated this project, entitled Development of Integrated Water Quality Analyses for the Shared
Waters of the United States and Mexico (U.S.-Mexico Shared Waters), to support specific
objectives of the Border 2012: U.S.-Mexico Environmental Program (Border 2012) that require
assessment and management of water quality data along the U.S.-Mexico border. In support of
these objectives, the U.S.-Mexico Shared Waters project
Assembled, centralized, and standardized in one repository existing water quality data
from both sides of the border
Developed a watershed approach that can be used to analyze water quality issues on the
U.S.-Mexico border
« Created a prototype of a hydrographic data set, the Mexico Border Reach File (MBRF),
and described its potential use for assessing and managing water quality data towards
improving water conditions in the border region.
The U.S.-Mexico Shared Waters project created a U.S.-Mexico Border Waters Data Repository,
populated this Repository with U.S. and Mexican data, and reviewed the assembled data to
identify data gaps. Additionally, common water quality analysis methodologies, such as water .
quality status and trends analysis, were investigated as examples of potential uses of the
repository.
1.1 Background
The Agreement between the United States of America and the United Mexican States on
Cooperation for the Protection and Improvement of the Environment in the Border Area, also
known as the La Paz Agreement, was signed by the United States and Mexico at La Paz, Baja
California, in August 1983 and entered in force in February 1984 (U.S. EPA, 2004). The La Paz
Agreement is the legal basis for the creation of Border 2012.
Border 2012a 10-year, results-oriented environmental program that serves as the main legal
framework within which the United States and Mexico can pursue solutions for improving the
environmental conditions along the borderis the latest multiyear, binational planning effort to
be implemented under the La Paz Agreement. It succeeds Border XXI, a.5-year program that
ended in 2000 (U.S. EPA, 2005a). Border 2012 was designed to empower the federal
environmental authorities in the United States and Mexico to undertake cooperative initiatives.
The U.S. EPA and Mexico's Secretariat of Environment and Natural Resources (SEMARNAT)
serve as national coordinators for these initiatives.
One of the goals of Border 2012 is to reduce water contamination by building on infrastructure
projects initiated by the Border Environment Cooperation Commission (BECC) and the North
American Development Bank (NADB). Since 1995, BECC and NADB, both created by North
American Free Trade Agreement (NAFTA), have had the primary role of working with
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Development ofU.S.-Mexico Water Quality Analyses
communities to develop and construct infrastructure projects. The main objectives of Border
2012, which build on those early projects, are as follows:
" Objective 1. By 2012, promote a 25 percent increase in the number of homes
connected to potable water supply and wastewater collection and treatment systems.
Objective 2. By 2012, assess significant shared and transboundary surface waters and
achieve most of the water quality standards currently being exceeded in those waters.
Objective 3. By 2006, implement a monitoring system for evaluating coastal water
quality at the international border beaches. By the end of 2006, establish a 2012
objective toward meeting both countries' coastal water quality standards.
Objective 4. By 2005, promote the assessment of water system conditions in 10
percent of the existing water systems in the border cities to identify opportunities for
improvement in overall water system efficiencies.
In support of these objectives, in particular objectives 2 and 3, EPA initiated the U.S.-Mexico
Shared Waters project to provide the information and tools needed to help determine indicators
for measuring program progress and assessing environmental and health changes in the region.
The U.S.-Mexico Shared Waters project is consistent with observations and recommendations
presented in the Good Neighbor Environmental Board's (GNEB) recent report on water quality
for the border region (U.S. EPA, 2005b). This eighth report by GNEB to the President and
Congress reiterates GNEB's 1995 recommendation that environmental data gaps and data
accessibility be addressed as a high priority. Specifically, GNEB's Recommendation 2 in the
report is
"Develop and sign formal U.S.-Mexico border-region water resources data
agreements. Such agreements should support the collection, analysis, and sharing
of compatible data across a wise range of uses so that the border region water
resources can be more effectively managed."
To support this recommendation, the GNEB report goes on to describe that border water
data are needed by water resource managers to help them understand "overarching forces
that continue to affect the fate of the regions water resources (such as current and
projected land use) in managing water quantity, quality, and use. The 2005 GNEB report
also references the 2003 report of the U.S.-Mexico Binational Council as stating that
".. .an accurate and harmonious system of data collection would serve as a fundamental
starting point for cross-border management."
The GNEB report identifies several remaining barriers to adequate border water quality
data, which this project has helped to overcome:
Barrier 1. Data gaps on water quantity and quality. The U.S.-Mexico
Shared Waters project has identified surface water data gaps (Section
3.2.2) and provides recommended next steps to fill them (Section 6).
Barrier 2. Different methods, inability to compare. As described in
Section 3.1, the project has brought data from both sides of the border into
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Development ofU.S.-Mexico Water Quality Analyses
a common format to promote and inform ongoing binational discussions
towards developing and applying standardized, comparable measures and
protocols.
Barrier 3. Inaccessibility of data. The U.S.-Mexico Border Waters Data
Repository provides a standardized format and database structure that can
be interfaced with Web-based systems that (1) enable data-providing
organizations to upload, review, and maintain data and (2) access data
. through map-based and tabular queries. Because the Repository was
designed and built as a cooperative effort between U.S. and Mexican
agencies and organizations (Section 1.2), the project has built the capacity
and trust needed for prompt availability and access of data collected on
both sides of the border.
Barrier 4. Limited, ad hoc data exchange systems. In recommending
next steps for establishing an annual U.S.-Mexico water quality data
exchange, page 27 of the GNEB report specifically endorses this project
and its subsequent phases as a collaborative, cross-border effort that
should be strongly supported.
As described in Section 3.1, the U.S.-Mexico Border Waters Data Repository is designed to
efficiently assemble data from existing U.S. and Mexican data systems into a common system to
enable cross-border sharing and comparison of data, and through the cooperation of Mexican and
U.S. agencies and organization, has been populated with most of the readily available water
quality data in the border region.
1.2 Stakeholder Workgroup
The U.S.-Mexico Shared Waters project has provided a unique opportunity to bring together
organizations and individuals from both sides of the U.S.-Mexico border to help with the design
and creation of the first version of the U.S.-Mexico Border Waters Repository and the MBRF
prototype. When planning this project, EPA and RTI recognized that the expertise and guidance
of stakeholders and experts on both sides of the border would be essential to accomplishing the
objectives of this project, from designing a robust and maintainable data repository to populating
it with U.S. and Mexican data. To meet this need, we worked with the following key players
involved with U.S.-Mexico border environmental issues:
Angel Kosfizer, U.S. EPA Region 6
Eugenia McNaughton, U.S. EPA Region 9
Eric Gutierrez Lopez, Carolina Molina Segura, Comision Nacional del Agua (CNA),
Mexico Distrito Federal, Mexico
Antonio Rasc6n, Comision Internacional de Limites y Aguas (CILA), Juarez, Mexico
Carlos Pena, International Boundary and Water Commission (IBWC), El Paso, TX
" Rick Van Schoik, Southwest Consortium for Environmental Research and Policy
(SCERP), San Diego, CA
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Development ofU.S.-Mexico Water Quality Analyses
" Daene McKinney and Carlos Patifio, University of Texas at Austin (UTA), Austin,
TX
Jean Parcher, U.S. Geological Survey (USGS), Dallas, TX.
These individuals and others in their organizations represent vast experience dealing with water
resources and water quality issues along the U.S.-Mexico border. Many of them have been
working for years on important environmental problems on the border region. Through meetings,
conference calls, and e-mail, the stakeholders contributed data, comments, and recommendations
at every stage of this project. Specific input was solicited and used for the following aspects of
the project:
Selection of the study area basins (Section 2)
« Agreement on the water quality parameters to be addressed in the project (Section 3)
" Design of the data repository (Section 3)
Collection of the data to be incorporated in the Repository, especially for the Mexican
side of the border (Section 3)
Review of the draft final report
Recommendations for activities to be included in the next phase of the study (Section
6).
Building this work group was critical to the completion of this report, and EPA thanks each
individual and organization for their valuable contributions to the project.
The future cooperation of these stakeholders will be essential in planning the subsequent phases
of this project. For example, recent (November and December 2005) meetings have confirmed
the value of this effort to all parties and their commitment and desire to continue the work. The
next meeting of the group, to be held in February 2006, will focus on developing common,
standardized binational measures and benchmarks that can be used to focus future data
collection efforts and allow regular assessment of water conditions in the border region. Topics
will include finalizing system requirements (e.g., for data sharing and updates) and identifying
resources for continuing the effort.
1.3 Document Content and Organization
This report documents the following activities that RTI performed in support of this project:
Collected and centralized in one repository a significant amount of existing water
quality data on both sides of the U.S.-Mexico border
Standardized the format in which water quality data on both sides of the border are
collected and stored
Facilitated the integration of existing and future water quality data with other
repositories, such as EPA's STOrage and RETrieval system (STORET) and the
National Water Information System (NWIS)
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Development of U.S.-Mexico Water Quality Analyses
Identified data gaps in the water quality indicators for which data are being collected
at the monitoring stations along the border
Provided a watershed approach to analyzing water quality issues on the U.S.-Mexico
border
Developed a prototype of the MBRF and described its potential benefits for water
quality analysis. *
The rest of this document is organized as follows:
Section 2, Study Area, defines the study area and provides a brief overview of the
major basins in the transboundary region.
Section 3, Data Repository, describes the methodology used to develop the data
repository and the findings from the data collected so far.
Section 4, Developing Effective 2012 Water Quality Indicators for the U.S.-
Mexico Border, provides background and recommendations for developing an
effective set of indicators that can be used to assess the quality of the shared waters of
the United States and Mexico. '
« Section 5, Mexico Border Reach File, describes the prototype reach file developed
for the U.S.-Mexico border region.
Section 6, Future Work, describes future enhancements or analyses that could build
upon the work described here.
Section 7, References, lists the works cited in this report.
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Development of U.S.-Mexico Water Quality Analyses
2.0 Study Area
The border region was defined in the La Paz agreement (Article 4) as the area located within 100
km on either side of the inland border between the United States and Mexico. Figure 1 shows the
border region with this 100-km buffer (outlined in red). The border region includes territory in
four U.S. states (California, Arizona, New Mexico, and Texas) and six Mexican states (Baja
California, Sonora, Chihuahua, Coahuila, Nuevo Leon, and Tamaulipas).
Legend
t I tMMlioundafy SaMn
~- US/Me>«»Boni8f,,
100 Km Study Area
Figure 1. U.S.-Mexico border study area.
The 100-km buffer encompasses eight basins that were defined in the mid-1990s by a U.S.
Department of the Interior (DOI) committeethe U.S.-Mexico Border Field Coordinating
Committee (BFCC)that was created to promote and facilitate coordination among the DOI
bureaus and the U.S.-Mexico border organizations. The BFCC, which is no longer active,
proposed a new definition for the U.S.-Mexico border, using hydrologic and hydrogeologic
criteria to delineate the extent of the border area (Woodward and Durall, 1996).
These basins do not, of course, coincide perfectly with the 100-km buffer, nor do state and
international lines coincide with the basins. Consequently, it makes sense to discuss the border
waters and their status and trends from a shared-waters perspective. This report is organized
around such a shared-waters perspective. For simplicity, we combined some of the eight DOI
basins that had similar hydrologic and physiographic characteristics to define five
"transboundary regions" (shown outlined in black in Figure 1):
Pacific/Salton Sea Basins (DOI Basin 1)
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Development of U.S.-Mexica Water Quality Analyses
Colorado River/Sea of Cortez Basin (DOI Basin 2)
" Central Desert/Closed Basins:
- Mexican Highlands Basin (DOI Basin 3)
- Mimbres/Animas Basin (DOI Basin 4)
Upper Rio Grande Basin:
- Rio Grande IElephant Butte Reservoir to above Rio Conchos Basin (DOI Basin
5)
- Rio Grande IIRio Conchos to Amistad Reservoir Basin (DOI Basin 6)
- Rio Grande IIIBelow Amistad Reservoir to Falcon Reservoir Basin (DOI
Basin 7)
Lower Rio Grande Basin (Basin 8).
Table 1 summarizes the characteristics of each of these transboundary regions, including the DOI
basins of which they are composed. The remainder of this section provides a brief description
and a more detailed map for each of the transboundary regions. Appendix A describes the
geography and hydrology of each of the transboundary regions in more detail.
Table 1. Transboundary Basin Characteristics
Transboundary
j Region
Pacific/Salton
Sea Basins
Colorado R./Sea
of Cortez Basin
Central Desert/
Closed Basins
Upper Rio
Grande Basin
Lower Rio
Grande Basin
DOI
Basin
1
2
3
4
5
. 6
7
8
DOI Basin
Name
Pacific
Basins/Sal ton
Sea
Colorado
R./Sea of
Cortez
Mexican
Highlands
Mimbres/
Animas
Rio Grande I
Rio Grande II
Rio Grande III
Lower Rio
Grande
Total U.S.-Mexico Border area
Total Area
sq. mi.
14,000
22,590
21,840
12,450
28,940
34,630
12,910
10,240
157,600
km1
36,000
59,000
57,000
32,000
75,000
90,000
33,000
27,000
408,000
Area in Mexico
sq. mi.
4,870
8,370
5,395
6,185
5,760
13,910
7,840
6,155
58,485
km1
13,000
22,000
14,000
16,000
15,000
36,000
20,000
16,000
151,000
AreainU.S [
sq. mi.
9,130
14,220
16,445
6,265
23,180
20,720
5,070
4,085
99,115
: km* j
24,000
37,000
43,000
16,000
60,000
54,000
13,000
11,000
257,000 .
Source: Woodward and Durall (1996)
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Development of U.S,-Mexico Water Quality Analyses
2.1 Pacific/Salton Sea Transboundary Basins
The Pacific/Salton Sea Basins drain an area of 14,000 square miles (36,000 km2), to either the
Pacific Ocean or inland seas. These basins have a very dry, semiarid climate with few fresh
water resources. The most important watersheds are
the San Diego, Cottonwood-Tijuana, and Salton
Sea. Except for the Salton Sea watershed, flow is
primarily from east to west, with stream flows
originating from precipitation in the mountains
flowing toward the Pacific Ocean. The flow in these
streams is controlled through a series of hydraulic
structures, including reservoirs. Land use varies
considerably, ranging from urbanized to agricultural
to wilderness. The Salton Sea watershed includes
the fertile Imperial Valley and the manufacturing
center of Mexicali.
Pacific/Salton Sea Basins.
The Tijuana River is one of the main streams in the
basin and one of the City of Tijuana's major natural resources. The river flows northwest through
the city of Tijuana before crossing into California near San Ysidro and then flowing into the
Pacific Ocean. Figure 2 shows the Pacific/Salton Sea Basins and their most important
characteristics.
Figure 2. Pacific/Salton Sea Basins.
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Development ofU.S.-Mexico Water Quality Analyses
2.2 Colorado River/Sea of Cortez Transboundary Basins
The Colorado River/Sea of Cortez
Basins contain watersheds that drain
either to the Colorado and Gila
Rivers, or directly to the Gulf of
California (Sea of Cortez). These
basins drain 22,590 square miles
(59,000 km2) and cover portions of
the states of Arizona and Sonora.
Land use is primarily agricultural
and grazing, although there are
important wildlife refuges and
wilderness areas, along with urban
areas such as Yuma and San Luis
Rio Colorado.
Lower Colorado River.
The Colorado River flows into the basin through heavily urbanized areas near Yuma and San
Luis Rio Colorado and then through wetlands before flowing into the Sea of Cortez. Currently,
most of the water flowing into the delta comes from agricultural drainage and periodic flood
flow from the United States and Mexico, with little perennial flow in the lower Colorado River.
This has significantly altered the delta's once extensive estuaries and salt flats. Figure 3 shows
the Colorado River/Sea of Cortez Basins and their most important characteristics.
Figure 3. Colorado River/Sea of Cortez Basins.
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Development ofU.S.-Mexico Water Quality Analyses
2.3 Central Desert/Closed Transboundary Basins
The Central Desert/Closed Basins include the Mexican
Highlands basins and the Mimbres and Animas basins.
Figure 4 shows the Central Desert/Closed Basins and their
most important characteristics. The Mexican Highlands Basin
contains watersheds that drain to rivers in southern Arizona
(e.g., the San Pedro and Santa Cruz Rivers), southwestern
New Mexico, northern Sonora (e.g., Aqua Prieta), or the
extreme northwestern tip of Chihuahua. The
Mimbres/Animas Basin contains watersheds that drain
internally in southern New Mexico and northern Chihuahua.
Together, these watersheds drain 34,290 square miles
(89,000 km2) (Woodward and Durall, 1996). Water resources
are scarce and competition for this limited resource is a major
water resource management theme in the region.
Santa Cruz River between Nogales
and Tumacacori.
The Mexican Highland basins are broad valleys separated by
steep mountain ranges, with each basin a mostly closed,
independent hydrologic system. Although classified as a desert, the region is renowned for
relatively lush vegetation and diverse aquatic habitats. All streams are ephemeral, except in the
valleys of Animas Creelc. The Central Closed Basin (which includes the Mimbres, Playa, and
Marmel watersheds) ranges from sub-humid in the north to arid in the south (Papoulias et al.,
1997).
A «*»<»«*» ttmm; rl JMoiiMr"iw
T*»Mfam*ai» iui*a» '** J US%to»M»
" %
Figure 4. Central Desert/Closed Basins.
10
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Development of U.S.-Mexico Water Quality Analyses
2.4 Upper Rio Grande Transboundary Basins
The Upper Rio Grande/Rio Bravo Basin is defined as
the area from the Elephant Butte Reservoir in New
Mexico to the Falcon Reservoir on the U.S.-Mexico
Border. The Rio Grande Basin drains 76,480 square
miles (200,000 km2) (Woodward and Durall, 1996).
Figure 5 shows the Upper Rio Grande Basins and their
most important characteristics. The basins are divided
into three segments: (1) from Elephant Butte Reservoir
to Rio Conchos, (2) from Rio Conchos to the Amistad
Reservoir, and (3) below the Amistad Reservoir to the
Falcon Reservoir. For most of this length the river
defines the U.S.-Mexico border and is the major source of surface water for the area (Blackstun
etal., 1996)
International Amistad Reservoir.
The climate of the Upper Rio Grande basins is semi-arid to arid, and the availability of water in
the river greatly affects water quality in the river. Flows are controlled largely by the series of
reservoirs along the river, and the availability of water determines almost all land use within the
basin. Land use is varied, including rangeland, agriculture, light industrial uses, mining, and
urban areas (five pairs of sister cities on either side of the .border). Where reservoirs and other
water storage devices are available, urban population and industries can be sustained. Where
canals are available to transport water, rangeland, ranches, and agriculture can be supported.
Colonias, communities on the U.S. side of the border without basic infrastructure, have a
significant impact of water quality and other water issues, and upgrading their infrastructure is
one focus for managing water quality in the region.
Figure 5. Upper Rio Grande Basins.
11
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Development of U. S. -Mexico Water Quality Analyses
2.5 Lower Rio Grande Transboundary Basin
The Lower Rio Grande Valleybelow Falcon
Reservoir to the Gulf of Mexicocontains
watersheds that drain either to the Rio Grande, to
the lower reach of the Rio San Juan below the
gaging station at Santa Rosalia, or to Arroyo
Colorado in southern Texas. It drains an area of
10,240 square miles (27,000 km2) of the Gulf
Coastal Plain. Figure 6 shows the Lower Rio
Grande Basin and its most important features.
The climate for lower Rio Grande basin becomes
more humid downstream, with vegetation ranging
from semiarid scrub land near the Falcon Reservoir,
to oak forests, and then to marshes and wetlands
near the gulf. Urban areas represent a significant
proportion of land use within the basin, along with irrigated cropland for vegetables, sorghum,
and cotton. Water supplies in the lower Rio Grande are limited and largely controlled by releases
from the Falcon Resevoir. Increasing demands from both sides of the border create a water
management challenge. Surface water has been and will continue to be the major source of water
supply in the basin, and increasing municipal and agricultural demands have significantly
decreased the amount of water available for refuge wetlands in the delta region near the Gulf,
with negative impacts on plants and wildlife in the estuaries and marshes near the mouth of the
river (Buckler et al., 1997).
Collecting water quality and flow data at
Arrovo Colorado.
Figure 6. Lower Rio Grande Basin.
12
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Development of U.S.-Mexico Water Quality Analyses
3.0 U.S.-Mexico Border Waters Data Repository
The U.S.-Mexico Border Waters Data Repository was developed to compile water quality data
from both sides of the U.S.-Mexico border. It was designed to be compatible with and receive
data from both U.S. and Mexican water quality data sources and to allow retrieval of comparable
data to compare and assess water quality conditions in the border region over time. By
establishing baseline water quality conditions on both sides of the border and tracking changes
over time, the Repository will help measure progress towards the effective management of the
border region's shared water resources.
The Repository contains secondary data of known quality, and it is not intended to replace or
supplant the water quality data systems that U.S. and Mexican agencies have established to
assess and manage their surface water resources. Instead, it is designed to hold data migrated
from these sources to enable easy access to the combined data on the shared water resources of
the border region. Data quality procedures were followed to ensure the accurate transfer and
processing of the data from the original data sources, but the Repository depends on the primary
data systems for ensuring adequate data quality.
This section discusses the Border Waters Data Repository that was built and populated during
this project. Section 3.1 describes the methodology used to build the Repository and to collect
and process the initial data set from U.S. and Mexican data sources. Section 3.2 describes
significant findings from this initial data set, including data content and data gaps.
3.1 Methodology
The main objective of the U.S.-Mexico Border Waters Repository is to provide a means to store
and retrieve water quality information for the U.S.-Mexico border areas. Important aspects of the
methodology used to build the Repository include its design, data sources, parameters collected,
data processing steps, and quality assurance and quality control (QA/QC) measures used to
populate the Repository. These aspects are described in the following sections.
3.1.1 Repository Design
The U.S.-Mexico Border Waters Repository is comprehensive but also simple: a repository that
can store and maintain data but that is also compatible with other existing systems. The
Repository was designed to be easily enhanced, because many data standards are still-under
development and water quality collection activities seem to be increasing along the Border.
The Repository is a flexible tool designed to allow the easy importation of water quality data
from a variety of sources from both sides of the border. In this initial effort, the Repository was
populated with data from both U.S. and Mexican sources. For the U.S. side, both recent and
historic (legacy) data were included to enable analysis of current and past water quality
conditions.
We designed the U.S.-Mexico Border Waters Repository to be
Easy to maintain, update, and expand
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Development of U.S. -Mexico Water Quality Analyses
" Easily integrated with EPA's STORE!
Easy to use
Compliant with EPA Environmental Sampling and Results (ESAR) standards and
Latitude/Longitude standards
Flexible enough to accommodate future changes that may be caused by data standard
protocols currently under development by EPA.
Robust enough to allow for storage of non-water-quality information, such as water
flow data
Able to store maps, text files, diagrams, and other information files.
To achieve those goals, we used
A simple database structure based-largely on STORET
Best practices in database design to ensure integrity of the links between tables
Numerous lookup tables, which make aid in navigation and querying and are easy to
add or modify as needed
Binary object storage techniques (to store maps, etc).
In addition, we incorporated many data elements from the EPA ESAR and Latitude/Longitude
data standards. The Repository complies with EPA's Latitude and Longitude data standards in
that every monitoring station for which data are stored is referenced with geographic coordinates
and additional geographic information. This is an important condition for linking water quality
data to a georeferenced system that holds hydrological and physiographic information about a
region.
The Repository structure is compatible with existing systems (most importantly the U.S.
STORET system) but has been simplified to facilitate data entry, maintenance, and access.
Appendix B explains in detail the technical design objectives considered when building the data
structure for the Repository. Appendix B also shows the data dictionary and entity relational
diagrams for the Repository.
The Repository is currently stored as a Microsoft Access database. Microsoft Access 2000 or
later is required to use the Repository. However, the Repository was designed so that it could be
migrated to another relational database software system, such as open-source MySQL, Oracle,
SQL Server, or open-source PostGRESQL.
The Repository does not yet have a user interface; therefore, a basic knowledge of relational
databases and structured query language (SQL) is needed to review Appendix B and write
queries to extract data summaries from the Repository. In the next phase of the project, we can
develop standard queries and include them in the Repository to produce reports and output tables
that can be viewed as text files or in standard spreadsheet software, such as Microsoft Excel.
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Development of U.S.-Mexico Water Quality Analyses
3.1.2 Water Quality Data Sources
We identified and accessed water quality data sources for the project through collaboration with
the U.S.-Mexico stakeholder work group. The current Repository includes water quality data
extracted from the following sources:
U.S. EPA (modernized and legacy STORET)
USGS (NWIS)
» Texas Commission on Environmental Quality (TCEQ)
International Border Waters Commission (IBWC)
Southwest Consortium for Environmental Research and Policy (SCERP)
Comision Nacional del Agua (CNA)
Comision Internacional de Limites y Aguas (CILA).
Some of the water quality data collected during this project were not included in the current
Repository because the data sources did not have location coordinates for water quality sampling
points:
Certain CILA data in PDF, jpg and Excel formats (example: data from the wastewater
treatment plant in Ciudad Acuna, Coahuila)
Data from the Beach and Bay Status Report from the Department of Environmental
Health, County of San Diego.
Finally, data from several other sources were received near the end of the project. These sources
were not included in the current Repository, but may contain useful water quality data:
" City of San Diego. Dry weather bio-assessment and chemical monitoring of creeks
and rivers.
« City of San Diego Metropolitan Wastewater Department. Sampling and analysis of
Tijuana wastewater.
San Diego County Water Authority. Regional Colorado River Conveyance Feasibility
Study Final Report, which compares Colorado River quality to recommended water
quality standards.
' State of California. Data report on discontinued water quality stations. Southern Great
Basin from Mexican Border to Mono Lake Basin, and Pacific Slope Basins from
Tijuana River to Maria River.
San Diego State University. Monitoring and Modeling of Water Quality in the
Tijuana River Watershed.
San Diego State University. An overview of the existing literature of the water quality
and quantity of the Tijuana River Watershed.
City of San Diego Water Department. Water quality monitoring at Barrett and
Morena Reservoirs. .
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Development ofU.S.-Mexico Water Quality Analyses
Tijuana State Commission of Public Services. Drinking Water and Wastewater
Master Plan for Tijuana and Playas de Rosarito. Water quality data.
Tijuana State Commission of Public Services. Information about Flow, Water
Quality, and Efficiency at the wastewater treatment plants.
Data from these sources can be explored during the next phase of this project.
3.1.3 Water Quality Parameters Collected
The stakeholder group selected 12 water quality parameters for data collection and entry in the
U.S-Mexico Border Waters Repository. This selection was based on the importance of these
parameters in evaluating how water resources are impaired in the border region and their
availability in data sources for both sides of the border. The 12 water quality parameters are
Dissolved Oxygen (DO)
Nutrients (nitrogen compounds, phosphorus compounds)
« Chlorophyll/biomass
Conductivity/total dissolved solids/salinity
Chlorides
Sulfates
" Acidity/pH/alkalinity
Chemical oxygen demand (COD)
Biochemical oxygen demand (BOD)
» Total suspended solids, total solids
Fecal bacteria (fecal coliform, fecal streptococci)
Temperature.
These water quality parameters are consistent with the water quality parameters listed on EPA's
Border 2012 Web site (http://www.epa.gov/usmexicoborder/indicators.htm) as part of the effort
to define water quality environmental indicators. EPA plans to refine these indicators and use
them as base-forming measures that should contribute to the development of more complex,
integral integrators. (Section 4.0 of this report provides suggestions and recommendations for
this further development.)
3.1.4 Flow Data
Flow data are an important component of the Repository both because water supply is a critical
issue in the border region and because flow data are needed to accurately calculate and assess
water quality status and trends, especially in arid and semiarid areas where seasonal flow can
vary greatly. The Repository was designed to hold flow data, and some flow data were collected
for the current Repository. Because stations that collect water quality data do not always collect
flow information and flow gaging stations do not necessarily collect water quality data, adding
16
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Development of U.S.-Mexico Water Quality Analyses
flow data to the Repository often requires adding additional station information and locations.
Potential sources of water flow data for the border region include:
IBWC Web site
STORET
USGS NWIS gage stations
San Diego Water Department.
3.1.5 Data Processing
The original sources of water quality data vary both in the methods used to measure the
parameters of interest and in how these parameters are named in the databases. For all data
sources, data are stored in the Repository in the same format as the original data source,
preserving the original water quality indicator name and units, as well as the original water
quality indicator ID. However, the Repository needed to have a consistent set of names to enable
comparable queries from different data sources, so we created lookup tables in the Repository to
link the source-specific indicator names to a standardized name (e.g., chlorophyll a) so that the
data can be extracted and analyzed for a particular indicator regardless of the different source-
specific names. As we import additional data sources into the Repository, we can easily modify
these lookup tables to match new source-specific names to the standardized names. These
standardized (or "generic") names can then be used to query the Repository database. Thirty-six
generic water quality parameters are included in the Repository database to represent the 12
selected water quality parameters listed in Section 3.1.3:
1. Fecal coliform
2. Fecal streptococci
3. Chlorophyll a
4. Biomass, periphyton
5. Chlorophyll c
. 6. Chlorphyll (a+b+c)
7. Chlorophyll b
8. Sulfate
9. Total dissolved solids (TDS)
10. Chloride
11. Dissolved oxygen (DO)
12. Flow rate
13. Conductivity, specific conductance
14. Alkalinity
15. Acidity
16. Hardness
t
17. Salinity
18. Sodium Adsorption Ratio
19. Turbidity
20. Chemical Oxygen Demand (COD)
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Development of U.S.-Mexico Water Quality Analyses
21. Total Oxygen Demand
22. Inorganic nitrogen
23. Total phosphorus
24. Organic nitrogen
25. Nitrogen ion
26. Total nitrogen (TN)
27. Nitrite
28. Phosphate
29. Nitrate
30. Ammonia
31. Nitrite plus nitrate
32. Biological oxygen demand (BOD)
33. pH
34. Temperature
35. Total Suspended Solids (TSS)
36. Dissolved'solids.
Appendix C of this report lists each standard variable name that has multiple designations in the
source data and describes how the variable was assigned in the Repository in terms of its
description and units. The Repository data table TL_CHARACTERISTIC, described in
Appendix B, is a lookup table that contains information about all water quality indicators for
which data were collected in the Repository, and relates the name and indicator ID in the original
data source to the generic water quality parameters listed above.
Data were extracted from the original data sources by a specific methodology for each source, as
described in Appendix C. In summary, we downloaded the data from the data source Web site
(or obtained the data files from the responsible organization). Most of the data files were in text
format. We imported each text file into a temporary database with the same structure as the
Repository. The text file was also placed in a separate Access data table with the same structure
as the original data source. Data were checked for completeness and cleaned and converted as
needed to bring it into the Repository format. These steps are described in Appendix C for each
data source.
3.1.5 Quality Assurance/Quality Control
Several QA/QC measures were used to ensure accurate transfer of data from the original data
sources into the Repository. The first QA/QC step was to count the number of records transferred
from the downloaded file into the temporary Access database to ensure that all records from the
downloaded file were properly transferred.
The next QA/QC step was to compare the two Access databases (one with the data in the original
file structure and one with the data in the Repository structure). A portion of the records stored in
these databases were checked to ensure that all information was carried from the original
downloaded file to the temporary Access database. This check was done by querying the original
data against the restructured data and by visual comparison. We checked 3 to 10 percent of all
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Development of U.S.-Mexico Water Quality Analyses
records for the tables containing results, sample data, location data, and station data. We checked
100 percent of records for the tables containing organization data, analytical methods data, and
characteristic data. The rest of the tables are lookup tables that were reviewed for accuracy as
they were created or obtained from another data source (i.e., STORET).
3.2 Findings and Recommendations
Different analyses were performed on the collected data to. provide examples of the type of
analyses that could be done with the data stored in the Repository. These analyses are presented
in Appendices D and E. Section 3.2.1 summarizes the data collected and Section 3.2.2 describes
the gaps identified in these data. Sections 3.2.3 to 3.2.6 describe the major findings from the
Repository and the recommendations that follow from those findings.
Appendix F is a summary of water quality status for a limited number of U.S. watersheds along
the border. These summaries are taken from the National Assessment Database (NAD) and
represent state assessments of water quality conditions (impaired or not) with respect to specific
designated uses (e.g., swimming, drinking water, fish consumption). Because they represent
regulatory assessment, data from the NAD can provide a solid baseline for water quality
conditions on the U.S. side of the border.
3.2.1 Data Summary
The U.S.-Mexico Waters Repository holds close to 200,000 data points for many different water
quality indicators at stations along the border. For each water quality indicator, data frequency is
defined as the number of stations with measured values of that indicator. Data frequency of data
collected on the U.S.-Mexico Repository was summarized by generic water quality indicator for
each basin.
Tables 2 through 5 summarize the number of stations sampling, generating, or reporting data by
geographic location (country, state, or transboundary region) in summary (Tables 2 and 3) and
by water quality parameter (Tables 4 and 5). Table 2 shows the number of stations by country
and state. Table 3 shows the number of stations by transboundary region. Table 4 shows the
number of stations by country and water quality indicator. Table 5 shows the number of stations
by transboundary region and water quality indicator.
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Development ofU.S.-Mexico Water Quality Analyses
Table 2. Number of Stations Sampling, Generating, or Reporting Data, by State8
| ; state.' , iT^v.: ...' -!I.:1J
i,, - .TotarNijttbeivbf ; ':
:''> ":'r: '.''Stations ;""..". :
! Number of Stations with
sV- "k'' FlowJipata ^r".;'
United States
California
Arizona
New Mexico
Texas
U.S. Total
114
12
30
276
432
1
0
0
146
16
Mexico
Baja California
Sonora
Chihuahua
Coahuila
Nuevo Leon
Tamaulipas
Mexico Total
7
1
'2
2
1
4
77
0
0
0
0
1
0
/
Some monitoring stations were not assigned to a country or state because of
inconsistencies between the station description and the reported latitude and
longitude (e.g., coordinates that were not in the state in the description or in the
study area at all).
Table 3. Number of Stations Sampling, Generating, or Reporting
by Transboundary Region"
;Tranisb6iaiiliiiai^'"Regibii: * 7 .,;
Paciflc/Salton Sea
Colorado River/Sea of Cortez
Central Desert/Closed
Rio Grande
Lower Rio Grande
Total
.'_;; TptaLNamberof Stations
119
5
18
147
160
449
Some monitoring stations were not assigned to a region
because of inconsistencies between the station description and
the reported latitude and longitude.
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Development of U.S.-Mexico Water Quality Analyses
Table 4. Number of Stations Sampling, Generating, or Reporting
Data on a Water Quality Parameter, by Country"
1 Water Quality Parameter '; jV-r/OvVTv
Fecal coliform
Fecal streptococci
Chlorophyll a
Sulfate
TDS .
Chloride
DO
Conductivity
COD
Inorganic Nitrogen
Phosphorus
Organic Nitrogen
Nitrogen
Nitrite
Orthophosphate
Nitrate
Ammonia
Nitrite and Nitrate
BOD
pH
Temperature
TSS
Total Solids
'..,,', ₯T C'; "*
:, , '..."U*l3':" :'
203
5
214
270
27
279
305
280
51
21
276
37
269
224
268
150
321
286
108
376
399
22
10
;M«fcp..;]
16
5
3
9
11
10
12
13
12
0
2
7
5
7
11
5
9
2
13
14
13
13
9
Totals do not add to stations totals in Table 3 because each station may
sample multiple parameters.
Table 5. Number of Stations Sampling, Generating, or Reporting Data on a Water
Quality Parameter, by Transboundary Region
Transboundary Region
i . .
\ Water Quality
j Indicator ,
Fecal coliform
Fecal streptococci
Chlorophyll a
Sulfate
TDS
Chloride
DO
Pacific/Salton
Sea
10
1
12
53
12
51
57
Colorado
River/Sea of
Cortez
4
4
1
6
4
6
6
Central
Desert/Closed
7
0
4
15
1
18
16
Rio Grande
122
6
115
134
17
139
132
Lower Rio 1
Grande j
103
1
112
106
6
110
139
(continued)
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Development of U.S.-Mexico Water Quality Analyses
Table 5. (continued)
r
j
j Water Quality
! Indicator
5 ... .- -
Conductivity
COD
Inorganic Nitrogen
Phosphorus
Organic Nitrogen
Nitrogen
Nitrite
Orthophosphate
Nitrate
Ammonia
Nitrite and Nitrate
BOD
PH
Temperature
TSS
Total Solids
Transboundary Region , |
Pacific/Salton
Sea
78
I
0
43
12
37
80
51
21
82
61
7
109
108
13
2
Colorado
River/Sea of
Cortez
6
4
0
0
4
1
4
4
3
4
2
4
6
6
4
4
Central
Desert/Closed
10
0
7
18
7
18
8
9
0
18
18
1
18
17
2
1
Rio Grande .
107
17
14
133
21
134
84
129
79
142
128
43
150
154
14
10
Lower Rio 1
Grande }
119
43
0
113
2
112
76
117
72
115
106
73
141
164
4
4
3.2.2 Data Gaps
Although some water quality indicators have been measured consistently at many stations for
years, important data gaps occur in all regions. For the purposes of this project, a data gap may
be defined as the lack of values for some parameter at a given monitoring station at a given point
in time, provided that the monitoring station was supposed to collect data for that parameter at
that time. A data gap can be of three types:
Temporal: data for a given-parameter were expected at a monitoring station or
location at a specific point in time. The station might have collected data at other
times for that same parameter.
Spatial: data for a given parameter were expected at different times at a location or
locations. These locations may or may not have monitoring stations. Other nearby
monitoring locations might have collected data for that same parameter at the same
period of time.
Combination of spatial and temporal: a data set with a parameter that is monitored
on a given segment of a river does not have any data records for different points of
the river at different points in time.
Temporal gaps affect trends analyses. In general, the fewer temporal gaps we have for a given
parameter at a given monitoring station, the better the trends analyses. Appendix G documents
the temporal data gaps found for the water quality parameters of interest.
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Development of U.S. -Mexico Water Quality Analyses
Spatial gaps can be important when determining water quality status for a particular river
segment. Recent data are preferable for establishing water quality status based on water quality
standards, water designated use, and stream flow level; therefore, it is important to address
spatial and temporal data gaps within five years of a water quality status study.
Spatial gaps can be determined for each transboundary region based on simple observation of
water quality monitoring station locations on the maps of each region presented in Section 2:
» In the Pacific/Salton Sea Transboundary Basins, a few water quality stations are
located in the Tijuana Watershed, on the Tijuana River on the U.S. side, but there are
no stations on the Mexico side. Water quality monitoring stations could be added to
the Repository for rivers such as Arroyo Florido, Rio de Las Palmas, or Arroyo Seco
to fill in spatial gaps. Many monitors are located near the Sweetwater River,
Sweetwater Reservoir, and the San Diego Bay. Some stations are located near other
important rivers and waterbodies such as the Mission Bay, San Diego River, and San
Dieguito River. To the east, many stations are located at the Salton Sea and its
tributaries, the Alamo River, and the New River. In Mexico, no stations are found in
the Repository for Laguna Salada.
For the Colorado River/Sea ofCortez Basin, the Repository does not include many
stations for the Colorado River and just a few for the Gila River. The Repository has
no stations from the Mexico side mainly because these are desert areas. Spatial data
gaps also exist along the Lower Colorado River and Lower Gila River.
For the Central Desert/Closed Basins, the repository includes data from many
stations for the most important rivers: the Santa Cruz River and the San Pedro River.
Data are sparse for the Mimbres River and there are no stations on the Mexico side
stored on the Repository.
The Upper Rio Grande Basin has plenty of monitoring stations on the Rio Grande
from the Elephant Butte Reservoir to El Paso/Juarez, but just a few on the segment of
Rio Grande from El Paso/Juarez to Amistad Reservoir. There are also a few stations
at the Pecos River and a few stations downstream of Amistad Reservoir. More data
from stations on the Rio Conchos and other Rio Grande Mexican tributaries could be
added to the Repository if they exist. Additionally, more sampling points could be
used along the Rio Grande above International Falcon Reservoir.
« The Lower Rio Grande Basin has just a few stations below International Falcon
Reservoir and above Anzalduas Dam. On the Mexico side, there are a couple of
stations on the Rio San Juan and Rio El Alamo, both tributaries of Rio Grande. There
are plenty of stations on the Arroyo Colorado, Laguna Madre, and South Bay. More
data from stations on the Rio Grande from Anzalduas Dam to the South Bay estuary
are needed if they exist.
One additional kind of spatial gap is the case when a river or segment of a river has a number of
monitoring stations, but those stations do not allcollect data for the same water quality
parameters. If an analysis requires evenly located data on a river segment for a given parameter,
this can pose a data gap for that particular analysis. For example, stations TCEQ-15561, TCEQ-
15562, TCEQ-15563 and TCEQ-15561 are located on the Arroyo Colorado at the Lower Rio
Grande Basin with a maximum distance'of 4 km between the stations. Dissolved oxygen, pH,
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Development ofU.S.-Mexico Water Quality Analyses
and turbidity are monitored at all four stations, but chlorophyll a, chloride, and sulfate are
monitored only at stations TCEQ-15561 and TCEQ-15562.
Data gaps can also be caused by missing data elements in the source data. These records cannot
be entered into the Repository because necessary data fields, such as locational information
(latitude and longitude), are missing from the data set.
3.2.3 Finding 1: The Variability of the Study Area Makes It Difficult to Draw
General Conclusions
The border region reflects great diversity in geography, physiography, and hydrology. This
diversity affects how monitoring stations collect information and what kind of information
monitoring stations collect. For example, a station on the Salton Sea will be very different from a
station on the Rio Grande, and there are differences between the upper Rio Grande, which has
been dramatically altered by reservoirs and irrigation infrastructure, and the lower Rio Grande,
which is a delta/estuary. As a result, it is difficult to draw general conclusions about water
quality status along the border. However, conclusions can be drawn about individual border
segments of similar character.
Water quality comparisons can be done for specific data points, but standards vary by state, and
variability is so great that it can be difficult to draw general conclusions about water quality even
for a single watershed. We can select specific monitoring stations located along a given river
segment or lake/reservoir and use recorded water quality data to reach some conclusions about
that river segment status. As shown in the examples included in Appendix D, the analyst first
selects a benchmark value from existing water quality standards assigned to that river segment
for a particular use category. Next, the analyst compares each water quality reading from the
monitoring stations with the benchmark. The analyst will then determine the percentage of data
points exceeding the benchmark. For example, the analyst can find out that 50 percent of the data
points recorded on a station for a particular parameter (e.g., nitrates) are exceeding the
established water quality standard for that segment.
Recommendations: Because of the diversity of the study area, water quality conditions should
be analyzed and assessed in smaller segments or watersheds along the border. The development
of indicators (see Section 4) should also consider the complex framework of water management
and use that impacts water quality in the border region.
3.2.4 Finding 2: The Lack of Unified Water Quality Standards Leads to
Ambiguity in Assessing the Status of Waterbodies that Cross the
Border
Water quality standards in the four U.S. border states have been established for different
waterbodies and rivers, for many pollutants, and for different use categories. As in the United
States, Mexico has also adopted surface water quality standards for some pollutants based on use
categories. In most cases, water quality standards differ between the two countries. Even within
the United States, water quality standards vary from state to state, and in some cases, water
quality standards may vary from one river segment to another, depending on use and other
24
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Development of U.S.-Mexico Water Quality Analyses
waterbody characteristics. The lack of unified water quality standards leads to ambiguity in
determining the status of a stream or waterbody that crosses a national or state border.
Recommendation: While acknowledging the many difficulties inherent in reaching a binational
consensus on border water quality issues, the stakeholders have expressed their desire to work
towards the creation of a unified body of water quality benchmarks. A unified set of benchmarks
would help with the implementation of equivalent sampling and analytical methods on both sides
of the border, which would improve the comparability of the data in the Repository and enable
the use of these data to assess water quality for the shared waters in the border area. A unified set
of benchmarks is therefore an important first step in developing and implementing a
measurement program for effective indicators of water quality in the border region. (Section 4
provides suggestions for developing and applying such indicators.)
3.2.5 Finding 3: The Repository Contains Far Less Data for Mexico than the
United States, Making Balanced, Binational Analysis Difficult
The Repository contains surface water quality data for a number of monitoring stations on the
U.S. side of the border, located on rivers and streams, springs, lakes and reservoirs, and canals,
as well as at facilities. However, there are far less data in the Repository from the Mexico side of
the border, with data points from a very limited number of locations. These locations identified
latitude and longitude; the date when the reading was made; and the parameter name, value, and
units, but do not include metadata about sampling or analytical methods used to obtain the value.
This disparity in quantity and completeness of data makes it difficult to conduct balanced,
binational analysis.
Recommendations: We identified additional sources of Mexico water quality data late in this
study. These sources should be explored and considered for inclusion in the next phase of the
project. In addition, the Mexico stakeholders have expressed a desire to continue efforts to
identify additional data sources that may contain metadata for existing stations, but have
requested a Web-based system to facilitate review of the data they have contributed and input of
new data to the Repository as available. The next steps on the project should include
implementation of a simple Web site to allow secure data uploads and downloads to facilitate
this data exchange. Finally, Phase 2 of the project could support field work in Mexico to position
new monitoring points to fill spatial data..Global positioning system (GPS) technology can be
used to accurately position such points and locate important sources of water pollution, such as
discharges from industrial facilities and wastewater treatment plants.
3.2.6 Finding 4: The Lack of Flow Data in the Repository Hinders Analysis
The Repository currently includes only a small amount of flow data from STORET and NW1S.
Flow data are needed for the following kinds of analyses:
* Water quality status analyses where standards are established based on flow levels
Water supply/demand studies, water budget analyses, and general watershed
hydrology studies that can complement water quality analyses
Detailed pollutant modeling on a given watershed.
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Development ofU.S.-Mexico Water Quality Analyses
Recommendation: To enable such analyses, additional flow data can be added to the Repository
for targeted waterbodies or (as available) for the entire border area. We are aware of the
availability of large records of flow data collected by IBWC (and available on their Web site) for
the Rio Grande/Rio Bravo. In addition, data from the USGS NWIS system should be fully
accessed and included in the repository.
4.0 Developing Water Quality Indicators for the U.S.-Mexico
Border
The Border 2012 program mandates that water quality indicators be developed and used to
demonstrate real, meaningful, and measurable results in meeting the goals of Border 2012. To
ensure that these goals are met and to increase overall capacity to respond to environmental and
health problems at the border, the Border Indicators Task Force (BITF) was established in
December 2003. The role of BITF is to coordinate with all Border 2012 groups and stakeholders
to define a set of indicators and develop protocols for the collection, analysis, and quality control
of the data necessary for the calculation and interpretation of those indicators.
Indicators are useful, informative tools when they are related to a conceptual framework that
hoHstically describes the interactions within a system. The Pressure-State-Response (PSR)
conceptual framework has been used as a starting point to help define needed border area
indicators. This model follows a linear logic where a pressure causes a change in state, which
then evokes a response. More recently, the Driving Forces-Pressure-State-Impact-Response
(DPSIR) conceptual framework, an extension of the PSR model, has been applied in developing
a conceptual framework more suitable for Border 2012 needs. DPSIR seems well suited to the
Border 2012 program because it allows for the identification and analysis of relationships
between border-specific development actions and the effects produced on the environment and
human health. The enhanced understanding of these relationships would allow policy makers to
develop the region in a sustainable manner, aware of potential environmental and human health
consequences. Additional information on the emerging Border 2012 Program's Strategy for
Indicator Development is available at http://www.epa.gov/usmexicoborder/pdf7"
indicator_strat.pdf.
Indicators can be used on either an ongoing basis or for a finite period of time. Regardless of the
length of data collection or indicator usage, a review process is necessary to evaluate the
performance of the indicator. What may be a useful indicator now may change with time, given
the development of technology, further improvements along the border, changing needs of the
public, or increased insights in policy or science. The BITF proposes that a review occur two
years after an indicator is first implemented and then every five years thereafter. At a minimum,
the review should answer the following questions:
PurposeWhy was the indicator developed?
Data collection and managementWhat protocol was followed?
Data reliabilityIs the source reliable?
>
Quality assuranceHow accurate and precise are the data?
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Development of U.S. -Mexico Water Quality Analyses
InformationWhat does the indicator convey? Is it true to its purpose? How does
the information compare to the standard?
LimitationsWhat are the outstanding gaps or limitations of the indicator?
ConclusionAre the data useful and should the indicator continue to be used?
Parameters that could be applied in the development of water quality indicators are included in
recommendations for a Binational Set of Indicators for the Border 2012 Program (available at
http://www.epa.gov/usrnexicoborder/pdf/indicators_set.pdf). These materials cover several types
of proposed environmental indicators, with the aim of stimulating discussion and consideration
among the various workgroups regarding the appropriateness of the indicators for measuring
program progress and assessing environmental and health changes in the region's conditions.
This list of potential indicators, given further refinement, will eventually become the official
Binational Set of Indicators for the Border 2012 Program. Environmental indicators to support
Goal 1 (Reduce Water Contamination) include the set of 12 physical, chemical, and biological
parameters related to surface water quality conditions that were selected for data collection and
entry in the U.S-Mexico Border Waters Repository (see Section 3.1.3). The Repository has
assembled all readily available ambient monitoring data related to this set of parameters. As
described in Section 3, the Repository provides a good platform to investigate different
alternatives for developing the needed 2012 water quality state indicators. As illustrated in
Figure 7, this development process would lead to indicators that are consistent with the overall
Border 2012 conceptual framework.
Water Quality Indicators wrthin tha
Overall 2012 Indicator Conceptual
Figure 7. Process for developing water quality indicators within
the Border 2012 conceptual framework.
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Development ofU.S.-Mexico Water Quality Analyses
The parameters in the Repository include measures commonly applied directly in water quality
standards criteria and measures, such as COD and BOD, commonly used in permits to achieve
pollutant discharge reductions needed to safeguard the standards for receiving waters. The
proposed indicators include parameters related to the protection of aquatic-life designated uses
and other parameters (e.g., fecal coliform) related to human-health-oriented body contact
recreation uses. Microbial parameters are also used as indicators to safeguard drinking water
uses, as are parameters such as chlorides and sulfates as applied to inland fresh waters (river and
lakes). Table 6 summarizes these considerations for the different Border 2012 parameters
collected in the Repository.
Table 6. Repository Parameters Related to Aquatic Life or Public Health Uses and Typical
Applicability as Ambient Water Standards or for Use in Permitting
j Water Quality
L Indicator-
Fecal coliform
Chlorophyll a
Sulfate"
IDS'
Chloride'
DO
Conductivity*
COD
Orthophosphate
Nitrate
Ammonia
BOD
PH
Temperature
TSS
Aquatic Life
.Support Uses
*
Public Health
Uses "."
Ambient
v. Water
; Permitting
" Applied mainly to inland fresh waters.
Water quality indicators for major uses of water resources can be related to the water quality
standards developed under both U.S. and Mexican water quality management programs. The
parameter criteria from these water quality standards can be combined with appropriate
benchmarks (or norms) to define indicators of the environmental state or condition of individual
monitoring standards or associated assessment segments. The site-specific indicator information
can then be aggregated over larger geographical units such as basins. The Interagency Task
Force on Monitoring (ITFM), a joint EPA and USGS initiative, helped establish a framework for
applying available water quality monitoring information to establish water quality indicators for
the status and trends tracking of environmental conditions. The ITFM work showed how broad
categories of environmental indicatorsfor instance, ecological health or human health
concernscan be related to major types of water uses that can represent specific management
objectives. These management objectives are analogous to the designated uses that U.S. states set
in their water-quality standards and report to the U.S. EPA as part of the Clean Water Act's
Section 305(b) Integrated Reporting process.
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Development of U. S. -Mexico Water Quality Analyses
The work of ITFM continues through the USGS-sponsored interagency Water Information
Coordination Program and the Advisory Committee on Water Information (http://water.usgs
.gov/wicp/). These interagency initiatives are based on directives in the Office of Management
and Budget (OMB) Memorandum No. 92-01, which designates DO1, through USGS, as the lead
agency. Other U.S. federal organizations (including the EPA) that fund, collect, or use water
resources information work with USGS to implement program recommendations. Documents
stemming from the work of ITFM can be found at http://water;usgs.gov/wicp/itfin.html. The '
work of ITFM has been very influential for EPA in the design and ongoing enhancement of the.
performance measures used in EPA programs as part of the Government Performance and
Results Act or the related OMB Program Assessment Rating Tool systems.
Outcome indicators similar to the water quality indicators recommended for development by the
Border 2012 initiative are found in performance measures EPA is developing
(http://www.epa.gov/ water/waterplan/) for programs operating within the United States and for
special measures under development dealing with .water quality standards attainment for waters
in the U.S.-Mexico border area. These proposed outcome measures related to the evaluation of
programs in the United States under the Clean Water Act can be developed in ways that
compliment the Border 2012 indicator initiatives, thus achieving significant efficiencies in
creating and maintaining the data infrastructures needed for operational status and trends
outcome measures. Further information on EPA reporting measures relevant to the development
of Border 2012 water quality indicators can be found in the National Water Program Guidance:
FY 05 Midyear Reporting on Final Measures and Commitments (available at
http://www.epa.gov/water/waterplan/documents/FY05measuremidyeardata.pdf).
The major actions needed to apply information in the Repository are to select appropriate
benchmarks (or norms) to help interpret the parameter information relative to concepts of
designated use attainment or non-attainment. Benchmark information can be taken for either .
implemented water quality standards criteria or from the national criteria guidelines developed
by EPA or corresponding Mexican government agencies that guide management programs
delegated to states and other water resource agencies. These benchmarks are typically applied
according to major waterbody types (e.g., rivers, lakes, and estuaries/near coastal waters). The
benchmarks can also be organized according to major designated use categories (e.g., aquatic life
support and public health uses).
To facilitate checks on data adequacy and help pinpoint areas where there may be apparent data
gaps, the indicators would be developed parameter by parameter for assessment segments in the
vicinity of the primary ambient monitoring sites. This site-specific information could then be
analyzed for its suitability in creating indicators for larger geographic units, such as border area
basins (e.g., the Rio Grande Basin). Such basin-level indicators could be organized by waterbody
type, major designated use category (aquatic life or public health), and parameter. Because data
gaps are likely to exist for some parameters within a basin, the organization in terms of
designated use categories will be helpful in taking available parameter information to develop
indicators of use attainment. This development approach would be consistent with practices
followed in Clean Water Act assessment programs in the United States and would help provide
indicators of immediate value to ongoing management activities in the border area.
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Development of U.S.-Mexico Water Quality Analyses
5.0 Mexico Border Reach File
The MBRF Is a prototype product created using a method similar to the one used to create the
U.S. National Hydrography Dataset (NHD), which is a comprehensive set of digital spatial data
that contains information about such surface water features as lakes, ponds, streams, rivers,
springs, and wells. Within the NHD, surface water features are combined to form "reaches,"
which provide the framework for linking water-related data to the NHD surface water drainage
network.
5.1 Methodology
The MBRF prototype was created to showcase the potential of an NHD-like hydrographic
network in Mexico in which all waterbody and river reaches are uniquely identified and linked in
a network. RTI then reach indexed the water quality monitoring stations to the MBRF so that
each station was uniquely identified by a river or lake reach in the network. The reach indexing,
or pinpointing, of stations onto the MBRF was possible because of the MBRF's unique
networking features and the existence of latitude/longitude information for a given station. The
reach indexing itself was made possible by the existence of tools such as EPA's Reach Indexing
Tool (RTF). Because each station was indexed to the MBRF network, all the water quality data
related to the stations can be also related to a unique point in the MBRF network. This prototype
shows the potential of what a future official Mexican reach file can do to perform water quality
modeling and assessments in the entire Mexican territory.
The MBRF was derived from several initial shapefiles2 received from CNA. CNA had already
appended the linework into a large national-scale file comprising the northern portion of Mexico.
There were no cataloging unit (CU) boundaries, and no NHD data existed that could be conflated
(transferred) onto the Mexican linework. Despite these differences, it was possible to alter the
attribute information stored on the nodes, lines, and polygons of the Mexican linework so that
the NHD Create software could operate on it. To create an NHD-style data set, RTI used NHD
Create to append the linework and conflated existing reach codes from the NHD data onto the
linework.
CNA also provided point name data, which could be converted to something that emulates the
U.S. Geographic Names Information System (GNIS). This was not done because the linework
from CNA did not include name data and the level of effort to manually assign point names to
linear features (and thereby name) a relatively small number of reaches using tools in NHD
Create was deemed excessive.
Appendix H explains the process of creating the MBRF in detail.
The prototype MBRF can be used to showcase the functionality of reach indexing water-quality-
related information to a hydrography network. The monitoring stations on the Mexico side, and
therefore all the water quality data contained within the stations, were reach indexed using
2 A shapefile is an editable spatial database format generated in the desktop software application Arc View that stores
the location, shape, and attribute information of geographic features.
30
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Development of U.S. -Mexico Water Quality Analyses
EPA's RIT to illustrate how different tools can be combined to provide more valuable
information for water quality analyses and modeling.
5.2 Findings and Recommendations
The MBRF represents an initial step to creating a NHD-like geographic information system
(GIS) hydrography layer for the Mexican side of the border. Another attempt to create a
binational hydrography was made by the University of Texas at Austin (UTA). UTA has created
a hydrologic geodatabase for the Rio Grande/Rio Bravo Basin using ArcHydro and available
data from either side of the border. Some important findings relating these efforts include the
following:
The raw linework obtained from CNA to create the MBRF was acceptable, although
some connectivity and arc direction issues surfaced that will need to be corrected in
the next version. The final MBRF network is functional, but it requires further editing
to ensure proper connectivity and flow direction.
Additional editing is required to include reach names.
The Rio Grande is depicted as it was in the original linework. Considerable effort will
be required to integrate the U.S. side into the Mexican data set. Because of scale and
CU delineation issues, a complete integration of the U.S. and Mexican systems many
not be feasible.
UTA's Rio Grande basin geodatabase has some advantages over the MBRF: it is built
in a modem, flexible geodatabase format called ArcHydro, and the hydrography
linework has been edited to obtain good flow characteristics. UTA's geodatabase also
contains higher quality linework for the Rio Grande/Rio Bravo basin than does the
MBRF.
Based on a review of these two efforts, the U.S.-Mexico Border Waters stakeholders group has
come to the conclusion that the ArcHydro model developed by UTA provides the best option for
developing a GIS hydrography layer for the Mexico side of the border because the ArcHydro
data model is more flexible and does not require strict definition of hydrologic units as part of
the feature-naming conventions. The NHD-based hydrography developed for this project can be
easily imported into ArcHydro. Future enhancements should include completing the ArcHydro
hydrographic dataset for the entire border, using the available NHD creation tools as appropriate
and importing the resulting coverages into ArcHydro. This development could include
development of metadata standards similar to those established for the NHD. Additional study
and collaboration between U.S. and Mexico stakeholders is needed to develop a detailed
approach for developing the Mexican GIS ArcHydro hydrography coverage for the border area
and developing options for linking that network to the NHD coverage on the U.S: side.
6.0 Future Work
The U.S.-Mexico Border Waters project represents a very important first step towards the
creation of a multidisciplinary and multiorganizational team that will identify needs on water
resources management along the border. It is important to identify funding sources and obtain
resources to build on this effort by performing studies and improving these tools to help reach
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Development of U.S.-Mexico Water Quality Analyses
the goals set forth by EPA's Border 2012 program and other programs pursuing the improvement
of the quality of the shared waters in the border area.
Future phases of this project need to build on the extensive expertise of organizations that have
worked on environmentally related issues in the border area, such as SCERP, UTA, University
of Texas at El Paso, San Diego State University, New Mexico State University, Arizona State
University, University of Utah, Universidad Aut6noma de Baja California, Universidad
Autonoma de Sonora, and other universities in Mexico and the United States. CNA, CILA, and
IB WC have also built on their own expertise working on border water resources issues. SCERP
is currently developing a Transborder Watershed Research Program that focuses on land use
practices in the San Pedro and Tijuana watersheds. Other organizations are currently working on
a variety of projects with the goal of improving the human condition on the U.S.-Mexico Border.
Many different future activities have been identified during the development of this project, to be
proposed and prioritized for completion on subsequent phases. The completion of this report in
particular has shed light on how the U.S-Mexico Border Waters Repository can be enhanced and
improved as new benchmarks are developed and information become available, and on how
robust indicators can be developed to measure improvements in water quality conditions for the
shared waters along the border.
The implementation of more sophisticated analytical methodologies will become possible as
more water quality data are stored and maintained in the Repository and benchmarks and
indicators are further developed. The addition of GIS-based tools and the georeferencing of
water-quality related data will also provide us with the opportunity to perform more statistically
sound and realistic analyses to support the border water assessment efforts. The creation of the
MBRF prototype and the georeferencing of stations show the potential of combining water
quality data with GIS-based tools.
6.1 Maintaining and Enhancing the Repository
The U.S.-Mexico Border Waters Repository can be enhanced by adding new data standards as
they become available. These standards, such as EPA's ESAR standards, try to create uniformity
among the different existing repositories such as STORET and other surrogate systems. CNA
may consider the benefits of including some of these data standards into its own water quality
system (Sistema Nacional de Informaci6n de la Calidad del Agua [SNICA]) and by transferring
the water data already collected and stored in the Repository.
The Repository should be migrated to a more robust relational database management system,
such as the commercial ORACLE or SQL Server systems or open source systems such as
MySQL or PostGRESQL. This migration would ensure referential integrity of data and provide
enhanced security and user management tools. A graphical user interface can be built on top of
the Repository to facilitate data entry and maintenance. The Repository could also be enhanced
with additional lookup tables to provide more thematic information related to water resources
and to allow for simpler and more powerful querying of the stored data.
An important next step is a Web-based system to provide tools to enable the Mexico data
providers to review and verify Repository data, edit data already in the Repository, and upload
32
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Development of U.S.-Mexico Water Quality Analyses
additional water quality data into the system.3 Such a data verification and input tool would help
automate the review and update processes for a distributed client network making use of modern
Internet-based techniques, and is especially critical as a way to fill the data gaps on the Mexico
side of the border. This data verification tool would query the underlying relational database
tables to produce data formats that would be convenient for end users to examine and verify their
water quality information. Similarly the tool could provide table formats to enable data providers
to conveniently upload data to the Repository.
Future Repository enhancements could include
Mechanisms to allow uploads of additional water quality (or flow) data for
established stations
Tools to provide basic locational information for both established and new stations (a
streamlined locational tool to help in verifying lat/long station locations)
. Analytical programs to provide basic summary statistics on data availability for
individual stations, and for groups of station over defined watershed basins, to help
identify where sufficient data are available to move forward to develop Border 2012
indicators and where there are still data gaps.
As end users provide additions or corrections to the Repository, the Web-enabled system could
be periodically refreshed with updates to these basic summary statistics.
6.2 Water Quality Analysis
Water quality analyses and modeling can be scaled up to accommodate more variables and
scenarios as more data and tools are incorporated into the Repository. The Repository can
become a key component within a decision support system that includes GIS-based analysis
tools, mapping tools, and Web interfaces for downloading additional information. Water quality
analysis and modeling would then be able to better simulate the complex universe behind water
resources and uses on the U.S.-Mexico border.
One of the key ideas stemming from this project is to create a decision support tool for Mexico
that incorporates some components of SNICA, the Repository, the MBRF prototype, and
analysis tools from EPA's BASINS (Better Assessment Science Integrating Point and Nonpoint
Sources). This decision support tool should be tested for a watershed on the border, most likely
on the Rio Grande/Rio Bravo watershed because an important project has already been
developed there by UTA. This effort would require, among other activities, the collection of flow
data for the most important rivers on the border watersheds, the georeferencing of industrial
discharge points in Mexico, and the acquisition and storage of industrial discharge data from
Mexico. CNA has expressed its interest in pursuing this effort to enhance SNICA and to build
upon its current system by incorporating publicly available tools such as BASINS.
3 Because Repository data for the U.S. side of the border is extracted directly from existing EPA and USGS systems
(STORET and NWIS) that have extensive data quality measures in place, a data upload and verification system is
not needed for the U.S. data.
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Development of U.S.-Mexico Water Quality Analyses
6.3 Mexico Border Reach File
The completion, demonstration, and use of an MBRF is needed at the next stage of this project to
relate water quality information to an ArcHydro-based network of the Mexican hydrographic
system and to convey the advantages of having reach-indexed water quality data for future water
quality analyses and modeling. This could also be a first step towards creating an official
national Mexico hydrography network. Training of officials from CNA, CILA, and other
Mexican agencies on the MBRF and BASINS are also proposed activities for subsequent phases.
During the stakeholders meeting in Juarez in November 2004, two resource intensive activities
were identified as future needs for subsequent phases. One of these activities is the
geopositioning of all wastewater and industrial discharges on both sides of the border using
global positioning system (GPS) equipment. It was proposed that SCERP could help with
students from the different universities in their Consortium to assist in getting this information.
The other identified activity was the use of remote sensing techniques to identify water quality
indicators, with emphasis on the Rio Grande. Mexican and U.S. agencies are very much
interested in implementing this technology because it can identify pollution sources and measure
indicators via satellite imagery, reducing considerably the costs of sampling and monitoring
necessary to measure progress towards improving water quality conditions for the shared waters
of U.S. and Mexico.
7.0 References
Blackstun, D., L. Woosley, and M. Flora. 1996. Water Resource Issues in the Rio Grande-Rio
Conchos to AmistadReservoir Subarea. U.S.-Mexico Border Field Coordinating
Committee Fact Sheet 3. U.S. Department of the Interior.
Buckler, D., D. Papoulias, G. Ozuna, D. Woodward, M. Flora, and L. Ditto. 1997. Water
Resource Issues in the Rio Grande-Below Falcon Reservoir to the Gulf of Mexico
Subarea. U.S.-Mexico Border Field Coordinating Committee Fact Sheet 4. U.S.
Department of the Interior.
Papoulias, D., D. Woodward, M. Flora, and D. Buckler. 1997. Water Resource Issues in the
Mexican Highlands Subarea. U.S.-Mexico Border Field Coordinating Committee Fact
Sheet 2. U.S. Department of the Interior.
U.S. EPA (Environmental Protection Agency). 2004. U.S.-Mexico Border Environmental
Program: Border 2012La Paz Agreement (EPA online information). Web site:
http://yosemite.epa.gov/oia/MexUSA.nsf/LaPazWeb. Accessed October 25,2005.
U.S. EPA (Environmental Protection Agency). 2005a. U.S.-Mexico Border Environmental
Program: Border 2012Border News (EPA online information). Web site:
http://epa.gov/border2012/index.htm. Accessed October 25,2005.
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Development ofU.S.-Mexico Water Quality Analyses
U.S. EPA (Environmental Protection Agency). 2005b. Water Resources Management on the
U.S.-Mexico Border. Eighth Report to the President and the Congress of the United
States. EPA 130-R-05-001. Good Neighbor Environmental Board. Washington, DC.
http://www.epa.gov/ocem/gneb. Accessed November 2005.
Woodward, D.G., and R.A. Durall. 1996. United States-Mexico Border Area, As Delineated By a
Shared-Water Resources Perspective. U.S. Department of the Interior. U.S.-Mexico
Border Field Coordinating Committee Fact Sheet 1.
35
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Appendix A - Study Area Description
Appendix A
Detailed Study Area Descriptions
This Appendix provides more detailed descriptions of the geography and hydrology of
the five transboundary regions that make up the study area. These summaries draw heavily on
previous work on the U.S.-Mexico border project conducted by Parsons Engineering Science,
Inc. (U.S. EPA, 2000), as well as USGS factsheets for three of the basins (Central Desert/Closed
Basins: Papoulias et al., 1997; Rio Grande Basin: Blackstun et al.,. 1996; and Lower Rio Grande
Basin: Buckler etal. 1997).
A.I Pacific/Salton Sea Transboundary Basins
The Pacific/Salton Sea Basins contain watersheds that drain either to the Pacific Ocean or
to inland seas. The basins drain an area of 14,000 square miles (36,000 km2). These basins have
a very dry, semiarid climate with few fresh water resources. Flow is primarily from east to west,
with stream flows originating from precipitation in the mountains flowing toward the Pacific
Ocean. The flow in these streams is controlled through a series of hydraulic structures, including
reservoirs. The Tijuana River is one of the main streams in the basin and one of the City of
Tijuana's major natural resources. The river flows northwest through the city of Tijuana before
crossing into California near San Ysidro and then flowing into the Pacific Ocean. Figure A-l
shows the Pacific/Salton Sea Basins and their most important characteristics.
*5,7-*-.vr :~^f- r - ., .,-:.
T *-;J/'jMi''' ^California", g,
sig jrt'-V^;."-' -. ,: _. '..' ' jv
Figure A-1. Pacific/Salton Sea Basins.
A-l
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Appendix A - Study Area Description
A.1.1 Geography of the Pacific/Salton Sea Basins
The San Diego, Cottonwood-Tijuana, and Salton Sea watersheds are the most important
watersheds within the Pacific/Salton Sea Basins. They also cover part of the North-East Baja
California basin in Mexico.
The San Diego watershed encompasses San Diego County, parts of southwestern
Riverside County, and southwestern Orange County. It comprises three distinct areas: the coastal
plain, the central mountain valley area, and the eastern mountain valley area. The coastal plain
ranges from sea level to about 1,200 feet (370 m) above sea level and extends for 10 miles (16
km) inland from the coast. The central mountain valley area is characterized by ridges and
basins, which extend from the coastal plain northeast to the Elsinore fault zone. The basins
range in elevation from 500 to 5,000 feet (150 to 1,500 m) above sea level, with the exception of
the El Cajon area, where the mountain elevation reaches only 1,500 feet (1,500 m). To the
northeast of the Elsinore fault zone, in the area known as the eastern mountain valley area, the
valleys range from 1,000 to 3,500 feet (300 to -1,100 m) above sea level, while the surrounding
peaks reach elevations of 4,000 to 7,500 feet (1,200 to 2,300 m).
South of San Diego, the Tijuana watershed is separated from the San Diego watershed by
the San Isidro and San Miguel Mountain range at the southern end of the San Diego County, and
by the Sierra Juarez in Mexico. The highest mountain elevation is Sierra Juarez at 6,500 feet .
(2,000 m) above sea level.
Land use varies considerably and.ranges from urbanized areas to wilderness such as the
Cleveland National Forest. Major cities include San Diego in California and Tijuana, Tecate,
Rosarito, and Ensenada in Baja California. Smaller cities and towns include Descanso in
California; various suburbs of San Diego; and Valle Bonito, San Luis, and La Joya in Baja
California.
There are also numerous Indian lands on the U.S. side of the border, including the
Campo, La Posta, Manzanita, Cuyapaipe, Barona Ranch, Capitan Grande, Cahuilla, Santa Rosa,
Pechanga, Mission, Pala, Rincon, La JoHa, San Pasqual, Los Coyotes, Santa Ysabel, and Mesa
Grande Reservations. The northern part of the basin encompasses the Camp Pendteton Marine
Corps base, and further down along the coast are many scenic beach areas, on both the Mexican
and U.S. sides of the border.
The Tijuana watershed serves as habitat for coastal shrubs and a chaparral ecosystem that
extends from Baja California into California near the Pacific Ocean. This'chaparral ecosystem
gives way to pine forests and coastal vegetation along valleys and intermittent streams. Among
the more serious threats to this ecosystem are erosion and slope instability. Increased
sedimentation from urbanization and unregulated road development has negatively affected the
flora and fauna and has also significantly affected other resources in the area. In addition to
erosion and sedimentation concerns, estuarine and wetland areas have been reduced significantly
in this basin, to the point where only 20 to 40 percent of the original wetland area remains intact.
The watershed also contains several environmentally sensitive areas, such as the Tijuana River
Estuary, which straddles the U.S.-Mexico border. The estuary is approximately 2,000 acres (800
hectares) of salt water marsh with several stretches of open water. The estuary is generally open
A-2
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Appendix A - Study Area Description
to the ocean, and its water quality generally is the same as that of the shoreline open ocean
waters. However, during periods of excess runoff, a variety of wastes originating upstream in the
Tijuana River in Mexico can be carried into the estuary. Tidal flushing is considered to be
crucial to the estuary's health, and thus a program to control erosion, manage sediment, and
strategically dredge parts of the estuary has been initiated.
In the North East Baja California basin, the major surface water is Laguna Salada. The
Sierra Juarez range discharges surface runoff to the Laguna Salada. As the range slopes towards
the Sea of Cortez, the mountains give way to sand dunes and wetlands. Of these dune areas, one
of the most important is Constitution National Park, located south of Laguna Salada, which has
been designated as a protected area by the Mexican government.
The Salton Sea watershed stretches north from the northeast section of Baja California in
Mexico into the southeast portion of California in the United States. The watershed has a gross
contributing drainage area of 7,500 square miles (19,000 km2), most of which is in the United
States. The western boundaries of the watershed are contiguous with the western boundaries of
the Imperial Valley and the eastern side of the Anza Borrego area in California. To the north, the
basin is bounded by the Salton Sea along California Route 10 from the San Bernardino National
Forest through the Joshua Tree National Monument and to the Colorado River, which forms the
eastern side of the boundary. The southern boundary of the watershed is formed as the Imperial
Valley lowlands drop to the Sea of Cortez.
The watershed's central feature is the flat, fertile Imperial Valley. The Imperial Valley
consists primarily of farming communities, although there are several larger cities in the basin,
including the border city of Mexicali in Baja California, a thriving manufacturing center. The
main communities in the watershed on the U.S. side of the border are Calexico, El Centre, and
Brawley, which are all located along California Route 86 east of the New River. Other
communities within the basin area on the California side of the border include Blythe, Indio,
Palo Verde, Salton Sea, Seeley, and Westmorland.
A. 1.2 Hydrology of the Pacific/Salton Sea Basins
The mountain ranges running along the coasts of California and Baja California divide
the precipitation falling there: precipitation that falls on the western slopes flows toward the
Pacific Ocean, and precipitation that falls on the eastern slopes flows east into the Imperial
Valley and the lands below Mexicali and on into the Sea of Cortez. In California, a series of
stream systems originating in the highlands flow west to the Pacific Ocean. These streams
include the Aliso, San Juan, San Mateo, San Onofre, San Marcos, and Escondido Creeks, and the
Santa Margarita, San Luis Rey, San Dieguito, San Diego, Sweetwater, Otay, and Tijuana Rivers.
Most of these streams and creeks consist of both perennial and ephemeral segments, primarily
because of man-made controls and impoundments throughout the watersheds. This has created a
series of reservoirs and lakes, which include Vail, O'Neill, Henshaw, Hodges, and Sutherland
Lakes, and the Lower Otay, Sweetwater, and San Dieguito Reservoirs. Further south, major
streams in Mexico include the Santo Tomas Pino, Las Palmas, Las Cabaza, Agua Caliente, and
El Baron.
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Appendix A - Study Area Description
Little rain falls within the basin, which is semi-arid. On the U.S. side of the border, 70 to
90 percent of the region's water has to be imported from northern California and the Colorado
River. The basin is served by the Metropolitan Water District of Southern California (MWD),
which serves more than 16 million people in the California coastal plain. The MWD manages
the importation and distribution of water from the Colorado River and the California State Water
Project. Small amounts of water are also available from the regional impoundments described
above.
Despite the fact that most of the rivers flowing through this basin are not used for human
water consumption, they are very important as natural systems that can carry pollutant loads and
polluted runoff downstream. Of particular concern in this respect is the Tijuana River. The
Tijuana River originates east of the city of Tijuana, Mexico, then flows west through the center
of Tijuana, where it is heavily channelized. In Tijuana, the river is joined by the Alamar, another
highly channelized watercourse. As the river flows west through Tijuana, it also bends north and
flows near San Ysidro, California. The Tijuana River drains approximately 1,286 square miles
(3,300 km2), approximately two-thirds in Baja California and one-third in California. The river
flows into the Pacific through the Tijuana Estuary, which is designated as a federal reserve by
the U.S. government.
The primary hydrologic features of the Salton Sea watershed are the New River and
Alamo rivers, which both flow north into the Salton Sea. The New River originates in Mexico
near Mexicali, while the Alamo River intersects and receives flow from the All American Canal
near Bond's Corner, California. Most of the west side of the Salton Sea basin drains to several
individual internal sinks or playas, while the southern area generally drains to the Salton Sea.
The Salton Sea is the largest salt waterbody in the basin. The sea, which is located on the
site of a prehistoric lake, was created in 1905 when the Colorado River breached an irrigation
canal during a large flood and filled a natural depression between the Imperial and Coachella
valleys in Riverside and Imperial Counties, California. The sea serves as a drainage reserve for
irrigation return water and stormwater from the Coachella, Imperial, and Borrego valleys. It also
receives water from the Mexicali Valley in Mexico. Replenishment of the Salton Sea comes
predominantly from farm drainage and seepage, with occasional storm runoff from the Coachella
Valley, Imperial Valley, and the Anza Borrego areas on the U.S. side of the border and from the
Mexicali Valley on the Mexican side.
The Salton Sea is an extension of the Sea of Cortez drainage area and is 30 miles (48 km)
long, about 10 to 15 miles (16 to 24 km) wide, and is 30 feet (9 m) deep on average. It has an
area of approximately 360 square miles (930 km2) and its surface elevation, although variable, is
approximately 227 feet (69 m) below mean sea level. This basin has an average annual
precipitation of about 2.6 inches (6.6 cm); however, in the Coyote Mountains west of the Salton
Sea near Mountain Spring, California, average annual precipitation can reach 8 inches (20 cm).
The New River and Alamo River convey agricultural irrigation water from the farmlands
in the Imperial Valley, surface runoff, and smaller flows from treated municipal and industrial
wastewaters from the Imperial Valley.
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Appendix A Study Area Description
The flow in the New River also contains agricultural drainage, treated and untreated
sewage, and industrial waste discharges from Mexicali, Mexico. Surface waters mostly drain
toward the Salton Sea and enter a series of canals, creeks, and washes in the Imperial Valley
south of the Salton Sea. These waters are diverted on the north by the Little San Bernardino
Mountains and Orocopia Mountains, on the west by the Anza Borrego Park (Vallecito and Santa
Rosa Mountains), and on the east by the Chocolate Mountains.
The Colorado River is the most important waterway in the region because it supplies
water for use within and outside the region. Regional drainage comes from an area of 280 square
miles (730 km2) on the west side of the Colorado River. Surface water is diverted by several
dams (including the Parker, Palo Verde, and Imperial dams) into several canals and valleys. The
Colorado is also the primary water source for irrigation, industrial, and domestic water via the
All American Canal.
A.2 Colorado River/Sea of Cortez Transboundary Basins
The Colorado River/Sea of Cortez Basins contain watersheds that drain either to the
Colorado River below the gaging station at Parker Dam, or to the Sea of Cortez (which is also
known as the Sea of Cortez). These basins drain 22,590 square miles (59,000 km2) and cover
portions of the states of Arizona and Sonora.
The major surface waters in these basins are the lower Colorado River delta. From the
north, the Colorado River flows into the basin through heavily urbanized areas near Yuma,
Arizona, and San Luis Rio Colorado, Sonora, and then through wetlands before flowing into the
Sea of Cortez. Presently, most of the water that the delta receives comes from agricultural
drainage from the United States and Mexico, with little perennial flow in the lower Colorado
River. Figure A-2 shows the Colorado River/Sea of Cortez Basins and their most important
characteristics.
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Appendix A - Study Area Description
A v*»'o»M) (meant I- I w'm«M»*M
Figure A-2. Colorado River/Sea of Cortez Basins.
A.2.1 Geography of the Colorado/Sea of Cortez Basins
The Lower Gila, Gulf of California, and Colorado River watersheds are the most
important watersheds within this transboundary region.
The Gulf of California watershed consists of horseshoe-shaped lowlands ringed by the
Sierra Juarez and the Sierra San Pedro Martir mountain ranges to the west, and the Desierto de
Altar (Sonoran Desert) and the Northwest Chihuahua highlands to the east. To the north, the
Colorado River flows into the basin through a heavily urbanized area, and then through a series
of swampy lowlands before ending in the Sea of Cortez. The watershed encompasses the eastern
part of the Mexican State of Baja California and northwestern and northern parts of the State of
Sonora.
Reaching heights of up to 6,500 feet (2,000 meters), the Sierra Juarez mountain range is
part of the coastal range of California and Baja California that extends from the tip of Baja
California north well into central California. In the border area, the Sierra Juarez extend
approximately 31 miles (50 km) west and 93 miles (150 km) south of Mexicali, Baja California.
The range discharges surface runoff to the Lower Colorado River delta and the Sea of Cortez to
the east. As the range slopes towards the Sea of Cortez, the mountains give way to sand dunes
and wetlands.
The most important features of the basin are the Colorado River and the Desierto de
Altar. The Colorado River begins in the United States and flows for more than 1,200 miles
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Appendix A Study Area Description
(1,900 km) to the international border, where it enters Mexico on the east side of Mexicali and
continues for 100 miles (160 km) before ending in the Sea of Cortez. At one time, the Colorado
delta at the Sea of Cortez was a vast area of wetlands and salt flats that covered more than 3,800
square miles (9,800 km2) of Sonora Desert. Historically, the delta was an important estuary that
supported coastal vegetation and fresh, brackish, and intertidal wetlands. However, the delta has
been significantly altered by human activity, principally through the development and diversion
of water for upstream use. Perennial flow from the Colorado is minimal, and most of the water
that the delta receives.is from agricultural drainage from the United States and Mexico, as well
as periodic flood flow.
The Sonora Desert includes parts of south-central and southwestern Arizona as well as
southeastern California, and extends into Sonora to the shores of the Sea of Cortez. The desert
has an extremely rough topography and supports diverse flora and fauna communities. There are
a series oflands in the basin managed and protected by federal and state agencies, including the
Alto Golfo de California, the Delta del Rio Colorado, La Purica National Forest, El Pinacate,
Sierra de los Ajos, Sierra Buenos Aires, Sierra San Antonio, and others.
The Colorado River drains approximately 246,000 square miles (640,000 km2) in
Wyoming, Utah, Colorado, Nevada, California, New Mexico, and Arizona in the United States
and is important economically, ecologically, and culturally to the western U.S. As the river
flows southwest through northern Arizona, it flows through Lake Mead and then turns south to
form the borders between Nevada, California, and Arizona. The Colorado enters the border area
as it flows past Blythe, California, and then continues south through Yuma, Arizona. As it
crosses the border to Mexico, the Colorado becomes the International Boundary between Baja
California in Mexico and Arizona in the United States. The river then flows through the Morelos
Diversion Structure near San Luis Rio Colorado, Baja California, Mexico and into the Sea of
Cortez near Golfo de Santa Clara, Mexico. At this point, the Colorado forms the boundary
between the Mexican states of Baja California and Sonora.
In the border area, the Colorado River basin ranges from the eastern part of California
east of the Chocolate, Chuckwalla, and McCoy Mountains, and extends east into New Mexico at
the headwaters of the Gila River in the Gila National Forest. To the south, the basin is defined
by the mesas and plateaus of the New Mexico and Arizona highlands. As the Colorado crosses
the border below Yuma, it empties into the wide, low Sea of Cortez delta.
Land use in the Lower Colorado River basin in the border area consists primarily of
agricultural and grazing tracts, although large parcels of land belong both to the U.S. government
(including several military ranges and four National Wildlife Refuges [the Cibola, the Imperial,
the Kofa, and the Cabeza Prieta refuges]). The Colorado River, Yuma, and Cocopah Indian
Reservations are also located along the reaches of the Lower Colorado. As the river flows across
the border into Mexico, the land becomes much more urbanized between Mexicali, Baja
California, to the west, and San Luis Rio Colorado, Sonora, to the east. Further to the east, in the
Santa Cruz and San Pedro subbasins, most of the privately-owned land is devoted to grazing,
although there are also a variety of mine operations in the area. However, as with the land
around Yuma, much of the land in these subbasins is owned by the U.S. government or by Indian
tribes. Reservations in the Santa Cruz subbasin include the Papago, the San Xavier, the Ak-Chin
Maricopa, and the Gila River, while the San Carlos Indian Reservation lies along the northern
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Appendix A Study Area Description
part of the San Pedro River where it joins the Gila River. Wilderness areas in the subbasins
include the Coronado National Forest and several other designated wilderness areas.
The Lower Colorado River basin and its subbasins contain several major U.S. and
Mexican cities, including Yuma, Arizona; the suburbs of Tucson, Arizona, in Pima County; San
Luis Rio Colorado, Sonora, Mexico; and the cities of Agua Prieta and Cananea in the San Pedro
subbasin, and Nogales in the Santa Cruz subbasin, Sonora. The primary communities in the Sea
of Cortez basin are the Sonoran cities of Altar, Arizpe, Bavispe, Caborca, Imuris, Magdalena de
Kino (Magdalena), Puerto Penasco, Santa Ana, Sasabe, and Sonoyta, and the Arizona city of
Lukeville, which is located at the border within Organ Pipe Cactus National Monument. Several
of these cities, including Sasabe and Sonoyta, are border cities, while Caborca and Altar are
located further within Sonora. Only one of these cities, Puerto Penasco, lies on the Sea of Cortez.
A.2.2 Hydrology of the Colorado/Sea of Cortez Basins
Flow in the Sea of Cortez occurs as smaller streams drain from the higher areas to the
east and west of the basin and flow directly into the Sea of Cortez, while flow from the northern
plateaus is directed into the Colorado River, and then into the Sea of Cortez. The major surface
waters in the basin are the Colorado River and its delta. The lower Colorado River in turn
supports the Cienaga de Santa Clara; Sonoita Creek; and the Santa Cruz, Magdalena, San Pedro,
and Yaqui Rivers. Perennial flow from the Colorado is minimal, with most of the flow resulting
from agricultural drainage from the United States and Mexico, as well as periodic flood flow.
Residual flows from the Colorado River into Mexico, irrigation return flows, and highly
concentrated briny waters have negatively affected the ecology of the upper Sea of Cortez and
the Cienaga de Santa Clara.
Drainage into the Sea of Cortez also comes from the higher lands to the east. Some
surface water drainage flows southwest from elevations of up to 8,300 feet (2,500 meters) from
the areas between Nogales and Agua Prieta. This flow forms smaller tributaries among the
different mountain ranges and eventually discharges through several creek systems into the Sea
of Cortez.
The Lower Colorado River basin in the border area consists of the Lower Colorado and
many smaller streams and washes, some perennial and some ephemeral, that flow across the
border. These include the Nogales Wash near Nogales, Arizona; the Greenbush Draw near
Naco, Arizona; and the Whitewater Draw near Douglas, Arizona. The basic flow regimes in the
basin occur as the Santa Cruz and San Pedro Rivers (which both originate in the highland areas
of the northern Sonora Desert, Mexico) flow north across the border and into the Gila River,
which itself originated in the Gila National Forest and flows from east to west across the
southern part of Arizona. The Gila empties into the Lower Colorado near Yuma, Arizona.
The Lower Colorado River and its tributaries are the main source of water for the entire
lower southwest United States. The Lower Colorado proper supports 700,000 acres (280,000
hectares) of farmland in the Imperial, Coachella, Bard, and Palo Verde Valleys of California.
The river supplies water to 25 million people throughout its watershed, and almost all of the
river's flow is allocated for use to specific consumers. Current river usage agreements guarantee
8.5 million acre-feet (10.5 billion m3) per year of water to the Lower Colorado Basin and 1.5
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Appendix A -Study Area Description
million acre-feet (1.9 billion m3) per year to Mexico. A series of dams and reservoirs store water
for consumer use, but the use is such that, in periods of low flow, the flow of the river can be
reduced significantly. The river is diverted and controlled by a series of drains and irrigation
canals, including the East and West Main Canals, the Main Drain, the A Canal, and the Mohawk
Canal. These canals distribute water, as necessary, to agricultural operations in the surrounding
areas. Return flows from these canals re-establish flows in the river; however, in conjunction
with agricultural runoff, these return flows are thought to contribute to salinity problems in the
river.
A.3 Central Desert/Closed Transboundary Basins
The Central Desert and Closed Basins consist of the Mexican Highlands watersheds and
the Mimbres and Animas watersheds. Figure A-3 shows the Central Desert and Closed Basins
and their most important characteristics. The Mexican Highlands Basin contains watersheds that
drain to rivers in southern Arizona, southwestern New Mexico, northern Sonora, or the extreme
northwestern tip of Chihuahua. The Mimbres/Animas Basin contains watersheds that drain
internally in southern New Mexico and northern Chihuahua. Together, these watersheds drain
34,290 square miles (89,000 km2) (Woodward and Durall, 1996).
fi^^^^^ffi
Figure A-3. Central Desert/Closed Basins.
A.3.1 Geography of the Central Desert/Closed Basins
The Mexican Highlands watersheds are characterized by broad valleys or basins
separated by steeply rising mountain ranges. Each .basin is essentially an independent hydrologic
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Appendix A - Study Area Description
system. The watersheds drain to rivers in southern Arizona, southwestern New Mexico, northern
Sonora, and the northwestern tip of Chihuahua.
The Mexican Highlands watersheds are classified as desert. However, this desert area,
unlike many others, is renowned for its lush vegetation and diverse aquatic habitats, remnants
from a time when the area was wetter. The uniqueness of this desert has attracted humans since
early history. The U.S. and Mexican 1990 censuses estimated the population of the area to be
about 935,000. Selected regions in the Mexican Highlands area have experienced intense human
pressure with subsequent effects on its water resources and associated plant, fish, and wildlife
species. (Papoulias et al., 1997)
The Mimbres and Animas watersheds consist mostly of topographically closed basins
with piedmont and basin-floor alluvial surfaces grading to central playa (ephemeral lake)
depressions that are designated "bolsons." All stream systems are ephemeral, except in the
valleys of Animas Creek (New Mexico Environment Department, 2002).
The area is further subdivided into the Mimbres, Playas, and Marmel watersheds. The
eastern part of the area is contiguous with the Upper Rio Grande basin area. This area is known
as the Central Closed Basin area. Most flows in the Central Closed Basin area are intermittent,
and all of the surface flows within the basin's boundaries are self-contained. The Central Closed
Basin consists of several subbasins. The Rio Grande-Mimbres subbasin extends from the
Elephant Butte Reservoir to the junction of Mexico, New Mexico, and Texas at the International
Boundary, and includes parts of the Jornada del Muerto highlands, the Mimbres River, Playas,
and other closed areas west of the Rio Grande. The Rio Grande-Caballo area includes the
Caballo Mountains; the southern reaches of the Jornada del Muerto highlands; and the cities of
Las Cruces, New Mexico, and El Paso, Texas. On the Mexican side of the border, the basin
encompasses the northwestern part of the state of Chihuahua. This area is defined to the west by
the Sierra Madre Occidental Mountain Range, which begins almost from the Sonora-Chihuahua
Border and extends south. Within the Sierra Madre Occidental are several smaller mountain
ranges, including the Sierra Boca Grande, the El Fresnal, the Gapulin, the Encendida, the
America, the La Catarina, the Las Tunas, the El Nido, and the Los Arados ranges.
The basin area is a topographically closed, high plateau area with few ephemeral streams
that drain internally and do not contribute flow to any of the surrounding basins. Its boundaries
are formed by the Continental Divide on the west, the Rio Grande Basin to the north and east,
and the Chihuahua Highlands and Route 45 from Ciudad Juarez to the city of Chihuahua to the
south. The northern part of the basin area consists of wooded areas with elevations from 6,500
to 10,000 feet (2,000 to 3,000 m); moving further south, the topography changes to desert and
semi-arid plains. To the east of the basin, in the northern section of Chihuahua, are several
wetland areas called El Barreal. Climatologically, the basin ranges from sub-humid in the north
to dry and arid in the south. Annual rainfall ranges from 25 inches (64 cm) in the northern
wooded areas to 8 to 10 inches (20 to 25 cm) in the southern elevations.
Land in the basin area is primarily desert, and urbanized areas make up the majority of
developed and utilized land. However, range and open land also make up a significant portion of
the basin.
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Appendix A - Study Area Description
The principal cities within this region in the United States are Columbus and Sunland
Park, New Mexico. In Mexico, the principal cities are Las Palomas, Ascension, and Janos
Nuevo Casas Grandes,'and General Rodrigo M. Quevedo, Chihuahua.
A.3.2 Hydrology of the Central Desert/Closed Basins
The most important major rivers include the Gila, Santa Cruz, and San Pedro Rivers. In
addition, many smaller streams and washes, some perennial and some ephemeral, flow across the
border. These include the Nogales Wash near Nogales, Arizona; the Greenbush Draw near
Naco, Arizona; and the Whitewater Draw near Douglas, Arizona. The basic flow regimes in the
basin occur as the Santa Cruz and San Pedro Rivers, which both originate in the highland areas
of the northern Sonora Desert, Mexico, flow north across the border and into the Gila River,
which itself originates in the Gila National Forest and flows from east to west across the southern
part of Arizona. The Gila empties into the Lower Colorado near Yuma, Arizona.
The Santa Cruz River originates in the Coronado National Forest west of Nogales,
Arizona, and flows south into Mexico before looping back towards the United States near
Nogales, Sonora, Mexico. At Nogales, the river flows north through the city, across the border,
and into the United States. The river's drainage area is approximately 8,200 square miles
(21,000 km2), with populations concentrated in the Pima County suburbs of Tucson and in the
cross-border community of Nogales. Because of the extensive use of groundwater throughout the
basin, most parts of the river flow only as a'result of runoff or wastewater discharge. However,
some tributary streams remain perennial. Of the tributary streams and washes, one of particular
concern is the Nogales Wash, which is often composed of raw wastewater and sewage
discharged from Nogales on the Mexican side of the border.
The San Pedro River originates in Mexico in a ranching, agriculture, and mining area,
and flows into the United States near Palominas, Arizona. The San Pedro River then flows north
for almost 100 miles (160 km) before reaching the Gila River. The basin encompasses
approximately 3,740 square miles (9,700 km2), with most of the land owned by the State of
Arizona. The population centers in the San Pedro subbasin are primarily small towns, and
include Naco, Bisbee, Tombstone, Willcox, and Douglas, Arizona, and the larger communities of
Agua Prieta, Cananea, and Naco, Sonora, Mexico. As with the Santa Cruz subbasin, there are
several smaller waterbodies of concern in the San Pedro subbasin, including the Whitewater
Draw, which drains the town of Douglas, Arizona, and flows into Mexico where it discharges
into the Agua Prieta River; and the Greenbush Draw, which drains the Bisbee-Naco area into the
San Pedro River.
During the early part of the 20th century, surface water in the basin was almost fully
appropriated; thus, further augmentation of water supplies has had to depend almost entirely on
groundwater resources. Extensive development of groundwater depletes stream flow, captures
natural discharge, and decreases water levels in the aquifer, resulting in reduced stream flows
and spring flows and decreased riparian habitat. The Santa Cruz and San Pedro Rivers are the
dominant streams in the basin. Their flows largely depend on precipitation in the mountains in
Arizona and Mexico. Near their headwaters, certain reaches of these rivers flow continuously,
but their flows decrease dramatically as the rivers travel northward. For example, the Santa Cruz
River near Nogales, Sonora, generally flows continuously. However, the natural flow in the river
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Appendix A - Study Area Description
typically does not reach the Nogales International Wastewater Treatment Plant (located along the
river about 6 miles [10 km] north of Nogales, Arizona). Flow downstream from the treatment
plant is composed entirely of effluent return, and this water rarely flows past the Santa Cruz
County line (located about 12 miles [19 km] downstream from the treatment plant) before it
completely seeps into the subsurface. (Papoulias et al., 1997)
An important perennial river in this basin is the Mimbres River, which flows only in the
upper reaches outside of the border area. The Bear Canyon Reservoir, which is fed by the
Mimbres River at Bear Canyon, lies in the.northern part of the basin; it is capable of impounding
700 acre-feet (860,000 m3) of water for conservation storage and recreation. The principal rivers
in Northwest Chihuahua are the Rio Casa Grandes, the Rio Santa Maria, and the Rio Santa Clara.
There are also several lakes in this region, including Laguna Colorado, Laguna Victorio, Laguna
de Santa Maria, Laguna de la Ascension, Laguna de Guzman, Laguna Fierro, Laguna Redonda,
Laguna la Vieja, Laguna Seca, Laguna Encinitas, and Laguna San Rafael. The Ochenta y Nueve
irrigation district also lies in the basin.
Unlike the other major basins straddling the U.S.-Mexico border region, no perennial
streams flow across the border in this basin. While some ephemeral streams, such as the Wamels
Draw and other unnamed streams, flow across the border during runoff events, few streams flow
perennially in the entire basin.
Groundwater is the major source of water within the basin. Four underground basins (the
Mimbres, the Animas Valley, the Playas Valley, and the Nutt-Hockett Aquifers) have been
identified on the U.S. side of the border. Of these aquifers, the Animas Valley, the Playas
Valley, and the Nutt-Hockett aquifers lie in the border region. The Animas Valley aquifer
encompasses approximately 426 square miles (1,100 km ) underneath Hidalgo County and parts
of Arizona in the Colorado River basin; the Playas Valley aquifer underlies 515 square miles
(1,300 km2) in Hidalgo County; and the Nutt-Hockett underlies approximately 133 square miles
(340 km2) in portions of Luna, Sierra, and Dona Ana Counties. Because of the lack of reliable
alternative water sources, safeguarding groundwater from pollution is a critical issue within this
basin.
The conflicts resulting from competition for the region's limited water resources are well
illustrated in the Santa Cruz River Basin. Competing water needs and uses include municipal,
domestic, industrial, and agricultural uses; irrigation; and support of riparian habitat and fish and
wildlife. The withdrawal of groundwater, the basin's principal source of supply for municipal,
industrial,' and agricultural uses, is greater than natural basin recharge. The two largest
population centers occur in the Santa Cruz River Basin: Tucson (about 579,000 people) and the
sister cities of Nogales-Nogales (about 137,000 people). As a result, more than 75 percent of the
people in the subarea live in the Santa Cruz River Basin. The Nogales-Nogales area also supports
one of the largest maquiladora clusters along the U.S.-Mexico border. About 26,000 acres
(11,000 hectares) of agricultural lands are irrigated in the basin upstream from Tucson, including
about 2,300 acres (930 hectares) in Mexico. (Papoulias et al., 1997)
Overdraft of groundwater supplies is a major concern to the basin because of the rapid
growth rates in this region of the border. Increased groundwater withdrawal from the Tucson
Basin has resulted in increased well pumping costs, reduced groundwater quality, decreased well
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Appendix A - Study Area Description
capacities due to the consolidation of sand in the-aquifer, and the potential for land surface
subsidence. Groundwater-surface water interactions in the area are poorly understood, but as
groundwater withdrawals exceed natural recharge, greater volumes of surface flows from the
Santa Cruz River will be drawn into the aquifer and eventually the river will run dry. Subsidence
and aquifer overdraft also concern federal land managers, and the results on wetlands and springs
could directly affect the ability to protect ecological resources. (Papoulias et at., 1997)
Water in the San Pedro River is supplied by flow from Mexico and by discharge from the
adjacent aquifer. The San Pedro Riparian National Conservation Area is a narrow corridor of
riparian habitat hosting a wide variety of plant and animal species. The water requirements of the
San Pedro Riparian National Conservation Area, municipalities, industry, the military, and
agriculture in the San Pedro Basin must all be met from the same, limited resource. The issues of
the San Pedro Basin include (1) maintenance of sufficient river flows for the protection of the
riparian environment, (2) resolution of conflicting water-use interests and the legal determination
of water rights, and (3) identification of the effects of water-resource development in the basin
within the upper reaches in Mexico. (Papoulias et al., 1997)
These water quantity issues are exacerbated by problems associated with insufficient data
for the San Pedro River System. At present, there is a poor understanding of the origin of surface
flows, groundwater-surface water interaction, and the importance of the riparian system. We are
only beginning to understand the significance of large riparian cottonwood and willow forests to
the biological health of the river system. (Papoulias et al., 1997)
The area contains two National Wildlife Refuges, each dependent on a sustaining water
supply. The fish and wildlife resources of San Bernardino National Wildlife Refuge are
inextricably tied to the water resources of the San Bernardino artesian basin, more than half of
which is in Mexico. Another system of great importance to wildlife, particularly to migratory
birds, is the Arivaca Oenega (a type of wetland) of Arivaca Creek within the Buenos Aires
National Wildlife Refuge. In addition, springs and intermittent drainages support approximately
30 acres (12 hectares) of riparian' habitat at the Fort Bowie National Historic Site, 180 acres (73
hectares) within the Chiricahua National Monument, and more than 300 acres (120 hectares) of
riparian wetland habitat, including 101 acres (41 hectares) of Oak Riparian Forest in the
Coronado National Memorial. (Papoulias et al., 1997)
Federal (United States) bureaus are participating in the Arizona adjudication of water
rights, particularly as it addresses the issues of allocation and ground- and surface-water
interaction in the Mexican Highlands. Under Arizona law, uses of surface water must adhere to
the doctrine of prior appropriation (the rule of "first in time, first in right"), and most
groundwater uses are limited by the doctrine of reasonable use. The reasonable-use doctrine
provides no limits on the quantity and timing of withdrawal. The U.S. Bureau of Land
Management, U.S. Fish and Wildlife Service, and U.S. National Park Service have submitted
claims in adjudications to protect water rights for surface- and groundwater uses, including uses
that maintain riparian habitat. The U.S. Bureau of Indian Affairs has supported Gila River Indian
Community claims, and the U.S. Bureau of Reclamation has Central Arizona Project authority
on the San Pedro River. This adjudication, referred to as the Gila River Adjudication, will
resolve several issues that are significant to management of the San Pedro Riparian National
Conservation Area. (Papoulias et al., 1997)
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Appendix A - Study Area Description
A.4 Upper Rio Grande Transboimdary Basins
The Rio Grande/Rio Bravo Basin on the U.S.-Mexico Border is defined as the area from
the Elephant Butte Reservoir to the Falcon Reservoir. The Rio Grande Basin drains 76,480
square miles (200,000 km2) (Woodward and Durall, 1996). Figure A-4 shows the Rio Grande
Basins and their most important characteristics.
Legend
, ' f
1 ITiindwwKHijrBaui (" ly$fM«i«Y»i(!««»»«i
lili««iOowr»;
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Figure A-4. Upper Rio Grande Basins.
A.4.1 Geography of the Upper Rio Grande Basins
The Rio Grande basin extends from the Rio Grande's headwaters in the San Juan
Mountains of southern Colorado all the way to its end in the Gulf of Mexico in the Mexican state
of Tamaulipas and the U.S. state of Texas. The Rio Grande is approximately 1,900 miles
(3,100 km) long and drains an area of 182,215 square miles (470,000 km2) in three U.S. states
(Colorado, New Mexico, and Texas) and five Mexican states (Chihuahua, Coahuila, Durango,
Nuevo Leon, and Tamaulipas). As the river flows through El Paso, Texas, it begins to define the
International Boundary between Mexico and the United States, and does so until its mouth at the
Gulf of Mexico. In this area along the International Boundary, the river is also known by its
Mexican name, the Rio Bravo.
A-14
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Appendix A - Study Area Description
In the border area, the Rio Grande/Rio Bravo basin stretches from New Mexico to the
International Falcon Reservoir, which lies in the northwestern portions of Tamaulipas, Mexico,
and the southwestern part of Texas, near Zapata and Falcon, Texas, and Nuevo Ciudad Guerrero,
Tamaulipas. Below the International Falcon Reservoir, the hydrography of the Rio Grande basin
changes, and thus this area of the basin has been defined as a separate basin, designated the
Lower Rio Grande Basin. The Lower Rio Grande Basin is discussed fully in Section A.5.
The Rio Grande basin as defined in the border area is bounded by the official 100-km
border designation about 65 miles (105 km) north of the border, below the elephant Butte
Reservoir near the towns of Salem and Hatch, New Mexico. Near this northern boundary, the
Rio Grande flows through the Mesilla Valley, at an approximate elevation of 3,700 feet (1,100
m) above sea level. As the Rio Grande flows south, it becomes the border between New Mexico
and Texas, and then, at El Paso, Texas, it becomes the International Boundary between Mexico
and the United States. As it flows to the Gulf of Mexico, the Rio Grande/Rio Bravo basin
encompasses all or part of 31 western Texas counties. The Rio Grande/Rio Bravo valley
encompasses a narrow strip of land bordered by the Guadalupe, Davis, and Santiago mountain
ranges in western Texas, and a series of ranges along the eastern reaches of Chihuahua, including
the Sierra La Armagosa, Sierra San Jose del Frisco, Sierra La Lagrima, Sierra Pilares, Sierra,
Sierra La Esperanza, and the Sierra El Peguis. As the river flows south past the International
Amistad Reservoir, its floodplain widens as the valleys between the Sierra Madre Occidental and
the Serranias del Burro of Coahuila, Nuevo Leon, and Tamaulipas give way to lower valleys
supporting the tributaries of the river. On the U.S. side of the border, the Rio Grande river valley
widens below the Edwards Plateau of northwestern Texas. Below the Reservoir, the lower lands
and valleys become wide enough to support more agricultural uses.
The Rio Grande section from Rio Conchos to Amistad Reservoir area is hot, and the
climate varies from semiarid to arid. Average annual rainfall (1961-90) ranged from about 11
inches (28 cm) per year at Presidio, Texas., to about 19 inches (48 cm) per year at the upper
elevations of the Chisos Mountains in Big Bend National Park. This sparsely populated area
(1990 U.S. population less than 40,000) is predominantly open range and is divided between the
Basin and Range and Great Plains physiographic provinces. The Basin and Range province, from
Big Bend National Park westward, is characterized by isolated mountain ranges separated by
desert basins characteristic of the northern Chihuahua Desert. (Blackstun et al., 1996)
Both sides of the international border have protected areas. The Maderas del Carmen and
Canon de Santa Elena in Mexico contain nearly 1.2 million acres (490,000 hectares). Although
much of this land is privately held, the Mexican government has given these areas special
environmental status. Although much of the land in Texas is privately owned, the U.S. National
Park Service (NPS) and the Texas Parks and Wildlife Department (TPWD) protect significant
areas along the border including Big Bend National Park (NPS), the Rio Grande Wild and Scenic
River (NPS), and Amistad National Recreation Area and Big Bend Ranch State Park (TPWD).
(Blackstun etal., 1996)
In the northern reaches of the basin in New Mexico, the Rio Grande flows through
portions of the Chihuahua Desert, where precipitation is less than 8 inches (20 cm) per year and
annual evaporation may be more than 1,000 percent of this annual input. As the river flows
southeast, rainfall increases, ranging from approximately 12 inches (30 cm) per year at Fort
A-15
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Appendix A - Study Area Description
Stockton to 20 inches (5.1 cm) at Laredo to over 25 inches (64 cm) at Brownsville. As described
above, most of the Rio Grande is semi-arid desert scrub land with vegetation consisting of
shrubs, short grasses, and cacti. At the higher elevations along some isolated peaks, small forests
of oak, juniper, and pine can be supported. The basin supports several biotic communities in
both the scrub desert ecosystems, as well as in the riparian corridor of the river itself. The river
is also an important ecosystem and is home to as many as 80 species of northern Chihuahua
desert fish species. The Rio Grande/Rio Bravo basin also contains many protected lands,
including the Canon de Santa Elena Reserve in Chihuahua, the Maderas del Carmen area in
Coahuila, and Big Bend National Park and the Big Bend Natural Ranch Area in Texas. .
Land use in this area of the Rio Grande/Rio Bravo basin is primarily devoted to
rangeland, agriculture, light industrial uses, mining, and urban areas. As discussed above, the
availability of water determines almost all of the land uses in the basin. In areas where water
control devices allow the regulation and storage of water, larger human populations can be
sustained and industries can flourish. In other areas, the use of canals to transport water supports
ranching, rangeland, and agricultural practices. Areas with no water control most likely remain
as scrub desert.
Major cities in the Rio Grande basin are primarily composed of five pairs of sister cities
(El Paso/Ciudad Juarez, Presido/Ojinaga, Del Rio/Ciudad Acuna, Eagle Pass/Piedras Negras, and
Laredo/Nuevo Laredo) located along the Rio Grande/Rio Bravo. These pairs of sister cities
account for the largest population segments in the basin. In addition, because of their proximity
to each other and their location on the International Boundary, these communities represent the
interrelated natures of the cross-border economies, populations, and environmental issues
characteristic of the border area
In addition to these incorporated communities, unincorporated "colonias" play a
significant role in water issues and infrastructure planning in the Rio Grande/Rio Bravo basin.
Colonias are permanent communities that have been built for the most part without basic
infrastructure, including water and wastewater systems. Colonia communities are located
throughout New Mexico and Texas, and are estimated to have a population of over 300,000.
While most colonias are located in Hidalgo, Starr, Cameron, and Willacy Counties in
southeastern Texas, 25 percent lie along the Rio Grande/Rio Bravo basin in the border area.
Most of the colonias in this area lie in Maverick County near Eagle Pass. Because of their
proximity to the Rio Grande, and their lack of basic infrastructure to ensure safe drinking water
and adequate disposal of wastes, the colonias can have a major effect on water quality and other
water issues. Some Texas cities have already begun to incorporate the colonias into their
strategic planning, and a number of entities, including EPA, the U.S. Department of Agriculture,
the U.S. Department of Housing and Urban Development, and the States of New Mexico and
Texas have already initiated various programs to upgrade infrastructure in the colonias.
A.4.2 Hydrology of the Upper Rio Grande Basins
The primary waterbodies in the Rio Grande basin are the Rio Grande/Rio Bravo River
and its major tributaries, including the Rio Concho, the Rio Salado, and the Rio San Rodrigo in
Mexico, and the Pecos and Devils Rivers in Texas. Pecos River and Devils River contribute
flow directly to Amistad Reservoir. Other surface water features include springs, ephemeral and
A-16
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Appendix A Study Area Description
intermittent streams, and tinajas (water pockets often below small waterfalls). The Rio Grande
flows through deep, steep-walled canyons of limestone, forming a ribbonlike oasis of riverine
and riparian environment sand providing a stark comparison to the adjacent desert landscape.
The Rio Conchos watershed in its entirety contains almost half the entire Rio Grande drainage
area in Mexico. (Blackstun et al., 1996)
The Rio Grande/Rio Bravo has also been dammed in several places to create reservoirs,
including the International Amistad Reservoir and the International Falcon Reservoir. Two
reservoirs, the Centenario and the San Miguel Reservoirs, are also located west of the Rio
Grande/Rio Bravo, below the International Amistad Reservoir between Ciudad Acuna and
Piedras Negras, Coahuila, Mexico.
The hydrography of the Rio Grande/Rio Bravo basin has been substantially altered by
humans. The entire basin area is semi-arid, and human populations can only be supported in
areas with reliable water supplies. The extremely high demand for water throughout the basin
has resulted in a complex series of dams, reservoirs, canals, diversions, and other man-made
structures that control, divert, and store water for human use, including drinking water supplies,
agricultural irrigation water supply, and other uses. These control structures are located
throughout the basin, and in fact begin outside of the border area in the upper reaches of the Rio
Grande. The increasingly competitive natures of water interests have made the hydrography of
the Rio Grande/Rio Bravo a matter of increasing concern, both economically and ecologically,
with many regional planning decisions affected by both the quantity and quality of water
available.
Flow in the Rio Grande/Rio Bravo has historically been the result of spring snowmelts in
the upper reaches of the river, as well as localized inputs from summer thunderstorms. With the
exception of the major rivers, many of the tributaries flowing into the Rio Grande are
intermittent streams that flow only during the wet period of the year. As a result of this water
balance, most flow in each segment of the basin is basically controlled by man-made diversions
in the segment upstream. Thus, flow through El Paso is controlled by releases from the Elephant
Butte Reservoir in New Mexico, flow through Ciudad Acuna and Del Rio is controlled by the
International Amistad Reservoir upstream, and flow to the lower Rio Grande/Rio Bravo is
controlled by the International Falcon Reservoir. Between these water storage structures are a
series of water diversion structures that divert the water to localized uses. Water is diverted in the
El Paso/Ciudad Juarez area by the American Canal and the Acequia Madre; flow around Del Rio
is diverted by the Maverick Canal; and flow below the International Falcon Reservoir is diverted
by the Anzalduas and other canals.
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Appendix A - Study Area Description
(1.3 billion m3) per year, and inflows are 1,649,000 acre-feet (2.0 billion m3) per year, nearly half
of which are Maverick Canal return flows.
The construction of dams and implementation of flood-control practices, channelization,
increased water diversions, and displacement of native cottonwood and willow with tamarisk
(salt cedar) have resulted in the Rio Grande becoming seasonally intermittent between Fort
Quitman, about 70 miles (110 km) southeast of El Paso/Ciudad Juarez, and Presidio. On the Rio
Grande upstream from the area, Elephant Butte and Caballo Reservoirs (in southern New
Mexico), impound and release virtually all Rio Grande flows for urban, industrial, and
agricultural uses in the El Paso/Ciudad Juarez region. Existing water rights, international treaties,
and operational policies administered by the Rio Grande Compact Commission limit Rio Grande
flow from this region. The limited return flows to the Rio Grande from these uses have
significantly degraded water quality. Those return flows are significantly reduced between Fort
Quitman and Presidio as they pass through a reach overgrown with tamarisk and are
evapotranspired. This often results in little or no surface flow from the Rio Grande entering the .
subarea from above the Rio Conchos. (Blackston et al., 1996)
Water quantity, water quality, and aquatic-biological characteristics within the Rio
Conchos area are heavily influenced by the Rio Conchos. In the Rio Conchos watershed,
upstream from the area, expanding agricultural, mining, and timber harvesting activities as well
as urban and industrial development affect both the quantity and quality of Rio Grande flows
through the area. (Blackston et al., 1996)
The Pecos and Devils Rivers are tributaries at Amistad Reservoir. The natural discharge
of saline groundwater into the Pecos River in New Mexico also affects the water quality of
Amistad Reservoir. (Blackston et al., 1996)
The availability of streamflows sufficient in variability, magnitude, and duration to
protect natural resources that are dependent on these flows is the most serious water quantity
issue in this subarea. If sufficient streamflow is not available to fully support and satisfy all
competing water needs, the issue of water quality becomes academic. Before 1915, the Rio
Grande flowed unimpeded through relatively undisturbed lands in the sparsely populated
subarea. At Presidio/Ojinaga, a dramatic change in the river is visible due to the dominating
influence of inflow from the Rio Conchos. The Rio Conchos typically supplies the largest
percentage of Rio Grande flows allocated by Mexico in accordance with the 1944 Treaty
between the United States and Mexico. The total annual flow of the Rio Conchos averaged
737,000 acre-feet (909 million m3) through the 1980s, more than five times the flow of the Rio
Grande measured just above its confluence with the Rio Conchos. Also, the flood-peak histories
of the Rio Grande and Rio Conchos are dramatically different, even though both rivers are
heavily regulated. (Blackston et al., 1996).
Dams on the Rio Conchos are operated primarily for water storage. Consequently, the
Rio Conchos sometimes experiences high peak flows71,300 cubic feet per second (cfs)
(2,020 nvVsec) in 1978 and 45,900 cfs (1,300 nrVsec) in 1991. As flood control becomes an issue
in the developing Rio Conchos watershed, changes in the annual volume and peak levels of
streamflow entering the Rio Grande could affect the long-term maintenance of existing aquatic
A-18
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Appendix A - Study Area Description
and riparian habitats and further affect the variability of the flow regime downstream. (Blackston
etal., 1996)
Flow from the Pecos and Devils Rivers' watersheds directly enters Amistad Reservoir.
The Rio Grande, which was impounded at Amistad Dam in 1969, has .a drainage area of 123,142
square miles (320,000 km2) at the IBWC streamflow gage located 2.2 miles (3.5 km)
downstream from the dam. Relative contributions of flow to the reservoir for the period 1968-
1993 are as follows: the Rio Grande above the Pecos River, about 66 percent (1,836 cfs, or 52
mVsec), the Pecos River, about 11 percent (298 cfs, or 8.4 m3/sec), and the Devils River, about
23 percent (656 cfs, or 19 nrVsec). Mean annual flow from Amistad Reservoir is 2,454 cfs (69
m3/sec). Although the Devils River watershed is only about 12 percent of the size of the Pecos
River watershed, its mean annual flow is more than twice that of the Pecos. Reasons for
significant differences in water yields from the two watersheds are as follows: (1) the Pecos
River watershed is mostly arid, whereas the Devils River watershed is mostly semiarid; (2) along
much of its length, the Pecos River contains alluvial deposits which allow recharge to
groundwater by seepage from the river, whereas the Devils River lies almost entirely within
incised limestone canyons, resulting in less groundwater recharge; (3) spring discharge accounts
for a higher baseflow for the Devils River, and water diversions for irrigation are greater along
the Pecos River. (Blackston et al., 1996)
Groundwater is a source of baseflow for streams in the subarea, and its interaction with
surface water accounts for differences in water yields between watersheds. The Edwards-Trinity
aquifer system is the principal source of water for domestic, livestock, and public supply east of
Big Bend National Park. Although surface water is fully developed, use of water from the
Edwards-Trinity aquifer system for irrigation over the subarea is limited due to the poor soils and
the generally rocky terrain. In the Big Bend area, groundwater occurs in alluvial deposits along
the Rio Grande and intermittent streams. These areas provide important sources of water for
wildlife and habitat for the endangered Big Bend Gambusia. (Blackstun etal., 1996)
In some areas sufficient yields can be obtained for domestic, stock, and public water
supply uses. Geothermal springs are also a local tourist attraction in Big Bend National Park.
River rafting and other forms of recreation are popular along the Rio Grande; contact recreation
occurs both in the river and at hot springs along the river's edge in the subarea. (Blackstun et al.,
1996)
A.5 Lower Rio Grande Transboundary Basin
The Lower Rio Grande Valleybelow Falcon Reservoir to the Gulf of Mexico basin
contains watersheds that drain either to that reach of the Rio Grande, to the lower reach of the
Rio San Juan below the gaging station at Santa Rosalia, or to Arroyo Colorado in southern
Texas. It drains an area of 10,240 square miles (27,000 km2). Figure A-5 shows the Lower Rio
Grande Basin and its most important characteristics.
A.5.1 Geography of the Lower Rio Grande Basin
The Lower Rio Grande Basin is physiographically characterized as Gulf Coastal Plain.
This basin encompasses a total of 10,240 square miles (27,000 km2), of which 6,155 square
A-19
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Appendix A - Study Area Description
miles (16,000 km2) are in Mexico and 4,085 square miles (11,000 km2) are in the United States.
A small portion (approximately 174 square miles, or 450 km2) of this area is under the ownership
or administration of the U.S. Federal Government. Federally owned or managed areas include
the Santa Ana, Lower Rio Grande Valley, and Laguna Atascosa National Wildlife Refuges
administered by the U.S. Fish and Wildlife Service, and the Palo Alto Battlefield National
Historic Site administrated by the U.S. National Park Service. (Buckler et al., 1997)
,
'
Figure A-5. Lower Rio Grande Basin.
From Falcon Reservoir, the Rio Grande/Rio Bravo flows southeastward approximately
275 river miles (440 km), terminating in the coastal wetlands and marshes of the Gulf of Mexico,
including the Laguna Madre off the coasts of Texas and Tamaulipas. Among the unique habitats
of this segment of the U.S.-Mexico border are the resacas (oxbow lakes) of the Lower Rio
Grande Valley. The basin is classified as Tamaulipan brushland, which is characterized by dense,
woody, and thorny vegetation and a high degree of biological diversity. Vegetation is taller and
more lush in riparian areas than in the drier uplands and provides not only important nesting and
feeding habitat, but also serves as corridors for more rainfall than most other basins of the
border, with an average annual rainfall of about 26 inches (66 cm) at the mouth of the river and
about 16 inches (41 cm) at Falcon Dam. As in other border basins, the water resources and
associated plant, fish, and wildlife communities of the Lower Rio Grande Valley are increasingly
subject to the pressures of human activities. (Buckler et al., 1997)
Vegetation, climate, and temperatures are similar on both sides of the border. Along the
coastal area, marshes and wetlands dominate the landscape; moving up the watershed, these wet
areas give way to oak forests, and then to arid scrub areas near the Falcon Reservoir. The basin
supports a unique biotic community that includes several rare plant communities and numerous
A-20
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Appendix A - Study Area Description
species of mammals, snakes, lizards, and tortoises. Annual rainfall averages about 26 inches
(66 cm) in the lower Rio Grande Valley.
Land use in this area of the Lower Rio Grande ranges from semi-arid open scrub lands
below the Falcon Reservoir to agricultural lands and then wetlands and other protected areas.
Urban areas also represent a large proportion of the land in this basin. Alluvial soils along the
upper reaches of this basin are ideal for irrigated crops, and the region is a major producer of
vegetables, sorghum, and cotton. Traveling further downstream in the basin, the land becomes
marsh and wetland and has been left primarily undeveloped. However, these wetland areas are
widely used for recreation, including fishing. The Lower Rio Grande also contains several
wildlife refuges, including the Santa Ana National Wildlife Refuge between McAllen and
Brownsville, and the Laguna Atascosa National Wildlife Refuge north of the Rio Grande delta
on the Gulf of Mexico.
Major cities in the Lower Rio Grande Basin include Mier, Ciudad Miguel Aleman,
Ciudad Camargo, Gustavo Diaz Ordaz, Reynosa, and Matamoros in Tamaulipas. In Texas, the
primary population centers are Roma, Rio Grande City, McAllen, Harlingen, and Brownsville.
The total 2000 population of these cities is estimated to be in excess of 1,500,000.
A.5.2 Hydrology of the Lower Rio Grande Basin
Water supplies in the Lower Rio Grande are very limited, and increasing demands for
water from both sides of the border put a heavy burden on the river, as well as on the water
managers that must both protect and utilize the river's resources. Use of groundwater to meet
usage demands will also likely increase, making it imperative that water quality in the Rio
Grande, its tributaries, estuaries, bays, resacas, and also groundwater aquifers below the Gulf of
Mexico basin be protected.
In the upper part of the basin, just below the Falcon Reservoir in northwestern Stan-
County, the Lower Rio Grande is confined to a narrow course and the flood plain is less than a
mile (1.6 km) wide. However, as the river flows southeast, it widens, with the flood plain
reaching a width of 6 miles (10 km) in the middle reaches in Hidalgo County. Near its mouth on
the Gulf of Mexico,'the river enters a broad delta characterized by wetlands, salt marshes, and
open waters and lakes.
Other major rivers in this basin are the Rio Alamo and the Rio San Juan, which discharge
into the Rio Grande/Rio Bravo near Mier and near Ciudad Camargo, respectively. One of the
major tributaries to the Rio Grande is the Arroyo Colorado, which is the major drainage way in
the lower Rio Grande Valley and it is separated into two segments, the above tidal reach and the
tidal reach. Originally this was a tributary to the Rio Grande/Rio Bravo, but it was dredged in
the lower reach and channels built in several places. The flow in the above tidal section is mainly
for irrigation return flows and domestic waste effluent. The creek drains into the Laguna Madre
and becomes the estuary for the Rio Grande.
The Rio Grande discharges directly into the Gulf of Mexico, except during high flows,
when much of the water is diverted into flood channels throughout the Reynosa/Matamoros
corridor and then directly into the Laguna Madre. This canal system serves a dual purpose;
A-21
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Appendix A Study Area Description
besides providing flood control, the canal system also distributes water throughout the region.
These canals play a major role in the hydrology and water balance of the Lower Rio Grande and
the Gulf of Mexico basin.
Flow in the Lower Rio Grande through the Gulf of Mexico basin is controlled through
releases from the International Falcon Reservoir. Throughout the basin on both sides of the
border, other water structures, such as reservoirs and dams, control and store flow to meet the
region's water needs. In addition to their functions as storage facilities, these structures are used
for flood control, irrigation, water supply, and power generation. As noted above, these water
diversion structures play a major role in the hydrography of the region. Below the Falcon
Reservoir, various diversions remove approximately 994,000 acre-feet (1.2 billion m3) of water
annually from the Rio Grande on the U.S. side of the border, while approximately 987,000 acre-
feet (1.2 billion m3) of water are diverted annually to the Anzalduas Canal in Mexico. Even with
the approximately 500,000 acre-feet (620 million m3) of inflow from the Rio Alamo, Rio San
Juan, and irrigation return flows from the Mexican side of the border, this still leaves a deficit of
1.5 million acre-feet (1.9 billion m3) of water in the Lower Rio Grande.
Mexico's Rio Conchos and Rio San Juan have been the primary sources of water for this
section of the Lower Rio Grande for several decades. Flow in these rivers is being rapidly
diminished by increasing demands in their upper watersheds. The Rio Conchos supplies many
cities in northwestern Mexico, while Monterrey (Mexico's second largest city) is drawing much
of the Rio San Juan's water. (Buckler et al., 1997)
Within the basin, the rapidly growing cities of Reynosa, McAllen, Brownsville, and
Matamoros are placing increasing demands on the Rio Grande for freshwater. Groundwater is
usually not a suitable alternative water source for these urban areas due to high salinity, and
elsewhere in the basin there is concern that increased future water demands could exacerbate the
problem due to saltwater encroachment into the aquifer. Within the basin, a high percentage of
the surface water supply is currently allocated to agriculture, and increased municipal and
industrial demands are raising concerns as to whether sufficient water supplies will be available
during dry periods. (Buckler et al., 1997)
Surface flow in the Rio Grande below Falcon Reservoir is highly controlled. Falcon
Reservoir, which is the most downstream of the major international storage.reservoirs, was
authorized for construction by the U.S.-Mexico Water Treaty of 1944. The reservoir has a
storage capacity of about 2.7 million acre-feet (3.3 billion m3) and a maximum storage capacity
of about 4 million acre-feet (4.9 billion m3). Much of the water released from the reservoir is
diverted during April, May, and June to satisfy irrigation needs. Average diversions during
January through June exceed the total annual flow in the Rio Grande at Brownsville. (Buckler et
al., 1997)
Water for use in the United States is diverted along the river by local irrigation districts
and stored in holding ponds. Most of the water for use in Mexico is diverted at Anzalduas Dam.
The most downstream tributary to the river is located 10 miles (16 km) west of Mission, Texas.
A low ridge extends from the southern edge of the upland plain near Mission in Hidalgo County
preventing runoff in the area north of the ridge from flowing to the river. Much of the eastern
part of the valley is drained by small coastal streams, the Arroyo Colorado, resacas, and drainage
A-22
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Appendix A - Study Area Description^
ditches that flow into the Laguna Madre. Two floodways, constructed by IBWC to receive
excess floodwater, dissect the valley. A small portion (less than 10 percent) of the water
withdrawn for irrigation is returned to the Rio Grande. (Buckler et al., 1997)
The Arroyo Colorado carries much of the natural drainage and irrigation return flows to
the Laguna Madre just north of the Laguna Atascosa. Much of the drainage from the northeastern
parts of the study area is carried to the Laguna Madre by the RaymondviHe Drain. As a result of
these diversions, the Rio Grande itself delivers only a portion of the water in the basin to the
Gulf of Mexico. (Buckler et al., 1997)
The principal flow to the Laguna Atascosa National Wildlife Refuge is through the Cayo
Atascoso. The Cayo Atascoso flows into Laguna Atascosa, which is the largest lake on the
refuge. The Cayo Atascoso continues past the northern side of the refuge and ultimately
discharges into the Arroyo Colorado. Although the Cayo Atascoso continues past Laguna
Atascosa, sediment has been deposited near the outlet of the laguna to such an extent that it can
no longer be completely drained. The refuge also receives agricultural drainwater through the
Resaca de los Cuates. (Buckler et al., 1997)
Groundwater in the area is obtained from the Gulf Coast aquifer system of Texas and is
produced in small volumes from Eocene-age strata and the Miocene-age Oakville Sandstone.
Moderate to large volumes come from the Evangeline and Chicot aquifers (part of the Gulf Coast
aquifer system) in Cameron, Hidalgo, and Willacy Counties. These aquifers are hydraulically
connected and function as a unit. (Buckler et al., 1997)
Water levels in the area have declined dramatically since the 1950s due to irrigation
pumpage and severe drought. In 1985, the total pumpage of groundwater in the Lower Rio
Grande Valley was 17,268 acre-feet (21.3 million m ). Total surface water use was 824,250 acre-
feet (1.0 billion m3). Surface water has been, and will continue to be, the most important source
of water supply for the basin. (Buckler et al., 1997)
The four southernmost counties of Texas have one of the highest diversities of plants and
animals in the continental United States, which sustains ecotourism in south Texas and
northeastern Mexico. Seven of the eleven biotic communities in these counties are riparian or
partially riparian. Additionally, the extreme lower section of the river supports a very diverse
estuarine community and serves as a valuable nursery area for sport and commercial species of
shrimp, crabs, and fish. (Buckler et al., 1997)
The Santa Ana, Lower Rio Grande Valley, and Laguna Atascosa National Wildlife
Refuge in this basin provide habitat to a wide variety of species and serve as important wintering
and production habitat for migratory waterfowl and neotropical birds. (Buckler et al., 1997)
The natural resources under protection in the Lower Rio Grande Valley are closely
associated with both the coastal estuary systems and the flows of the Rio Grande and its
associated floodplain wetland systems. Maintenance of many of these wetland resources, in
particular the resacas, requires a natural cycling of flood events, which no longer regularly
occurs in the system due to water management practices. (Buckler et al., 1997)
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Appendix A - Study Area Description
Increased municipal and agricultural demands for water have significantly decreased the
quantity of water available for refuge wetlands. Additionally, agricultural systems and water
control structures now intercept overland flow that historically inundated much of the river
floodplain. Annual average flow in the lower part of the Rio Grande has been reduced by 30 to
50 percent by water diversions, and over the past decades, several fish species have disappeared
from the river. Additionally, river-dependent natural stands of plants, such as the Sabal Palm and
the Montezuma Bald Cypress, have been reduced to remnant numbers. (Buckler et ah, 1997)
A.6 References
Blackstun, D., L. Woosley, and M. Flora. 1996. Water Resources Issues in the Rio Grande-Rio
Conchos to Amisiad Reservoir Subarea. U.S. Department of the Interior. U.S.-Mexico
Border Field Coordinating Committee Fact Sheet 3.
Buckler, D., D. Papoulias, G. Ozuna, D. Woodward, M. Flora, and L. Ditto. 1997. Water
Resources Issues in the Lower Rio Grande Valley - Below Falcon Reservoir to the Gulf
of Mexico Subarea. U.S. Department of the Interior. U.S.-Mexico Border Field
Coordinating Committee Fact Sheet 4.
Papoulias, D., D. Woodward, M. Flora, and D. Buckler, D. 1997. Water Resources Issues in the
Mexican Highlands Sub-area. U.S. Department of the Interior. U.S.-Mexico Border
Field Coordinating Committee Fact Sheet 2.
U.S. EPA (Environmental Protection Agency). 2000. U.S.-Mexico Border Surface Water
Quality and Public Health Assessment Report. Prepared by Parsons Engineering Science,
Inc., for the Office of Water. January.
Woodward, D.G., and R.A. Durall. 1996. United States-Mexico Border Area, As Delineated By
a Shared-Water Resources Perspective. U.S. Department of the Interior. U.S.-Mexico
Border Field Coordinating Committee Fact Sheet 1.
A-24
-------
Appendix B - Data Dictionary
Appendix B
U.S.-Mexico Border Waters Repository Data Dictionary
B.I Introduction
This Appendix provides the data dictionary for the U.S-Mexico Waters Repository,
which describes each table in the database. Each table consists of a number of fields or columns.
Field information includes field name, type, size, whether the field value is required, and a field
description. Each table has a primary key, indicated with a "PK" next to the field. The primary
key is the column or columns that uniquely identify a row in a table.
B.2 Design Objectives
RTI's design team sought to satisfy the following objectives in designing the repository:
Provide a database structure that is compatible with existing systems (most
importantly STORET) but simple enough to facilitate data entry and maintenance.
Include data elements that comply with EPA's data-standardization efforts.
Include data elements that add value to the water quality information in the context of
this project. These data elements must provide additional information that is not:
contained in existing systems such as STORET. Examples of these data elements are
ecoregions and transboundary regions.
To meet these objectives, RTI based the Repository design primarily on EPA's STORET
data dictionary and business rules. STORET is a repository for water quality, biological, and
physical data and is used by state environmental agencies, EPA, and other U.S. federal agencies,
as well as by universities, private citizens, and many others. RTI simplified STORET's design
and incorporated the most important data elements into the U.S.-Mexico Border Waters
Repository design (U.S. EPA, 2005).
Figure B-l shows a high-level representation of the U.S.-Mexico Border Waters
Repository. The boxes reflect major categories of data that characterize the data collection
process. As part of the data collection process, organizations carry out station visits to sampling
stations. At the sampling stations, they conduct monitoring activities that then generate results
(U.S. EPA, 2003). The repository contains a variety of data tables for each element in this
process.
B-l
-------
Appendix B - Data Dictionary
Organizations
Sampling Stations
Station! Visits
Monitoring Activities
Results
Figure B-l. High-level components of the U.S.-Mexico Border Waters Repository.
Similarly to STORETas stated in STORET's business rules (U.S. EPA, 2003)the
U.S.-Mexico Border Waters Repository may contain many organizations. Each organization is at
the top of its own data and information pyramid, which includes not only its own description, but
also the descriptions of its stations, visits, monitoring activities, and associated results.
B.2.1 Environmental Sampling, Analysis, and Results Standard
The U.S.-Mexico Border Waters Repository design incorporated many of the standards
described in EPA's Environmental Sampling, Analysis, and Results (ESAR) protocol. The
ESAR standard is still under development and is applicable to cataloging and exchanging
information about projects, sampling stations/locations, sample collection activities, analyses,
and results. This standard defines the data elements that describe projects, sampling
stations/locations, sample collection activities, analytical processes and results, and any ancillary
information needed to accompany environmental data (U.S. EPA, 2004).
Examples of data elements from ESAR are as follows:
Organization Descriptionorganization identifier, name, description, etc.
Organization Electronic Addresselectronic address text and type
Organization Physical Addressaddress type, location address, state, country, etc.
Monitoring Location Identityidentifier, name, type, description, etc.
Monitoring Activityidentifier, type, media, media subdivision, end date, end time,
depth/altitude measure, etc.
« Samplecollection method, collection equipment, holding container material,
holding container color, preservation thermal code, etc.
B-2
-------
Appendix B - Data Dictionary
« Resultdetection condition, characteristic name, sample fraction, value measure,
units, statistical base, value type, weight basis, time basis, temperature basis, particle
size, comments, etc.
B.2.2 Latitude/Longitude Standard
The U.S.-Mexico Border Waters Repository design incorporated many of the data
elements listed in EPA's final version of the Latitude/Longitude standard. Latitude and longitude
information is provided for the monitoring stations. The Latitude/Longitude standard represents a
clarification and update of the EPA locational data policy originally outlined in the Method
Accuracy Description (MAD) documentation. The MAD codes were developed by the
Locational Data Policy (LDP) Sub-Work Group to meet EPA's needs to standardize the coding
of geographic coordinates and associated attributes for method, accuracy, and description codes
for all environmental measurements (U.S. EPA, 2004).
Data elements included in the repository are as follows:
Latitude measure
Longitude measure
Source map scale number
Horizontal accuracy measure
Horizontal collection method
Horizontal reference datum.
B.3 Data Dictionary
B.3.1 Table: T_ORGANIZATION
Description: An organization is a state, federal, local, academic, commercial, or other
group united for a particular purpose. An organization may establish sampling stations where
readings for. a characteristic are taken.
Field Name
TJDRGANIZATIONJD (PK)
ORGANIZATION.
ORGANIZATION.
.TYPE
_NAME
SHORT_NAME
Type
Long
Integer
Text
Text
Text
Size
4
30
60
20
Required
Yes
Yes
Description
A system-generated value used to
uniquely identify an occurrence of
this table.
Text that describes the type of
organization.
The formal full length of the
Organization.
The short name or abbreviation for
the organization.
(continued)
B-3
-------
Appendix B - Data Dictionary
Field Name
DESCRIPTIONJTEXT
CONTACT_NAME
CONTACT_ADDRESS_TYPE
CONTACT_ADDRESS
CONTACT_PHONE
CONTACT_LOCALITY_NAME
TL_STATE_ID
TL_TRIBAL_GROUPJD
ELECTRONIC_ADDRESS
ELECTRONIC_ADDRESS_TYPE
LAST_UPDATE
TL_USER_ID
Type
Text
Text
Text
Text
Text
Text
Text
Text
Text
Text
Date
Text
Size
254
30
8
50
50
30
8
3
120
8
8
8
Required
Yes
Yes
Description !
The text describing details of the
organization that users may wish to
provide. For example, this field
may be used to describe the
purpose, mission, or goals of the
Organization.
The name of the person who is the
contact for this Organization
Address Type: 'Location',
'Mailing', or 'Shipping'.
The contact mail address of the
Organization
The telephone number for the
contact person on this Organization
The name of a city, town, village or
other locality where the contact
person is located.
The foreign key to TL_STATE
implements: "A state can have
many organizations."
The foreign key to
TL_TRIBAL_GROUP implements:
"The organization may be a tribal
group."
A resource address, usually
consisting of the access protocol,
the domain name, and optionally,
the path to a file or location.
The name that describes the
electronic address type.
System generated value that
represents the calendar date and
time on which this information was
posted to the database or when a
subsequent modification was made.
The foreign key to TLJJSER
implements: "This table can be
modified by many Users."
B-4
-------
Appendix B - Data Dictionary
B.3.2 Table: T_STATION
Description: Information about the monitoring site where data were collected. In this
version, each station can only have one latitude/longitude point.
Field Name
T_STATIONJD(PK)
T_ORGANIZATION_1D
TL_COUNTRY_ID
TL_STATE_1D.
TLJJSCOUNTYJD
TL_USGS_CU_ID
TL_MEX_BASIN_ID
TL_BINATIONAL_REGION_ID
TL_LEVEL_II_ECOREGION_ID
IDENTIFICATION_CODE
STATIONJNAME
STATION_TYPE
ESTABLISHMENT DATE
DESCRIPTION_TEXT
STATION_BINARY_OBJECT
Type
Text
Long
Integer
Text
Text
Long
Integer
Text
Integer
Long
Integer
Text
i
Text
Text
Text
Date
Memo
Long
Binary
Size
30
4
2
8
4
8
2
4
4
15
60
20
8
0
0
Required
Yes
Yes
Yes
Yes
Description [
A system-generated value used to uniquely
identity an occurrence of this table.
The foreign key to ^ORGANIZATION
implements: "One Organization may have
many Stations."
The foreign key to TL_COUNTRY
implements "One Country may have many
Stations."
The foreign key to TL_STATE implements
"One State may have many Stations."
The foreign key to TLJJSCOUNTY
implements "One County in the United
States may have many Stations."
The foreign key to TL_USGS_CU
implements "One US Cataloging Unit in the
United States may have many Stations."
The foreign key to TL_MEX_BASIN
implements "One Mexican basin may have
many Stations."
The foreign key to
TL_BINATIONAL_REGION_ID
implements "One trans-boundary watershed
may have many Stations."
The foreign key to TL_LEVELJI_REGION
implements "One Level II Region in North
America may have many Stations."
The alpha-numeric code assigned by the
owning Organization which uniquely
identifies the Station within the Organization.
The name by which an Organization refers to
a Station.
The word describing the station type.
Permitted values are stored in table
TL_PERMITTED_VALUE.
The date the Station was established.
The Organization user-defined description of
a Station. May include distance to left shore
or right shore to the Station.
The actual binary object representing the
station.
(continued)
B-5
-------
Appendix B - Data Dictionary
\ Field Name
STATION_OBJECT_FILENAME
STATION_OBJECT_FILETYPE
LASTJJPDATE
TL_USERJD
Type
Text
Text
Date
Text
Size
255
6
8
8
Required
Yes
Yes
Description j
Name of the attached binary object (file),
including file extension.
File type associated with the attached file.
System generated value that represents the
calendar date and time on which this
information was posted to the database or
when a subsequent modification was made.
The foreign key to TLJJSER implements:
"This table can be modified by many Users."
B.3.3 Table: T_ABSLOCATION
Description: The latitude and longitude of points associated with a station where a
sample is taken.
Field Name
T_STATION_1D (PK)
LAT_DIRECT10N
LAT_DEC_DEG_MSR
LONG_D1RECTION
LONG_PEC_DEGJVISR
SOURCEMAP_SCALE_NUMBER
D1ST_TO_US_MEX_BORDER
HORZTL_ACCURACY_MSR
HORZTL_COLLECT_METHOD
HORZTL_REF_DATUM
Type
Text
Text
Double
Text
Double
Long
Integer
Double
Double
Text
Text
Size
30
1
8
1
8
4
8
8
60
60
Required
Yes
Yes
Yes
Yes
Yes
, Description j
The foreign key to T_STATION implements
"One Station have only one Absolute Location
Points."
The direction of the latitude measurement. "N"
denotes a positive value of the latitude. "S"
denotes a negative value of the latitude.
The measure of latitude in decimal degrees (-
90.0000 to 90.0000) indicating angular distance
North or South of the Equator.
The direction of the longitude measurement. "E"
denotes a positive value of the latitude." W"
denotes a negative value of the latitude.
The measure of longitude in decimal degrees (-
180.0000 to 180.0000) indicating angular
distance East or West of the prime meridian.
The number that represents the proportional
distance on the ground for one unit of measure
on the map or photo.
Shortest distance from station to US-Mexico
border in meters.
The measure of the accuracy (in meters) of the
latitude and longitude coordinates.
The text that describes the method used to
determine the latitude and longitude coordinates
for a point on the Earth. Permitted values are
stored in table TL_PERMITTED_VALUE.
The name that describes the reference datum
used in determining latitude and longitude
coordinates. Permitted values are stored in table
TL_PERMITTED_VALUE.
(continued)
B-6
-------
Appendix B - Data Dictionary
Field Name
LOCATION J3INARYJ)BJECT
LOCATION JDEJECTJILENAME
LOCATION OBJECT FILETYPE
LASTJJPDATED
TLJJSERJD
Type
Long
Binary
Text
Text
Date
Text
Size
0
255
6
8
8
Required
Yes
Yes
Description ]
The actual binary object representing the
absolute location.
Name of the attached binary object (file),
including file extension.
File type associated with the attached file.
System generated value that represents the
calendar date and time on which this information
was posted to the database or when a subsequent
modification was made.
The foreign key to TLJJSER implements: "This
table can be modified by many Users."
B.3.4 Table: T_STATION_VISIT
Description: This table represents a period of time spent at a station during which
measurements, observations, and/or sampling activities may take place.
(Field Name
T_STATION_VISIT_ID (PK)
T_STATIONJD
ARRIVAL DATE
ARRIVAL TIME
ARRIVAL_TIME_ZONE
DEPARTURE DATE
DEPARTURE TIME
DEPARTURE_TIME_ZONE
COMMENTJTEXT
LASTJJPDATE
TLJJSERJD
Type
Text
Text
Date
Date
Text
Date
Date
Text
Memo
Date
Text
Size
50
50
8
8
50
8
8
50
0
8
8
j
Required
Yes
Yes
Yes
Yes
Yes
Description
T Station ID&VisitID number
The foreign key to T_STATION implements:
"One Station may receive many Station Visits."
Date that the Station Visit commenced.
Time at which the Station Visit commenced.
Time zone in which the visit arrival time is
reported. Permitted values are stored in table
TL PERMITTED VALUE.
Date that the Station Visit is concluded.
Time at which the Station Visit ended.
Time zone in which the visit Departure time is
reported. Permitted values are stored in table
TL PERMITTED VALUE.
Free text attribute where field notes may be
recorded.
System generated value that represents the
calendar date and time on which this
information was posted to the database or when
a subsequent modification was made.
The foreign key to TLJJSER implements:
"This table can be modified by many Users."
B-7
-------
Appendix B - Data Dictionary
B.3.5 Table: T_SAMPLE
Description: Samples are quantities of material (e.g., water, sediment, biota) presumed to
be representative of the environment. May be collected in the field or created from other samples
for the purpose of analyses to identify constituents or pollutants.
j Field Name
T_SAMPLEJD(PK)
T_STATION_VISIT_ID
LAB_NAME
SAMPLING_LAB_COMMENT
SAMPLING_METHOD
SAMPLJNG_METHOD_COMMENT
SAMPLING_CONDITION
SAMPLE_COLLECTION_EQUIPMENT
SAMPLE_HOLDING_CONTAINER_MATERIAL
SAMPLE_HOLDING_CONTAINER_COLOR
MEDIUM_TYPE_NAME
type
Text
Text
Text
Text
Text
Text
Text
Text
Text
Text
Text
Size
60
50
60
150
60
150
30
40
35
15
20
Required
Yes
Yes
Description 1
T station ID&T STATION VI
SIT ID&T SAMPLE ID
The foreign key to
T_STATION_VISIT
implements: "Many Samples
may be taken during one Station
Visit."
The name of the laboratory
where the sample is analyzed.
Free text for any comments from
the lab on this Sample.
The sampling method used
when collecting this Sample.
Permitted values are stored in
table
TL_PERMITTED_VALUE.
Free text for adding comments
on the sampling method.
Weather condition when Sample
was taking. Permitted values are
stored in table
TL PERMITTED VALUE.
The equipment used in
collecting the sample. Permitted
values are stored in table
TL_PERMITTED_VALUE.
The material from which the
sample container is made.
Permitted values are stored in
table
TL PERMITTED VALUE.
The color of the sample
container. Permitted values are
stored in table
TL PERMITTED VALUE.
The name of the medium or
matrix where the activity
occurred during the Station
Visit. Examples: Air, Sediment,
Water. Permitted values are
stored in table
TL_PERMITTED_VALUE.
(continued)
B-8
-------
Appendix B - Data Dictionary
Field Name , ... ;,
MEDIUM_SUB_DIVISION
RELTV_DEPTH_NAME
DEPTH_REF_POINT
DEPTH_TO_ACTIVITY
TEMP_PRESERV_TYPE
SAMPLE_OBJECT
SAMPLE_OBJECT_
SAMPLE_OBJECT_
.FILENAME
.FILETYPE
LAST_UPDATE
TL_USER_ID
Type
Text
Text
Text
Double
Text
Long
Binary
Text
Text
Date
Text
Size
20
15
30
8
25
0
255
6
8
8
Required
Yes
Yes
Description ,
Name or code indicating the
environmental matrix as a
subdivision of the sample media.
Permitted values are stored in
table
TL_PERMITTED_VALUE.
The name that indicates the
approximate location within the
water column at which the
activity occurred. Permitted
values are stored in table
TL_PERMITTED_VALUE.
The text that describes the
reference point from which the
depth is measured, typically
"Surface." Permitted values are
stored in table
TL PERMITTED VALUE.
Distance in meters from the
reference point to the point in
the water column at which the
activity is conducted.
A default for the name of the
type of temperature based
physical preservation. Permitted
values are stored in table
TL_PERMITTED_VALUE.
The binary object with
information about the sample.
Name of the attached binary
object (file), including file
extension.
File type associated with the
attached file.
System generated value that
represents the calendar date and
time on which this information
was posted to the database or
when a subsequent modification
was made.
The foreign key to TLJJSER
implements: "This table can be
modified by many Users."
B-9
-------
Appendix B - Data Dictionary
B.3.6 Table: T_RESULT
Description: Information about an environmental characteristic determined as a result of
either field measurements, observations or analytical procedures performed on samples. This will
be the largest table in the database..
Field Name
T_RESULTJD(PK)
T_CHARACTERISTIC_ID
T_DATA_SOURCE_ID
T_SAMPLEJD
T_ANALYTICAL_METHOD_ID
VALUEJTEXT
VALUE_MEASURE
T_UNIT_MEASURE_ID
DESCRIPTIONJTEXT
DETECTION_CONDITION
DETECTION_QUANT_LEVEL_TYPE
WEIGHT_BASIS_TYPE
Type
Text
Long Integer
Long Integer
Text
Text
Text
Double
Long Integer
Memo
Text
Text
Text
Size
70
4
4
60
50
30
8
4
0
40
35
15
Required
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Description }
Source&ID number
The foreign key to
T_CHARACTERISTIC implements
"One Characteristic may be the thing
measured or reported for many Results."
The foreign key to T_DATA_SOURCE
implements "One Data Source may be
the source of many Results.
The foreign key to T_SAMPLE
implements "One Sample may produce
many Results.
The foreign key to
T_ANALYTICAL_METHOD
implements: "An Analytical Method may
have been used to obtain many Results."
The alpha-numeric representation of the
result of analyzing, measuring, or
observing a Characteristic.
The numeric representation of the result
of analyzing a Characteristic with an
analytical procedure.
The foreign key to T_UNIT_MEASURE
implements "One Unit of Measure may
be the unit of measure for many Results.
Long free text associated with a Result in
this database.
The textual descriptor of a result.
Permitted values are stored in table
TL_PERMITTED_VALUE.
Text describing the type of detection or
quantitation level used in the analysis of
a characteristic. Permitted values are
stored in table
TL_PERMITTED_VALUE.
The name that represents the form of the
sample or portion of the sample which is
associated with the result value (e.g., wet
weight, dry weight, ash-free dry weight).
(continued)
B-10
-------
Appendix B - Data Dictionary
Field Name
TEMPERATURE_BASIS_TYPE
PARTICLE_SIZE_BASIS_TYPE
DUR_BASIS_TYPE
SAMPLE_FRAC_TYPE
STATISTIC_TYPE
VALUE_TYPE_NAME
ANALYSIS_DATE
RESULT_OBJECT
RESULT_OBJECT_FILENAME
RESULT_OBJECT_FILETYPE
LAST_UPDATE
TL_USER_ID
type
Text
Text
Integer
Text
Text
Text
Date
Long Binary
Text
Text
Date
Text
Size
12
15
2
15
20
10
8
0
255
6
8
8
Required
-
Yes
Yes
Description J
The name that represents the controlled
temperature at which the sample was
maintained during analysis, e.g. 25 deg
BOD analysis.
User defined free text describing the
particle size class for which the
associated result is defined.
The period of time (in days) over which a
measurement was made. For example,
BOD can be measured as 5 day or 20 day
BOD.
The text name of the portion of the
sample associated with results obtained
from a physically partitioned sample.
Examples: dissolved, suspended, total.
Permitted values are stored in table
TL PERMITTED VALUE.
A statistic or calculation type which
described the reported result (e.g.
average, mode). Permitted values are
stored in table
TL_PERMITTED_VALUE.
A name that represents the process which
was used in the determination of the
result value (e.g., actual, estimated,
calculated). Permitted values are stored
in table TL PERMITTED VALUE.
The date on which laboratory analysis of
the sample for this particular result was
performed.
The binary object with information about
the methodology used to extract data
from this source.
Name of the attached binary object (file),
including file extension.
File type associated with the attached
file.
System generated value that represents
the calendar date and time on which this
information was posted to the database or
when a subsequent modification was
made.
The foreign key to TL_USER
implements: "This table can be modified
by many Users."
B-ll
-------
Appendix B - Data Dictionary
B.3.7 Table: T_ANALYTICAL_METHOD
Description: Allows for the optional association of an analytical method employed either
in the lab or in the field with any result.
Field Name , ' ,- ;
T_ANALYTICAL_METHOD_ID (PK)
ANALYTICAL_METHOD_ORGANIZATION
ANALYTICAL_METHOD_NAME
ANALYT1CAL_METHOD_OBJECT
ANALYTICAL_METHODJDBJECT_FILENAME
ANALYTICAL_METHOD_OBJECT_FILETYPE
Type
Text
Text
Text
Long
Binary
Text
Text
Size
50
120
150
0
255
6
Required
Yes
Description .
ID Code, unique within Context,
which identifies the formally
documented method used to
obtain the result. Methods may
have been used either in the Field
or in the Lab. These are methods
or procedures which yield results.
Name of the organization which
published the method used to
obtain the result. Methods may
have been used either in the Field
or in the Lab.
Free text name of the method
used to obtain the result. Methods
may have been used either in the
Field or in the Lab.
The binary object with
information about the analytical
method used to obtain the result.
Name of the attached binary
object (file), including file
extension.
File type associated with the
attached file.
B.3.8 Table: T_DATA_SOURCE
Description: This table holds information about the source (non-primary sources) where
data come from. Sources could be existing databases such as STORET, the (U.S.) National
Water Information System (NWIS), or the (Mexico) Comision Nacional del Agua (CNA) data
repositories.
Field Name
DATA_SOURCE_ID (PK)
SOURCE_NAME
T*PC
Long
Integer
Text
Size
4
50
Required
Description j
A system-generated value used to
uniquely identify an ocurrence of
this table.
The name and type of the source for
data. Example: STORET, NWIS,
etc. Source types are: database,
organization, etc. Permitted values
are stored in table
TL PERMITTED VALUE.
(continued)
B-12
-------
Appendix B - Data Dictionary
JFieldNamc
EXTRACT_DATE
EXTRACTJJSERJD
LAST_UPDATED
TL_USER_1D
EXTRACT_METHODOLOGY
EXTRACT_METHOD_OBJECT_FILENAME
EXTRACT_METHOD_OBJECT_FILETYPE
Type
Date
Text
Date
Text
Long
Binary
Text
Text
Size
8
8
8
8
0
255
6
Required
Description '
Date when data was extracted from
secondary source.
A code that identifies the specific
person extracting the data. A foreign
key to TLJJSER implements:
"Data from an existing source can
be extracted by many Users"
System generated value that
represents the calendar date and
time on which this information was
posted to the database or when a
subsequent modification was made.
A foreign key to TLJJSER
implements: "This table can be
modified by many Users." The
person who extracts the data from
an existing database does not
necessarily enter the data in this
database.
The binary object with information
about the methodology used to
extract data from this source. It
could be stored in text or PDF
format.
Name of the attached binary object
(file), including file extension. .
File type associated with the
attached file.
B.3.9 Table: TL_CHARACTERISTIC
Description: A lookup table imported from STORET. Characteristic is the name of the
"thing" being investigated. For example, in an analysis for phosphorus, the name of the
characteristic is phosphorus.
Field Name
T_CHARACTERISTIC_ID (PK)
TL_GEN_CHAR_ID
ORIGINAL_CHARJD
ORIGINAL_SOURCE
type
Long
Integer
Long
Integer
Text
Text
Size
4
4
20
20
Required ;
Yes
Yes
Yes
Yes
f Description
A system-generated value used to uniquely
identify an ocurrence of this table.
The foreign key to
TL_GENERIC_CHARACTERISTIC
implements: "One Generic Characteristic may
group together many Characteristics."
Original characteristic ID from the originating
database.
Original database name where characteristic
name is taken from.
(continued)
B-13
-------
Appendix B - Data Dictionary
Field Name :
UNITJTYPE
SEARCHJSTAME
DISPLAY_NAME
D_SCR_TYPE_CD
PROC_REQ_IND_CD
VALID_FOR_QC_IND
SAMP_FRAC_REQ_CD
' Type;-. :
Text
Text
Text
Text
Text
Text
Text
Size
5
110
110
4
1
1
1
Required
Yes
Yes
Yes
Description j
The category that represents the braod class of
a related set of units. Examples: Volume,
Concentration, Mass, Area, Velocity, Flow.
The standardized form of the name as
determined by EPA.for use in searching the list
of environmental characteristics. AH caps for
consistent search reports.
The name of the environmental characteristic
as it is to be displayed on windows and reports.
The code that represents the type of data to be
displayed. See STORET data dictionary for
Domain/Permitted Values.
A code indicating whether an analytical
procedure is required for a result for this
Characteristic.
A code indicating whether this Characteristic is
a valid report for QC samples.
A code indicating whether a sample fraction is
required for this Characteristic. This will be
used primarily for Chemical Characteristics.
B.3.10 Table: TL_GENERIC_CHARACTERISTIC
Description: A lookup table with the generic characteristics to group the characteristics
inTL characteristics.
{Field Name '.,.;
TL_GEN_CHAR_ID (PK)
GEN_CHAR_NAME
GEN CHAR DESC
Type
Long
Integer
Text
Text
Size
4
50
70
Required
Yes
Yes
Yes
Description
Automatic generated identification code for each
Generic Characteristic.
Name of the generic characteristic grouping more
than one Characteristic of similar nature.
Description of the Generic Characteristic
B.3.11 Table: TL_BINATIONAL_REGION
Description: The 8 transboundary watersheds as defined by the Department of the
Interior's U.S.-Mexico Field Coordinating Committee in 1996. Surface-water drainage basins
were used as the-primary basis for defining and delineating the extent of the border area.
Field Name
TL_B1NATIONALJ*EGION_1D (PK)
BINATIONAL.
BINATIONAL
.REGIONJSJAME
REGION DESC
Type
Long
Integer
Text
Text
Size
4
70
100
Required
Yes
Yes
Yes
Description \
Identification code for the binational
subareas
Binational subareas that have similar
hydrologic and physiographic features and
defined by the United States Department of
the Interior U.S.-Mexico Border Field
Coordinating Committee.
Description of the binational subarea
B-14
-------
Appendix B - Data Dictionary
B.3.12 Table: TL_COUNTRY
Description: A lookup table with list of country names and the ISO 3166-l-alpha-2 code
elements.
\ Field Name
TL_COUNTRY_ID (PK)
COUNTRY NAME
Type
Text
Text
Size
2
50
Required
Yes
Yes
Description . ; . 1
ISO 3166-l-alpha-2 code elements given in ISO 3166-1.
Country name in English
B.3.13 Table: TL_LEVEL_II_ECOREGION
Description: The 52 level II ecological regions provide a more detailed description of the
large ecological areas nested within the level I regions. These are useful for national and
subcontinental overviews of physiography, wildlife, and land use.
Field Name
TL_LEVEL_II_ECOREGION_ID (PK)
ECOREGION_NAME_ENG
ECOREGION_NAME_SP
Type
Text
Text
Text
Size
4
60
60
Required;
Yes
Yes
Yes
, Description
The North American Commission for
Environmental Cooperation classification code
of ecological regions.
Ecological region in English
Ecological region in Spanish
B.3.14 Table: TL_MEX_BASIN
Description: A lookup table with information on the Mexican Hydrologic Units.
Field Name
TL_MEX_BASINJD (PK)
BASIN_NAME
Type
Integer
Text
Size
2
50
Required
Yes
Yes
r Description ;
Unique identifier for a Mexican HydroJogic Unit
Text for basin name.
B.3.15 Table: TL_PERMITTED_VALUE
Description: A lookup table with permitted values for specific fields in some tables of
this database. The TABLE_NAME and COLUMN_NAME fields of this table are used to cross
reference the field to which given permitted values will apply.
i Field Name
TL_PERMITTED_VALUEJD (PK)
TABLE_NAME
COLUMN_NAME
SEQUENCE_NUMBER
PERMITTED_VALUE
VALUE_DESC
Type
Long
Integer
Text
Text
Integer
Text
Text
Size
4
30
30
2
255
255
Required
Yes
Yes
Yes
Yes
Yes
' Description
A system-generated value used to uniquely
identify an occurrence of this table.
Table name where permitted value is required.
Column name where permitted value is
required.
A sequence number used for ordering the
display of a list of permitted values for a
specific table and field as referenced.
The text that describes the permitted value to be
entered in a given table for a given field on this
database.
Text description or definition for the term held
in the PERMITTED VALUE column.
B-15
-------
Appendix B - Data Dictionary
B.3.16 Table: TL STATE
Description: A lookup table that stores information about states in the United States and
Mexico.
j Field Name
TL_STATE_ID (PK)
TL_STATE_NAME
TLjCOUNTRYJD
US_REGION
USJSTATE_FIPS_CODE
Type
Text
Text
Text
Text
Text
Size
8
30
2
2
2
Required
Yes
Yes
Yes
Description , |
State abbreviation (two-letter abbreviation in the US)
US state name
The foreign key to TL_COUNTRY implements "One
Country has many States."
US Region where US state is located.
Federal Information Processing Standards (FIPS) Code
in the US for a state.
B.3.17 Table: TLJTRIBAL _GROUP
Description: A lookup table with tribal group codes that represent the American Indian
tribe or Alaskan Native entity.
Field Name
TL_TR1BAL_GROUPJD (PK)
TRIBAL_GROUP_NAME
Type
Text
Text
Size
3
255
Required
Yes
Yes
Description I
Unique code to represent the American Indian
tribe or the Alaskan native entity.
Text description for the tribal group.
B.3.18 Table: TL_UNIT_MEASURE
Description: A lookup table imported from STORET. This table defines the domain of
valid values for units of measure.
[Field Name
TL_UNIT_MEASURE_ID (PK)
UNITJTYPE
SHORT_NAME
DESCR1PTIONJTEXT
TyPe
Long
Integer
Text
Text
Text
Size
4
iO
50
50
Required
Yes
Yes
Yes
Description j
A system-generated value used to uniquely
identify an occurrence of this table.
The category that represents the broad class of a
related set of units. Examples: Volume,
Concentration, Mass, Area, Velocity, Flow.
The abbreviation for the name of the unit of
measure.
The full name of the unit of measure.
B-16
-------
Appendix B Data Dictionary
B.3.19 Table: TL_US_COUNTY
Description: A lookup table with U.S. county information.
Field Name
TL_USCOUNTY_ID (PK)
TL_STATE_ID
F1PS_COUNTY_CODE
COUNTYJMAME
Type
Long
Integer
Text
Text
Text
Size
4
8
3
70
Required
Yes
Yes
Yes
Yes
Description
A system-generated value used to uniquely identify an
occurrence of this table.
The foreign key to TL_STATE implements "One State
in the United States has many Counties."
Federal Information Processing Standards (PIPS) Code
in the US for this county.
County name
B.3.20 Table: TL_USER
Description: A lookup table with user information. Users are allowed to view, enter,
and/or modify data depending on the privileges given on this table.
j Field Name
TL_USER_ID (PK)
USER_NAME
VIEW_DATA
ENTER_DATA
UPADTE_DATA
Type
Text
Text
Boolean
Boolean
Boolean
Size
8
40
1
1
1
Required
Yes
Yes
Yes
Yes
Yes
Description J
Unique text identifier for a user of this database
Full name of user of this database
User can view data
User can insert new data
User can update existing data
B.3.21 Table: TL_USGS_CU
Description: A lookup table with USGS 8-digit HUCs identifying the hydrologic units in
the United States. The United States is divided and subdivided into successively smaller
hydrologic units: regions, subregions, accounting units, and cataloging units.
Field Name
TL_USGS_CU_ID (PK)
DESCRIPTION
AREA
STATES
Type
Text
Text
Double
Text
Size
8
255
8
255
Required
Yes
Yes
Description
First 2 digits: regional area defined by the U.S. WRC;
second 2 digits are subregions defined by IHRC; third 2
digits are NWDN Accounting Units and last 2 digits are
cataloging units maintained by OWDC.
Text description for this cataloging unit.
Area in sq. miles for this cataloging unit.
States in the US where cataloging unit is located.
B-17
-------
Appendix B Data Dictionary
B.3.22 Table: TL_METADATA_TABLE
Description: A lookup table to include all tables that are part of this database and their
descriptions. This lookup table will support future graphical user interfaces for this database.
Field Name
TABLE_NAME (PK)
TABLE_DESCR1PTION
IS_LOOKUP
IS_CROSSWALK
IS_PARENT
HAS_PARENT
PARENT_NAME
Type
Text
Memo
Boolean
Boolean
Boolean
Boolean
Text
Size
50
0
1
I
1
1
50
Required:
Yes
Yes
Description j
Unique table name of table in this database
Text describing table functionality in this
database
Whether or not this table is a lookup table
Whether or not this table is a cross-walk
table
Whether or not this table is a parent table
Whether or not this table has a parent table
Parent table name if this table has a parent
table
B.3.23 Table: TL_METADATA _COLUMN
Description: A lookup table to include all columns from all tables that are part of this
database and their descriptions. This lookup table will support future graphical user interfaces for
this database.
i Field Name
TABLE_NAME (PK)
COLUMN_NAME
COLUMN_DESCR1PTION
IS_PRIMARY_KEY
IS_UNIQUE_KEY
DISPLAY_ORDER
Type
Text
Text
Memo
Boolean
Boolean
Integer
.Size
50
100
0
1
1
2
Required
Yes
Yes
Yes
Description \
Unique table name of table in this database
Column name of column within table in this
database
Text describing column functionality within
table in this database
Whether or not this column is part of the
primary key of table
Whether or not this column is part of a
unique key in table
Order in which column is located within
column
B-18
-------
Appendix B - Data Dictionary
B.4 Repository Structure
Figure B-2 shows a more detailed diagram of the U.S.-Mexico Border Waters Repository
structure. This is an Entity Relational Diagram that includes only the most important tables.
TjsnTK»LVEnjD
T_sfAtic*ijD ,*. "'-;'':
ARRIVALjiATi? ;.:' -.'
5AWLDK METWO.COMMNI
SAWUNG COtClTKIN
.
COWACTlADORESS' TWt~ '
ACTiAOORESS . " ".
' ~
CONfACTiSCAUnJIAME-i ";«
.
STATION OeXa FUENAME
STATJONiOBICT
LASTiUPOATE
UDNGJXMCTMN
USNSJJKjliesJ .
SOJRGBW JC»t£ JUMOR
,
HOKCTI jeaificr «JHO
'
EXTRACT JJATE'
Eaufcrusfn
LASTlUPOATib. '
HJJBEIUD:
l^lf ANALY5B.DATI '.'
H,Sf|| RESufosia^.'
RESULTiOBKCLfllfltMC
..
EXTSACT.JCTHbD -OBiEcf Fll£f**e'*
Figure B-2. U.S.-Mexico Border Waters Repository entity relationship diagram.
B.5 References
U.S. EPA (Environmental Protection Agency). 2003. STORETv2.0 Business Rules. Office of
Wetlands, Oceans and Watersheds.
U.S. EPA (Environmental Protection Agency). 2004. Environmental Data Registry: Data
Standards (EPA online information. Web site: http://oaspub.epa.gov/edr/epastdS.startup.
Accessed October 25, 2005.
U.S. EPA (Environmental Protection Agency). 2005. STORETSystem Updates: Factsheets
(EPA online information). Web site: http://www.epa.gov/storet/updates.htmPfactsheets.
Accessed October 25, 2005.
B-19
-------
Appendix B-Data Dictionary
[This page intentionally left blank.]
B-20
-------
Appendix C ~ Water Quality Indicators
Appendix C
Water Quality Indicators Included in the U.S.-Mexico
Border Waters Repository
This Appendix includes a list of all "generic water quality indicators" included in a
lookup table within the U.S.-Mexico Border Waters Repository. Each one of these generic water
quality indicators points to a group of water quality indicators found in the original data sources.
For some of these generic indicators, this Appendix includes tables with the corresponding
original indicators as found in the data sources.
C.I Data Collection Process
/
RTI included surface water data on the parameters of interest in the Repository if they
met the following criteria:
Collected in 1992 or later
" Collected from stations located within 100 km of the U.S.-Mexico border
/
Included latitude and longitude coordinates.
This section explains the methods used to download data from the most important online
data sources. All data were subject to the QA/QC procedures described in Section 3.1.5.
C.I.I STORET Modernized
STORET is the U.S. Environmental Protection Agency's (EPA's) largest computerized
environmental data system. It is a repository for water quality, biological, and physical data
collected by federal, state, and local agencies; Native American tribes; volunteer groups;
academics; and others. STORET contains data collected beginning in 1999, along with older data
that have been properly documented and migrated from the STORET Legacy Data Center. For
the area near the U.S.-Mexico border, STORET contains no data from Texas, very little data
from New Mexico and California, and a significant amount of data from Arizona.
RTI performed the following steps to download Modernized STORET data:
1. Opened "http://www.epa.gov/STORET/dw_home.html."
2. Under "STORET Regular Results," clicked on "Regular Results by Geographic
Location."
3. For California and New Mexico, downloaded data for each state. For Arizona,
conducted separate downloads for each county along the border because the data sets
were large.
C-l
-------
Appendix C - Water Quality Indicators
4. Downloaded data from 1992 to 2004 for the selected parameters.
5. Imported the data sets for California and New Mexico into a processing database and
filtered them to select only stations that were located in counties along the border.
6. Further refined the stations list by using Arc View to map all the stations that were in
counties of interest and that had data for the parameters of concern during the years of
concern. Dropped from the data set any station that was not within the 100 km buffer.
C.1.2 Legacy STORET
The STORET Legacy Data Center is the world's largest repository of ambient water
quality data. The database holds more than 200 million water sample observations from about
700,000 sampling sites for both surface water and groundwater. However, the data in Legacy
STORET are of undocumented quality. Further, the data in this system are static and only
include data from 1999 and earlier. All newer data are stored in STORET Modernized.
To collect data from Legacy STORET, RTI performed the following steps:
1. Opened "http://www.epa.gov/storpubl/legacy/gateway.htm."
2. At the bottom of this Web page, clicked on "Download" by STATE, ALL STORET
Legacy DATA for each state, via a compressed self-extracting tab-delimited flat file.
This option directed RTI to U.S. EPA's FTP (file transfer protocol) site, where there
were executable files available for download for all 50 U.S. states.
3. Downloaded executable files for Texas, California, New Mexico, and Arizona.
4. Unzipped executable files to RTI's server. Organized text files by county, with
separate files in each county for station information and water quality data.
5. Imported text files for the counties along the border into a processing database.
6. After all the separate text files were appended into a single stations table, filtered out
stations that did not contain data for the period of concern (1992 to present).
7. Checked the remaining stations to determine whether they contained data for a
number of parameters.
8. Further refined the stations list by using ArcView to map all stations that were in
counties of interest and that had data for the parameters of concern during the years of
concern. Dropped from the data set any station that was not within the 100 km buffer.
C.1.3 National Water Information System (NWIS)
The United States Geological Survey (USGS) has collected water resources data at
approximately 1.5 million sites in the United States, Puerto Rico, and Guam. Water quality data
are available for both surface water and groundwater. Flow data are also available but were not
C-2
-------
Appendix C - Water Quality Indicators
downloaded at this time. NWIS-Web makes available current and historical data. Other programs
within USGS, such as the National Water Quality Assessment Program (NAWQA) and the
National Stream Quality Accounting Network (NASQAN), make their data available through
NWIS-Web. Users can retrieve data by categorysuch as surface water, groundwater, or water
qualityand by geographic area. On subsequent pages, users can further refine their searches by
selecting specific information and defining the output desired.
RTI's procedure for acquiring NWIS data was as follows:
9. Opened the NWIS Web site "http://waterdata.usgs.gov/nwis."
10. Clicked on "Water Quality," and then clicked on "Samples."
11. For the site-selection criteria, checked the "Latitude-Longitude" box.
12. Used the following coordinates to create a latitude-longitude box for the area of
interest: North latitude = 33.8; East longitude = -96.0; South latitude = 24.7; West
longitude = -118.3.
13. Entered the years of interest, 1992 to 2004.
14. Because the data set created was too large to download, downloaded smaller data sets
separately by adding the border state into the query criteria.
15. Imported downloadable tab-delimited text files created by NWIS-Web into a .
processing database.
16. Removed stations that are not in the U.S. counties that fall within the 100 km buffer.
17. Included stations that had data for selected parameters.
18. Further refined the stations list by using ArcView to map the all the stations that were
in counties of interest and that had data for the parameters of concern during the years
of concern. Dropped from the data set any station that was not within the 100 km
buffer.
C.1.4 Texas Commission on Environmental Quality
The Texas Council on Environmental Quality (TCEQ) contracts out its monitoring
requirements from the Clean Water Act to various smaller organizations, such as the
International Boundary and Water Commission (IBWC). As part of these contract requirements,
IBWC must make its data available to the public, and it does so by posting Excel files on the
Clean Rivers Program Web site. The IBWC also must submit its data to TCEQ, which must
make the data publicly available on its Web site. Therefore, the TCEQ and IBWC Clean Rivers
Program should have overlapping data, with the TCEQ Web site containing more data, because it
includes organizations other than the IBWC, such as USGS. Therefore, a download of TCEQ
data retrieves all the data for the IBWC Clean Rivers Program in addition to the TCEQ data.
C-3
-------
Appendix C - Water Quality Indicators
The IBWC-originated results are differentiated by having "1BWC" in the
T_SAMPLE.LAB_NAME field in this database.
RTI downloaded TCEQ data for the following Level III ecoregions of Texas: regions 21,
22, 23, 24, and 25, which border Mexico.
C.I.5 Southwest Consortium for Environmental Research and Policy
(SCERP) Data
SCERP provided two data sets in Microsoft Excel format, one for the New River and one
for wastewater. We imported these files directly into Microsoft Access.
C.I.6 Com is ion Nacional del Agua (CNA) Data
CNA provided its data to us in Microsoft Excel format. We imported the data directly
into Microsoft Access.
C.I.7 Comision Internacional de Limites y Aguas (CILA) Data
CILA provided some of its data to us in Microsoft Excel format. We imported those data
into Microsoft Access using a tab-delimited format. We also downloaded additional data from
CILA's Web site. RTI's procedure for acquiring CILA data from the Web site was as follows:
1. Opened the CILA Web site "http://cila.sre.gob.mx."
2. Clicked on "Calidad del Agua" [Water Quality]
3. Clicked on "Estudio Binacional sobre el Monitoreo Intensive de la Calidad de las
Aguas del Rio Bravo en el Tramo de Nuevo Laredo, Tamaulipas-Laredo Texas, entre
Mexicoico Estados Unidos del 6 al 16 de noviembre de 2000 (Informe Complete)"
(the first link). [Binational Study on the Intensive Monitoring of the Water Quality of
the Rio Grande in Laredo, Tamaulipas/Laredo Texas between Mexico and the United
States, November 6-16,2000 (Complete Report)] This Nuevo Laredo/Laredo area
report was the only report containing data that met all the criteria noted above.
4. Saved the PDF (Adobe portable document format) file for the above report.
5. Scanned tables containing analysis results from U.S. laboratories (Tables 9, 11, 13,
15, and 17). All data in these tables met the date, location, and location coordinates
criteria, so no data were filtered out.
6. Processed the scanned data using OCR (optical character reader) software and
performed a 100 percent QC check of the resulting file against the hardcopy,
correcting any OCR errors.
7. Added station location coordinates from Table 3 of the downloaded PDF file.
C-4
-------
Appendix C - Water Quality Indicators
C.2 Generic Water Quality Indicators
The original sources of water quality data vary both in the methods used and the means
by which they name the analyses in the data. Data were stored in the same format as the original
data source, preserving the water quality indicator name and units, as well as the original water
quality indicator ID. We created lookup tables in the database to link the source-specific
indicator names to a standardized name (e.g., chlorophyll a) so that we could analyze data for a
particular indicator regardless of the different source-specific names. These lookup tables can be
easily modified to add new source-specific names as needed.
Table C-l lists the 23 generic indicator designations associated with the 12 parameters
we collected for the Repository. The 12 parameters are shown in bold. Where more than one
generic indicator was associated with a parameter, those are listed indented under the bolded
parameter name. If only one generic indicator was associated with the parameter, it had the same
name as the parameter and only the bolded parameter is listed.
Most of the 23 generic indicators had multiple designations in the source data. Table C-l
also identifies the indicators with multiple designations and provides a cross reference to the
more detailed table (Tables C-2 through C-22) listing the multiple designations. For each
indicator with multiple designations, Tables C-2 to C-22 (one table per indicator) describe how
the variable was assigned in the border waters database in terms of its description and units.
C.3 References
Nelson, R. 2004. "Texas monitoring data." Personal communication from Ryan Nelson,
International Boundary and Water Commission (IBWC), to Eric Solano, RTI. October
27.
C-5
-------
Appendix C Water Quality Indicators
Table C-l. Generic Indicators by Parameter
Parameter
Generic Indicator Name
Fecal coliform
Fecal coliform
Fecal streptococci
Chlorophyll a
Sulfate
Conductivity/TDS
TDS
Conductivity
Chloride
DO
COD
Nutrients
Inorganic Nitrogen
Phosphorus
Organic Nitrogen
Nitrogen
Nitrite
Orthophosphate
Nitrate
Ammonia
Nitrite+Nitrate
BOD
pH
Temperature
Total suspended solids
TSS
Total Solids
Detail Table for Indicators with
Multiple Designations
Table C-2
Table C-3
Table C-4
Table C-5
Table C-6
Table C-7
Table C-8
Table C-9
Did not have multiple designations
Table C- 10
Table C- 11
Table C-l 2
Table C- 13 .
Table C- 14
Table C- 1 5
Table C-l 6
Table C-l 7
Table C-l 8
Table C-l 9
Table C-20
Table C-2 1
Did not have multiple designations
Table C-22
C-6
-------
Appendix C- Water Quality Indicators
Table C-2. Water Quality Indicators in Repository Related to "Fecal Coliform"
Water Quality
Indicator ID
1042
1090
1090
1090
1091
1091
1091
1091
1091
1164
1165
1166
1167
1170
1181
1274
1277
1283
1285
1288
1291
1363
1434
1440
1457
1457
1475
Indicator Display Name
Fecal coliform, M-FC MF (0.7 micron)
method, water
Escherichia coli
Escherichia coli
Escherichia coli
Fecal Coliform
Fecal Coliform
Fecal Coliform
Fecal Coliform
Fecal Coliform
E. COLI, GEOMETRIC MEAN
(#/100ML)
FECAL COLIFORM GEOMETRIC
MEAN (COLONIES/ 100ML)
FECAL COLIFORM,MEMBR
FILTER,M-FC BROTH, #/100ML
E. COLI, MTEC, MF, #/100 ML
E. COLI, COLILERT, IDEXX METHOD,
MPN/100ML
FECAL COLIFORM MPN/100ML 5/2,3
OIL FERMENT METHO
COLIFORM,TOT,MEMBRANE
[FILTERJMMED.M-ENDO MED.35C
COLIFORM,TOT,MPN,CONFIRMED
TEST,35C(TUBE31506)
FECAL COLIFORM,MEMBR
FILTER,M-FC AGAR,44.5C,24HR
FECAL COLIFORM,MPN,EC
MED,44.5C(TUBE31614)
FECAL COLIFORM,MPN,BORIC ACID
LACTOSE BR,43C,48HR
FECAL COLIFORM, MF.M-FC, 0.7 UM
FECAL COLIFORM, GENERAL
(PERMIT)
Fecal Coliform (CPU/100 ml)
Fecals
COLIFORM, TOTAL
COLIFORM, TOTAL
Coliform F
Original Source
NWIS
STORET
STORET
STORET
STORET
STORET
STORET
STORET
STORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
SCERP-New River
SCERP-Wastewater
CNA
CNA
CILA
Units
cfu/lOOml
ctVlOOml
MPN/lOOml
none
#/100ml
cfu/lOOml
cpu/lOOml
MPN/lOOml
none
#/100ml
#/ 100ml
#/100ml
#/100ml
MPN/lOOml
MPN/lOOml
m-Endo agar
LES/100 Ml
MPN/lOOml
m-FCagar/lOOml
MPN
MPN
m-FCagar/lOOml
none
cpu/ 100ml
Fecals
cpu/lOOml
MPN/lOOml
cfu/lOOml
C-7
-------
Appendix C - Water Quality Indicators
Table C-3. Water Quality Indicators in Repository Related to "Fecal Streptococci'
Water Quality,;
Indicator ID
1043
1169
1459
i -"^^.:;i:- !.": :I^:,^--;':'-i. .71-; :.:;,:
' ../;r;./;;;ind^toit!DispIay.N8iines,;. ; i_,. , >.'.;'
Fecal streptococci,
method, water
KF streptococcus MF
FECAL STREPTOCOCCI, MBR FILT,KF
AGAR,35C,48HR
Fecal streptococci
Original Source
NWIS
.LegSTORET
CNA
. . '.Units ':,;,!
cfu/lOOml
#/100ml
MPN/lOOml
Table C-4. Water Quality Parameters in U.S.-Mexico Waters Repository
Related to "Chlorophyll a"
Water Quality
Indicator ID
227
227
1044
1172
1179
1296
1297
1303
1309
1473
Indicator Display Name
Chlorophyll a, unconnected for pheophytin
Chlorophyll a, uncorrected for pheophytin
Chlorophyll a, periphyton, chromatographic-
fluorometric method
Chlorophyll a ug/1 spectrophotometric acid, method
Chlorophyll a, phytoplankton ug/1, chromo-flouro
Chlorophyll a ug/1 fluorometric corrected
Chlorophyll a ug/1 trichromatic uncorrected
Chlorophyll a,% of(pheophytin a+chl a),spec-acid.
Chlorophyll a (mg/1)
Chlorophyll a
Original Source
STORET
STORET
NWIS
Legacy STORET
Legacy STORET
Legacy STORET
Legacy STORET
Legacy STORET
Legacy STORET
CILA
Units
none
ug/1'
mg/m2
ug/1
ug/1
ug/i
ug/1
%
mg/1
ug/1
* Micrograms per liter.
Table C-5. Water Quality Indicators in Repository Related to "Sulfate"
I Water Quality
j Indicator ID
1047
1161
1186
1207
1265
1429
1444
1471
Indicator Display Name . ,,
Sulfate, water, filtered
SULFATE (MG/L AS SO4)
SULFATE, SO4, SED, DRY WT, WTR
EXTRACT, (MG/KG)
SULFATE'(AS S) WHOLE WATER, MG/L
SULFATE, DISSOLVED (MG/L AS SO4)
Sulfate (S04)
sulfate
Dissolved Sulfate
-;. Original Source
NWIS
LegSTORET
LegSTORET
LegSTORET
LegSTORET
SCERP-New River
SCERP-Wastewater
CNA
Units
mg/1
mg/1
mg/kg
mg/1
mg/1
mg/1
mg/1
mg/1
C-8
-------
Appendix C - Water Quality Indicators
Table C-6. Water Qualify Indicators in Repository Related to "TDS"
; Water Quality
Indicator ID ".'
... /
553
1176
1177
1431
1445
'"'j.S ->^, : ^ ' - \, .' 4 ,A(, ii vj. . .,'_,"
"5- X' . r- Indicator Display Name (>'- ;'."'!.
Dissolved Solids
SOLIDS,TOTAL, DISS, ELECTRICAL-
CONDUCTIVITY,MG/L
SOLIDS, D1SSOLVED-SUM OF
CONSTITUENTS (MG/L)
Total Filter Residue (TDS)
TDS
' ''Original Source
STORET
LegSTORET
LegSTORET
SCERP-New River
SCERP-Wastewater
Units
mg/1
mg/1
mg/1
mg/1
mg/1
Table C-7. Water Quality Indicators in Repository Related to "Conductivity"
Water Quality
Indicator ID
266
266
266
1072
1081
1110
1111
1115
1116
1117
1417
; .Indicator Display Name ~ '-
Specific conductance
Specific conductance
Specific conductance
Specific conductance, water, unfiltered
Specific conductance, water, unfiltered,
laboratory
SPECIFIC CONDUCT ANCE,F1ELD
(UMHOS/CM @ 25C)
SPECIFIC CONDUCTANCE (UMHOS/CM @
25C)
SPECIFIC CONDUCTANCE, UMHOS/CM,
FIELD, 24HRAVG
SPECIFIC CONDUCTANCE, UMHOS/CM,
FIELD, 24HR MAX
SPECIFIC CONDUCTANCE, UMHOS/CM,
FIELD, 24HR MIN
Conductivity (uohms/cm)
OriginalSource
STORET
STORET
STORET
NWIS
NWIS
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
SCERP-New River
Units
none
umho/cm
uS/cm
uS/cm
uS/cm
umho/cm
umho/cm
umho/cm
umho/cm
umho/cm
umho/cm
C-9
-------
Appendix C Water Quality Indicators
Table C-8. Water Quality Indicators in Repository Related to "Chloride"
Water Quality
Indicator ID
1046
1087
1087
1159
1264
1425
1437
Indicator Display Name
Chloride, water, filtered
Chloride
Chloride
CHLORIDE (MG/L AS CL)
CHLORIDE, DISSOLVED IN WATER MG/L
Chloride (Cl)
Cl
Original Source
NWIS
STORET
STORE!
LegSTORET
LegSTORET
SCERP-New River
SCERP-Wastewater
Units
mg/1
mg/1
none
mg/1
mg/1
mg/1
mg/1
Table C-9. Water Quality Indicators in Repository Related to "DO"
Water Quality
Indicator ID
502
502
1073
1074
1089
1089
1089
1127
1128
1189
1190
1191
1211
1418
Indicator Display Name
Oxygen, (O2)
Oxygen, (O2)
Dissolved oxygen, water, unfiltered
Dissolved oxygen, water, unfiltered
Dissolved oxygen (DO)
Dissolved oxygen (DO)
Dissolved oxygen (DO)
OXYGEN, DISSOLVED (MG/L)
OXYGEN, DISSOLVED (PERCENT OF
SATURATION)
DISSOLVED OXYGEN, 24-HOUR MIN.
(MG/L) MIN. 4 MEA
DISSOLVED OXYGEN, 24-HOUR MAX.
(MG/L) MIN. 4 MEA
DISSOLVED OXYGEN, 24-HOUR AVG.
(MG/L) MIN. 4 MEA
OXYGEN DISSOLVED, ANALYSIS BY
PROBE MG/L
Dissolved Oxygen (mg/1)
Original Source
STORET
STORET
NWIS
NWIS
L STORET
STORET
STORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
SCERP-New River
Units '
mg/1
none
mg/1
%
%
mg/1
none
mg/1
%
mg/1
mg/1
mg/1
mg/1
mg/1
C-10
-------
Appendix C- Water Quality Indicators
Table C-10. Water Quality Indicators in Repository Related to "Inorganic Nitrogen"
Water Quality
Indicator ID
. 1249
Indicator Display Name
NITROGEN, INORGANIC, TOTAL (MG/L
ASN)
Original Source
LegSTORET
Units
mg/1
Table C-ll. Water Quality Indicators in Repository Related to "Phosphorus"
Water Quality
Indicator ID
1063
1064
1101
1101
1101
1102
1102
1154
1155
1252
1443
1477
Indicator Display Name
Phosphorus, water, unfiltered
Phosphorus, water, filtered
Phosphorus
Phosphorus
Phosphorus
Phosphorus as P
Phosphorus as P
PHOSPHORUS, TOTAL, WET METHOD
(MG/L AS P)
PHOSPHORUS, DISSOLVED (MG/L AS P)
PHOSPHOROUS DISSOLVED TOTAL
WHATMAN GF/F MG/L P
P
Total Phosphorus
Original Source
NWIS
NW1S
STORET
STORET
STORET
STORET
STORET
LegSTORET
LegSTORET
LegSTORET
SCERP-
Wastewater
CILA-south/north .
Units
mg/1
mg/1
mg/kg
mg/1
none
mg/1
none
mg/1
mg/I
mg/1
mg/1
mg/1
Table C-12. Water Quality Indicators in Repository Related to "Organic Nitrogen"
'Water Quality
Indicator ID
1239
1241
1462
Indicator Display Name
NITROGEN, ORGANIC, TOTAL (MG/L AS N)
NITROGEN, ORGANIC, DISSOLVED (MG/L AS
N) .
NITROGEN, ORGANIC
Original Source
LegSTORET
LegSTORET
CNA
Units
mg/1
mg/1
mg/1
C-ll
-------
Appendix C - Water Quality Indicators
Table C-13. Water Quality Indicators in Repository Related to "Nitrogen"
Water Quality
Indicator ID
554
1058
1059
1094
1094
1094
1147
1148
1235
1432
1447
Indicator Display Name
Nitrogen ion (N)
Ammonia plus organic nitrogen, water, filtered
Ammonia plus organic nitrogen, water, unfiltered
Nitrogen, Kjeldahl
Nitrogen, Kjeldahl
Nitrogen, Kjeldahl
NITROGEN, KJELDAHL, DISSOLVED (MG/L AS
N)
NITROGEN, KJELDAHL, TOTAL (MG/L AS N)
NITROGEN, TOTAL (MG/L AS N)
Total Nitrogen (TN)
TKN
Original Source
STORET
NWIS
NWIS
STORET
STORET
STORET
LegSTORET
LegSTORET
LegSTORET
SCERP-New
River
SCERP-
Wastewater
Units
mg/1
mg/1
mg/1
mg/kg
mg/1
none
mg/1
mg/1
mg/1
mg/1
mg/1
Table C-14. Water Quality Indicators in Repository Related to "Nitrite"
Water Quality
Indicator ID
1054
1055
1098
1098
1099
1099
1099
1144
1145
1356
1427
indicator Display Name
Nitrite, water, filtered
Nitrite, water, unfiltered
Nitrogen, Nitrite (NO2) as N
Nitrogen, Nitrite (NO2) as N
Nitrogen, Nitrite (N02) as NO2
Nitrogen, Nitrite (NO2) as NO2
Nitrogen, Nitrite (NO2) as NO2
NITRITE, DISSOLVED (MG/L AS N)
NITRITE NITROGEN, TOTAL (MG/L AS N)
NITRITE NITROGEN,TOTAL (MG/L AS N02)
Nitrite-Nitrogen (NO2-N)
Original Source
NWIS
NWIS
STORET
STORET
STORET
STORET
STORET
LegSTORET
LegSTORET
LegSTORET
SCERP-New
River
Units
mg/1
mg/1
mg/1
none
mg/1
none
ug/1
mg/1
mg/1
mg/1
mg/1
C-12
-------
Appendix C - Water Qualify Indicators
Table C-15. Water Quality Indicators in Repository Related to "Orthophosphate"
Water Quality
Indicator ID
1065
1066
1100
1100
1103
1103
1104
1104
1104
1157
1178
1255
1269
1271
1272
1327
1328
1329
1343
1428
1460
1461
1463
Indicator Display Name
Orthophosphate, water, filtered
Orthophosphate, water, unfiltered
Phosphate
Phosphate
Phosphorus, Orthophosphate as P
Phosphorus, Orthophosphate as P
Phosphorus, Orthophosphate as PO4
Phosphorus, Orthophosphate as PO4
Phosphorus, Orthophosphate as PO4
ORTHPHOSPHATE
PHOSPHORUS,DISS,MG/L,FLDFILT<15MIN
ORTHPHOSPHATE
PHOSPHORUS,DISS,MG/L,FILTER >1 5MIN
PHOSPHATE, ORTHO (MG/L AS PO4)
PHOSPHATE, TOTAL, LAND MG/KG
ORTHOPHOSPHATE.DRY WEIGHT.LAND
MG/KG
PHOSPHATE HYDROLYZED, DRY WEIGHT,
LAND MG/KG
ORTHOPHOSPHORUS AS P, WATER MG/L
ORTHOPHOSPHATE AS P, WATER MG/L
PHOSPHATE, TOTAL AS P, WATER MG/L
PHOSPHATE,TOTAL,COLORIMETRIC METHOD
(MG/L AS P)
Phosphate (P04-P)
PHOSPHATE, SOLUBLE
PHOSPHATE, TOTAL
Orthophosphate
Original Source
NWIS
NWIS
STORET
STORET
STORET
STORET
STORET
STORET
STORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
SCERP-New
River
CNA
CNA
CNA
Units
mg/1
mg/1
mg/1
none
mg/1
none
mg/1
none
ug/1
mg/1
mg/1
mg/1
mg/kg
mg/kg
mg/kg
mg/1
mg/1
mg/1 .
mgA
mg/1
mg/1
mg/1 .
mg/1
C-13
-------
Appendix C - Water Quality Indicators
Table C-16. Water Quality Indicators in Repository Related to "Nitrate"
| Water Quality
1 Indicator ID
1056
1095
1095
1096
1096
1096
1146
1244
1354
1355
1426
Indicator Display Name
Nitrate, water, filtered
Nitrogen, Nitrate (NO3) as N
Nitrogen, Nitrate (NO3) as N
Nitrogen, Nitrate (NO3) as NO3
Nitrogen, Nitrate (NO3) as NO3
Nitrogen, Nitrate (NO3) as NO3
NITRATE NITROGEN, TOTAL (MG/L AS N)
NITRATE NITROGEN, DISSOLVED (MG/L AS N)
NITRATE NITROGEN,TOTAL (MG/L AS N03)
NITRATE NITROGEN, DISSOLVED (MG/L AS
NO3)
Nitrate-Nitrogen (NO3-N)
Original Source
NW1S
STORET
STORET
STORET
STORET
STORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
SCERP-New
River
Units ;
!
mg/1
mg/l
none
mg/1
none
ug/1
mg/1
mg/1
mg/1
mg/1
mg/1
Table C-17. Water Quality Indicators in Repository Related to "Ammonia'*
1 Water Quality
[ Indicator ID
446
1052
1053
1086
1086
1092
1092
1093
1093
1093
1141
1142
1143
1267
1352
1422
1448
Indicator Display Name
Nitrogen, ammonium (NH4) as NH4
Ammonia, water, filtered
Ammonia, water, unfiltered
Ammonia, unionized
Ammonia, unionized
Nitrogen, ammonia (NH3) + ammonium (NH4) -
Nitrogen, ammonia (NH3) + ammonium (NH4)
Nitrogen, ammonia as N
Nitrogen, ammonia as N
Nitrogen, ammonia as N
NITROGEN, AMMONIA, DISSOLVED (MG/L AS
N)
NITROGEN, AMMONIA, TOTAL (MG/L AS N)
AMMONIA, UNIONIZED (MG/L AS N)
NITROGEN-NITRATE IN WATER PERCENT
NITROGEN, AMMONIA, TOTAL (MG/L AS NH4)
Ammonia Nitrogen (NH3-N)
Total NH4-N
Original Source
STORET
NWIS
NWIS
STORET
STORET
STORET
STORET
STORET
STORET
STORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
SCERP-New
River
SCERP-
Wastewater
I
Units 1
ug/1
mg/1
mg/1
mg/1
none
mg/1
none
mg/kg
mg/1
none
mg/1
mg/l
mg/1
%
mg/1
mg/1
mg/1
C-14
-------
Appendix C - Water Quality Indicators
Table C-18. Water Quality Indicators in Repository Related to "Nitrite+Nitrate"
Water Quality
Indicator ID
1060
1061
1097
1097
1097
1140
1151
1152
1270
1442
1474
Indicator Display Name
Nitrite plus nitrate, water, unfiltered
Nitrite plus nitrate, water, filtered
Nitrogen, Nitrite (NO2) + Nitrate (NO3) as N
Nitrogen, Nitrite (NO2) + Nitrate (NO3) as N
Nitrogen, Nitrite (NO2) + Nitrate (NO3) as N
NO2 PLUS NO3-N, TOTAL, WHATMAN GF/F
FILT (MG/L)
NITRITE PLUS NITRATE, TOTAL 1 DET. (MG/L
ASN)
NITRITE PLUS NITRATE, DISS 1 DET. (MG/L AS
N)
NITRATE + NITRITE.DRY WT,LAND MG/KG
NO2-NandNO3-N
Nitrite plus nitrate
Original Source
NWIS
NWIS
STORET
STORET
STORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
SCERP-
Wastewater
CILA
Units
mg/1
mg/1
mg/kg
mg/1
none
mg/1
mg/1
mg/1
mg/kg
mg/1
mg/1
Table C-19. Water Quality Indicators in Repository Related to "BOD"
j Water Quality
1 Indicator ID
85
85
1129
1130
1131
1132
1133
1182
1423
1436
Indicator Display Name
BOD, Biochemical oxygen demand
BOD, Biochemical oxygen demand
BIOCHEM OXY DEM,INHIB, DISS(MG/L,5DAY-
20C, CBOD)
BIOCHEM OXY DEM.NIT INHIB.TOT (MG/L,20
DAY-20C)
BIOCHEM OXY DEM.NIT INHIB DISS(MG/L,20
DAY-20C)
BIOCHEMICAL OXYGEN DEMAND (MG/L, 5
DAY - 20DEG C
BIOCHEM OXY DEM NIT INHIB, TOT (MG/L, 5
DAY-20C)
BOD, CARBONACEOUS, 5 DAY, 20 DEC C
Biological Oxygen Demand (BOD)
BOD
Original Source
STORET
STORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
SCERP-New
River
SCERP-
Wastewater
Units j
!
mg/1
none
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
C-15
-------
Appendix C Water Quality Indicators
Table C-20. Water Quality Indicators in Repository Related to "pH"
Water Quality
Indicator ID
29
1076
1077
1118
1119
1135
1136
1233
Indicator Display Name
PH
pH, water, unfiltered, field
pH, water, unfiltered, laboratory
PH, S.U., 24HR MAXIMUM VALUE
PH, S.U., 24HR, MINIMUM VALUE
PH (STANDARD UNITS)
PH (STANDARD UNITS) LAB
PH, FIELD, STANDARD UNITS SU
Original Source
STORET
NWIS
NWIS
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
Units
i
none
none
none .
none
none
none
none
none
Table C-21. Water Quality Indicators in Repository Related to "Temperature"
Water Quality
Indicator ID
257
257
257
480
480
1067
1068
1105
1106
1112
1113
1114
1420
1446
Indicator Display Name
Temperature, water
Temperature, water
Temperature, water
Temperature, air
Temperature, air
Temperature, water
Temperature, air
TEMPERATURE, WATER (DEGREES
CENTIGRADE)
TEMPERATURE, AIR (DEGREES
CENTIGRADE)
TEMPERATURE, WATER (DEGREES
CENTIGRADE, 24HR AVG
WATER TEMPERATURE, DEGREES
CENTIGRADE, 24HR MAX
TEMPERATURE, WATER (DEGREES
CENTIGRADE) 24HR MIN
Temperature (deg C)
Temp
Original Source
STORET
STORET
STORET
STORET
STORET
NWIS
NWIS
LegSTORET
LegSTORET
LegSTORET
LegSTORET
LegSTORET
SCERP-New River
SCERP-Wastewater
Units |
degC
degF
none
degC
none
degC
degC
degC
degC
degC
degC
degC
degC
degC
Table C-22. Water Quality Indicators in Repository Related to "Total Solids"
| Water Quality
( Indicator ID
216
216
Indicator Display Name
Total Solids
Total Solids
Original Source
STORET
STORET
Units
mg/1
none
C-16
-------
Appendix D - Water Quality Comparisons
Appendix D
Water Quality Comparisons against Benchmarks
This Appendix summarizes the water quality standards in each U.S. border state and
Mexico and shows the comparisons of some water quality indicators from the U.S.-Mexico
Waters Repository to those standards.
D.I Water Quality Standards and Comparisons for the United
States
For the U.S. side of the border, water quality standards vary by state. We reviewed
published regulations in Arizona, California, New Mexico, and Texas on surface water quality
standards. All four states established standards based on specific water quality objectives. Texas
establishes water quality standards specific to river segments-specific. Water quality standards
may differ for waterbodies with recreational purposes and waterbodies used for consumption
purposes.
Table D-l shows the water quality indicators for which the four U.S. states have
established water quality standards. A single bullet in this table may represent a series of
standards for a state for a water quality indicator. For more detailed information on all specific
standards refer to the documents published by the States (ADEQ, 2003; CSWRCB, 1994a and
1994b; NMED, 2002; TNRCC, 2000). Tribes in the United States also issue their own water
quality standards subject to EPA oversight and approval. Tribal water quality regulations may be
considered in future assessments of water quality status using the Repository.
Table D-l. List of Water Quality Parameters with Legal Standards in U.S. Border States
Water Quality Parameter > ' > ,
Ammonia
BOD5
Chloride (Cl)
COD
Conductivity
DO
Escherichia coli (E. coii)
Fecal Coliform Organisms
Hardness (CaCO3)
Nutrients
PH
Phosphorus
'.--' -i :..." - .; '-'. ',.-: state,- . "."'. . ; ,..-. "*~\\
':' Arizona'*-., _
-
^California"
"New Mexico
Texas,'-':]
(continued)
D-l
-------
Appendix D - Water Quality Comparisons
Table D-L (continued)
j Water Quality Parameter ...;
Sulfate (SO4)
Temperature
Total dissolved solids
Toxic Materials
Turbidity
Others
v,.; .:' .1-1,;. _:' -;Ci.. '.-state./ : : :.;:. ; >; --\
\i ' '.: Ariiona!; .. ;; .
.
: California*':"..:*
New Mexico.
. . Texas .. - |
* Standards for the California border basins only.
In addition to state water quality standards in the United States, U.S. EPA has published
recommended nutrients standards for rivers, streams, lakes, and reservoirs in the National
Strategy for the Development of Regional Nutrient Criteria (U.S. EPA, 1998). EPA divided the
United States into nutrient regions and proposed standards for each region. The border states fall
in three of the Nutrient Regions:
Nutrient Region III includes Arizona, California, New Mexico, and Southwest
Texas to the Amistad Reservoir. Stations in the Pacific/Salton Sea, Colorado
River/Sea of Cortez, and Central Desert transboundary regions and some stations in
the Rio Grande transboundary region are located in Nutrients Region III.
Nutrient Region IV includes Texas from the Amistad Reservoir to the Falcon
Reservoir. Some stations in the Rio Grande transboundary region are located in
Nutrients Region IV.
" Nutrient Region X includes the Texas-Louisiana Coastal and Mississippi Alluvial
Plains and Texas from the Falcon Reservoir to the Gulf of Mexico. Stations on the
Lower Rio Grande transboundary region are located in Nutrient Region X.
For those three regions, Table D-2 shows the nutrients criteria for rivers and streams and
Table D-3 shows the nutrients criteria for lakes and reservoirs.
Table D-2. Nutrient Criteria for Rivers and Streams by Nutrient Region
! Parameter
Chlorophyll a (ng/L)
Secchi disc depth (m)
Total Nitrogen (mg/L)
Total Phosphorus (ng/L)
Turbidity (Nephelometric Turbidity Units)
Region 111
1.8
-
0.38
22
2.34
Region IV
2.4
-
0.56
23
4.21
Region X
2.1
-
0.76
-
17.50
D-2
-------
Appendix D -Water Quality Comparisons
Table D-3. Nutrient Criteria for Lakes and Reservoirs by Nutrient Region
j Parameter ,
Chlorophyll a (ug/L)
Secchi disc depth (m)
Total Nitrogen (tng/L)
Total Phosphorus (ug/L)
Turbidity (Nephelometric Turbidity Units)
Region III
3.4
2.7
0.40
17
Region IV
2.0
2.0
0.44
20
-
Region X
5.5
0.8
0.57
60
-
D.I.I Water Quality Comparisons for Arizona
The Arizona Department of Environmental Quality (ADEQ) reviews and approves on a
triennial basis the Arizona Surface and Groundwater Quality Standards (ADEQ, 2003).
Currently, ADEQ is preparing for its 2006 triennial review. Arizona establishes water quality
standards for nontoxics, toxics, and radiochemicals based on designated uses. Arizona's
regulations also include surface water quality nutrient standards, aquifer water quality standards,
and groundwater standards for organic chemicals, pesticides, etc. Table D-4 shows some of the
surface water quality standards approved by Arizona in 2003.
Table D-4. Water Quality Standards for Arizona
{Parameter
DO (mg/L)
E. coft(CFU/100ml)
Fecal coliform (CFU/100 ml)
Nitrate as nitrogen (NOj as N) (mg/L)
Nitrite as nitrogen (NO2 as N) (mg/L)
PH
Total dissolved solids (mg/L)
Turbidity (Nephelometric Turbidity Units)
Criteria
' >7.0
<580
<800
<224
< 14
6.5-9.0
< 1,000
<50NTU
Comment
Aquatic and wildlife uses
Single sample maximum
Single sample maximum
Water contact recreation
Water contact recreation
Aquatic and wildlife uses, water contact recreation
U.S. EPA criteria more sensitive crops
Aquatic and wildlife uses, streams and lakes
Tables D-5 to D-7 compare Repository data on chlorophyll a, dissolved oxygen, and pH,
respectively, to these standards.
Table D-5. Water Quality Comparisons for Arizona: Chlorophyll-a
(Water Quality Indicator ID: 227)
,
Station ID
ModSTORET-100183
ModSTORET-100000
ModSTORET-1 00035
ModSTORET- 100034
Station Name
SCROS-A
SCARI-A
SCLAK-B
SCLAK-A
Data Points :
6
4
1
1
Values
Exceeding
5
4
1
1
Percentage
values
exceeding
83%
100%
100%
100% '
D-3
-------
Appendix D - Water Quality Comparisons
Table D-6. Water Quality Comparisons for Arizona: Dissolved Oxygen
(Water Quality Indicator IDs: 1073,1089,1127 and 1211)
..- ""
Station ID
ModSTORET-100000
ModSTORET-100183
ModSTORET-100035
ModSTORET-101177
ModSTORET-101080
ModSTORET-101176
ModSTORET-101178
ModSTORET-101179
ModSTORET-101152
NWIS_3218361 11064800
ModSTORET-100938
ModSTORET-100653
ModSTORET-100639
ModSTORET-100281
ModSTORET-100275
NWIS 321227110331201
NWIS_3213441 10320601
NWIS_320842109252401
ModSTORET-100937
NWIS_3131441 11271501
NWIS_3 13530109302701
NWIS 321156110420001
NWIS_321 1571 10362901
' . Station Name
SCARI-A
SCROS-A
SCLAK-B
SCCIE010.20
SCRED002.17
SCCIEO 14.39
SCCIE002.66
SCCIE001.49
SCSAB004.39
BARREL SPRINGS STOCK TANK
RMRUC005.63
SPSPR095.71
UGSCV002.26
SPSPR077.66
SPSPR1 13.55
D-14-17 13DDA
D-14-18 07DAB
D-15-28 12ACC1
UGCAV006.55
CARPENTER TANK AT BUENOS AIRES
NWR
POOL AT LESLIE CREEK AT LESLIE
CANYON NWR
LOMA VERDE WASH AT SAGUARO NP
CH1MENEA CREEK AT SAGUARO NP
Data
Points
33
22
6
4
4
4
4
4
4
3 '
3
3
3
3
3
3
3
2
2
1
1
t
1
Values
Exceeding,
16
19
2
1
1
2
2
2
1
2
1
1
2
2
1
3
3 .
2
1
1
1
1
1
Percentage
values
exceeding
48%
86%
33%
25%
25%
50%
50%
50%
25%
67%
33%
33%
67%
67%
33%
100%
100%
100%
50%
100%
100%
100%
100%
Table D-7. Water Quality Comparisons for Arizona: pH
(Water Quality Indicator IDs: 29,1076,1077,1135 and 1136)
1' '
(Station ID ,
ModSTORET-100000
ModSTORET-100183
ModSTORET-100872
ModSTORET-59761
NWIS 312250110041901
NWIS 313756110240801
NWIS 321344110320601
i
Station Name
SCARI-A
SCROS-A
SCTHC004.01
GARRETT RANCH
GREENBUSH DRAW PRECIP
UPPER BABOCOMARI PRECIP
D-14-1807DAB
Data
Points
39
34
1
2
10
12
6
Values
Exceeding
8
15
1
1
2
4
2
Percentage [
values j
exceeding J
21%
44%
100%
50%
20%
33%
33%
D-4
-------
Appendix D ~ Water Quality Comparisons
D.1.2 Water Quality Comparisons for California
California has adopted water quality criteria on a regional basis. The Water Quality
Control Plan for the Colorado River Basin (CSWRCB, 1994a) and the Water Quality Control
Plan for the San Diego Basin (CSWRCB, 1994b) were used as references for water quality
criteria in the border area of California. General water quality objectives for the Colorado River
Basin apply for all waters of the region. These include aesthetic, toxicity, temperature, pH,
bacteria, and other general standards. Specific surface waters objectives are also enforced for the
Colorado River above and below the Imperial Dam and for the New River. The designated water
quality control plan for the San Diego Basin includes different water quality objectives:
temperature control, agricultural supply beneficial use, ammonia control, contact and noncontact
recreation, shellfish harvesting, etc. Table D-8 shows the water quality standards'for the
Colorado River Basin, Table D-9 for the New River at the International Boundary, and Table D-
10 for the San Diego Basin.
Table D-8. Water Quality Standards for the Colorado River Basin
f Parameter
Dissolved oxygen (mg/L)
Escherichia coli (E. colt) (#/100 mL)
Fecal coliform (#/100 mL)
pH
Total dissolved solids (mg/L)
Criteria
>8.0
<400
<200
6.0-9.0
< 4,500
Comment I
For Warm uses and Cold uses
For water contact recreation (for noncontact water
recreation the value is 2,000)
For water contact recreation ,
Regional waters are somewhat alkaline
Maximum at Imperial Valley Drains and New River
Table D-9. Water Quality Standards for the New River at the International Boundary
Parameter
BOD5
COD
DO
Fecal coliform
organisms
PH
New River at
Boundary
-
-
5.0 mg/L (daily
grab sample)
-
6.0-9.0
Lagoon Discharge
Canal
30 mg/L filtered
(monthly grab sample)
70 mg/L filtered
-
-
-
New-River Upstream of Discharge Canal
30 mg/L unfiltered (monthly 12-hr composite
sample)
100 mg/L unfiltered (monthly 12-hr composite
sample)
-
30,000 colonies per 100 ml, with no single
sample to exceed 60,000 colonies per lOOmL
-
Table D-10. Water Quality Standards for the San Diego Basin
1 Parameter
Ammonia (rng/L)
Dissolved oxygen (mg/L)
£co//(MPN/100mL)
Fecal coliform (MPN/100 mL)
pH
Criteria
< 0.025
>5.0
<235
<400
6.5 to 8.5
: Comment i
Nonionized
For warm uses (for cold uses it must be > 6)
For water contact recreation (designated beach)
For water contact recreation (for noncontact water recreation the
value is 4,000)
Inland surface waters
D-5
-------
Appendix D - Water Quality Comparisons
Tables D-l 1 to D-17 compare Repository data on total phosphorus, total nitrogen,
chlorophyll a, pH, dissolved oxygen, fecal coliform, and ammonia, respectively, to these
standards.
Table D-ll. Water Quality Comparisons for California: Total Phosphorus
(Water Quality Indicator ID: 1154)
Station ID
21CAL-4-LL-SD-06
1 1NPSWRD-
JOTR_NPS_BOSP
21CAL-4-LL-SD-01
21CAL-4-LL-SD-07
21CAL-4-LL-SD-10
21CAL-4-LL-SD-13
11NPSWRD-
JOTR NFS SSPL
21CAL-4G-LL-WW-01
21CAL-4-LL-LW-01
21CAL-4-LL-LW-02
21CAL-4-LL-LW-03
21CAL-4-LL-LW-04
21CAL-4-LL-LW-05
Station Name
LINDO LAKE PARK WEST BASIN NE-
BANK / CALIFORNIA / SAN DIEGO
BOLSTER CANYON SPRING / COLORADO
RIVER / DEAD BASIN
LINDO LAKE PARK EAST BASIN SE-
BANK / CALIFORNIA / SAN DIEGO
LINDO LAKE PARK WEST BASIN N-
BANK / CALIFORNIA / SAN DIEGO C
LINDO LAKE PARK WEST BASIN NW-
BANK / CALIFORNIA / SAN DIEGO
LINDO LAKE PARK WEST BASIN S-BANK
/ CALIFORNIA / SAN DIEGO C
STUBBE SPRING LOWER / COLORADO
RIVER /DEAD BASIN
LINDO LAKE PARK EAST BASIN SE-
BANK / CALIFORNIA / SAN DIEGO*
LINDO LAKE PARK EAST BASIN SE-
CENTER / CALIFORNIA / SAN DIEG
LINDO LAKE PARK EAST BASIN NW-
CENTER / CALIFORNIA / SAN DIEG
LINDO LAKE PARK WEST BASIN E-
CENTER / CALIFORNIA / SAN DIEGO
LINDO LAKE PARK WEST BASIN W-
CENTER / CALIFORNIA / SAN DIEGO
LINDO LAKE PARK WEST BASIN SW-
CENTER / CALIFORNIA / SAN DIEG
Data
Points
3
2
2
2
2
2
1
1
1
1
1
1
1
Values
Exceeding
3
2
2
2
2
2
1
1
1
1
1
1
I
Percentage
values
exceeding
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
D-6
-------
Appendix D - Water Quality Comparisons
Table D-12. Water Quality Comparisons for California: Total Nitrogen
(Water Quality Indicator ID: 1148)
Station ID
1 1NPSWRD-
JOTR_NPS_BOSP
11NPSWRD-
JOTR NFS SSPL
21CAL-4-LL-SD-01
21CAL-4-LL-SD-06
21CAL-4-LL-SD-07
21CAL-4-LL-SD-10
21CAL-4-LL-SD-13
Station Name
BOLSTER CANYON SPRING / COLORADO
RIVER /DEAD BASIN
STUBBE SPRING LOWER / COLORADO
RIVER /DEAD BASIN .
LINDO LAKE PARK EAST BASIN SE-
BANK / CALIFORNIA / SAN DIEGO
LINDO LAKE PARK WEST BASIN NE-
BANK / CALIFORNIA / SAN DIEGO
LINDO LAKE PARK WEST BASIN N-
BANK / CALIFORNIA / SAN DIEGO C
LINDO LAKE PARK WEST BASIN NW-
BANK / CALIFORNIA / SAN DIEGO
LINDO LAKE PARK WEST BASIN S-BANK
/ CALIFORNIA / SAN DIEGO C
Data
Points
2
1
4 ,
6
4
4
4
'Values
Exceeding
2
1
4
6
4
4
4
Percentage
values
exceeding
100%
100%
100%
100%
100%
100%
100%
Table D-13. Water Quality Comparisons for California: Chlorophyll-a
(Water Quality Indicator ID: 227)
Station ID
ModSTORET-CA99-0047
ModSTORET-CA99-0048
ModSTORET-CA99-0044
ModSTORET-CA99-0045
Station Name
San Diego Bay
San Diego Bay
Mission Bay
San Diego River
Data
Points
3
3
2 '
1
Values
Exceeding
1
2
2
1
Percentage
values
exceeding
33%
67%
100%
100%
D-7
-------
Appendix D - Water Quality Comparisons
Table D-14. Water Quality Comparisons for California: pH
(Water Quality Indicator IDs: 29,1076,1077,1135 and 1136)
Station ID
NWIS 324114115551801
NWISJ241301 17002501
NWISJ241311 17000101
NWISJ242091 16585001
NWIS_324703 1 16473 101
NWIS_3254281 14282601
NWIS 331259116214501
Station Name
017S010E11HPRECIP
SWEETWATER RES NR PUMP TOWER
UPPER
SWEETWATER RES CTR OF MIN POOL
UPPER
SWEETWATER RES E END RES FILL
BNDRY UPPER
LOVELAND RES NR DAM SITE 1 UPPER
014S022W32QPRECIP
011S006E16NPRECIP
Data
Points
4
178
174
35
298
3
4
Values
Exceeding
1
7
10
5
27
2
1
Percentage
values
exceeding
25%
4%
6%
14%
9%
67%
25%
Table D-15. Water Quality Comparisons for California: Dissolved Oxygen
(Water Quality Indicator IDs: 1073,1089,1127 and 1211)
| Station ID
NWIS 324703116473101
NWISJ241301 17002501
NW1S_324131 117000101
NWISJ242091 16585001
NWISJ2431 11 16565901
' Station Name
LOVELAND RES NR DAM SITE 1 UPPER
SWEETWATER RES NR PUMP TOWER
UPPER
SWEETWATER RES CTR OF MIN POOL
UPPER
SWEETWATER RES E END RES FILL
BNDRY UPPER
SWEETWATER R A LOW FLOW BARRIER
A SWEETWATER RES
Data
Points
265
161
159
33
9
Values
Exceeding
210
126
128
11
5
Percentage
values
exceeding
79%
78%
81%
33%
56%
Table D-16. Water Quality Comparisons for California: Fecal Coliform
(Water Quality Indicator ID: 1042)
i
1 Station ID
NWIS 10254670
NWIS_1 1022200
NWISJ 1022480
Station Name
ALAMO R AT DROP 3 NR CALIPATRIA CA
LOS COCHES C NR LAKESIDE CA
SAN DIEGO R A MAST RD NR SANTEE CA
Data
Points
11
1
1
Values
Exceeding
11
1
1
Percentage i
values exceeding i
100%
100%
100%
D-8
-------
Appendix D - Water Quality Comparisons
Table D-17. Water Quality Comparisons for California: Ammonia
(Water Quality Indicator IDs: 1052,1058,1059)
I
1 Station ID
NWIS 10254005
NWIS_10254670
NWIS_3240181 15355201
NWIS_324320115260401
NWIS_3243241 15384601
NWIS 324350115395000
NWISJ245041 15182201
NWISJ2453 11 15260401
NWIS_3245451 15204800
NWISJ2461 11 15 182101
NWIS 324650115205200
NWIS_3247521 15260200
NWISJ248181 15401701
NWISJ249041 15372401
NWIS_324923 11 5302601
NWIS_3249301 15413101
NW1S_32493111539I301
NWIS_3249561 1521 1401
NWIS_324956115261701
NW1S_3249581 15290101
NWIS_3249591 15255201
Station Name
SALTON SEA NR WESTMORLAND CA
ALAMO R AT DROP 3 NR
CALIPATRIA CA
BROCKMAN DR NO 2 AB CONF NR
CALEXICO CA
SOUTH CENTRAL DR A FAWCETT RD
NR CALEXICO CA
WISTARIA DR NO 7 NR GREESON DR
NR MT SIGNAL CA
GREESON DR NR NEW R CA
VERDE DR A CHELL RD NR
HOLTVILLE CA
SOUTH CENTRAL DR A HILFIKER RD
NR HOLTVILLE CA
VERDE DR NR CONFLUENCE W
ALAMO R CA
WARREN DR NO. 2 ON HUNT RD NR
HOLTVILLE CA
WARREN DR NR ALAMO R
SOUTH CENTRAL DRAIN NR ALAMO
R
ELDER 14 DR S OF EL CENTRO
NAVAL STA NR SEELEY CA
CENTRAL DR NO 10 AB CONF NR EL
CENTRO CA
CENTRAL DR BETWEEN CENTRAL
DR 6&7 NR EL CENTRO CA
ELDER 14 DRAIN NR NEW R NR
SEELEY CA
RICE DRAIN NO. 5 A ATEN RD NR
SEELEY CA
PALMETTO DR A BRIDENSTEIN RD
NR HOLTVILLE CA
CENTRAL DR/ROSITAS WASTE NR
HOLTVILLE CA
MESQUITE DR NO 6 AB CONF NR
HOLTVILLE CA
PALMETTO C ON MORRISN RD NR
ALAMO R NR HOLTVILLE C
Data
Points
4
22
1
1
1
2
1
1
2
1
2
2
1
1
1
2.
1
1
2
1
2
Values
Exceeding
4
22
1
1
1
' 2
1
1
2
1
2
2
1
1
1
2
1
1
2
1
2
Percentage
values
exceeding
100%
100%
100%
100% '
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
(continued)
D-9
-------
Appendix D - Water Quality Comparisons
Table D-17. (continued)
Station ID
NWISJ3252071 1 5 19520 1
NWIS_3252101 15391601
NWIS_3253541 153 10001
NWISJ253541 153 10002
NW1S_3253541 15310003
NWIS_3254341 15215501
NWISJ25449 11 5293001
NWIS_3255381 15294800
NWIS_3255481 15233301
NWIS 325552115270900
NWISJ25853115245101
NWISJ258541 15272601
NWIS_325855115211301
NWISJ25855 11521 1302
NW!S_3303071 15412101
NWISJ304541 15413301
NWISJ304591 15430101
NWISJ305201 15305901
NWIS_330521 11 5265901
NWIS_33052211 5223701
NWIS_3306151 15331101
NWISJ306161 15361701
NWIS_3306171 15385201
Station Name
HOLTVILLE DRNO. 1 ON WRIGHT
RD NR HOLTVILLE CA
RICE DRAIN NO. 5 NR NEW R NR
SEELEY CA
014S014E27N01SLYS S-154 AT 19 FT
014S014E27N02SLYS S-154 AT 14 FT
014S014E27N03SLYS S-154 AT 9 FT
HOLTVILLE MAIN DRAIN A COOPER
RD NR HOLTVILLE CA
MESQUITE DR NR HWY S27 NR
ALAMORIO CA
ROSE DRAIN A PUMP STA CA
HOLTVILLE DRNO. 8 A ADAMS RD
NR ALAMORIO CA
HOLTVILLE DR NR ALAMO CA
OSAGE DR W OF HASTIAN RD NR
ALAMORIO CA
OSAGE DR NR ALAMO R NR
ALAMORIO CA
OSAGE DR ON SILLIMAN RD NR
HOLTVILLE CA
OSAGE CANAL ON SILLIMAN RD NR
HOLTVILLE CA
TRIFOLIUM DR NO. 2 A BANNISTER
RD NR CALIPATR1A CA
TRIFOLIUM DRAIN NO. 2 A BAKER
RD NR WESTMORLAND CA
TRIFOLIUM N01 DRAIN AT OUTLET
TO SALTON SEA, CA
NETTLE DRAIN NR ALAMO R NR
CAL1PATRIA CA
NETTLE DRAIN A HWY 115 NR
CALIPATRIA CA
NETTLE DR W OF E HIGHLINE
CANAL NR CALIPATRIA CA
VAIL DRAIN ON VAIL RD NR
WESTMORLAND CA
VAIL DR ON VAIL RD E OF GENTRY
RD NR CALIPATRIA CA
VAIL DRAIN A LACK RD NR
CALIPATRIA CA
Data
Points
1
2
2
2
2
1
1
2
1
2
1
2
2
2
1
1
2
2
1
1
1
1
2
Values
: Exceeding
1
2
2
1
1
1
1
2
1
2
1
2
2
2
1
1
2
2
1
1
1
1
2 .
Percentage f
values |
exceeding |
100%
100%
100%
50%
50%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
(continued)
D-IO
-------
Appendix D - Water Quality Comparisons
Table D-17. (continued)
> "
1
(station ID
NWIS_330703 115324001
NWIS_330706115385201
NWISJ307581 15392601
NW1S_330835 11 5434501
NWIS_3309151 15361701
NWISJ310231 15473701
NWIS_3310341 15334501
NWISJ310341 15371800
NWIS 331036115265801
NWIS 331036115310501
NWIS_3312151 15410001
NWIS_3312461 15341301
NWIS 331400115380001
NWISJ314001 15450001
NWIS_33 15321 15344401
NWISJ316001 15453001
NWIS_3319301 15484001
NWIS_332400 11 5553001
NWISJ32637115512001
NWIS_3329081 1601 1501
NWIS_3329581 16023501
Station Name
C DR NR ALAMO R NR CALIPATR1A
CA
VAIL 6 DRAIN A BOWLES RD NR
CALIPATRIA CA
VAIL CUT OFF DR AT YOUNG RD
OUTLET TO SALTON SEA
SALTON SEA IN NEW R DELTA CA
VAIL 3-A DRAIN A KUNS RD NR
NILANDCA
SALTON SEA IN SAN FELIPE C
DELTA CA
K DRAIN A BRANDT RD NR ALAMO
RNR NILANDCA
PUMICE DRAIN NR SALTON SEA CA
K DRAIN A WIEST RD NR NILAND CA
K DRAIN A HWY 1 1 1 NR NILAND CA
SALTON SEA BETWEEN S BASIN
AND NEW ALAMO R DELTA
P DR 0.5 MI E OF CONF WITH P
LATERAL NR NILAND CA
SALTON SEA IN ALAMO R DELTA CA
SALTON SEA NR CENTER OF S
BASIN CA
WASH AT DAVIS RD NR W DRAIN NR
NILAND CA
SALTON SEA A CENTER OF S BASIN
CA
SALTON SEA NR CENTER OF LAKE
BETWEEN N AND S BASIN
SALTON SEA A CENTER OF N BASIN
CA
SALTON SEA IN SALT C DELTA CA
SALTON SEA BETWEEN N BASIN
AND WHITEWATER RIVER
SALTON SEA IN WHITEWATER R
DELTA CA
Data
Points
1
1
4
2
1
2
2
2
1
1
2
1
2
2
1
2
2
2
2
11
2
Values
Exceeding
1
1
4
2
1
2
2
2
1
1
2
1
2
2
1
2
2
2
2
11
2
Percentage
values
exceeding
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
D-ll
-------
Appendix D Water Quality Comparisons
D.3 Water Quality Comparisons for New Mexico
The New Mexico Water Quality Control Commission established surface water quality
standards for interstate and intrastate surface waters (NMED, 2002). General standards are
established to sustain and protect existing or attainable uses of surface waters of the state. These
general standards apply to all surface waters of the state at all times, unless a specified standard
is provided elsewhere on a river segment. Specific standards for a river segment depend on the
designated use and flow level. Table D-18 shows the highest standards across the state.
Table D-18. Water Quality Standards for New Mexico
1 Parameter , ;
Chloride (mg/L) (1)
Dissolved oxygen (mg/L)
Fecal coHform (CFU/100 ml)
pH
Sulfate (mg/L) (1)
Total dissolved solids (mg/L) *
Turbidity (Nephelometric Turbidity Units)
- Criteria
<25
>5.0
<200
6.6-8.8
<150
<500
<10NTU
Comment |
Highest standard across the state
Most uses
Highest standard across the state
In most reaches of Rio Grande Basin
Highest standard across the state
Highest standard across the state
Fisheries
Rio Grande BasinThe main stem of the Rio Grande, from Taos Junction bridge upstream to the New
Mexico-Colorado State line.
Tables D-19 to D-27 compare Repository data on total phosphorus, total nitrogen,
chlorophyll a, dissolved oxygen, fecal coliform, sulfate, chloride, pH, and total dissolved solids,
respectively, to these standards.
\
D-12
-------
Appendix D - Water Quality Comparisons
Table D-19. Water Quality Comparisons for New Mexico: Total Phosphorus
(Water Quality Indicator ID: 1154)
Station ID
21NMEX-
LRGlOl'.OOOllO
21NMEX-LRG046
21NMEX-LRG053
21NMEX-
LRG101.000101
21NMEX-
LRG101.000125
21NMEX-LRG046.5
21NMEX-
LRG101.000109
21NMEX-LRG047
21NMEX-LRG045.5
21NMEX-
SWC804.006048
21NMEX-LRG046.3
21NMEX-
LRG101.000107
21NMEX-
SWC803.002530
21NMEX-
SWC803.002501
21NMEX-
SWC804.003035
21NMEX-
LRG103.002030
21NMEX-
SWC803.002001
21NMEX-
SWC803.000105
21NMEX-
LRG101000109.5
Station Name
RIO GRANDE NEAR ANTHONY ON MM
HIGHWAY 225 BRIDGE / WESTERN G
RIO GRANDE AT PICACHO AVE IN LAS
CRUCES / WESTERN GULF / UPP
RIO GRANDE AT NM HIGHWAY 226 NEAR
BERING / WESTERN GULF / UP
RIO GRANDE BELOW SUNLAND PARK / /
RIO GRANDE NEAR MESQUITE ON
HIGHWAY 1 92 BRIDGE / WESTERN GUL
RIO GRANDE AT BRIDGE NEAR LA
MESILLA / WESTERN GULF / UPPER
RIO GRANDE AT SANTA TERESA / /
RIO GRANDE AT MESILLA DIVERSION
DAM / WESTERN GULF / UPPER R
RIO GRANDE AT NM HWY 430 NEAR
DONA ANA / WESTERN GULF / UPPE
MIMBRES RIVER AT COONEY
CAMPGROUND CROSSING 150A /
WESTERN G
LAS CRUCES WWTP EFFLUENT DITCH
AT RIO GRANDE / WESTERN GULF
SUNLAND PARK WWTF EFFLUENT / /
MIMBRES RIVER UPSTREAM OF HWY 90
BRIDGE / WESTERN GULF / UPP
MIMBRES RIVER ABOVE CONFLUENCE
WITH GALLINAS CR. / WESTERN G '
MIMBRES RIVER ABOVE MIMBRES
GAGE / WESTERN GULF / UPPER RIO
RIO GRANDE BELOW E. BUTTE DAM AT
USGSGAGE/ /
GALLINAS CREEK ABOVE MIMBRES
RIVER / WESTERN GULF / UPPER RI
M1MBRES.RIVER FOUR MILES S. OF
DWYER / WESTERN GULF / UPPER
RIO GRANDE AT BORDERLAND ROAD
BRIDGE / WESTERN GULF / UPPER
Data
Points
19
19
17
16
16
15
14
14
13
13
12
12
9
9
9
7.
6
5
5
Values
Exceeding;
19
19
17
16
16
15
14
14
13
13
12
12
9
9
9
.7
6
5
5
Percentage
values
exceeding
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%.
100%
100%
100%
100%
100%
(continued)
D-13
-------
Appendix D - Water Quality Comparisons
Table D-19. (continued)
Station ID
21NMEX-
LRG101000107.5
21NMEX-LRG058
21NMEX-
LRG101.000103
21NMEX-LRG101000108
21NMEX-
LRG 10 1000 109.7
21NMEX-LRG101000139
21NMEX-
LRG103.002020
21NMEX-
LRG101.000102
21NMEX-
BEARCANYONDAM
21NMEX-
OT01AP.STINKY
21NMEX-DAOIAN.S-
LUCERO
21NMEX-DA02AO.N-
LUCERO
21NMEX-
DA03BI.DAVIES
21NMEX-
HI01AK.SACATONP
21NMEX-
HI02AL.NLORD
21NMEX-
LCRSSC.TSCC05
21NMEX-
SWCANC.TCLD20
21NMEX-
SWCANC.TCDC30
21NMEX-
SWCANC.TDAC10
21NMEX-
OT02BJ.MALPAISP
: Station Name
RIO GRANDE ABV SUNLAND PARK
WWTF OUTFALL / WESTERN GULF / UP
RIO GRANDE AT AMERICAN DAM / RIO.
GRANDE /
10 M ABOVE EL PASO ELECTRIC
OUTFALLS 001 003 / WESTERN GULF
RIO GRANDE BELOW WEST DRAIN /
WESTERN GULF / UPPER RIO ABOVE
RIO GRANDE AT VINTON ROAD BELOW
ANTHONY / WESTERN GULF / UPP
RIO GRANDE BELOW 1-10 BRIDGE NEAR
LAS CRUCES / WESTERN GULF
RIO GRANDE BELOW WILLIAMS / /
100 M BELOW EL PASO ELECTRIC 001 003
/ WESTERN GULF / UPPER
SLIGHTLY E. OF DAM CENTER 1/8
DISTANCE FROM DAM / COLORADO R
LAKE STINKY / WESTERN GULF / UPPER
RIO GRANDE ABOVE PECOS RI
SAMPLE STATION ON WEST END OF
LAKE VIA MISSLE RA / WESTERN G
SAMPLE STATION NEXT TO RANGE RD
10 ON MISSLE RNG / WESTERN G
STATION ON W END OF TANK 1/4 MI E.
OF ROAD. / WESTERN GULF M
PLAYA LAKE DUE N FROM DUNES OF N
LORDSBURG PLAYA / COLORADO
N LORDSBURG PLAYA / COLORADO
RIVER /
SKELETON CANYON CREEK/ /
CLANTON DRAW AT GRAY RANCH
HEADQUARTERS / /
CLOVERDALE CREEK / /
DOUBLE ADOBE CREEK / /
STATION APPROX. 100 YDS S OF SPRING
IN POOL AREA / WESTERN G
Data
Points
5
5
4
4
4
4
4
4
3
1
1
1
1 .
1
1
1
1
!
1
1
Values
Exceeding
5
5
4
4
4
4
4
4
3
1
1
1
1
1
1
1
1
1
1
1
Percentage |
values |
exceeding i
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
D-14
-------
Appendix D - Water Quality Comparisons
Table D-20. Water Quality Comparisons for New Mexico: Total Nitrogen
(Water Quality Indicator ID: 1148,1235)
i ' './".
[Station ID ;
2INMBHO-BHO002
21NMBHO-BHO003
21NMBHO-BHO019
21NMBHO-BHO022
21NMBHO-BHO024
21NMBHO-BHO026
21NMBHO-BHO050
21NMBHO-BHO061
21NMBHO-BHO092
21NMBHO-BHO094
2JNMBHO-BHO095
21NMBHO-BHO098
21NMBHO-BHO105
21NMBHO-BHO106
21NMBHO-BH0111
21NMBHO-BHO1 19
21NMBHO-BHOI24
21NMBHO-BHO125
21NMBHO-BHO126
21NMBHO-BHO133
Station Name
1 529 Road Runner Ln-Las Cruces 80005 /
WESTERN GULF / UPPE
1705 Road Runner Ln-Las Cruces 80005 /
WESTERN GULF / UPPE
Calle Ruiz #215- / WESTERN GULF /
UPPER RIO GRANDE ABOVE PE
417 Koenig-Mesquite/ WESTERN GULF /
UPPER RIO GRANDE ABOVE
428 Moonlight-San Miguel / WESTERN
GULF / UPPER RIO GRANDE
1 198 Wanabe Road #3»Mesquite 88048 /
WESTERN GULF / UPPER
1313 W Main St-La Union / WESTERN
GULF / UPPER RIO GRANDE A
1095 Sierra Vista-Berino / WESTERN GULF
/ UPPER RIO GRANDE
5405 Santa Teresita-Santa Teresa 88008 /
WESTERN GULF / UP
643 Pinabetes-Las Cruces 88001 /
WESTERN GULF / UPPER RIO
388 Meadow Park-Fair Acres / WESTERN
GULF / UPPER RIO GRAND
7335 Harvey Rd-Las Cruces 88005 /
WESTERN GULF / UPPER RIO
17835 N Hwy 85-Radium Springs 88005 /
WESTERN GULF / UPPER
2268 Alta Mira-Las Cruces / WESTERN
GULF / UPPER RIO GRANDE
Hwy 28-San Miguel / WESTERN GULF /
UPPER RIO GRANDE ABOVE P
2601 W O'Hara Rd-Anthony 88021 /
WESTERN GULF / UPPER RIO
441 Minter Rd-Mesquite 88048 / WESTERN
GULF /UPPER RIO GR
11859JarmenDr.-Mesquite 88048 /
WESTERN GULF / UPPER RIO
456 Wannabe Rd-Mesquite 88048 /
WESTERN GULF / UPPER RIO G
1 10 Ashtray Rd-Mesquite 88048 /
WESTERN GULF / UPPER RIO G
Data
Points
1
1
3
2
1
2
1
1
1
1
1
1
1
1
1
2
1
1
2
1
Values
Exceeding
1
1
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Percentage
values
exceeding
100%
.100%
67%
50%
100%
50%
100%
100%
100%
100%
100%
100%
100%
100%
100%
50%
100%
100%
50%
100%
(continued)
D-15
-------
Appendix D - Water Quality Comparisons
Table D-20. (continued)
Station ID
21NMBHO-BHO135
21NMBHO-BHO137
21NMBHO-BHO138
21NMBHO-BH0140
21NMBHO-BHO141
21NMBHO-M004
21NMEX-
BEARCANYONDAM .
21NMEX-DA01AN.S-
LUCERO
21NMEX-DA02AO.N-
LUCERO
21NMEX-
DA03BI.DAVIES
2INMEX-
HI01AK.SACATONP
21NMEX-
HI02AL.NLORD
21NMEX-
HI03AM.SLORD
21NMEX-LRG045.5
21NMEX-LRG046
21NMEX-LRG046.3
21NMEX-LRG046.5
21NMEX-LRG047
21NMEX-LRG053
21NMEX-LRG058
21NMEX-LRG101.000101
Station Name
1660 Burke Rd-Las Cruces 88005 /
WESTERN GULF / UPPER RIO
2460 Burke Rd-Las Cruces 88005 /
WESTERN GULF / UPPER RIO
1060 Road Runner Rd»Las Cruces 88005 /
WESTERN GULF / UPPE
711 Long River Lane-Fair Acres / WESTERN
GULF /UPPER RIO G
730 Tamaris -Rio Grande Estates /
WESTERN GULF / UPPER RIO
DEMING.NM / /
SLIGHTLY E. OF DAM CENTER 1/8
DISTANCE FROM DAM / COLORADO R
SAMPLE STATION ON WEST END OF
LAKE VIA MISSLE RA / WESTERN G
SAMPLE STATION NEXT TO RANGE RD
10 ON MISSLE RNG / WESTERN G
STATION ON W END OF TANK 1/4 MI E.
OF ROAD. / WESTERN GULF M
PLAYA LAKE DUE N FROM DUNES OF N
LORDSBURG PLAYA / COLORADO
N LORDSBURG PLAYA / COLORADO
RIVER/
S LORDSBURG PLAYA / COLORADO
RIVER/
RIO GRANDE AT NM HWY 430 NEAR
DONA ANA / WESTERN GULF / UPPE
RIO GRANDE AT PICACHO AVE IN LAS
CRUCES / WESTERN GULF / UPP
LAS CRUCES WWTP EFFLUENT DITCH
AT RIO GRANDE / WESTERN GULF
RIO GRANDE AT BRIDGE NEAR LA
MESILLA / WESTERN GULF / UPPER
RIO GRANDE AT MESILLA DIVERSION
DAM / WESTERN GULF / UPPER R
RIO GRANDE AT NM HIGHWAY 226
NEAR BERING / WESTERN GULF / UP
RIO GRANDE AT AMERICAN DAM / RIO
GRANDE /
RIO GRANDE BELOW SUNLAND PARK /
/
Data
Points
1
1
1
1
1
1
6
2
2
2
2
2
2
26
36
24
28
28
34
10
32
Values
Exceeding
1
1
1
1
1
1
6
2
2
2
2
2
2
26
31
24
28
28
34
10
32
Percentage
values
exceeding
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
86%
100%
100%
100%
100%
100%
100%
(continued)
D-16
-------
Appendix D- Water Quality Comparisons
Table D-20. (continued)
Station ID
21NMEX-LRG101.000102
21NMEX-LRG101.000103
21NMEX-LRG101.000I07
21NMEX-LRG101.000109
21NMEX-LRG101.0001 10
21NMEX-LRG101.000125
21NMEX-
LRG101000107.5
21NMEX-LRG101000108
21NMEX-
LRG101000109.5
21NMEX-
LRG101000109.7
21NMEX-LRG101000139
21NMEX-LRG103.002020
21NMEX-LRG103.002030
21NMEX-
OT01AP.STINKY
21NMEX-
OT02BJ.MALPAISP
21NMEX-SWC803.000105
2 1 NMEX-S WC803 .00200 1
21NMEX-SWC803.002501
21NMEX-SWC803.002530
21NMEX-SWC804.003035
21NMEX-SWC804.006048
21NMEX-
SWCANC.TCLD20
Station Name
100 M BELOW EL PASO ELECTRIC 001
003 / WESTERN GULF / UPPER
10 M ABOVE EL PASO ELECTRIC
OUTFALLS 001 003 / WESTERN GULF
SUNLAND PARK WWTF EFFLUENT / /
RIO GRANDE AT SANTA TERESA / /
RIO GRANDE NEAR ANTHONY ON NM
HIGHWAY 225 BRIDGE / WESTERN G
RIO GRANDE NEAR MESQUITE ON
HIGHWAY 192 BRIDGE / WESTERN GUL
RIO GRANDE ABV SUNLAND PARK
WWTF OUTFALL / WESTERN GULF / UP
RIO GRANDE BELOW WEST DRAIN /
WESTERN GULF / UPPER RIO ABOVE
RIO GRANDE AT BORDERLAND ROAD
BRIDGE / WESTERN GULF / UPPER
RIO GRANDE AT VINTON ROAD BELOW
ANTHONY / WESTERN GULF / UPP
RIO GRANDE BELOW 1-10 BRIDGE NEAR
LAS CRUCES / WESTERN GULF
RIO GRANDE BELOW WILLIAMS / /
RIO GRANDE BELOW E. BUTTE DAM AT
USGS GAGE / /
LAKE STINKY / WESTERN GULF / UPPER
RIO GRANDE ABOVE PECOS RI
STATION APPROX. 100 YDS S OF SPRING
IN POOL AREA / WESTERN G
MIMBRES RIVER FOUR MILES S. OF
DWYER / WESTERN GULF / UPPER
GALLINAS CREEK ABOVE MIMBRES
RIVER / WESTERN GULF / UPPER RI
MIMBRES RIVER ABOVE CONFLUENCE
WITH GALLINAS CR. / WESTERN G
MIMBRES RIVER UPSTREAM OF HWY 90
BRIDGE / WESTERN GULF / UPP
MIMBRES RIVER ABOVE MIMBRES
GAGE / WESTERN GULF / UPPER RIO
MIMBRES RIVER AT COONEY
CAMPGROUND CROSSING 150A /
WESTERN G
CLANTON DRAW AT GRAY RANCH
HEADQUARTERS / /
Data
Points
8
8
24
27
37
32
10
8
10
8
8
4
8
2
2
10
12
18
18
18
26
2
Values
Exceeding
8
8
24
27
36
32
10
8
10
\
8
8
3
6
2
2 -
6
5
7
13
4
7
2
Percentage
values
exceeding
100%
100%
100%
100%
97%
100%
100%
100%
100%
100%
100%
75%
75%
100%
100%
60%
42%
39%
72%
22%
27%
100%
D-17
-------
Appendix D - Water Quality Comparisons
Table D-21. Water Quality Comparisons for New Mexico: Chlorophyll-a
(Water Quality Indicator IDs: 1172,1297)
1 Data Points ;
21NMEX-
BEARCANYONDAM
21NMEX-
DA03BI.DAVIES
21NMEX-
HI01AK.SACATONP
21NMEX-LRG101.000102
21NMEX-LRG101 .0001 10
21NMEX-LRG101.000125
21NMEX-
LRG101000107.5
21NMEX-
LRG101000109.5
21NMEX-
OT01AP.STINKY
Values Exceeding '.
SLIGHTLY E. OF DAM CENTER 1/8
DISTANCE FROM DAM / COLORADO R
STATION ON W END OF TANK 1/4 MI E.
OF ROAD. / WESTERN GULF M
PLAYA LAKE DUE N FROM DUNES OF N
LORDSBURG PLAYA / COLORADO
100 M BELOW EL PASO ELECTRIC 001
003 / WESTERN GULF / UPPER
RIO GRANDE NEAR ANTHONY ON NM
HIGHWAY 225 BRIDGE / WESTERN G
RIO GRANDE NEAR MESQUITE ON
HIGHWAY 192 BRIDGE / WESTERN GUL
RIO GRANDE ABV SUNLAND PARK
WWTF OUTFALL / WESTERN GULF / UP
RIO GRANDE AT BORDERLAND ROAD
BRIDGE / WESTERN GULF / UPPER
LAKE STINKY / WESTERN GULF / UPPER
RIO GRANDE ABOVE PECOS RI
Station
ID
4
2
2
2
2
2
2
2
2
Station
Name
4
2
2
2
2
2
2
2
2
Indicator \
ID 1
100%
100%
100%
100%
100%
100%
100%
100%
100%
D-18
-------
Appendix D - Water Quality Comparisons
Table D-22. Water Quality Comparisons for New Mexico: Dissolved Oxygen
(Water Quality Indicator ID: 1127,1211,1191,1089,1073,1189,1190)
Station ID
21NMEX-
BEARCANYONDAM
21NMEX-
SWC804.006048
21NMEX-
LRG 103.002030
21NMBHO-BH0043
21NMBHO-BHO051
21NMBHO-BHO050
21NMBHO-BHO049
21NMBHO-BHO048
21NMBHO-BHO047
21NMBHO-BH0046
21NMBHO-BHO052
21NMBHO-BHO044
21NMBHO-BHO055
21NMBHO-BHO042
21NMBHO-BHO041
21NMBHO-BHO040
21NMBHO-BHO045
21NMBHO-BH0066
21NMBHO-BHO054
21NMBHO-BHO037
; Station Name
SLIGHTLY E. OF DAM CENTER 1/8 DISTANCE
FROM DAM / COLORADO R
MIMBRES RIVER AT COONEY CAMPGROUND
CROSSING 150A / WESTERN G
RIO GRANDE BELOW E. BUTTE DAM AT
USGS GAGE / /
301 Mendez-La Union 88021 / WESTERN GULF /
UPPER RIO GRAND
398 Alvarez-La Union / WESTERN GULF /
UPPER RIO GRANDE ABOV
1313 W Main St-La Union / WESTERN GULF /
UPPER RIO GRANDE A
125 N. Alvarez-La Union / WESTERN GULF /
UPPER RIO GRANDE A
125 N. Virginia-La Union 88021 / WESTERN
GULF /UPPER RIO
105 N. Virginia-La Union 88021 / WESTERN
GULF /UPPER RIO
412 S. Virginia-La Union / WESTERN GULF /
UPPER RIO GRANDE
1626 Paloma-La Union / WESTERN GULF /
UPPER RIO GRANDE ABOV
324 S. Virginia-La Union 88021 / WESTERN
GULF / UPPER RIO
1400 Main St-La Union 88021 / WESTERN GULF
/ UPPER RIO GRA
1526 Amador-La Union 88021 / WESTERN GULF
/ UPPER RIO GRAN
272 South Virginia-La Union 88021 / WESTERN ,
GULF / UPPER R
413 Mendez-La Union 88021 / WESTERN GULF /
UPPER RIO GRAND
412 S. Virginia-La Union 88021 / WESTERN
GULF /UPPER RIO
124 Miranda St--Vado / WESTERN GULF / UPPER
RIO GRANDE ABOVE
immediately west of BHO053-La Union /
WESTERN GULF / UPPER
Mustang Dr-Vado / WESTERN GULF / UPPER
RIO GRANDE ABOVE PEC
Data
Points
26
9
3
t
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Values
Exceeding
17
3
1
1
1
.1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Percentage
values
exceeding
65%
33%
33%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
(continued)
D-19
-------
Appendix D - Water Quality Comparisons
Table D-22. (continued)
!
| ' "" :
i Station ID
21NMBHO-BHO056
21NMBHO-BHO057
21NMBHO-BHO058
21NMBHO-BHO059
21NMBHO-BHO060
21NMBHO-BHO061
21NMBHO-BHO062
21NMBHO-BHO063
21NMBHO-BHO064
21NMBHO-BHO065
21NMBHO-BHO053
21NMBHO-BHO019
21NMBHO-BH0003
21NMBHO-BH0004
21NMBHO-BHO005
21NMBHO-BHO006
21NMBHO-BHO007
21NMBHO-BHO008
21NMBHO-BHO009
21NMBHO-BHO010
21NMBHO-BHO011
Station Name
701 Lopez Rd-Chamberino 88027 / WESTERN
GULF / UPPER RIO G
601 Medina-Chamberino 88027 / WESTERN
GULF / UPPER RIO GRA
201 Lopez -Chamberino 88027 / WESTERN GULF
/ UPPER RIO GRA
4372 S Hwy 28-San Pablo 88005 / WESTERN
GULF /UPPER RIO G
4169 Sauco Ln.--San Pablo 88005 / WESTERN
GULF /UPPER RIO
1095 Sierra Vista-Berino / WESTERN GULF /
UPPER RIO GRANDE
near valley view dairy-- / WESTERN GULF /
UPPER RIO GRANDE A
946 Lechuga-Vado / WESTERN GULF / UPPER
RIO GRANDE ABOVE PE
733 Lechuga Rd~Vado / WESTERN GULF /
UPPER RIO GRANDE ABOVE
795.Lechuga Rd~Vado / WESTERN GULF /
UPPER RIO GRANDE ABOVE
1201 Main --La Union / WESTERN GULF / UPPER
RIO GRANDE ABOVE
Calle Ruiz #215- / WESTERN GULF / UPPER RIO
GRANDE ABOVE PE
1705 Road Runner Ln~Las Cruces 80005 /
WESTERN GULF /UPPE
1400 Burke Road-Las Cruces 80005 / WESTERN
GULF / UPPER RI
1230 Burke Rd-Las Cruces 80005 / WESTERN
GULF /UPPER RIO
1 120 Burke Rd-Las Cruces 80005 / WESTERN
GULF / UPPER RIO
231 Boggy Lane-Mesilla Park 88047 / WESTERN
GULF / UPPER R
201 Boggy Lane-Mesilla Park 88047 / WESTERN
GULF / UPPER R
320 Boggy Lane-Mesilla Park 88047 / WESTERN
GULF/ UPPER R
330 Boggy Lane-Mesilla Park 88047 / WESTERN
GULF / UPPER R
4633 Lamar Rd-Las Cruces / WESTERN GULF /
UPPER RIO GRANDE
Data
Points
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Values
Exceeding
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Percentage j
values
exceeding !
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
(continued)
D-20
-------
Appendix D - Water Quality Comparisons
Table D-22. (continued)
Station ID
21NMBHO-BHO012
21NMBHO-BHO013
21NMBHO-BHO014
21NMBHO-BHO039
2INMBHO-BH0018
21NMBHO-BHO038
21NMBHO-BHO020
21NMBHO-BHO021
21NMBHO-BH0023
21NMBHO-BH0024
21NMBHO-BHO025
21NMBHO-BHO028
21NMBHO-BHO029
21NMBHO-BHO030
21NMBHO-BH0032
2INMBHO-BH0035
21NMBHO-BHO036
21NMBHO-BHO071
21NMBHO-BHO016
21NMBHO-BHO133
21NMBHO-BHO116
Station Name
4597 Lamar Rd-Las Cruccs 88005 / WESTERN
GULF / UPPER RIO
near Lamar Rd-Las Cruces / WESTERN GULF /
UPPER RIO GRANDE
El Farro St. #4443- / WESTERN GULF / UPPER
RIO GRANDE ABOVE
304 Provencio Rd.-Chamberino / WESTERN GULF
/UPPER RIO GRA
Ashtray Road- / WESTERN GULF / UPPER RIO
GRANDE ABOVE PECOS .
216 Lopez St-Chamberino / WESTERN GULF /
UPPER RIO GRANDE A
Ashtray Road- / WESTERN GULF / UPPER RIO
GRANDE ABOVE PECOS
Ashtray Road- / WESTERN GULF / UPPER RIO
GRANDE ABOVE PECOS
(Moonlight) Rt 1 Box 479-La Mesa / WESTERN
GULF /UPPER RIO
428 Moonlight-San Miguel / WESTERN GULF /
UPPER RIO GRANDE
538 Costilla PI- / WESTERN GULF / UPPER RIO
GRANDE ABOVE PE
Vistosos Loop #2--Berino / WESTERN GULF /
UPPER RIO GRANDE A
Calle Vistoso Loop #35--Berino / WESTERN GULF
/UPPER RIO GR
1093 Sierra Vista-Berino / WESTERN GULF /
UPPER RIO GRANDE
6821 Portilla Rd-Vado / WESTERN GULF /
UPPER RIO GRANDE ABO
810 Lechuga Rd-Vado / WESTERN GULF /
UPPER RIO GRANDE ABOVE
7524 Mustang- Vado / WESTERN GULF / UPPER
RIO GRANDE ABOVE P
133 Boone Circle-Anthony 88021 / WESTERN
GULF / UPPER RIO
846 Pajara Rd-Las Cruces 88005 / WESTERN
GULF /UPPER RIO
1 10 Ashtray Rd-Mesquite 88048 / WESTERN
GULF / UPPER RIO G
1800 Overcast Rd- Anthony / WESTERN GULF /
UPPER RIO GRANDE
Data
Points
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Values
Exceeding
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Percentage
values
exceeding
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%'
100%
100%
100%
100%
100%
100%
100%
100%
(continued)
D-21
-------
Appendix D - Water Quality Comparisons
Table D-22. (continued)
Station ID
21NMBHO-BHO119
21NMBHO-BHO120
21NMBHO-BHO121
21NMBHO-BHO122
21NMBHO-BHO123
21NMBHO-BHO124
21NMBHO-BHO126
21NMBHO-BHO128
21NMBHO-BHO129
21NMBHO-BHO130
21NMBHOBH0067
21NMBHO-BHO132
21NMBHO-BHO111
21NMBHO-BH0134
21NMBHO-BH0135
21NMBHO-BHO136
21NMBHO-BHO137
21NMBHO-BHO138
21NMBHO-BHO139
21NMBHO-BH0140
21NMBHO-BHO141
Station Name
2601 W O'Hara Rd--Anthony 88021 / WESTERN
GULF / UPPER RIO
25 10 W O'Hara Rd-Anthony / WESTERN GULF /
UPPER RIO GRANDE
2500 O'Hara Rd-Anthony 88021 / WESTERN
GULF / UPPER RIO GR
7717 Hwy 28- / WESTERN GULF / UPPER RIO
GRANDE ABOVE PECOS
Hwy 28 & O'Hara- / WESTERN GULF / UPPER
RIO GRANDE ABOVE PE
441 Minter Rd»Mesquite 88048 / WESTERN
GULF /UPPER RIO GR
456 Wannabe Rd-Mesquite 88048 / WESTERN
GULF /UPPER RIO G
11816 Hatheway-Mesquite 88048 / WESTERN
GULF / UPPER RIO G
1 1781 Jarmen Dr-Mesquite 88048 / WESTERN
GULF /UPPER RIO
Hwy 192/County Rd B43-Mesquite 88048 /
WESTERN GULF / UPPE
1045 Miranda Rd-Vado / WESTERN GULF /
UPPER RIO GRANDE ABOV
216 W. San Miguel-Mesquite 88048 / WESTERN
GULF/ UPPER RI
Hwy 28--San Miguel / WESTERN GULF / UPPER
RIO GRANDE ABOVE P
1530 Burke Rd-Las Graces 88005 / WESTERN
GULF / UPPER RIO
1660 Burke Rd-Las Cruces 88005 / WESTERN
GULF / UPPER RIO
3719 Bales Rd-Las Cruces 88005 / WESTERN
GULF / UPPER RIO
2460 Burke Rd-Las Cruces 88005 / WESTERN
GULF / UPPER RIO
.1060 Road Runner Rd~Las Cruces 88005 /
WESTERN GULF /UPPE
1240 Burke Road-Las Cruces 88005 / WESTERN
GULF / UPPER Rl
71 1 Long River Lane-Fair Acres / WESTERN
GULF /UPPER RIO G
730 Tamaris -Rio Grande Estates / WESTERN
GULF / UPPER RIO
Data
Points
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Values
Exceeding
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Percentage
values
exceeding
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
(continued)
D-22
-------
Appendix D - Water Quality Comparisons
Table D-22. (continued)
Station ID
21NMBHO-BHO142
21NMBHO-BHO143
2JNMBHO-BHO144
21NMEX-
DA03BI.DAVIES
21NMBHO-BHO131
21NMBHO-BHO088
21NMBHO-BH0068
21NMBHO-BHO072
21NMBHO-BHO073
21NMBHO-BHO074
21NMBHO-BH0075
21NMBHO-BH0076
21NMBHO-BHO077
21NMBHO-BHO079
21NMBHO-BHO080
21NMBHO-BHO081
21NMBHO-BHO083
21NMBHO-BHO085
21NMBHO-BHO114
21NMBHO-BH0087
21NMBHO-BHO113
Station Name
3500 West View -Las Cruces / WESTERN GULF /
UPPER RIO GRAND
553 Fairpark Rd»Fair Acres / WESTERN GULF /
UPPER RIO GRAND
11836Jarmon-Mesquite 88048 / WESTERN
GULF / UPPER RIO GR
STATION ON W END OF TANK 1/4 MI E. OF
ROAD. / WESTERN GULF M
12409 Railroad Dr-Mesquite 88048 / WESTERN
GULF / UPPER Rl
Iglesias Rd-Mesilla Park / WESTERN GULF /
UPPER RIO GRANDE
Lara Rd-Chamberino / WESTERN GULF / UPPER
RIO GRANDE ABOVE
150 Boone Circle-Anthony 88021 / WESTERN
GULF / UPPER RIO
138 Boone Circle-Anthony 88021 / WESTERN
GULF / UPPER RIO
2001 Washington-Anthony 88021 /WESTERN
GULF /UPPER RIO G
1508 W. Washington-Anthony 88021 / WESTERN
GULF / UPPER RI
1509 W. Washington-Anthony 88021 / WESTERN
GULF / UPPER RI
1505 W. Washington-Anthony 88021 / WESTERN
GULF / UPPER RI
1401 W. Washington-Anthony 88021 /WESTERN
GULF/ UPPER RI
Pancho Place- / WESTERN GULF / UPPER RIO
GRANDE ABOVE PECOS
6040 Pancho Place- / WESTERN GULF / UPPER
RIO GRANDE ABOVE
6090 Mariachi Place-Mesilla Park / WESTERN
GULF / UPPER RIO
3810 Mariachi Place-Mesilla Park 88047 /
WESTERN GULF / UP
Hwy 28-1/2 mi south of Dairy-Santa Teresa /
WESTERN GULF /
6009 South Main-Mesilla Park / WESTERN GULF
/UPPER RIO GRA
McNutt and Borderland-Santa Teresa / WESTERN
GULF / UPPER R
Data
Points
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Values
: Exceeding
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Percentage
values
exceeding
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
(continued)
D-23
-------
Appendix D - Water Quality Comparisons
Table D-22. (continued)
Station ID
21NMBHO-BHO089
21NMBHO-BHO092
21NMBHO-BH0094
21NMBHO-BHO095
21NMBHO-BHO096
21NMBHO-BHO097
21NMBHO-BHCX)98
21NMBHO-BHO102
21NMBHO-BH0106
21NMBHO-BH0108
21NMBHO-BHO1 10
21NMBHO-BHO001
21NMBHO-BHO086
Station Name
2292 Old Hwy (Las Palmaras)- / WESTERN GULF
/UPPER RIO GRA
5405 Santa Teresita-Santa Teresa 88008 /
WESTERN GULF /UP
643 Pinabetes-Las Cruces 88001 / WESTERN
GULF /UPPER RIO
388 Meadow Park-Fair Acres / WESTERN GULF /
UPPER RIO GRAND
837 Clark Lane-Las Cruces / WESTERN GULF /
UPPER RIO GRANDE
705 Clark Lane-Las Cruces / WESTERN GULF /
UPPER RIO GRANDE
7335 Harvey Rd-Las Cruces . 88005 / WESTERN
GULF / UPPER RIO
13140 N Hwy 85-Radium Springs / WESTERN
GULF /UPPER RIO GR
2268 Alta Mira-Las Cruces / WESTERN GULF /
UPPER RIO GRANDE
18924 S. Hwy 28-San Miguel 88058 / WESTERN
GULF / UPPER RJ
Hwy 28-San Miguel / WESTERN GULF / UPPER
RIO GRANDE ABOVE P
1205 Road Runner Ln-Las Cruces 80005 /
WESTERN GULF / UPPE
Opal Rd- / WESTERN GULF / UPPER RIO
GRANDE ABOVE PECOS
Data
Points
1
1
1
1
1
1
1
1
1
1
1
1
1
Values
Exceeding
1
1
I
1
1
1
1
1
1
1
1
1
!
Percentage j
values (
exceeding \
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
Table D-23. Water Quality Comparisons for New Mexico: Fecal Coliform
(Water Quality Indicator IDs: 1166,1091)
I . .
1 Station ID
ModSTORET-NM0020010
ModSTORET-NM0020109
ModSTORET-NM00233 1 1
Station Name
Hatch WWTP .
Silver City WWTP
Las Cruces WWTP
Data
Points
2
2
2
Values
Exceeding
2
1
2
Percentage \
values
exceeding j
100%
50%
100%
D-24
-------
Appendix D - Water Quality Comparisons
Table D-24. Water Quality Comparisons for New Mexico: Sulfate
(Water Quality Indicator ID: 1161)
Station ID
21NMEX-LRG046.5
21NMEX-
LRG101.000109
21NMEX-LRG046
21NMEX-
LRG101.000110
21NMEX-LRG053
21NMEX-
LRG101.000101
21NMEX-
LRG101.000125
21NMEX-LRG045.5
21NMEX-
LRG103.002020
21NMEX-LRG047
21NMEX-LRG046.3
21NMEX-
LRG101. 000107
21NMBHO-BHO019
21NMBHO-BHO126
21NMBHO-BHO106
21NMBHO-BHO047
21NMBHO-BHO026
21NMBHO-BHO093
21NMBHO-BHO035
21NMBHO-BHO022
21NMBHO-BHO054
- Station Name
RIO GRANDE AT BRIDGE NEAR LA MESILLA
/ WESTERN GULF / UPPER
RIO GRANDE AT SANTA TERESA / /
RIO GRANDE AT PICACHO AVE IN LAS
CRUCES / WESTERN GULF / UPP
RIO GRANDE NEAR ANTHONY ON NM
HIGHWAY 225 BRIDGE / WESTERN G
RIO GRANDE AT NM HIGHWAY 226 NEAR
BERING / WESTERN GULF / UP
RIO GRANDE BELOW SUNLAND PARK / /
RIO GRANDE NEAR MESQUITE ON
HIGHWAY 192 BRIDGE / WESTERN GUL
RIO GRANDE AT NM HWY 430 NEAR DONA
ANA / WESTERN GULF / UPPE
RIO GRANDE BELOW WILLIAMS / /
RIO GRANDE AT MESILLA DIVERSION DAM /
WESTERN GULF / UPPER R
LAS CRUCES WWTP EFFLUENT DITCH AT
RIO GRANDE / WESTERN GULF
SUNLAND PARK WWTF EFFLUENT / /
Calle,Ruiz #215-- / WESTERN GULF / UPPER
RIO GRANDE ABOVE PE
456 Wannabe Rd-Mesquite 88048 / WESTERN
GULF /UPPER RIO G
2268 Alta Mira-Las Cruces / WESTERN GULF /
UPPER RIO GRANDE
105 N. Virginia-La Union 88021 / WESTERN
GULF / UPPER RIO
1 198 Wanabe Road #3-Mesquite 88048 /
WESTERN GULF / UPPER
McNutt-- / WESTERN GULF / UPPER RIO
GRANDE ABOVE PECOS
810 Lechuga Rd»Vado / WESTERN GULF /
UPPER RIO GRANDE ABOVE
417 Koenig-Mesquite / WESTERN GULF /
UPPER RIO GRANDE ABOVE
immediately west of BHO053 La Union /
WESTERN GULF / UPPER
Data
Points
7
6
6
6
5
5
4
4
4
4
4
4
3
2
2
2
2
2
2
2
1
Values
Exceeding
3
6
3
6
4
5
2
2
1
2
1
4
3
2
2
2
2
2
2
2
1
Percentage
values
exceeding
43%
100%
50%
100%
80%
100%
50%
50%
25%
50%
25%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
(continued)
D-25
-------
Appendix D - Water Quality Comparisons
Table D-24. (continued)
Station ID
21NMBHO-BHO085
21NMBHO-BHO056
21NMBHO-BHO057
21NMBHO-BHO058
21NMBHO-BHO081
21NMBHO-BHO060
21NMBHO-BHO061
21NMBHO-BHO062
21NMBHO-BHO064
21NMBHO-BHO067
21NMBHO-BHO079
21NMBHO-BHO059
21NMBHO-BHO099
21NMBHO-BHO003
21NMBHO-BHO005
21NMBHO-BHO023
21NMBHO-BHO028
21NMBHO-BHO029
21NMBHO-BHO030
21NMBHO-BHO038
21NMBHO-BH0032
21NMBHO-BH0050
Station Name
3810 Mariachi Place-Mesilla Park 88047 /
WESTERN GULF / UP
701 Lopez Rd-Chamberino 88027 / WESTERN
GULF /UPPER RIO G
601 Medina-Chamberino 88027 / WESTERN
GULF / UPPER RIO GRA
201 Lopez --Chamberino 88027 / WESTERN
GULF /UPPER RIO GRA
6040 Pancho Place- / WESTERN GULF / UPPER
RIO GRANDE ABOVE
4169 Sauco Ln.-San Pablo 88005 / WESTERN
GULF / UPPER RIO
1095 Sierra Vista-Berino / WESTERN GULF /
UPPER RIO GRANDE
near valley view dairy- / WESTERN GULF /
UPPER RIO GRANDE A
733 Lechuga Rd-Vado / WESTERN GULF /
UPPER RIO GRANDE ABOVE
1045 Miranda Rd-Vado / WESTERN GULF /
UPPER RIO GRANDE ABOV
1401 W. Washington-Anthony 88021 /WESTERN
GULF/ UPPER RI
4372 S Hwy 28--San Pablo 88005 / WESTERN
GULF / UPPER RIO G
6900 N Hwy 85-Las Cruces 88005 / WESTERN
GULF / UPPER RIO
1705 Road Runner Ln-Las Cruces 80005 /
WESTERN GULF / UPPE
1230 Burke Rd-Las Cruces 80005 / WESTERN
GULF /UPPER RIO
(Moonlight) Rt 1 Box 479-La Mesa/ WESTERN
GULF / UPPER RIO
Vistosos Loop #2-Berino / WESTERN GULF /
UPPER RIO GRANDE A
Calle Vistoso Loop #35-Berino / WESTERN
GULF / UPPER RIO GR
1093 Sierra Vista-Berino / WESTERN GULF /
UPPER RIO GRANDE
216 Lopez St-Chamberino / WESTERN GULF /
UPPER RIO GRANDE A
682 1 Portilla Rd-Vado / WESTERN GULF /
UPPER RIO GRANDE ABO
1313 W Main St-La Union / WESTERN GULF /
UPPER RIO GRANDE A
Data
Points
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Values
Exceeding
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Percentage
values
exceeding
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
(continued)
D-26
-------
Appendix D - Water Quality Comparisons
Table D-24. (continued)
{Station ID
21NMBHO-BHO037
21NMBHO-BHO088
21NMBHO-BHO040
21NMBHO-BHO041
21NMBHO-BH0043
21NMBHO-BHO048
21NMBHO-BHO031
21NMBHO-BHO142
21NMBHO-BHO096
21NMBHO-BHO135
21NMBHO-BHO136
21NMBHO-BHO137
21NMBHO-BHO138
21NMBHO-BH0139
21NMBHO-BHO132
21NMBHO-BHO141
21NMBHO-BHO130
21NMBHO-BH0143
21NMBHO-BHO144
21NMEX-DA01AN.S-
LUCERO
21NMEX-DA02AO.N-
LUCERO
21NMEX-
OT01AP.STINKY
ft .
' ' . Station Name , , ;
Mustang Dr-Vado / WESTERN GULF / UPPER
RIO GRANDE ABOVE PEC
Iglesias Rd-Mesilla Park / WESTERN GULF /
UPPER RIO GRANDE
413 Mendez--La Union 88021 / WESTERN GULF
/ UPPER RIO GRAND
272 South Virginia-La Union 88021 / WESTERN
GULF / UPPER R
301 Mendez--La Union 88021 / WESTERN GULF
/UPPER RIO GRAND
125 N. Virginia-La Union 88021 /WESTERN
GULF / UPPER RIO
121 Warthem-Berino / WESTERN GULF / UPPER
RIO GRANDE ABOVE
3500 West View -Las Cruces / WESTERN GULF /
UPPER RIO GRAND
837 Clark Lane-Las Cruces / WESTERN GULF /
UPPER RIO GRANDE
1660 Burke Rd-Las Cruces 88005 / WESTERN
GULF / UPPER RIO
3719 Bales Rd-Las Cruces 88005 / WESTERN
GULF / UPPER RIO
2460 Burke Rd-Las Cruces 88005 / WESTERN
GULF / UPPER RIO
1060 Road Runner Rd-Las Cruces 88005 /
WESTERN GULF /UPPE
1240 Burke Road-Las Cruces 88005 / WESTERN
GULF/ UPPER RI
216 W. San Miguel-Mesquite 88048 / WESTERN
GULF/ UPPER RI
730 Tamaris -Rio Grande Estates / WESTERN
GULF /UPPER RIO
Hwy 192/County Rd B43-Mesquite 88048 /
WESTERN GULF / UPPE
553 Fairpark Rd-Fair Acres / WESTERN GULF /
UPPER RIO GRAND
11836Jarmon--Mesquite 88048 / WESTERN
GULF /UPPER RIO GR
SAMPLE STATION ON WEST END OF LAKE
VIA MISSLE RA / WESTERN G
SAMPLE STATION NEXT TO RANGE RD 10
ON MISSLE RNG / WESTERN G
LAKE STINKY / WESTERN GULF / UPPER RIO
GRANDE ABOVE PECOS RI
Data
Points
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Values
Exceeding
1
1
1
1
1
1 '
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Percentage
values
exceeding
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
(continued)
D-27
-------
Appendix D - Water Quality Comparisons
Table D-24. (continued)
( .
! Station ID
21NMEX-
OT02BJ.MALPAISP
21NMEX-
SWC000.000050
21NMBHO-BHO140
21NMBHO-BHO103
21NMBHO-BH0090
21NMBHO-BHO092
21NMBHO-BHO094
21NMBHO-BHO095
21NMBHO-BHO002
21NMBHO-BHO098
21NMBHO-BHO133
21NMBHO-BHO100
21NMBHO-BHO089
21NMBHO-BHO105
21NMBHO-BHO108
21NMBHO-BHO116
21NMBHO-BH0124
21NMBHO-BHO125
21NMBHO-BHO128
21NMBHO-BHO129
21NMEX-
SWC000.000055
Station Name
STATION APPROX. 100 YDS S OF SPRING IN
POOL AREA / WESTERN G
APPROX 400 FT BELOW NM0027375
RIODEARENAS MHP / SOUTHWESTERN
71 1 Long River Lane-Fair Acres / WESTERN
GULF / UPPER RIO G
13633 N Hwy 85-Radium Springs / WESTERN
GULF / UPPER RIO OR
1023 Grace- / WESTERN GULF / UPPER RIO
GRANDE ABOVE PECOS
5405 Santa Teresita-Santa Teresa 88008 /
WESTERN GULF / UP
643 Pinabetes-Las Cruces 88001 7 WESTERN
GULF / UPPER RIO
388 Meadow Park-Fair Acres / WESTERN GULF /
UPPER RIO GRAND
1 529 Road Runner Ln-Las Cruces 80005 /
WESTERN GULF /UPPE
7335 Harvey Rd-Las Cruces 88005 / WESTERN
GULF / UPPER RIO
1 10 Ashtray Rd-Mesquite 88048 / WESTERN
GULF /UPPER RIO G
6335 N Hwy 85-Las Cruces 88005 / WESTERN
GULF /UPPER RIO
2292 Old Hwy (Las Palmaras)- / WESTERN
GULF / UPPER RIO GRA
1 7835 N Hwy 85-Radium Springs 88005 /
WESTERN GULF / UPPER
18924 S. Hwy 28-San Miguel 88058 / WESTERN
GULF / UPPER RI
1800 Overcast Rd~Anthony / WESTERN GULF /
UPPER R]O GRANDE
441 Minter Rd-Mesquite 88048 / WESTERN
GULF / UPPER RIO GR
1 1859 Jarmen Dr.-Mesquite 88048 / WESTERN
GULF / UPPER RIO
1 1816 Hatheway-Mesquite 88048 / WESTERN
GULF /UPPER RIO G
1 1781 Jarmen Dr-Mesquite 88048 / WESTERN
GULF / UPPER RIO
APPROX 20 FT ABOVE NM0027375
RIODEARENAS MHP / SOUTHWESTERN
Data
Points
1
1
1
1
1
1
1
1
1
1
1
1 '
1
1
1
1
1
1
1
1
1
Values
Exceeding
1
1
1
1
1
I
1
1
1
1
1
, 1
1
1
1
I
1
1
1
1
1
Percentage
values
exceeding
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
D-28
-------
Appendix D - Water Quality Comparisons
Table D-25. Water Quality Comparisons for New Mexico: Chloride
(Water Quality Indicator IDs: 1087,1159)
i . .;
[ Station ID
ModSTORET-NM002068 1
ModSTORET-NM002331 1
ModSTORET-NM0020109
ModSTORET-NMOOZOO 10
. Station Name
Truth or Consequences WWTP
Las Cruces WWTP
Silver City WWTP
Hatch WWTP
Data
Points
3
1
1
1
Values
Exceeding
. 3
1
1
1
Percentage
values
exceeding
100%
100%
100%
100%
Table D-26. Water Quality Comparisons for New Mexico: pH
(Water Quality Indicator IDs: 29,1076,1077,1135,1136)
Station ID
SCERP-West Mesa WWTF
Station Name
West Mesa Wastewater Treatment Facility
Data
Points
8
Values
Exceeding
6
Percentage
values
exceeding
75%
Table D-27. Water Quality Comparisons for New Mexico: Total Dissolved Solids
(Water Quality Indicator ID: 1445)
| f; -/
t ''.
\ Station ID
"SCERP-West Mesa WWTF
'
Station Name
West Mesa Wastewater Treatment Facility
Data
Points
31
Values
Exceeding
31
Percentage
values
exceeding
100%
D-29
-------
Appendix D - Water Quality Comparisons
D.1.4 Water Quality Comparisons for Texas
The Texas Commission on Environmental Quality, formerly known as the Texas Natural
Resource Conservation Commission has issued detailed surface water quality standards for the
State of Texas (TNRCC, 2000). General criteria apply to surface water in the state and
specifically apply to substances attributed to waste discharges or the activities of humans.
General criteria are superseded by specific exemptions. Specific toxic materials must meet
criteria for protecting aquatic life and human health. Site-specific uses and criteria exist for
contact and noncontact recreation for both freshwater and saltwater. Criteria exist for the
domestic water supply. Application of standards depends also on low flow conditions, mixing
zones, minimum analytical levels, etc. The regulations also include definitions of low flow for
each river segment in Texas. The standards corresponding to the International Amistad Reservoir
are shown in Table D-28. These standards are the strictest among all river segments on the Rio
Grande Basin.
Table D-28. Water Quality Standards for Texas
Parameter
Chloride (mg/L)(l)
Dissolved oxygen (mg/L)
Eco//(CFU/100ml)
Fecal Coliform (CFU/100 ml)
pH
Sulfate(mg/L)(l)
Total Dissolved Solids (mg/L)
Criteria
<150
>5.0
<126
<200
6.5-9.0
<270
<800
Comment [
International Amistad Reservoir
International Amistad Reservoir
International Amistad Reservoir
International Amistad Reservoir
International Amistad Reservoir
International Amistad Reservoir
International Amistad Reservoir
Tables D-29 to D-35 compare Repository data on chlorophyll a, fecal coliform, sulfate,
chloride, dissolved oxygen, e. coli, and total dissolved solids, respectively, to these standards.
D-30
-------
Appendix D - Water Quality Comparisons
Table D-29. Water Quality Comparisons for Texas:
(Water Quality Indicator ID: 1172)
Chlorophyll-a
Station ID
TCEQ-13074
TCEQ-15817
TCEQ-13560
TCEQ-15808
TCEQ-13177
TCEQ-13181
TCEQ-13228
TCEQ-13205
TCEQ- 13072
TCEQ- 13081
TCEQ- 13073
TCEQ- 13229
TCEQ-13272
TCEQ-15528
TCEQ-15795
TCEQ-13447
TCEQ-13446
TCEQ-16730
TCEQ-13185
TCEQ-13086
TCEQ- 13079
TCEQ-13082
TCEQ-16445
TCEQ-16141
TCEQ- 13071
TCEQ-14465
TCEQ-13257
;TCEQ-15114
TCEQ-13039
TCEQ-13246
TCEQ-I3276
TCEQ-13782
TCEQ-13056
TCEQ-15704
TCEQ-13225
TCEQ-13559
.; >:>"/- Station Name '. .-,!. '.b
ARROYO COLORADO /PT.HARLINGEN
RIO GRANDE AT WEBB/ZAPATA CO
RIO GRANDE AT MOODY RANCH
RIO GRANDE ABOVE PHARR BRIDGE
RIO GRANDE AT EL JARDIN PUMP
RIO GRANDE AT US 28 1
RIO GRANDE AT SANTA ELENA CNY
RIO GRANDE NR US277/EAGLE PAS
ARROYO COLORADO MAIN FLOODWAY
RIO GRANDE BELOW RIO CONCHOS
RIO GRANDE AT COURCHESNE BRDG
RIO GRANDE 1.3KM DWNSTRM WWTP
RIO GRANDE AT ALAMO CTRL STRU
LACUNA MADRE GIWW AND ARROYO
LACUNA MADRE GIWW CM 129
RIO GRANDE VILLAGE BOAT RAMP
ARROYO COLORADO AT DILWORTH R
ARROYO COLORADO & COMMERCE ST
ARROYO COLORADO AT CM 22
RIO GRANDE AT RIVERSIDE CANAL
PECOSRIVERATUS67
PECOS R. ABOVE US 290
PECOS R. NR. VAL VERDE CO. LN
RIO GRANDE ABOVE ANTHONY DRAI
ARROYO COLORADO CM 16
RIO GRANDE AT TORNILLO-CASETA
RIO GRANDE AT FM 2627
ARROYO COLORADO AT CM27, MI 1
Data
Points
59
57
45
44
43
42
41
41
38
38
38
37
35
31
26
25
25
24
23 '
21
21 .
21
21
20
20
19
19
19
19
18
18
18
18
18
17
17
Values
,,. Exceeding
55
49
29
32
40
31
37
30
34
35
34
33
34
24
24
20
11
24
23
19
21
18
18
19
14
16
14
16
17
14
12
|_ 14
10
17
11
15
Percentage
values exceeding
93%
86%
64%
73%
93%
74%
90%
73%
89%
92%
89%
89%
97%
77%
92%
80%
44%
100%
100%
90%
100%
86%
86%
95%
70%
84%
74%
84%
89%
78%
67%
78%
56%
94%
65%
88%
(continued)
D-31
-------
Appendix D - Water Quality Comparisons
Table D-29. (continued)
1 . ;: .;.':-''
|;StationJPV:;:;V
TCEQ-13184
TCEQ-13084
TCEQ-17113
TCEQ-13459
TCEQ-13460
TCEQ-14875
TCEQ-13448
TCEQ-15892
TCEQ-15814
TCEQ-15893
TCEQ-13285
TCEQ-15820
TCEQ- 13206
TCEQ-15529
TCEQ-13202
TCEQ-14942
TCEQ-13835
TCEQ-13103
TCEQ-13270
TCEQ-17407
TCEQ-17596
TCEQ-17114
TCEQ-17115
TCEQ-17247
TCEQ-17111
TCEQ-16379
TCEQ-13223
TCEQ-17112
TCEQ-15818
TCEQ-15274
TCEQ-15821
TCEQ-13189
TCEQ-13179
TCEQ-13116
TCEQ-14870
TCEQ-16288
TCEQ-14871
TCEQ-14865
TCEQ-13255
:".. ./.'.'':is'L:^J-Statiqii;iNaiiie;i;, :;,.;;.;' ;.'^ Cy
DRAINAGE DITCH HARDING RANCH
SOUTH BAY NEAR SHIP CM 17
BROWNSVILLE SHIP CHANNEL CM 3
BROWNSVILLE SHIP CHANNEL
LACUNA MADRE AT GIWW
AMISTAD RESERV RIO GRANDE ARM
RIO GRANDE AT INTL BRIDGE #2
AMISTAD RESERV DEVILS R ARM
PORT ISABEL AT SH 100
SAN FELIPE CK AT WEST SPRINGS
RIO GRANDE AT US 277
RIO GRANDE UPSTR HASKELL WWTP
RIO GRANDE LAREDO WTP PUMP
DOLAN SPRGS AT DEVILS R CONFL
SAN FELIPE CK AT GUYLER CONFL
RIO GRANDE UPSTRM OF CANDELAR
RIO GRANDE AT APACHE RANCH
HIDALGO POTW OUTFALL
MISSION POTW DISCHARGE DITCH
RIO GRANDE UPSTRM OF FM 1015
DONNA POTW DISCHARGE DITCH
PECOS RIVER BELOW US90W BR1DG
RIO GRNADE AT FOSTER RANCH
MERCEDES POTW DISCHARGE DITC
FALCON RES AT SAN YGNACIO WTP
RIO GRANDE AT IBWC WEIR DAM
SAN FELIPE CK AT BLUEHOLE GAT
RIO GRANDE AT RIVER BEND
LAGUN A MADRE NEAR LACUNA VIST
RIO GRANDE AT SABAL PALM
BROWNSVILLE SHIP CHANNEL
SOUTH BAY
PECOS RIVER AT FM 1901
Data
Joints;;
17
17
17
17
17
17
16
15
15
14
14
14
14
13
13
13
12
10
10
10
10
9
9
9
9
9
9
8
8
8
7
7
5
4
4
3
3
3
1
': : ' Values ' '
Exceeding; ,
17
14
8
5
7
15
10
8
11
7
5
5
9
13
7
1
4
8
3
10
10
9
6
5
2
7
2
7
6
1
2
7
4
4
2
2
2
2
1
Percentage i
values exceeding J
100%
82%
47%
29%
41%
88%
63%
53%
73%
50%
36%
36%
64%
100%
54%
8%
33%
80%
30%
100%
100%
100%
67%
56%
22%
78%
22%
88%
75%
13%
29%
100%
80%
100%
50%
67%
67%
67%
100%
D-32
-------
Appendix D Water Quality Comparisons
Table D-30. Water Quality Comparisons for Texas: Fecal Coliform
(Water Quality Indicator IDs: 1091,1166,1181)
Station ID
CNA-PSRB-02
CNA-PSRB-04
CNA-PSRB-23
CNA-PSRB-24
CNA-SSRB-25
CNA-SSRB-36
TCEQ-13039
TCEQ-13056
TCEQ-13072
TCEQ- 13073
TCEQ-13074
TCEQ-13079
TCEQ-13081
TCEQ-13082
TCEQ-13084
TCEQ-13086
TCEQ-13103
TCEQ-13177
TCEQ-13181
TCEQ-13185
TCEQ-13196
TCEQ-13201
TCEQ-13202
TCEQ-13205
TCEQ-13206
TCEQ-13225
TCEQ-13228
TCEQ-13229
TCEQ- 13270
TCEQ-13272
TCEQ-13276
TCEQ-13285
TCEQ-13447
TCEQ-13559
TCEQ-13560
. , * , -X , , ' ;! , . '' ._; _f , . r ... .{ ^ .J ';-!. ';_ ' . ' .:
; < ''.!..' ' s: . " ,'. '' *" .-'.-.; ;" ;,' , ,_
<:ij V~" '': , ":' <: '" : ' : Station Name ;,;VV ;' :. ;'i X :'';:V;- ;'"; ;:r
Km 0+000, PUENTE INTERNACIONAL CD. JUAREZ
PUENTE INTERNACIONAL FORT-HANKOK
PUENTE INTERNACIONAL 1. NUEVO LAREDO
R. BRAVO-PARQUE INDUSTRIAL ACUNA
PUENTE INTERNACIONAL REYNOSA
PUENTE INT. CAMARGO
.
ARROYO COLORADO /PT.HARLINGEN
ARROYO COLORADO MAIN FLOODWAY
RIO GRANDE AT EL JARDIN PUMP
RIO GRANDE AT US 281
RIO GRANDE BELOW LAREDO
RIO GRANDE LAREDO WTP PUMP
RIO GRANDE NR US277/EAGLE PAS
RIO GRANDE AT US 277
RIO GRANDE AT FM 2627
RIO GRANDE AT SANTA ELENA CNY
RIO GRANDE BELOW RIO CONCHOS
SAN FELIPE CK AT GUYLER CONFL
RIO GRANDE AT COURCHESNE BRDG
RIO GRANDE ABOVE ANTHONY DRAI
PORT ISABEL AT SHI 00
LACUNA MADRE GIWW AND ARROYO
ARROYO COLORADO AT CM27, MI 1
RIO GRANDE AT MOODY RANCH
;:.-. 'Data..-'-.
PoWts
1
1
8
9
6
4
6
6
25
21
26
16
26
17
8
17
6
35
34
22
30
29
44
43
14
11
26
35
6
109
11
7
22
10
44
Values i
Exceeding
1
1
8
2
1
1
5
5
9
7
21
12
25
17
5
16
4
14
13
2
24
24
12
24
2
3
8
27
4
95
6
1
1
2
23
Percentage
'values ."
exceeding
100%
100%
100%
22%
17%
25%
83%
83%
36%
33%
81%
75%
96%
100%
63%
94%
67%
40%
38%
9%
80%
83%
27%
56%
14%
27%
31%
77%
67%
87%
55%
14%
5%
20%
' 52%
(continued)
D-33
-------
Appendix D Water Quality Comparisons
Table D-30. (continued)
j Station IDj
TCEQ- 13782
TCEQ-14465
TCEQ-15528
TCEQ-15529
TCEQ-15704
TCEQ-15795
TCEQ-15808
TCEQ-15813
TCEQ-15814
TCEQ-15815
TCEQ-15817
TCEQ-15818
TCEQ-15820
TCEQ-16141
TCEQ-16445
TCEQ- 16730
TCEQ- 17000
TCEQ-17001
TCEQ-17111
TCEQ-17112
TCEQ-17113
TCEQ-17114
TCEQ-17115
- '& .... ; ^: .... .',, -'", ';." :'J~ , r; / ; ' .; < ' '' -. .;;"
" - ". ' '- ,,; ' " ..' " : . .* . ';: Station Name";"' : ; " -' ' ': ; ; ;.::
ARROYO COLORADO CM 16
RIO GRANDE AT RIVERSIDE CANAL
RIO GRANDE 1 .3KM DWNSTRM WWTP
RIO GRANDE UPSTR HASKELL WWTP
RIO GRANDE AT TORNILLO-CASETA
RIO GRANDE AT ALAMO CTRL STRU
RIO GRANDE ABOVE PHARR BRIDGE
RIO GRANDE AT CP&L POWER PLAN
RIO GRANDE AT INTL BRIDGE #2
RIO GRANDE AT MASTERSON RD
RIO GRANDE AT WEBB/ZAPATA CO
FALCON RES AT SAN YGNACIO WTP
SAN FELIPE CK AT WEST SPRINGS
ARROYO COLORADO & COMMERCE ST
ARROYO COLORADO AT OIL WORTH R
RIO GRANDE VILLAGE BOAT RAMP
RIO GRANDE PRESIDIO RR BRIDGE
RIO GRANDE PRESIDIO/OJINAGA
DONNA POTW DISCHARGE DITCH
MERCEDES POTW DISCHARGE DITC
DRAINAGE DITCH HARDING RANCH
HIDALGO POTW OUTFALL
MISSION POTW DISCHARGE DITCH
Data
' JPpiats;" '
10
79
110
94
1
28
35
17
45
31
38
6
1
12
17
11
21
20
9
9
8
9
9
Values
Exceeding:
1
32
73
65
1
16
15
2
37
26
13
3
1
10
15
2
20
4
8
9
6
9
8
Percentage!
values 1
exceeding |
10%
41%
66%
69%
100%
57%
43%
12%
82%
84%
34%
50%
100%
83%
88%
18%
95%
20%
89%
100%
75%
' 100%
89%
D-34
-------
Appendix D - Water Quality Comparisons
Table D-31. Water Quality Comparisons
(Water Quality Indicator ID:
for Texas: Sulfate
1161)
Station ID
TCEQ-13272
TCEQ-15528
TCEQ-15529
TCEQ-14465
TCEQ-13229
TCEQ- 13074
TCEQ-15817
TCEQ-13560
TCEQ-13177
TCEQ-13205
TCEQ-13079
TCEQ-13181
TCEQ-15808
TCEQ- 13228
TCEQ-13073
TCEQ- 13072
TCEQ- 15795
TCEQ- 13081
TCEQ-13185
TCEQ- 13223
TCEQ- 16730
TCEQ- 13447
TCEQ-13446
TCEQ-13184
TCEQ-16445
TCEQ- 13086
TCEQ-16141
TCEQ-13082
TCEQ-13071
TCEQ-13240
TCEQ-15114
TCEQ-13257
TCEQ-13039
TCEQ-13056
"V -*'"'' '£?:. - -Station -Naiaie'., -.'.,:'.';'/'_;',,,_>,'
RIO GRANDE AT COURCHESNE BRDG
RIO GRANDE 1.3KM DWNSTRM WWTP
RIO GRANDE UPSTR HASKELL WWTP
RIO GRANDE AT RIVERSIDE CANAL
RIO GRANDE BELOW RIO CONCHOS
ARROYO COLORADO /PT.HARLINGEN
RIO GRANDE AT WEBB/ZAPATA CO
RIO GRANDE AT MOODY RANCH
RIO GRANDE AT EL JARDIN PUMP
RIO GRANDE NR US277/EAGLE PAS
RIO GRANDE AT US 281
RIO GRANDE ABOVE PHARR BRIDGE
RIO GRANDE AT SANTA ELENA CNY
RIO GRANDE AT ALAMO CTRL STRU
ARROYO COLORADO MAIN FLOOD WAY
RIO GRNADE AT FOSTER RANCH
RIO GRANDE VILLAGE BOAT RAMP
LACUNA MADRE GIWW AND ARROYO
LACUNA MADRE GIWW CM 1 29
ARROYO COLORADO AT DILWORTH R
ARROYO COLORADO & COMMERCE ST
ARROYO COLORADO AT CM 22
PECOS RIVER NEAR LANGTRY
PECOS R. ABOVE US 290
PECOS RIVER AT US 67
Data
. Points
118
113
94
81
59
59
57
51
51
46
46
45
45
43
38
38
38
38
33
30
26
25
25
24
21
21
21
21
20
20
19
19
19
19
; Values
Exceeding
38
47
34
24
57
57
1
1
6
2
43
3
2
41
37
36
31
37
1
21
22
25
25
2
20
20
21
21
18
19
19
19
16
11
Percentage
values
exceeding
32%
42%
36%
30%
97%
97%
2%
2%
12%
4%
93%
7%
4%
95%
97%
95%
82%
97%
3%
70%
85%
100%
100%
8%
95%
95%
100%
100%
90%
95%
100%
100%
84%
58%
(continued)
D-35
-------
Appendix D - Water Quality Comparisons
Table D-31. (continued)
Station ID
TCEQ- 13782
TCEQ- 13246
TCEQ- 15704
TCEQ-13276
TCEQ- 13084
TCEQ-13225
TCEQ- 14875
TCEQ-13459
TCEQ-13448
TCEQ-13460
TCEQ- 13559
TCEQ-17113
TCEQ-13285
TCEQ- 17407
TCEQ-13103
TCEQ-17596
TCEQ-17247
TCEQ-17115
TCEQ-17114
TCEQ-16379
TCEQ-171 1 1
TCEQ-17112
TCEQ-18196
TCEQ-13116
TCEQ-14870
TCEQ-14871
TCEQ-14865
TCEQ-16288
TCEQ-13255
.. ' ' : ';'-' ;' 'Station Name V.: .:.>.'.-
ARROYO COLORADO CM 16
PECOS R. NR. VAL VERDE CO. LN
RIO GRANDE AT TORNILLO-CASETA
RIO GRANDE ABOVE ANTHONY DRA1
RIO GRANDE AT FM 2627
BROWNSVILLE SHIP CHANNEL
SOUTH BAY NEAR SHIP CM 17
LAGUNA MADRE AT GIWW
BROWNSVILLE SHIP CHANNEL CM 3
ARROYO COLORADO AT CM27, MI 1
DRAINAGE DITCH HARDING RANCH
PORT ISABEL AT SH 1 00
RIO GRANDE UPSTRM OF CANDELAR
RIO GRANDE AT APACHE RANCH
RIO GRANDE UPSTRM OF FM 1015
MISSION POTW DISCHARGE DITCH
HIDALGO POTW OUTFALL
PECOS RIVER BELOW US90W BRIDG
DONNA POTW DISCHARGE DITCH
MERCEDES POTW DISCHARGE DITC
UNNAMED DITCH SOUTH OF FM 510
LAGUNA MADRE NEAR LAGUNA VIST
BROWNSVILLE SHIP CHANNEL
SOUTH BAY
RIO GRANDE AT SABAL PALM
PECOS RIVER AT FM 1901
Data ,;'
, Points
18
18
18
18
17
17
17
17
17
17
17
17
14
10
10
10
10
9
9
9
9
9
5
4
4
3
3
3
1
, Values
Exceeding
18
18
10
4
17
15
17
17
.17
17
17
17
14
10
6
1
2
8
3
6
8
9
4
3
4
3
3
2
1
Percentage j
' . valuesr ' J
exceeding j
100%
100%
56%
22%
100%
88%
100%.
100%
100%
100%
100%
100%
100%
100%
60%
10%
20%
89%
33%
67%
89%
100%
80%
75%
100%
100%
100%
67%
100%
D-36
-------
Appendix D ~ Water Quality Comparisons
Table D-32. Water Quality Comparisons for Texas: Chloride
(Water Quality Indicator ID: 1159,1046,1087)
station lu
TCEQ-13272
TCEQ-15528
TCEQ-15529
TCEQ-14465
TCEQ-13229
TCEQ-13074
TCEQ-13177
TCEQ-13205
TCEQ-13079
TCEQ-13181
TCEQ-15808
TCEQ-13228
TCEQ-13081
TCEQ-13073
TCEQ-13072
TCEQ-15795
TCEQ-13185
TCEQ-13223
TCEQ-16730
TCEQ- 13447
TCEQ-13196
TCEQ-13446
TCEQ-13184
TCEQ-13082
TCEQ-16445
TCEQ-16141
TCEQ-13086
TCEQ-13071
TCEQ-13240
TCEQ-15114
TCEQ-13056
TCEQ-13039
TCEQ-13257
TCEQ- 13246
' ._ - .... .-; -g. -,..,' _ -. - .!>, !,", . -_?. - _;'_
' ";,-, ISlHuOu Maal* _.',:' " '!':
RIO GRANDE AT COURCHESNE BRDG
RIO GRANDE 1.3KM DWNSTRM WWTP
RIO GRANDE UPSTR HASKELL WWTP
RIO GRANDE AT RIVERSIDE CANAL
RIO GRANDE BELOW RIO CONCHOS
ARROYO COLORADO /PT.HARLINGEN
RIO GRANDE AT EL JARDIN PUMP
RIO GRANDE NR US277/EAGLE PAS
RIO GRANDE AT US 281
RIO GRANDE ABOVE PHARR BRIDGE
RIO GRANDE AT SANTA ELENA CNY
ARROYO COLORADO MAIN FLOODWAY
RIO GRANDE AT ALAMO CTRL STRU
RIO GRNADE AT FOSTER RANCH
RIO GRANDE VILLAGE BOAT RAMP
LAGUNA MADRE GIWW AND ARROYO
RIO GRANDE BELOW LAREDO
LAGUNA MADRE GIWW CM 129
ARROYO COLORADO AT DILWORTH R
ARROYO COLORADO & COMMERCE ST
ARROYO COLORADO AT CM 22
PECOS RIVER NEAR LANGTRY
PECOS R. ABOVE US 290
'
PECOS RIVER AT US 67
PECOS R. NR. VAL VERDE CO. LN
Data
. roincs ..
117
107
88
77
59
59
51
46
46
45
45
43
38
38
38
36
33
30
26
25
25
25
, 24
21
21
21
21
20
20
19
19
19
19
18
, Values
Exceeding
40
41
32
27
54
57
36
1
44
19
18
36
38
38
38
34
3
11
17
25
1
25
6
21
20
21
21
19
20
19
18
18
19
18
Percentage
values
exceeding
34%
38%
36%
35%
92%
97%
.71%
2%
96%
42%
40%
84%
100%
100%
100%
94%
9%
37%
65%
100%
4%
100%
25%
100%
95%
100%
100%
95%
100%
. 100%
95%
95%
100%
100%
(continued)
D-37
-------
Appendix D - Water Quality Comparisons
Table D-32. (continued)
Station ID
TCEQ- 13782
TCEQ-13276
TCEQ- 15704
TCEQ-13448
TCEQ-13459
TCEQ-13460
TCEQ-13559
TCEQ-13225
TCEQ-13084
TCEQ-14875
TCEQ-17H3
TCEQ-15892
CNA-PSRB-04
TCEQ-13285
CNA-PSRB-02
TCEQ-17247
TCEQ-175%
TCEQ-17407
TCEQ-13103
TCEQ-16379
TCEQ-17111
TCEQ-17112
TCEQ-17114
TCEQ-17115
CNA-SSRB-36
TCEQ-13179
TCEQ-18196
TCEQ-14870
TCEQ-13116
TCEQ-16288
TCEQ- 14871
TCEQ-14865
'.'' " -':" .. ' . .' Station Name ; ''- .,; ''' "->j; '';
ARROYO COLORADO CM 16
RIO GRANDE ABOVE ANTHONY DRAI
RIO GRANDE AT TORNILLO-CASETA
LAGUNA MADRE AT GIWW
SOUTH BAY NEAR SHIP CM 17
BROWNSVILLE SHIP CHANNEL CM 3
ARROYO COLORADO AT CM27, MI 1
RIO GRANDE AT FM 2627
BROWNSVILLE SHIP CHANNEL
DRAINAGE DITCH HARDING RANCH
AMISTAD RESERV RIO GRANDE ARM
PUENTE INTERNACIONAL FORT-HANKOK
PORT ISABEL AT SH 100
Km 0+000, PUENTE INTERNACIONAL CD. JUAREZ
RIO GRANDE UPSTRM OF FM 1015
RIO GRANDE AT APACHE RANCH
RIO GRANDE UPSTRM OF CANDELAR
PECOS RIVER BELOW US90W BRIDG
DONNA POTW DISCHARGE DITCH
MERCEDES POTW DISCHARGE DITC
HIDALGO POTW OUTFALL
MISSION POTW DISCHARGE DITCH
PUENTE INT. CAMARGO
RIO GRANDE AT RIVER BEND
UNNAMED DITCH SOUTH OF FM 510
LAGUNA MADRE NEAR LAGUNA VIST
RIO GRANDE AT SABAL PALM
BROWNSVILLE SHIP CHANNEL
SOUTH BAY
''.pata'r
Points
18
18
18
17
17
17
17
17
17
17
17 -
16
14
14
14
10
10
10
10
9
9
9
9
9
6
5
5
4
4
3
3
3
Values: :
Exceeding
18
3
18
17
17
17
17
8
17
17
17 '
4
10
14
4
4
1
10
9
9
9
9
9
9
6
4
5
4
3
3
3
3
Percentage}
values 1
exceeding j
100%
17%
100%
100%
100%
100%
100%
47%
100%
100%
100%
25%
71%
100%
29%
40%
10%
100%
90%
100%
100%
100%
100%
100%
100%
80%
100%
100%
75%
100%
100%
100%
D-38
-------
Appendix D - Water Quality Comparisons
Table D-33. Water Quality Comparisons for Texas: Dissolved Oxygen
(Water Quality Indicator IDs: 1211,1127,1089,1073)
t. V * **
Station ID
CNA-PSRB-02
CNA-PSRB-04
TCEQ- 13039
TCEQ-13056
TCEQ-13071
TCEQ-13072
TCEQ-13073
TCEQ-13074
TCEQ-13079
TCEQ-13081
TCEQ-13082
TCEQ-13084
TCEQ-13086
TCEQ-13103
TCEQ-13177
TCEQ-13179
TCEQ-13181
TCEQ-13185
TCEQ-13205
TCEQ-O209
TCEQ-13223
TCEQ-13229
TCEQ-13257
TCEQ-13272
TCEQ- 13276
TCEQ- 13285
TCEQ-13446
TCEQ-13447
TCEQ- 13448
TCEQ- 13460
TCEQ- 13559
TCEQ-13560
TCEQ-13782
TCEQ-13835
TCEQ-14465
,:;;; i: :''..':' ~V ^station Name.,;^'i..;:'A''!;!'..: ? ,"
Km 0+000, PUENTE INTERNACIONAL CD. JUAREZ
PUENTE INTERNACIONAL FORT-HANKOK
ARROYO COLORADO AT CM 22
ARROYO COLORADO /PT.HARLINGEN
ARROYO COLORADO MAIN FLOODWAY
RIO GRANDE AT EL JARDIN PUMP
RIO GRANDE AT RIVER BEND
RIO GRANDE AT US 28 1
RIO GRANDE NR US277/EAGLE PAS
RIO GRANDE BELOW AMISTAD DAM
RIO GRNADE AT FOSTER RANCH
RIO GRANDE BELOW RIO CONCHOS
PECOS RIVER AT US 67
RIO GRANDE AT COURCHESNE BRDG
RIO GRANDE ABOVE ANTHONY DRAI
PORT ISABEL AT SHI 00
LACUNA MADRE GIWW CM 129
LACUNA MADRE GIWW AND ARROYO
LACUNA MADRE AT GIWW
BROWNSVILLE SHIP CHANNEL CM 3
ARROYO COLORADO AT CM27, MI 1
RIO GRANDE AT MOODY RANCH
ARROYO COLORADO CM 16
RIO GRANDE AT RIVERSIDE CANAL
, f ,.
VData \
' Points
10
10
19
18
55
232
153
40
44
39
20
15
20
9
55
5
47
24
60
18
28
66
19
130
14
36
57
50
44
96
55
56
55
197
89
Values
.Exceeding
4
3
2
9
17
' 161
98
6
2
1
3
4
2
1
12
1
1
1
1
6
1
2
4
1
1
1
1
8
5
2
27
2
13
41
7
Percentage
values ';
exceeding
40%
30%
11%
50%
31%
69%
64%
15%
5%
3%
15%
27%
10%
11%
22%
20%
2%
4%
2%
33%
4%
3%
21%
1%
7%
3%
2%
16%
11%
2%
49%
4%
24%
21%
8%
(continued)
D-39
-------
Appendix D - Water Quality Comparisons
Table D-33. (continued)
5 " !! '.,.-
i Station ID "
TCEQ-14871
TCEQ-14875
TCEQ-15114
TCEQ-15704
TCEQ-15795
TCEQ-15808
TCEQ-15892
TCEQ-15893
TCEQ-16141
TCEQ-16730
TCEQ-17111
TCEQ-17113
TCEQ-17114
TCEQ-17115
TCEQ-17247
TCEQ-17621
TCEQ-17643
TCEQ-17644
TCEQ-17650
TCEQ-18196
: ^ V.'-'''-. ; Station Name ' ., ..." ,'-'-"
BROWNSVILLE SHIP CHANNEL
BROWNSVILLE SHIP CHANNEL
PECOS R. ABOVE US 290
RIO GRANDE AT TORNILLO-CASETA
RIO GRANDE AT ALAMO CTRL STRU
RIO GRANDE ABOVE PHARR BRIDGE
AMISTAD RESERV RIO GRANDE ARM
AMISTAD RESERV DEVILS R ARM
ARROYO COLORADO & COMMERCE ST
RIO GRANDE VILLAGE BOAT RAMP
DONNA POTW DISCHARGE DITCH
DRAINAGE DITCH HARDING RANCH
HIDALGO POTW OUTFALL
MISSION POTW DISCHARGE DITCH
RIO GRANDE UPSTRM OF FM 1015
RIO GRANDE 5 MI. DS OF SANTA
DRAINAGE DITCH AT FM 1846
DRAINAGE DITCH AT FM 2062
ARROYO COLORADO TIDAL P OF HA
UNNAMED DITCH SOUTH OF FM 5 10
- : ' i-
Data
Points
28
64
19
13
62
47
171
120
21
31
8
17
8
8
10
4
13
12
40
5
/Values -
: Exceeding
9
7
1
1
9
1
16
18
1
1
6
9
3
4
2
1
2
1
25
1
Percentage j
; -values:'']
exceeding I
32%
11%
5%
8%
15%
2%
9%
15%
5%
3%
75%
53%
38%
50%
20%
25%
15%
8%
63%
20%
D-40
-------
Appendix D - Water Quality Comparisons
Table D-34. Water Quality Comparisons for Texas: E. coli
(Water Quality Indicator IDs: 1167,1170,1090)
Station ID
TCEQ-13272
TCEQ-15814
TCEQ-15528
TCEQ-15815
TCEQ-13177
TCEQ-13201
TCEQ- 13205
TCEQ- 15795
TCEQ-13560
TCEQ- 15529
TCEQ-13196
TCEQ-13081
TCEQ-14465
TCEQ-15808
TCEQ-13181
TCEQ-17000
CILA_Monitoreo_
Laredo-2
Cl L A_Monitoreo_
Laredo-5
TCEQ-13084
TCEQ-13086
TCEQ-15704
TCEQ-13074
TCEQ-13228
TCEQ-13229
TCEQ-13276
TCEQ-13072
TCEQ-13079
TCEQ-13082
TCEQ-13185
TCEQ-13202
TCEQ-13071
TCEQ-13103
TCEQ-16141
s. i ' 4,1.
. ' > <
Station Name *-*">,:,., ....
RIO GRANDE AT COURCHESNE BRDG
RIO GRANDE AT INTL BRIDGE #2
RIO GRANDE 1 .3KM DWNSTRM WWTP
RIO GRANDE AT MASTERSON RD
RIO GRANDE AT EL JARDIN PUMP
RIO GRANDE NR US277/EAGLE PAS
RIO GRANDE AT ALAMO CTRL STRU
RIO GRANDE AT MOODY RANCH
RIO GRANDE UPSTR HASKELL WWTP
RIO GRANDE BELOW LAREDO
ARROYO COLORADO MAIN FLOODWAY
RIO GRANDE AT RIVERSIDE CANAL
RIO GRANDE ABOVE PHARR BRIDGE
RIO GRANDE AT US 281
RIO GRANDE PRESIDIO RR BRIDGE
Rio Bravo en Masterson Road
Rio Bravo 1.6 Km (1 milla) abajo del Arroyo Coyotes
(PIT ARN
RIO GRANDE AT TORNILLO-CASETA
ARROYO COLORADO /PT.HARLINGEN
RIO GRANDE AT SANTA ELENA CNY
RIO GRANDE BELOW RIO CONCHOS
RIO GRANDE ABOVE ANTHONY DRAI
RIO GRANDE LAREDO WTP PUMP
ARROYO COLORADO AT CM 22
ARROYO COLORADO & COMMERCE ST
Data
Points
39
31
32
23
28
21
26
20
26
24
22
19
19
23
24
14
7
7
10
7
7
15
24
18
12
8
5
7
24
28
4
6
4
.Values
Exceeding
37
23
21
18
17
17
17
17
16
15
14
13
12
10
8
8
7
7
6
6
6
5
5
5
5
4
4
4
4
4
3
3
3
Percentage
lvalues. ,
exceeding
95%
74%
66%
78%
61%
81%
65%
85%
62%
63%
64%
68%
63%
43%
33%
57%
100%
100%
60%
86%
86%
33%
21%
28%
42%
50%
80%
57%
17%
14%
75%
50%
75%
(continued)
D-41
-------
Appendix D - Water Quality Comparisons
Table D-34. (continued)
Station ID , :
TCEQ-16445
TCEQ-16730
TCEQ-13073
TCEQ-13246
TCEQ-13270
TCEQ-13116
TCEQ- 13225
TCEQ-13447
TCEQ-13782
TCEQ-15114
TCEQ-15817
TCEQ-16288
TCEQ-17001
TCEQ-17247
TCEQ-17596
-.." r< -,; " ' '-A -;.:- -.;> -"''' '.-'.-^ -:'. ': \ ~'-
Station Name .",.; ;i"::: ' ; ,:;- .' V / . :,:.:,, ;_^:
ARROYO COLORADO AT OIL WORTH R
RIO GRANDE VILLAGE BOAT RAMP
PECOS R. MR. VAL VERDE CO. LN
SAN FELIPE CK AT GUYLER CONFL
RIO GRANDE AT FM 2627
LAGUNA MADRE GIWW AND ARROYO
ARROYO COLORADO CM 16
PECOS R. ABOVE US 290
RIO GRANDE AT WEBB/ZAPATA CO
RIO GRANDE AT SABAL PALM
RIO GRANDE PRESIDIO/OJINAGA
RIO GRANDE UPSTRM OF FM 1015
RIO GRANDE AT APACHE RANCH
' ':^Pata\h;
Points-;-
7
19
2
13
4
1
6
I
1
8
17
2
14
10
10
Values
Exceeding
3
3
2
2
2
1
1
1
1
1
1
1
1
1
1
Percentage
.: .-values-3-*
exceeding
43%
16%
100%
15%
50%
100%
17%
100%
100%
13%
6%
50%
7%
10%
10%
Table D-35. Water Quality Comparisons for Texas: Total Dissolved Solids
(Water Quality Indicator ID: 1445)
iSiatioi:!lp;jl ;:
CNA-PSRB-02
CNA-PSRB-04
CNA-SSRB-36
; ;; :~J- J^'^i/V'-'statlpniNam*::-1 : > .£*'" v/'' i/4-^
Km 0+000, PUENTE INTERNACIONAL CD. JUAREZ
PUENTE INTERNACIONAL FORT-HANKOK.
PUENTE INT. CAMARGO
Data "
Points'
14
14
6
Values
Exceeding ;
5
14
6
Percentage
values
exceeding
36%
100%
100%
D-42
-------
Appendix D - Water Quality Comparisons
D.2 Water Quality Standards and Comparisons for Mexico
Table D-36 shows Mexico's ecological criteria for water quality (Norm 13) for various
water types/uses.
c
Table D-36. Water Quality Standards for Mexico: Ecological Criteria8
Parameter
Chlorides (as C1-)
Dissolved solids
Dissolved Oxygen'
Electrical conductivity
(mmhos/cm)
Elementary
phosphorus
Fecal coliform
Fluorides (as F-)
Nitrates (NO3 as N)
Nitrites (N02 as N)
PH1
Phosphates (as PO4)
Su!fates(SO4)
Suspended solids
Temperature (C)
Total Solids
Drinking
water
supply
source
250.0
500.0
4.0
-
-
1,000.0
1.5
5.0
0.05
5.0-9.0
0.1
500.0
500.0
Natural
Conditions +
2.5
1,000.0
Recreation
with direct
contact
-
-
-
-
-
e
-
-
-
-
-
-
-
-
Agri-
cultural
irrigation
147.5
500.0 b
-
1.0"
-
1,000.0
1.0
.
-
4.5-9.0
-
130.0
50.0
-
Livestock
-
1,000.0
-
-
-
-
2.0
90.0
10.0
-
-
-
-
Fresh water
250.0
-
5.0
-
0.0001
e
1.0
-
-
g
h
0.005
i
Natural
Conditions +
1.5
-
Marine
waters
.(coastal
areas)
-
-
5.0
-
0.0001
e
0.5
0.04
0.002
B
0.002
-
i
Natural
Conditions +
1.5
-
* Maximum levels in mg/L except when another unit is indicated
b The concentration of dissolved solids that have no harmful effect on any cultivation is from 500 mg/L, in sensitive
cultivation it is from between 500 and 1000 mg/1 in many harvests that require special handling it is between 1000
and 2000 mg/1 and for cultivation of tolerant plants in permeable soils it is between 2000 and 5000 mg/1 required
by special handling.
c For dissolved oxygen, the established levels shall be considered minimums.
d The level takes into consideration the use of water under average conditions of soil texture, speed of infiltration,
drainage, irrigation-plate used, climate and the tolerance of cultivation to salts. Considerable deviance from the
average value of these variables may make use of this water unsafe.
e Organisms shall not exceed 200 as the most probable number in 100 milliliters (NMP/lOOmI) in fresh or marine
water, and no more than 10% of the monthly samples may exceed 400 NMP/lOOml.
r For Hydrogen potential (pH), the established level shall be considered minimums and maximums.
8 There can be no variations greater than 0.2 pH units, using the normal seasonal value as a base.
h The total phosphates, measured as phosphorus, shall not exceed 0.005 mg/1 in tributaries to lakes or reservoirs or
0.025 mg/1 inside the lake or reservoir, in order to prevent the development of undesirable biological species and
control accelerated eutrophication; in the case of rivers and streams, concentrations of up to 0.1 mg/1 are permitted.
1 Suspended solids (including sediments) along with color shall not reduce the depth of the level of light
compensation for photosynthetic activity more than 10% over the normal value.
D-43
-------
Appendix D - Water Quality Comparisons
Tables D-37 to D-38 compare Repository data on pH and dissolved oxygen, respectively,
to these standards.
Table D-37. Water Quality Comparisons for Mexico: pH
(Water Quality Indicator ID: 29,1076,1135,1118,1119,1233,1136,1077)
1 Station ID
CILA-WWTP-Planta
Sur
CNA-PSBC-17
CNA-PSBC-20
SCERP-New River-
CD-04
::i.-:.i:*:il.. i^:::': l!/- Station Name - '''.-- -. :l'V:r- '"
RIO COLORADO-YURIMURY
CANAL ALIMENTADOR DEL AC. RIO COLORADO-
TIJUANA
DrenTulaOeste
Data
Points
35
72
96
8
Values
Exceeding
1
1
1
1
Percentage
> : values v:
exceeding
3%
1%
1%
13%
Table D-38. Water Quality Comparisons for Mexico: Dissolved Oxygen
(Water Quality Indicator ID: 1211,1127,1089,1073)
' ;;: : .. " ;. Tr " .. ' /. * '-«
Station ID j
CNA-SSBC-09
CNA-PSBC-20
CNA-PSRB-18
CNA-SSRB-26
j: ! .i'JTiJf..^ ' ' ' '.;.''''.£_ " : '' ' * ' . '. . ,' ;
"> .'.«!': : ' !* ' :'."*" "il" ' ; ',_.:,*, ' , , ' ,^ ' ' . ' ;
: '*' ' ; ' ' ' ' '',,'* * j' -*: .; ; : . " " " , ,''"'' "' '
!:'- i v -: *" "^ t;/ : "-. i'Station^airie-; ::K;-^,:' '''<- >'"'!** 'i
DESC. RIO ARDJ (RIO COLORADO)
CANAL ALIMENTADOR DEL AC. RIO COLORADO-
TIJUANA
PUENTE INTERNACIONAL V1EJO MATAMOROS
RIO BRAVO a.a. DE CD. ACUNA, POBLADO
BALCONES
Data
Points
49
48
18
2
Values
Exceeding
2
2
1
1
Percentage
values
; exceeding
4%
4%
6%
50%
D.3 References
ADEQ (Arizona Department of Environmental Quality). 2003. Arizona's Surface and
Groundwater Quality Standards. Available at
http://www.azdeq.gov/environ/water/assessment/download/305-02/acstand.pdf (accessed
October 26, 2005).
CSWRCB (California State Water Resources Control Board). 1994a. Water Quality Control
Plan for the Colorado River Basin. September.
CSWRCB (California State Water Resources Control Board). 1994b. Water Quality Control
Plan for the San Diego Basin.
NMED (New Mexico Environment Department). 2002. State of New Mexico Standards for
Interstate and Intrastate Surface Waters. Available at
http://www.nmenv.state.nm.us/NMED_regs/ swqb/20__6_4_nmac.html (accessed October
26, 2005).
D-44
-------
Appendix D - Water Quality Comparisons
TNRCC (Texas Natural Resource Conservation Commission). 2000. Chapter 307: Texas
Surface Water Quality Standards. Numerals 307.1 -307.10.
U.S. EPA (Environmental Protection Agency). 1998. National Strategy for the Development of
Regional Nutrient Criteria. Office of Water.
D-45
-------
Appendix D- Water Quality Comparisons
[This page intentionally left blank.]
D-46
-------
Appendix E - Water Quality Trends Scenarios
Appendix E
Water Quality Trends Scenarios
E.I Introduction
This Appendix presents water quality trends analyses for twelve case studies organized
by transboundary region. The purpose of these case studies is to illustrate a very basic approach
to identifying water quality trends and the effects of seasonally on measured values for a given
parameter. The U.S.-Mexico Border Waters Repository shows an important increase in the
number of monitoring stations reporting values along the U.S-Mexico Border in the last 5 to 6
years. Given its robust and flexible structure, the Repository is the most appropriate tool to store,
maintain, and retrieve this information for future years. More detailed and statistically sound
trends analyses can be performed in the future if data continue to be collected at the same rate as
in the last 5 or 6 years. At this time, there is not enough data to draw conclusions on water
quality trends for each transboundary region as a whole.
The analyses presented in this Appendix are grouped by transboundary region rather than
by state because waterbodies within the same region share common characteristics and it makes
more sense to select groups of rivers and waterbodies by hydrologic unit rather than by state for
analysis.
The remainder of this Appendix is organized as follows:
» Section E.2 explains the methodology used to identify water quality trends
» Section E.3 includes two case scenarios for the Pacific/Salton Sea Region
" Section E.4 includes two case studies for the Colorado River/Sea of Cortez Region
Section E.5 includes two case studies for the Central Desert/Closed Basins Region
Section E.6 includes four case studies for the Rib Grande Region
Section E.7 includes two case studies for the Lower Rio Grande Region.
Table E-l shows how the case studies within this entire section are organized by
transboundary regions. The case studies were selected based on data availability in the U.S.-
Mexico Border Waters Repository. Those stations with most data points for a given water quality
indicator were chosen for the case studies.
E-l
-------
Appendix E - Water Quality Trends Scenarios
Table E-l. Case Studies for Water Quality Trends Analyses
i Case
j Study
Water Quality indicator
i
Station
Pacific/Salton Sea (Section E.3)
1
2
Specific Conductance
DO
NWIS-3247-031 1-6473-101
NWIS-3247-03 1 1-6473-101 .
Colorado/Sea of Cortez (Section £.4)
3
4
Total Hardness as CaCO3
DO
CNA-PSBC-14
CNA-PSBC-14
Central Desert/Closed Basins (Section E.S)
5
6
DO
DO
ModSTORET-100034
ModSTORET-100035
Rio Grande (Section E.6)
7
8
9
10
DO
Sulfate
Specific Conductance
Specific Conductance
TCEQ-13272
TCEQ-13272
TCEQ-15892
TCEQ- 13205
Lower Rio Grande (Section E.7)
11
12
Specific Conductance
DO
TCEQ-13072
TCEQ- 13072
£.2 Methodology
Water quality trends analyses are important for detecting change in water quality status
for a given waterbody over time. Water quality trends may help decision makers determine the
appropriate actions to prevent the future impairment of specific waterbodies.
Water quality trends analyses require large data sets comprising data points that have
been consistently recorded over time in a given river point or segment. Furthermore, water
quality on a river segment may be affected by a number of factors, including precipitation
intensity, discharges, flow peaks, and many other climatic events. Seasonality certainly must be
included in water quality status and trends analyses, because water quality is affected by seasonal
events.
Quantitative trends analyses require appropriate methodologies and algorithms to capture
effects of seasonality, account for missing data, accommodate measurements below detection
limits, and resolve other data problems. For example, the Tau-Kendall methodology is often used
to perform trends analyses. However, applying that technique is time consuming and
computationally intensive, and it may not be the best technique for initial analyses where data are
somewhat limited (as in this project). For these reasons, complex quantitative trends measures
were not used.
Instead, initial water quality trends analyses were limited to visual inspection of plots of
all values for each indicator between 1993 and 2003 (Figure E-l provides an example). For a
E-2
-------
Appendix E- Water Quality Trends Scenarios
given water quality indicator at a specific station, all values were plotted, and outliers were
identified and eliminated. Stations with at least SO data points for a given water quality indicator
in the study period were selected for the scenarios. Basic statistics were calculated for the data
set after removing outliers. Given the importance of seasonality effecting water quality values,
univariate statistics were calculated for data points measured at different times of the year during
the study period. Box and whisker diagrams were used to show the differences in the data point
distributions at different times of the year.
Specific Conductance at Station
NWIS_324703116473101
£ 000
0 4en .
C 4SU
-------
Appendix E - Water Quality Trends Scenarios
Case Study 1: Specific Conductance at Station NWIS_324703116473101
Case Study 1 is defined by the following attributes:
" Water Quality Indicator: Specific Conductance, water, unfiltered. Indicator ID: 1072.
Measured in microsiemens per centimeter (jiS/cm).
Station ID: NWIS_324703116473101
Station Location: Latitude: 32.78422009 N; Longitude: 116.79279994 E
Station Name: LOVELAND RES NR DAM SITE 1 UPPER
Owning Organization: Arizona Department of Environmental Quality's Legacy &
Modernized STORET data.
Figure E-2 shows the plot of values measured within the study period, once the outliers
have been removed from the data set. A slight increasing trend can be observed on this plot.
Figure E-3 shows the cumulative normal distribution for this data set indicating about an
80 percent probability of measuring a specific conductance value of 400 nS/cm or greater at this
station. As a reference, the specific conductance of distilled water is about 1 uS/cm, which is
low, and that of seawater is about 50,000 uS/cm.
Table E-2 shows an average value of 493 uS/cm and a standard deviation of 95 uS/cm.
Table E-2 also shows the differences in the statistics for the seasonal values measured at
this station. Averages are similar for both seasons but the distribution of values is a little spread
out in March. Figure E-4 shows the March and September seasonal distributions for this water
quality indicator.
E-4
-------
Appendix E- Water Quality Trends Scenarios
Specific Conductance at Station
NWIS_3247031 1 64731 01
700 T "
£ 650 -
§ 600
0 500-
f 450 -
400
3 350
3 25°
200
__ *
il
, "t *
;!"'"
il-*1^
H- '
A
3/11/97 7/2J/88 12S/9S 4/t8i01 «fl/02 1/1404
Sampling date
Cumulative Distribution for Values at Station
NW1S 324703118473101
09
5 0.6.
S °5
0 0.4
£ 0.3.
0.2 .
0.1 .
0.0
f-
^1^^
^^
^T
y/.
0
DO
Figure E-4. Seasonal distributions for
specific conductance values during the
study period.
E-5
-------
Appendix E- Water Quality Trends Scenarios
Case Study 2: DO at Station NWIS_324703116473101
Case Study 2 is defined by the following attributes:
Water Quality Indicator: DO, water, unfiltered. Indicator ID: 1073. Measured in
mg/L.
Station ID: NWISJ24703116473101
Station Location: Latitude: 32.78422009 N; Longitude: -116.79279994 E
- Station Name: LOVELAND RES NR DAM SITE 1 UPPER
Organization Name: U.S. Geological Survey
Data Source: Arizona Department of Environmental Quality's Legacy & Modernized
STORET data.
Figure E-5 shows the plot of values measured within the study period once the outliers
have been removed from the data set. No trend can be identified on this plot.
Figure E-6 shows the cumulative normal distribution for this data set indicating a 56
percent probability of measuring a DO value of about 5.0 mg/L or below at this station.
Table E-3 shows an average value of 4.4 mg/L and a standard deviation of 3.7 mg/L,
Table E-3 also shows the differences in the statistics for the seasonal values measured at
this station. DO concentrations are greater in average in March than in September for this station.
Figure E-7 shows the March and September seasonal distributions for this water quality
indicator.
E-6
-------
Appendix E - Water Quality Trends Scenarios
Dissolved Oxygen at Station
NWIS_3247031 164731 01
C
>. 4n n .
o *
1
° 00-
! *
-jSjs
^ +
it ^*lk * .
i
*>
^1
. j
'3/11/97 7/24/96 12/6/99 4/19/01
Sampling Data
, »
i i '.',
* * *
9/1/02 1/14/04
Figure E-5. DO values during
the study period.
Cumulative Distribution for Values at Station
NW1S.3247031 1 64731 01
1 n
& °-'
5 06-
.Q
to n s
°- nq -
09 .
n n -
^-""^
X^ "
x^
x
X
V
X
y
*r
0.0 5.0 10.0 15.0
Dissolved Oxygen (mg/L)
Figure E-6. Cumulative normal
distribution for dissolved oxygen values
during the study period.
Table E-3. Statistics for DO Values
Measured at Station
NWIS 324703116473101
i
[Statistic
Count
Average
Median
Mode
Standard
Deviation
Min
Quartiie 1
Quartile 2
Quartiie 3
Max
First Reading
Last Reading
All Values
462
4.4
5.1
0.1
3.7
0.0
0.3
5.1
7.3
13.0
10-Sep-98
20-Aug-03
March
Values
90
7.6
7.1
8.9
2.5
0.3
6.0
7.1
8.9
13.0
02-Mar-99
19-Mar-02
September \
' , .Values {
86
2.5
' 0.4
0.1
3.3
0.1
0.1
0.4
6.8
8.3
10-Sep-98
18-Sep-02
0
March Values Distribution at Station NWIS-
324703116473101
n
mLJ
0 5.0 10.0 15.0
Dissolved Oxygen (mg/L)
September Values Distribution at Station
NWIS-324703116473101
!
0.0
5.0 10.0
Dissolved Oxygen (mg/L)
15.0
Figure E-7. Distributions for dissolved
oxygen seasonal values
during the study period.
E-7
-------
Appendix E - Water Quality Trends Scenarios
Table E-4. Statistics for Water Quality Indicator Values Measured at Different Stations in
Pacific/Salton Sea Transboundary Region
f ' ' .
s
i
f ' . "
i
j Statistic
Count
Average
Median
Mode
Standard Deviation
Min
Quartile 1
Quartile 2
Quartile 3
Max
First Reading
Last Reading
Trend
Temp. (°C) at
Station
NWIS-3247-
0311-6473-101
; Conductance
(uS/cm) at
Station
NWIS-3241-
3111-7000-101
DO(mg/L)at
Station
NWIS-3241-
3111-7000-101
Conductance
(uS/cm) at
Station
NWIS-3241-
2611-6595-701
DO(mg/L)at j
Station 1
NWIS-3241- (
3011-7002-501 j
i
1 Statistics Values '
493
14.5
12.7
11.3
4.2
10.4
11.5
12.7
15.7
27.0
10-Sep-98
20-Aug-03
Increasing
283
916
921
1040
114
740
796
921
1030
1120
09-Sep-98
19-Aug-03
Increasing
282
5.5
6.4
0.2
3.2
0.1
2.8
6.4
7.6
12.0
09-Sep-98
19-Aug-03
Not identifiable
87
791
787
795
37
736
766
787
796
875
10-Sep-98
12-Jul-99
Increasing
258
5.7
6.5
0.1
3.3
0.1
3.2
6.5
7.8
15.1
09-Sep-98
19-Aug-03
Not identifiable
Table E-5. Location of Additional Stations in the Pacific/Salton Sea Region
f Station ID
NWIS-3241-3111-
7000-101
NWIS-3241-2611-
6595-701
NWIS-3241-3011-
7002-501
Location
Lat: 32.69199773,
Lon: -11 7.001 13737
Lat: 32.69060889,
Lon: -11 7.0000262
Lat: 32.69171991,
Lon: -117.0078043
Name
SWEETWATER RES
CTR OF MIN POOL
UPPER
SWEETWATER RES
NR RECREATION
AREA UPPER
SWEETWATER RES
NR PUMP TOWER
UPPER
State
California
California
California
Owning
Organization
U.S. Geological
Survey
U.S. Geological
Survey
U.S. Geological
Survey
E-8
-------
Appendix E - Water Quality Trends Scenarios
E.4 Case Studies for the Colorado River/Sea of Cortez
Transboimdary Region
Two case studies were included for this region. Each case study is defined by a water
quality indicator measured at a given station in this region. Water quality trends and seasonally
were assessed for both scenarios and are summarized in Figures E-8 through E-13 and Tables E-
6 and E-7. Additional trends were assessed for other stations and are summarized in Table E-8.
E.4.1 General Characteristics
The Colorado River/Sea of Cortez Region contains 11 basins that drain either to the
Colorado River below the gaging station at Parker Dam or to the Sea of Cortez. The region
drains 22,590 square miles (58,500 km2). It covers portions of the states of Arizona, Sonora, and
Chihuahua and consists of lowlands flanked by the Sierra Juarez and the Sierra San Pedro Martir
mountain ranges to the west and the Desierto de Altar (Sonoran Desert) and the Northwest
Chihuahua highlands to the east.
The major surface waters in the region are the lower Colorado River delta and the Laguna
Salada. From the north, the Colorado River flows into the basin through heavily urbanized areas
near Yuma, Arizona, and San Luis Rio, Colorado, Sonora, and then through wetlands before
flowing into the Sea of Cortez.. Most of the water that the delta receives comes from agricultural
drainage from the United States and Mexico, with little perennial flow in the lower Colorado
River.
E-9
-------
Appendix E Water Quality Trends Scenarios
Case Study 3: Total Hardness at Station CNA-PSBC-14
Case Study 3 is defined by the following attributes:
Water Quality Indicator: Hardness, Total (as CaCOa), measured in mg/L. Indicator
ID: 1158
Station ID: CNA-PSBC-14
Station Location: Latitude: 32.5 N; Longitude: -114.8167 E
Station Name: Canal Sanchez Taboada
Country: Mexico
Owning Organization: Comision Nacional del Agua.
Figure E-8 shows the plot of values measured within the study period once the outliers
have been removed from the data set. A slight decreasing trend can be spotted on this plot.
Figure E-9 shows the cumulative normal distribution for this data set indicating a 100
percent probability of measuring a total hardness value greater than 120 mg/L, which is
considered very hard water.
Table E-6 shows an average value of 723 mg/L and a standard deviation of 60 mg/L.
Table E-6 also shows the differences in the statistics for the seasonal values measured at
this station. Total Hardness values are greater in average in June through August than in
December through February for this station. Values in December through February are more
spread out. Figure E-10 shows the December-February and the June-August seasonal
distributions for total hardness at Station CNA-PSBC-14.
E-10
-------
Appendix E - Water Quality Trends Scenarios
Total Hardness as CaCO3
<«ng/u
Hardness at Station CNA-PSBC-14
*u-.*.^'V%"" JA.
*»»«
\ !
7O4S8 12CJ99 4/19/01 9/1 TO 1/14104 5QW05
Sampling Date
Figure E-8. Total hardness values during
study period.
Cumulative Distribution for Values at
Station CNA-PSBC-14
0.9
08
0 5
§ 04
2 03
02 -
0 1 -
« *** "
.f*
jr
>
S
+*
f
j*t~
SOO 600
700 800 900
Total Hardness as CaCO3 (mg/L)
Figure E-9. Cumulative normal
distribution for total hardness values
during study period.
Table E-6. Statistics for Total Hardness
Values Measured at Station
CAN-PSBC-14
1
[Statistic
Count
Average
Median
Mode
Standard
Deviation
Min
Quartile 1
Quartile 2
Quartile 3
Max
First Reading
Last Reading
All Values
55
723
724
724
60
571
692
724
766
855
19-Jan-99
02-Dec-03
Dec-Feb
Values
13
706
710
-
67
571
660
710
730
837
19-Jan-99
02-Dec-03
Jun-Aug
Values
13
754
760
-
60
640
711
760
771
855
08-Aug-OO
12-Aug-03
D*c*mbirauBh Fibnniy VtluH Dlttribudon it Sttfion CMA-
PSBC-14
650 700 750 800
Tottl Hirdmtt«ClCO3 (mgA.)
JUM through Augui V*lu*< DimUwttm it Stttion CNA-PSBC-14
650 TOO 750
Toal Hardr»n«»c.cOS (rngfL)
Figure £-10. Seasonal distributions for
total hardness values during the study
period.
E-ll
-------
Appendix E Water Quality Trends Scenarios
Case Study 4: DO at Station CNA-PSBC-14
Case Study 4 is defined by the following attributes:
» Water Quality Indicator: DO, measured in mg/L. Indicator ID: 1089
» Station ID: CNA-PSBC-14
» Station Location: Latitude: 32.5 N; Longitude: -114.8167 E
Station Name: Canal Sanchez Taboada
Country: Mexico
Owning Organization: Comisi6n Nacional del Agua.
Figure E-l 1 shows the plot of values measured within the study period once the outliers
have been removed from the data set. A slight declining trend can be spotted on this plot.
Figure E-l2 shows the cumulative normal distribution for this data set indicating a 100
percent probability of getting a value higher than 5 mg/L and a 73 percent probability of getting
a value higher than 8 mg/L.
Table E-7 shows an average value of 8.4 mg/L and a standard deviation of 1.2 mg/L.
Table E-7 also shows the differences in the statistics for the seasonal values measured at
this station. DO values are greater on average in the December-February season. Figure E-l 3
shows the December-February and the June-August seasonal distributions for "this water quality
indicator.
E-12
-------
Appendix E - Water Quality Trends Scenarios
I
c
a
0
Dissolved Oxygen at Station CNA-PSBC-14
*
\ /*.. . ,A- .
* »" . . . v ' ,
7/2408 1 2*/99 4/1 9«1 9/1JCZ 1 M 4104 5J2M)5
Sampling Date
Figure E-ll. Dissolved oxygen values
during study period.
Cumulative Distribution for Values at
Station CNA-PSBC-14
« 0 7
n* -
^ ft 4
C A ^ .
A -t .
,« ' !-
**' i
I
X" i
X i
j» i
.X I
X i
^<*
. » i
5.0 7.0 9.0 11.0
Dissolved Oxygen (mg/L)
Figure E-12. Cumulative normal
distribution for dissolved oxygen values
during the study period.
Table E-7. Statistics for Dissolved Oxygen
Values Measured at Station CNA-PSBC-14
i
! Statistic
Count
Average
Median
Mode
Standard
Deviation
Min
Quartile 1
Quartiie 2
Quartile 3
Max
First Reading
Last Reading
All Values
57
8.4
8.2
7.8
1.2
6.1
7.6
8.2
9.1
11.0
19-Jan-99
02-Dec-03
Dec-Feb
Values
14
9.7
9.9
-
1.0
8.0
9.2
9.9
10.4
11.0
19-Jan-99
02-Dec-03
Jun-Aug
Values
15
7.6
7.6
-
0.9
6.1
7.0
7.6
8.2
9.1
08-Jun-99
12-Aug-03
June through August Values Distribution
at Station CNA-PSBC-14
I
5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0
Dissolved Oxygen (mg/L)
December through February Values
Distribution at Station CNA-PSBC-14
5.0 7.0 9.0 11.0
Dissolved Oxygen (mg/L)
Figure £-13. Distributions for suspended
volatile solids seasonal values during the
study period.
E-13
-------
Appendix E - Water Quality Trends Scenarios
Table E-8. Statistics for Water Quality Indicator Values Measured at Different Stations in
the Colorado River/Sea of Cortez Transboundary Region
* BOD: Biochemical Oxygen Demand
b COD: Chemical Oxygen Demand
;
;
Statistic
Count
Average
Median
Mode
Standard
Deviation
Min 7
Quartile 1
Quartile 2
Quartile 3
Max
First Reading
Last Reading
Trend
total Solids
(mg/L)at
Station CNA-
PSBC-14 i
57
2,675
2,744
2,847
339
1,256
2,607
2,744
2,862
3,114
19-Jan-99
02-Dec-03
Decreasing
Conductance
, (uS/cm) at
Station CNA-
PSBC-I4
57
3,824
3,880
4,210
484
1,999
3,590
3,880
4,195
4,650
19-Jan-99
02-Dec-03
Decreasing
Chloride
(mg/L) at
Station CNA-
PSBC-14
Statistics Values
54
561
627
637
212
3
574
627
670
808
19-Jan-99
02-Dec-03
Decreasing
BOD*(mg/L)at
Station CNA-
PSBC-14
57
2.0
1.4
1.1
1.7
0.5
1.1
1.4
2.3
9.4
19-Jan-99
02-Dec-03
Decreasing
COD" (mg/L) |
at Station j
CNA-PSBC14 j
i
I
57
50
50
50
21
9
39
50
60
118
19-Jan-99
02-Dec-03
Not identifiable
E-14
-------
Appendix E - Water Quality Trends Scenarios
E.5 Case Studies for the Central Desert/Closed Basins
Transboundary Region
Two case studies were included for this region. Each case study is defined by a water
quality indicator measured at a given station in this region. Water quality trends and seasonally
were assessed for both scenarios and are summarized in Figures E-14 through E-19 and Tables
E-9 and E-10. Additional trends were assessed for other stations and are summarized in Tables
E-l 1 and E-12. Both case studies fall in the Mexican Highlands portion of the region; there was
inadequate data to conduct a case study in the Mimbres/Animas basins.
E.5.1 General Characteristics
The Mexican Highlands basins contain 14 basins that drain to rivers in southern Arizona,
southwestern New Mexico, northern Sonora, or the extreme northwestern tip of Chihuahua. The
Mimbres/Animas basins contain 5 basins that drain internally in southern New Mexico and
northern Chihuahua. The Mexican Highlands region drains 21,840 square miles (56,600 km2)
and the Mimbres/Animas region drains 12,450 square miles (32,200 km2) (Woodward and
Durall, 1996).
The Mexican Highland Region, although is classified as desert, contains vegetation and
diverse aquatic habitats. The Santa Cruz and San Pedro Rivers are the dominant streams in the
region. Their flows largely depend on precipitation in the mountains in Arizona and Mexico.
Near their headwaters, certain reaches of these rivers flow continuously, but their flows decrease
dramatically as the rivers travel northward. The Santa Cruz river near Nogales, Sonora, generally
flows continuously, but the natural flow in the river does not reach the Nogales International
Wastewater Treatment Plant (located along the river about 6 miles north of Nogales, Arizona).
Flow downstream from the treatment plant is composed of effluent return, and this water rarely
flows past the Santa Cruz County line (Papoulias et al, 1997).
The Mimbres and Animas basin system consists mostly of topographically closed basins
with piedmont and basin-floor alluvial surfaces grading to central playa (ephemeral-lake)
depressions that are designated "bolsons." All stream systems in the basins are ephemeral, except
in the valleys of Animas Creek (NMED, 2002).
E-15
-------
Appendix E - Water Quality Trends Scenarios
Case Study 5: DO at Station ModSTORET-100034
Case Study 5 is defined by the following attributes:
Water Quality Indicator: DO, measured in mg/L. Indicator ID: 1089
Station ID: ModSTORET-10034
Station Location: Latitude: 32.1862411 N; Longitude: -110.81672 E
Station Name: SCLAK-A
Owning Organization: Arizona Department of Environmental Quality.
Figure E-14 shows the plot of values measured within the study period once the outliers
have been removed from the data set. No trend can be spotted on this plot.
Figure E-15 shows the cumulative normal distribution for this data set indicating a 40
percent probability of measuring a DO value of 5.0 mg/L or less at this station.
Table E-9 shows an average value of 5.8 mg/L and a standard deviation of 3.3 mg/L.
Table E-9 also shows the differences in the statistics for the seasonal values measured at
this station. Although values for July and August were available only for 1998, one can see that
the average values in December-February are much larger than in June-August. Figure E-16
shows the December-February and the June-August seasonal distributions for DO at Station
ModSTORET-100034.
E-16
-------
Appendix E - Water Quality Trends Scenarios
Dissolved Oxygen at Station
ModSTORET-100034
1
J5 .. in n -
-S- en -
1
O ft n .
i '
* 4 *
* * i
8**;<
*#*
* *
i !_*
3/11/97 7/2*98 12«»9 4/18/01 9/1/02
Sampling Date
Figure £-14. Dissolved oxygen values
during the study period.
(
1.0
t>.9
±? 0.7
= 0..
b Q.3
0.1
00
0
Cumulative Distribution for Values at
Station ModSTORET-100034
it*** ** " ] '
^* i
^tjF* *
& '
f* ''
W^ \
^* \
* !
** !
»** ' J
0 5,0 10.0 15.0
Dissolved Oxygen (mg/L)
Figure £-15. Cumulative normal
distribution for dissolved oxygen values
during the study period.
Table E-9. Statistics for Dissolved Oxygen
Values Measured at Station
ModSTORET-100034
{
i
;Statistic
Count
Average
Median
Mode
Standard
Deviation
Min
Quartile 1
Quartile 2
Quartile 3
Max
First Reading
Last Reading
Value
108
5.8
6.7
0.0
3.3
0.0
4.3
6.7
7.6
13.0
12-Dec-97
9-Jan-02
Dec-Feb
Values
29
8.3
8.5
-
2.3
4.2
6.8
8.5
9.3
12.6
12-Dec-97
09-Jan-02
Jun-Aug |
Values I
26
2.4
0.2
0.0
3.5
0.0
O.I
0.2
4.1
13.0
Ol-Jul-98
27-Aug-98
OtMmtof ftnugt Fibniiy VilunOUHIwliai it Slit IMSTOREMMOH
0.0 2.0 <0 6.0 8.0 10.0 120 14.0
Jam tnugh Augm Vlluu BtibuSw « SttiM (MSTORET-1IH3*
Figure E-16. Seasonal distributions for
dissolved oxygen values during study
period.
E-17
-------
Appendix E - Water Quality Trends Scenarios
Case Study 6: DO at Station ModSTORET-100035
Case Study 6 is defined by the following attributes:
« Water Quality Indicator: DO, measured in mg/L. Indicator ID: 1089
Station ID: ModSTORET-10035
Station Location: Latitude: 32.1862411 N; Longitude: -110.81672 E
Station Name: SCLAK-B
Owning Organization: Arizona Department of Environmental Quality.
Figure E-17 shows the plot of values measured within the study period once the outliers
have been removed from the data set. No trend can be spotted on this plot.
Figure E-18 shows the cumulative normal distribution for this data set indicating a 25
percent probability of measuring a DO value of 5.0 mg/L or less at this station.
Table E-10 shows an average value of 6.6 mg/L and a standard deviation of 2.5 mg/L.
Table E-10 also shows the differences in the statistics for the seasonal values measured at
this station. Values in December-February are also larger in average than the values in June-
August. Figure E-19 shows the December-February and June-August seasonal distributions for
DO at Station ModSTORET-100035.
E-18
-------
Appendix E - Water Quality Trends Scenarios
Dissolved Oxygen
*
12.0 .
Figure E-18. Cumulative normal
distribution for dissolved oxygen values
during the study period.
Table E-10. Statistics for Dissolved
Oxygen Values Measured at Station
ModSTORET-100035
.
Statistic
Count
Average
Median
Mode
Standard
Deviation
Min
Quartile 1
Quartile 2
Quartile 3
Max
First
Reading
Last Reading
Value
88
6.6
6.8
7.1
2.5
1.2
5.6
6.8
7.7
11.4
12-Dec-97
09-Jan-02
Dec-Feb
Values
25
8.3
9.3
-
2.4
3.8
5.6
9.3
10.4
11.4
12-Dec-97
09-Jan-02
Jun-Aug
, Values
18
4.7
3.4
-
3.3
1.2
1.6
3.4
7.6
10.8
Ol-Jul-98
27-Aug-98
December through February Value* Distribution at
Station ModSTORET-100035
0.0 2.0 4.0 6.0 8.0 10.0 12.0
' Dissolved Oxygen (mg/L)
June through August Values Distribution at Station
ModSTORET-100035
0.0 2.0 4.0 6.0 8.0 10.0
Dissolved Oxygen (mg/U)
12.0
Figure E-19. Seasonal distributions for
dissolved oxygen values during study
period.
E-19
-------
Appendix E - Water Quality Trends Scenarios
Table £-11. Statistics for Water Quality Indicator Values Measured at Different Stations in
the Central Desert/Closed Basins Transboundary Region"
: '
Statistic
Count
Average
Median
Mode
Standard
Deviation
Min
Quartile 1
Quartile 2
Quartile 3
Max
First Reading
Last Reading
Trend
DO (mg/L) at
Station
ModSTORET-
100000
pH at Station
ModSTORET-
100034
Conductance .
(uS/cm) at
Station
ModSTORET-
100034 ,
DO (mg/L) at
Station
ModSTOREt-
100028
Conductance
(uS/cm) at
Station
ModSTORET-
100035
Statistics Values \
63
5.5
6.9
0.1
4.4
0.1
0.2
6.9
9.1
12.9
03-Dec-97
28-Aug-Ol
Not identifiable
122
8.4
8.4
9.0
0.6
6.9
8.1
8.4
8.9
9.8
13-Aug-93
09-Jan-02
Not identifiable
122
450
488
277
141
274
307
488
534
715
13-Aug-93
09-Jan-02
Increasing
64
7.8
8.7
8.8
3.2
0.1
7.4
8.7
9.4
14.9
13-Aug-93
25-Nov-98
Not identifiable
105
451
493
277
136
274
307
493
527
717
13-Aug-93
09-Jan-02.
Increasing
These stations are all in the Mexican Highlands basins; there were not enough data points for the
Mimbres/Animas basins in the Repository for analysis.
Table £-12. Location of Additional Stations in the Central Desert/Closed Basins
Transboundary Region
| Station ID
ModSTORET-100000
ModSTORET- 100028
Location
Lat: 3 1.53289,
Lon: -11 1.25345
Lat: 32. 180 138,
Lon: -11 1.00752
Name
SCARI-A
SCKEN-A
State
Arizona
Arizona
Owning Organization
Arizona Department of
Environmental Quality
Arizona Department of
Environmental Quality
E-20
-------
Appendix E - Water Quality Trends Scenarios
E.6 Case Studies for the Rio Grande Transboundary Region
Four case studies were included for this region. Each case study is defined by a water
quality indicator measured at a given station in this region. Water quality trends and seasonality
were assessed for all four scenarios and are summarized in Figures E-20 through E-31 and
Tables E-13 through E-16. Additional trends were assessed for other stations and are
summarized in Tables E-17 through E-20.
E.6.1 General Characteristics
The Rio Grande/Rio Bravo Basin is subdivided into three regions. The Rio Grande-
Elephant Butte Reservoir to above Rio Conchos Region contains 14 basins that drain to that
reach of the Rio Grande below the gaging station at Elephant Butte dam. The Rio Grande-Rio
Conchos to Amistad Reservoir Region contains 32 basins that drain either to that reach of the
Rio Grande, to the lower reach of the Rio Conchos below the now suspended Falomir gaging
station (near the Luis Leon Dam), or to the lower reach of the Pecos River below the gaging
station at Girvin. The Rio Grande below Amistad Reservoir to Falcon Reservoir Region contains
13 basins that drain either to that reach of the Rio Grande or to the lower reach of the Rio Salado
below the gaging station at Las Tortillas. The Rio Grande-Elephant Butte Reservoir to above Rio
Conchos Region includes 28,940 square miles (75,000 km2); the Rio Grande-Rio Conchos to
Amistad Reservoir Region includes 34,630 square miles (89,700 km2); and the Rio Grande
below Amistad Reservoir to Falcon Reservoir Region includes 12,910 square miles (33,400 km2)
(Woodward and Durall, 1996).
The entire Rio Grande Basin extends 1,896 miles (3,051 km) from the river's headwaters
in the San Juan Mountains of southern Colorado to near its mouth in the Gulf of Mexico. The
Rio Grande/Rio Bravo drains an area of approximately 182,215 square miles (471,937 km2) in
the three U.S. states of Colorado, New Mexico, and Texas and the five Mexican states of
Chihuahua, Coahuila, Durango, Nuevo Leon, and Tamaulipas. Major cities along the Rio Grande
within the transboundary region include five sister city pairs: El Paso, TX/Juarez, Chihuahua;
Presidio, TX/Ojinaga, Chihuahua; Del Rio, TX/Acuna, Coahuila; Eagle Pass, TX/Piedras
Negras, Coahuila; and Laredo, TX/Nuevo Laredo, Tamaulipas.
The primary water courses in these regions are the Rio Grande/Rio Bravo and its
tributaries, including the Rios Conchos, Salado, San Juan, and San Rodrigo in Mexico, and the
Pecos and Devil's Rivers in Texas. On the main stream are the Amistad and the Falcon
Reservoirs. A feature of this region is the extent of control on the natural flow of the river
including dams, reservoirs, canals, and diversions for water supply and flow control. Flow in the
lower Rio Grande has become dependent on controlled releases and "return flows" back to the
river from agricultural and other commercial water uses (U.S. EPA, 2001).
E-21
-------
Appendix E - Water Quality Trends Scenarios
Case Study .7: DO at Station TCEQ13272 (Rio Grande-Elephant Butte Reservoir to above
Rio Conchos Region)
Case Study 7 is defined by the following attributes:
Water Quality Indicator: DO, measured in mg/L. Indicator ID: 1127
Station ID: TCEQ-13272
Station Location: Latitude: 31.802778 N; Longitude: -106.540276 E
" Station Name: RIO GRANDE AT COURCHESNE BRDG
Owning Organization:1 Texas Commission on Environmental Quality.
Figure E-20 shows the plot of values measured within the study period once the outliers
have been removed from the data set. A stable tendency around the average value of 8.0 mg/L
can be seen on this plot.
Figure E-21 shows the cumulative normal distribution for this data set indicating only a
1 percent probability of measuring a DO value of 5.0 mg/L or less at this station.
Table E-13 shows an average value of 8.0 mg/L and a standard deviation of 1.5 mg/L.
Table E-13 also shows the differences in the statistics for the seasonal values measured at
this station. Values measured in March are larger in average than the values measured in
September. Figure E-22 shows the March and September seasonal distributions for DO at Station
TCEQ-13272.
E-22
-------
Appendix E - Water Quality Trends Scenarios
Dissolved Oxygen at Station TCEQ13272
S iw
"c" 10 C
O an.
1
2 40
I 20
a
' *. * . » v ^ **
"- ' r * '*f *L * * '*"* *X i^ "* ** '
** % ^ ^jfy* V'*- ~"
' * .
W1M1 1««W VIM* 1M2M9 yiUBT 7Q«M tMM «1««1 V10J W1«M KI2BQS
Sampling Date
Figure E-20. Dissolved oxygen values
during the study period.
Cumulative Distribution for Values at
Station TCEQ13272
ft Q .
n A -
tn 7 .
net ,
£ °-5
a_ A o .
A O .
n 1 -
n n .
1^"*"^'" " '
* !
S i
X I
/ i
/
X '
/
^f \
»«* I
4.0 6.0 8.0 10.0 12.0
Dissolved Oxygen (mg/L)
Figure E-21. Cumulative normal
distribution for dissolved oxygen values
during the study period.
Table E-13. Statistics
Values Measured at
for Dissolved Oxygen
Station TCEQ13272
Statistic
Count
Average
Median
Mode
Standard
Deviation
Min
Quartile 1
Quartile 2
Quartile 3
Max
First
Reading
Last Reading
All Value
252
8.0
7.9
7.2
1.5
4.9
6.9
7.9
8.9
12.0
27-Jan-93
16-Dec-03
March
Values
36
8.7
8.6
8.5
0.6
7.8
8.4
8.6
9.0
10.0
09-Mar-93
18-Mar-03
September ,
Values
43
7.0
7.2
7.2
0.6
6.0
6.5
7.2
7.2
8.8
28-Sep-93
23-Sep-03
6
March Values Distribution at Station TCEQ-13272
.,,.. ,
mU
0 7.0 8.0 9.0 10.0
Dissolved Oxygen (mg(L)
6.
September Value* Diitributlon at Station TCEQ-1S272
^~
^^
0 6.5 7.0 7.S 8.0 B.5 9.0 9.5 10.0
Dissolved Oxygen (mg)L)
Figure E-22. Seasonal distributions for
dissolved oxygen values during the study
period.
E-23
-------
Appendix E - Water Quality Trends Scenarios
Case Study 8: Suifate at Station TCEQ13272 (Rio Grande-Elephant Butte Reservoir to
above Rio Conchos Region)
Case Study 8 is defined by the following attributes:
Water Quality Indicator: Suifate as SO4, measured in mg/L. Indicator ID: 1161
Station ID: TCEQ-13272
Station Location: Latitude: 31.802778 N; Longitude: -106.540276 E
Station Name: RIO GRANDE AT COURCHESNE BRDG
Owning Organization: Texas Commission on Environmental Quality.
Figure E-23 shows the plot of values measured within the study, period once the outliers
have been removed from the data set. No trend can be spotted on this plot.
Figure E-24 shows the cumulative normal distribution for this data set indicating an 87
percent probability of measuring a Suifate value of 150 mg/L or greater at this station.
Table E-14 shows an average value of 275 mg/L and a standard deviation of 114 mg/L.
Table E-14 also shows the differences in the statistics for the seasonal values measured at
this station. Values measured in February are slightly larger in average and more spread out than
the values measured in September. Figure E-25 shows the February and September seasonal
distributions for Suifate at Station TCEQ-13272.
E-24
-------
Appendix E- Water Quality trends Scenarios
Sulfate at Station TCEQ13272
7rtft
cnn .
?enn
£ 400 -
& ann ,
3 son -
W *UU
mo -
0 -
I
» I
t * t '
-. T t f * f f 1 ^ « I
r ;. v, t« ; ' . " \ » i
v-$. si^tfhF tf ;
* * ^fj,* »t»?F»: »* *. i
1
5(7SO tatm 10(26(95 7(24/98 4/19/01 1/14J04 10/10/06
Sampling Date
Figure E-23. Sulfate values during the
study period.
Cumulative Distribution for Values at
Station TCEQ13272
n Q
n a .
i o'fj
rr U.Q
« n 1
Q o «i -
C n Q .
n 9 -
0 1
n n <
^ !
X^ i
X !
/^ i
/ !
/ !
X i
/ i
X i
» !
0 200 400 600 800
Sulfate (rrtg/L)
Figure E-24. Cumulative normal
distribution for sulfate values during the
study period.
Table £-14. Statistics for Sulfate Values
Measured at Station TCEQ13272
Statistic
Count
Average
Median
Mode
Standard
Deviation
Min
Quartile 1
Quartile 2
Quartile 3
Max
First
Reading
Last Reading
All Value
249
275
223
210
114
1
197
223
346
594
21-Jan-93
19-Aug-03
February
Values
24
326
284
260
113
189
231
284
430
511
18-Feb-93
18-Feb-03
September
Values
21
259
240
300
62
173
217
240
300
452
16-Sep-93
17-Sep-02
February Valua* Distribution at Station TCEQ-13272
100
200
300 400
Sulfate (mg/L)
500
September Values attribution at Station TCEQ-13272
too
200
300 400
Sutfate (mg/L)
£00
Figure E-25. Distributions for sulfate
seasonal values during the study period
E-25
-------
Appendix E - Water Quality Trends Scenarios
Case Study 9: Specific Conductance at Station TCEQ-15892 (Rio Grande-Rio Concbos to
Amistad Reservoir Region)
Case Study 9 is defined by the following attributes:
Water Quality Indicator: Specific Conductance, field (UMHOS/CM @ 25C).
Indicator ID: 1110
" Station ID: TCEQ-15892
Station Location: Latitude: 29.625278 N; Longitude: -101.251114 E
Station Name: AMISTAD RESERV RIO GRANDE ARM
Owning Organization: Texas Commission on Environmental Quality.
Figure E-26 shows the plot of values measured within the study period once the outliers
have been removed from the data set. A slight decreasing trend can be seen on this plot.
Figure E-27 shows the cumulative normal distribution for this data set indicating a 95
percent probability of measuring a specific conductance value of about 1,000 uS/cm or greater at
this station.
Table E-15 shows an average value of 1,125 uS/cm and a standard deviation of 79
uS/cm.
Table E-15 also shows the differences in the statistics for the seasonal values measured at
this station. Values measured in March are larger in average and more spread out than the values
measured in October. Figure E-28 shows the March and October seasonal distributions for
Conductance at Station TCEQ-15892.
E-26
-------
Appendix E - Water Quality Trends Scenarios
I
Specific Conductance at Station TCEQ-15892
1 400
1 300
1 ?fin -
i inn -
1 nfifl -
Qflfl -
nnn .
f
Ji f.l "
r t $ ,^
1 r< . 1 , .
»
3/11S7 7J24J99 12«;99 4/19101 tnna I/I«M 5/2M5
Sampling Date
Figure E-26. Specific conductance values
during the study period.
Cumulative Distribution for Values at Station TCEQ-15892
> 03
^i.-*4**"'
^^
>
y
f
s
+
^+
i+
» ,*»»
900 1 ,000 1 . 1 00 1 ,200 1 ,300 1 ,400
Specific Conductance (uS/cm)
Figure £-27. Cumulative normal
distribution for specific conductance
values during the study period.
Table £-15. Statistics for Specific
Conductance Values Measured at
Station TCEQ15892
Statistic
Count
Average
Median
Mode
Standard
Deviation
Min
Max
Quartile 1
Quartile 2
Quartile 3
First
Reading
Last Reading
AH Values
187 .
1,125
1,109
1,117
79
963
1,087
1,109
1,173
1,321
05-Mar-98
02-Dec-03
March
Values
35
1,195
1,219
1,219
82
1,055
1,141
1,219
1,257
1,298
05-Mar-98
05-Mar-03
October
Values
44
1,089
uoo
1,117
58
983
1,089
1,100
1,117
1,242
06-Oct-99
29-Oct-02
March Values Distribution at Station TCEQ-1S892
900 950 1.000 1,050 1,100 1.150 1,200 1,250 1,300
Specific Conductance (us/cm)
»
October Value* Distribution at Station TCEQ-16832
n
u
X) 950 1.000 1.050 1,100 1,150 1,200 1,250 1,300
Specific Conductance (uS/cm)
Figure £-28. Seasonal distributions for
specific conductance values during the
study period.
E-27
-------
Appendix E - Water Quality Trends Scenarios
Case Study 10: Specific Conductance at Station TCEQ-13205 (Rio Grandebelow
Amistad Reservoir to Falcon Reservoir Region)
Case Study 10 is defined by the following attributes:
Water Quality Indicator: Specific Conductance, field (UMHOS/CM @ 25C).
Indicator ID: 1110
Station ID: TCEQ-13205
Station Location: Latitude: 28.663334 N; Longitude: -100.5 E .
Station Name: RIO GRANDE NR US277/EAGLE PASS
Owning Organization: Texas Commission on Environmental Quality.
Figure E-29 shows the plot of values measured within the study period once the outliers
have been removed from the data set. A slight decreasing trend can be spotted on this plot.
Figure E-30 shows the cumulative normal distribution for this data set indicating a 60
percent probability of measuring a Specific conductance value of about 1,000 uS/cm or greater at
this station.
Table E-16 shows an average value of 1,023 uS/cm and a standard deviation of 97
uS/cm.
Table E-16 also shows the differences in the statistics for the seasonal values measured at
this station. Values measured in June-August are larger .in average and less spread out than the
values measured in December-February. Figure E-31 shows the December-February and June-
August seasonal distributions for Conductance at Station TCEQ-13205.
E-28
-------
Appendix E - Water Quality Trends Scenarios
s
3
I
co
Specific Conductance at
Station TCEQ-1 3205
1,400-1
1 ?nn
1.000 -
* ^
% *^> * yjj* . JHjtV
* '^^nrv
50/90 1/31193 1 0128/95 7Q4/98 4/19/01 1/14/04 10r1ogH Ftbnuiy V«lw> DMrlbiMOT «l SUOon TCEO-13JM
(00 850 900 850 1.000 1,060 1,100 1,150 1.200 '.250 1,300
8p»dflc ConducUnc*
Jun. Ihraugh Augud Valuo. DiHribullon it Station TC6Q-13205
1.000 1,100
Specific Conductanc* (uS/cm)
1,200
1,300
Figure E-31. Seasonal distributions for
specific conductance values during study
period.
E-29
-------
Appendix E - Water Quality Trends Scenarios
Table E-17. Statistics for Water Quality Indicator Values Measured at Different Stations in
the Rio .Grande-Elephant Butte Reservoir to above Rio Conchos Region
Statistic
Count
Average
Median
Mode
Standard Deviation
Min
Quartile 1
Quartile 2
Quartile 3
Max
First Reading
Last Reading
Trend
Chloride
(mg/L) at
Station
TCEQ-13272
Conductance
(uS/cm) at
Station
TCEQ-13272
Total
Nitrogen
(mg/L) at
Station
TCEQ,13272
Fecal
Coliform
(#/100 ml) at
Station
TCEQ-13272
s
!
pH at Station |
TCEQ-15528 j
i
!
i
. , .'... ,..:r;S. ".. "Statistics .Values...' . '.. .f
251
157.5
119.0
110.0
99.9
1.0
94.0
119.0
190.0
752.0
21-Jan-93
18-Nov-03
Stable
175
1,469
1,190
1,170
765
288
1,058
1,190
1,760
8,490
27-Jan-93
16-Dec-03
Increasing
155
0.2
0.1
0.1
0.3
0.0
0.1
0.1
0.2
1.9
27-Jan-93
16-Dec-03
Increasing
151
1,236
567
300
1,649
1
219
567
1,535
9,700
27-Jan-93
16-Dec-03
Not identifiable
146
8.3
8.3
8.2
0.4 ,
6.5
8.1
8.3
8.5
9.7
20-Nov-97
16-Dec-03
Increasing
Table E-18. Statistics for Water Quality Indicator Values Measured at Different Stations in
the Rio Grande-Rio Conchos to Am is tad Reservoir Region
j
(Statistic
Count
Average
Median
Mode
Standard Deviation
Min
Quartile 1
Quartile 2
Quartile 3
Max
First Reading
Last Reading
Trend
DO (mg/L) at
Station TCEQ-
15892
pH at Station
TCEQ-15892
Conductance
(uS/cm) at
Station TCEQ-
13835
DO (mg/L) at
Station TCEQ-
13835
Conductance I
(uS/cm) at i
Station TCEQ- j
15893 !
Statistics Values j
197
7.9
8.0
7.8
1.9
0.3
7.2
8.0
9.1
11.1
05-Mar-98
02-Dec-03
Stable
197
8.1
8.1
8.1
0.2
7.5
8.0
8.1
8.3
8.5
05-Mar-98
02-Dec-03
Not identifiable
197
1,001
1,019
1,030
74
820
965
1,019
1,059
1,171
21-Jun-OO
02-Dec-03
Decreasing
197
7.0
7.8
8.0
2.8
0.1
6.1
7.8
8.9
11.7
21-Jun-OO
02-Dec-03
Not identifiable
141
553
534
435
160
327
416
534
691
932
06-Oct-99
02-Dec-03
Not identifiable
E-30
-------
Appendix E - Water Quality Trends Scenarios
Table £-19. Statistics for Water Quality Indicator Values Measured at Different Stations in
the Rio Grande below Amistad Reservoir to Falcon Reservoir Region
r . '
f
(Statistic
Count
Average
Median
Mode
Standard Deviation
Min
Quartile 1
Quartile 2
Quartile 3
Max
First Reading
Last Reading
Trend
DO(mg/L)at
Station TCEQ-
13205
pH at Station
TCEQ-13205
Conductance,
; (uS/cm) at
Station TCEQ-
13560
PO(mg/L)at
Station TCEQ-
13560
Chloride (mg/L)
at Station
TCEQ-13209
Statistics Values
114
8.5
8.3
10.7
2.0
3.9
7.1
8.3
9.7
15.4
23-Mar-93
1 l-Dec-03
Stable
113
8.1
8.0
8.0
0.7
6.9
7.7
8.0
8.2
10.5
23-Mar-93
ll-Dec-03
Stable
107
998
1,010
1,013
140
94
946
1,010
1,056
1,312
16-Mar-93
13-Nov-03
Decreasing
106
9.1
9.2
9.0
2.4
2.1
7.3
9.2
10.9
15.2
16-Mar-93
13-Nov-03
Stable
102
151.8
150.0
160.0
20.8
'60.9
138.4
150.0
160.0
200.0
20-Jan-93
12-Sep-02
Decreasing
Table E-20. Location of Additional Stations in the Rio Grande Transboundary Region
I Station ID
TCEQ-
15528
TCEQ-
13835
TCEQ-
15893
TCEQ-
13560
TCEQ-
13209
Location "
Lat: 31.752777,
Lon:- 106.41 8892
Lat: 29.458334,
Lon: -101. 05722
Lat: 29.601389,
Lon: -100.9761 12
Lat: 29.291 945,
Lon: -100.8761 14
Lat: 29.416666,
Lon: -10 1.033333
Name
RIO GRANDE 1.3KM
DWNSTRM WWTP
AMISTAD RESERVOIR AT
BUOY #1 . Ambient monitoring
station.
AMISTAD RESERV DEVILS
RARM
RIO GRANDE AT MOODY
RANCH
RIO GRANDE BELOW
AMISTAD DAM
State
Texas
Texas
Texas
Texas
Texas
Owning Organization
Texas Commission on
Environmental Quality
Texas Commission on
. Environmental Quality
Texas Commission on
Environmental Quality
Texas Commission on
Environmental Quality
Texas Commission on
Environmental Quality
E-31
-------
Appendix E - Water Quality Trends Scenarios
E.7 Case Studies for the Lower Rio Grande Transboundary
Region. .
Two case studies were included for this region. Each one is defined by a water quality
indicator measured at a given station in the region. Water quality trends and seasonality were
assessed for the scenario and are summarized in Figures E-32 through E-37 and Tables E-21 and
E-22. Additional trends were assessed for other stations and summarized in Tables E-23 and E-
24.
£.7.1 General Characteristics
The Lower Rio Grande Valley Region (below Falcon Reservoir to the Gulf of Mexico)
contains 11 basins that drain either to that reach of the Rio Grande, to the lower reach of the Rio
San Juan below the gaging station at Santa Rosalia, or to Arroyo Colorado in southern Texas. It
drains an area of 10,240 square miles (26,500 km2).
This region is physiographically characterized as Gulf Coastal Plain. From Falcon
Reservoir, the Rio Grande/Rio Bravo flows southeastward approximately 275 river miles (443
km), ending in the coastal wetlands and marshes of the Gulf of Mexico, including the Laguna
Madre off the coasts of Texas and Tamaulipas. Among the unique habitats of this segment of the
U.S.-Mexico border are the "resacas" (oxbow lakes) of the Lower Rio Grande Valley. Surface
water flow entering the Lower Rio Grande Valley Region via the Rio Grande mainstream is
greatly influenced by water management practices and upstream control structures. Mexico's Rio
Conchos and Rio San Juan have been the primary sources of water for this section of the Lower
Rio Grande for several decades (Buckler et al., 1997).
E-32
-------
-------
-------
Development of U.S.-Mexico Water Quality Analyses
Plates
U.S.-Mexico Transboundary Basins
-------
Development ofU.S.-Mexico Water Quality Analyses
[This page intentionally left blank.]
-------
Development ofU.S.-Mexico Water Quality Analyses
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