United States
Office Of Water (4204-M)
Environmental Protection Agency
EPA-832-R-00-001
January 2001
STATUS REPORT ON THE
WATER-WASTEWATER
INFRASTRUCTURE
PROGRAM FOR THE
US-MEXICO BORDERLANDS

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                                   Acronyms
      Acronyms used in this report are :
(ADEQ)
(BECC)
(BEIF)
(CRWQCB)
(CDC)
(CWA)
(CEC)
(EPA)
(FUMEC)
(IBWC)

(IWTP)
(mgd)
(CNA)
(NMED)
(NAAEC)
(NADBank)
(NAFTA
(PAHO)
(PDAP)
(SEMARNAP)
(SBIWTP)
(TNRCC)
(FUMEC)
(USER)
(USGS)
Arizona Department of Environmental Quality
Border Environment Cooperation Commission
Border Environmental Infrastructure Fund
California Regional Water Quality Control Board
Center for Disease Control
Clean Water Act
Commission on Environmental Cooperation
Environmental Protection Agency and its Office of Water
George E. Brown U.S.-Mexico Foundation for Science
International Boundary and Water Commission and its U.S. and Mexican
Sections
International Wastewater Treatment Plant
Million Gallons per Day
National Water Commission of Mexico a part of SEMARNAP
New Mexico Environment Department
North American Agreement on Environment Cooperation
North American Development Bank
North American Free Trade Agreement
Pan American Health Organization
Project Development Assistance Program
Secretariat of the Environment, Natural Resources and Fisheries
South Bay International Wastewater treatment Plant
Texas Natural Resource Conservation Commission
U.S.-Mexico Science Foundation
United States Bureau of Reclamation
United States Geological Survey

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                               TABLE OF CONTENTS

Sections                                                                         Page
Acronyms	i
Table of Contents	ii-iii
Figures	 iv-v
Tables	vi-vii

Executive Summary                                                                1-2

1            Introduction	3

2            The Border Team at Work	4
                    2.1 La Paz Accord	4-5
                    2.2 North American Free Trade Agreement  	5-6
                    2.3 Other Border Relationships	6
                    2.4 Major Data Sources	6
                    2.5 Public Health	6
                                 2.5.1 Description of Illnesses	7
                                 2.5.2 Remedial Progress 	8

3            The Watersheds of the Borderlands	9
                    3.1 Watershed Basins	9-10
                    3.2 Population of the Borderlands	9
                    3.3 Pacific Coastal Basin	11
                                 3.3.1 Geography	11
                                 3.3.2 Hydrology	11-12
                                 3.3.3 Water Quality 	13-15
                                 3.3.4 Public Health Conditions  	16
                                 3.3.5 Existing Water and Wastewater Infrastructure . 16-18
                    3.4 New River Basin  	19
                                 3.4.1 Geography	19
                                 3.4.2 Hydrology	20
                                 3.4.3 Water Quality	21-22
                                 3.4.4 Public Health Conditions	23
                                 3.4.5 Existing Water and Wastewater Infrastructure . 23-24
                    3.5 Gulf of California Coastal Basin	24
                                 3.5.1 Geography	24
                                 3.5.2 Hydrology	24
                                 3.5.3 Water Quality	25-26
                                 3.5.4 Public Health Conditions  	26
                                 3.5.5 Existing Water and Wastewater Infrastructure . 26-27
                                          11

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4
      3.6 Colorado River Basin	27
                   3.6.1 Geography	27
                   3.6.2 Hydrology	27-28
                   3.6.3 Water Quality  	28-30
                   3.6.4 Public Health Conditions  	31
                   3.6.5 Existing Water and Wastewater Infrastructure . 32-33
      3.7 Northwest Chihuahua Basin  	33
                   3.7.1 Geography	33
                   3.7.2Hydrology	33
                   3.7.3 Water Quality  	34-35
                   3.7.4 Public Health Conditions	36
                   3.7.5 Existing Water and Wastewater Infrastructure . .36-37
      3.8. Rio Grande Basin	37
                   3.8.1 Geography	37
                   3.8.2 Hydrology	37
                   3.8.3 Water Quality  	38-42
                   3.8.4 Public Health Conditions  	43-44
                   3.8.5 Existing Water and Wastewater Infrastructure . 45-50
      3.9. Gulf of Mexico Coastal Basin	50
                   3.9.1Geography	50
                   3.9.2 Hydrology	50
                   3.9.3 WaterQuality  	50-52
                   3.9.4 Public Health Conditions  ...	52
                   3.9.5 Existing Water and Wastewater Infrastructure	53

Current Water and Wastewater Infrastructure Needs  	54
      4.1 Pacific Coastal Basin	55
      4.2 New River Basin 	56-57
      4.3 Gulf of California Coastal Basin	: 57-58
      4.4 Colorado River Basin	59-60
      4.5 Northwest Chihuahua Basin  	61
      4.6 Rio Grande  Basin	62-66
      4.7 Gulf of Mexico Coastal Basin	67

Accomplishments	68
      5.1 BEIF	68
      5.2 PDAP	69
      5.3 FUMEC	69
      5.4 Border Tribal Assistance	69

Future of Water Infrastructure Management in the Border Area	70
      6.1 Summary of Near-and Long-Term Needs	70-71
      6.2 EPA and Other Needs Estimates	71
      6:3 Next Steps  	72

Information Resources  	73
      7.1References	73-74
                                          111

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                                LIST OF FIGURES

Figure No.   Title                                                              Page

3-1          U.S.-Mexico Border Population by Basin	9

3-2          U.S.-Mexico Watershed Basins Map		10

3-3          Satellite Image of Partial U.S. Mexico Border  	11

3-4          Average Fecal Coliform Concentration Before and After Start-Up
             of the International Wastewater Treatment Plant and Ocean Outfall  	13

3-5          Pacific Coastal Basin Map with Water Quality Monitoring Stations  	14

3-6          Completed Advanced Primary Wastewater Treatment Plant
             (IWTP) San Diego, CA	17

3-7          Construction of Ocean Outfall	17

3-8          Installation of 12 foot diameter outfall for IWTP 	18

3-9          Construction of Headworks and Odor Control Building at the IWTP	18

3-10         Satellite Image showing the New River Basin with the Salton Sea	19

3-11         Salton Sea	20

3-12         New River Basin Map with Water Quality Monitoring Stations	22

3-13         Gulf of California Coastal BasinMap	25

3-14         Colorado River Basin Map with Water Quality Monitoring
             Stations	29

3-15         Typical Watershed Basin showing Ridges and Valleys in the
             N.W. Chihuahua Area	33

3-16         Typical Semidesert Conditions in the Chihuahua Area	34

3-17         Northwest Chihuahua Basin Map  	35

3-18         Sewer Discharge to a Waterway containing Foaming Agents
             near the Rio Grande	38

3-19         Rio Grande Basin Map Water Quality Monitoring Stations
             (Northwest Section)   	39

                                         iv

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3-20


3-21

3-22

3-23


3-24


3-25

3-26

3-27

3-28
Rio Grande Basin Map Water Quality Monitoring Stations
(Southeast Section)  	
40
Sewer Installation in Ciudad Acufta, Coahuila, Mexico 	45

Sewer Inspection in Ciudad Acufta, Coahuila, Mexico	45

Pump Station under Construction at Ciudad Juarez Wastewater
Treatment Plant	46

Ciudad Juarez, Chihuahua Wastewater Treatment Plant under
Construction	46

Colonia Housing with Privy hi Background	47

Colonia.housing along the border '	48

Typical U.S. Colonia	48
 Gulf of Mexico Coastal Basin Map with Water Quality
 Monitoring Stations 	
                                                                                    51

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                                  LIST OF TABLES
Table
Title
Page
2-1           Comparison between US-Mexico Border and US Nationwide
              Waterborne Disease Rates	8

3-1           Comparison of Surface Water Quality Standards with Sampling
              Data for the Pacific Coastal Basin	15

3-2           Reported Waterborne Diseases in the Pacific Coastal Basin
              (Incidences per 100,000 People)  	16

3-3           Comparison of Surface Water Quality Standards with Sampling
              Data for the New River Basin	21
                                           r
3-4           Reported Waterborne Diseases in the New River Basin
              (Incidences per 100,000 People)  	23

3-5           Reported Waterborne Diseases in the Gulf of California Coastal Basin
              (Incidences per 100,000 People)	26

3-6           Comparison of Surface Water Quality Standards with Sampling
              Data for the Colorado River Basin	30

3-7           Reported Waterborne Diseases in the Colorado River Basin
              (Incidences per 100,000 People)	31

3-8           Reported Waterborne Diseases in the
              Northwest Chihuahua Basin (Incidences per 100,000 People)  	36

3-9           Comparison of Surface Water Quality Standards with
              Sampling Data for the Rio Grande Basin	41-42

3-10          Reported Waterborne Diseases in the Rio Grande Basin
              (Incidences per 100,000 People)  	44

3-11          Comparison of Surface Water Quality Standards with
              Sampling Data for the Gulf of Mexico Coastal Basin	52

3-12          Reported Waterborne Diseases hi the Gulf of Mexico Coastal Basin
              (Incidences per 100,000 People)  	52

4-1          Near-and Long-Term Needs in the Pacific Coastal Basin	55

4-2          Near- and Long-Term Needs in the New River Basin	57

4-3          Near- and Long-Term Needs in the Gulf of California Coastal Basin	58
                                          VI

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4-4




4-5




4-6




4-7




5-1




6-1
Near- and Long-Term Needs in the Colorado River Basin	60




Near- and Long-Term Needs in the Northwest Chihuahua Basin	61




Near- and Long-Term Needs hi the Rio Grande Basin	65-66




Near- and Long-Term Needs in the Gulf of Mexico Coastal Basin	67




Current EPA Participation U.S.-Mexico Border Infrastructure Needs 	68




Summary of Near-and Long-Term Water and Wastewater Infrastructure Needs 71
                                          vn

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                            EXECUTIVE SUMMARY

       This status report of the water and wastewater infrastructure program for the US-Mexico
border area emphasizes water quality and public health conditions. The report also analyzes the
current (2000) and future (2020) water and wastewater infrastructure  needs for the increasing
population along the border and highlights the accomplishments achieved by the binational water
groups which the U.S. Environmental Protection Agency (EPA), through its Office of Water, and
Mexico's Secretariat of the Environment, Natural Resources and Fisheries (SEMAKNAP), through
its National Water Commission (CNA), Border Environment Cooperation Commission (BECC),
North American Development Bank (NADBank) and International Boundary Water Commission
(IB WC). This group along with state and municipal governments cooperate in the management of
the water resources along the border area.

       Environmental problems have been compounded by rapid population growth  in the sister
cities,  all of which are the  main gateway for trade and travel between Mexico and the U.S. The
strategic positions of these cities attract industry and investment; however, it also carries problems
including pollution and its  impact on the health conditions of the people living in the border area.
The growth in population has overwhelmed the infrastructure capacity, overloading  the existing
treatment facilities and causing partly treated or untreated direct wastewater discharges to the surface
water bodies along the border. The population along the U.S.-Mexico Border is expected to further
increase from 12.6 million in the year 2000 to about 21 million in 2020.

       Surface water quality monitoring data contained in this report were gathered, compiled, and
analyzed for all the boundary area water bodies. The results are compared to the U.S. and Mexico
water quality standards, for fecal coliform and dissolved oxygen concentrations. The sampling data
results indicate that in the majority of the sampling locations the water quality standards for fecal
coliform and dissolved oxygen are  not met, typically  because of partially  treated  or untreated
wastewater discharges in all  seven border watershed basins.

       Public health problems along the border are exacerbated by the impact of cross-border travel
and commerce.  Primarily, the waterborne diseases are created by unsanitary conditions or lack of
treatment facilities. The report analyzes the following waterborne diseases: Amebiasis, Hepatitis
A, Shigellosis and Typhoid Fever. Along the border in both the U.S. and Mexico the incidence rates
for these diseases are higher than the U.S. national average.

        The North American Free Trade Agreement (NAFTA) increased binational emphasis on the
border area by creating new institutions.to manage improvements to the water and wastewater
 infrastructure.  They are the Border Environment Cooperation Commission (BECC) and the North
 American Development Bank (NADBank).  EPA provides funding  assistance for water and
 wastewater infrastructure projects that have been developed and certified by the BECC.
 NADBank administers the Border Environmental Infrastructure Fund (BEIF) for EPA and serves
 as the border financier, arranging affordable financing packages to make infrastructure projects
 viable. The BEIF Program was established with EPA contributions currently totaling $339 million
 in early 2001.

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       EPA has also funded the George E. Brown U.S.-Mexico Foundation for Sciences (FUMEC)
and the Border Tribal Assistance Program which has funded 22 tribal projects hi California and 3
in Arizona.

       EPA,  working with its various partners,  has partly financed a number  of water  and
wastewater treatment projects along the U.S.-Mexico-border.  In the Pacific Coastal Basin, major
wastewater projects have been the International Wastewater Treatment Plant in San Diego and the
San Antonio de los Buenos Plant in Tijuana, Mexico. The New River Basin has on-going projects
in Brawley, Heber, Mexican', and Westmorland.  In the Colorado River Basin, the Naco project is
almost completed and Nogales and Patagonia projects are just getting started. In the Rio Grande
Basin, these are projects in El  Paso and Ciudad Juarez.  Both are completed  and in operation
additionally, eleven other projects in the basin are hi various stages of completion.  In the Gulf of
Mexico Coastal Basin there are projects in Brownsville and Matamoros which have received direct
funding assistance.

       The estimated water and wastewater needs for the border populace through the year 2020
totals $4.5 billion. The projected EPA participation hi near-term needs is estimated at $691 million,
divided as follows: $342 million in the U.S. and $349 million hi Mexico.  Long-term needs are
estimated at $3.8 billion of which $1.3 billion is needed for the U.S. and $2.5 billion for Mexico.

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1.     Introduction

       Environmental conditions and human health in the U.S.-Mexico border area are
influenced to a significant degree by the quality of the available water sources. Many waterways,
some originating in Mexico and others hi the U.S., flow across or along the binational border.
Most of the border region is arid. Shared rivers, aquifers and marine resources are extremely
valuable. Population in urban areas along the border has increased significantly over the past few
years, influenced by the expansion of the maquiladora industry and relocation of industries from
both countries to the area, resulting hi an increase in jobs.

       The area of concern covers surface water quality and public health issues within the
border limits of the United States-Mexico covering the States of California (U.S.), Baja
California (Mexico), Arizona (U.S.), Sonora (Mexico), New Mexico (U.S.), Chihuahua
(Mexico), Texas (U.S.), Coahuila, (Mexico), Nueyo Leon (Mexico), and Tamaulipas (Mexico).

       Along the border, economic activity and population have continued to grow rapidly.
However, water and wastewater infrastructure has not kept up, resulting in a deterioration hi
surface water quality and an increase in the incidence of waterborne diseases. This report
summarizes the water quality and public health conditions along the border and evaluates the
need and effect of providing an adequate water and wastewater infrastructure for the border area.
The report also provides an analysis of the accomplishments of a binational, multi-agency
working group.  Finally, the report looks at the future water and wastewater infrastructure needed
to protect the water  environment and serve communities of the border area through the year
2020.

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2.     The Border Team at Work

       Members of the binational multi-agency water working group called the Border Team
include the U.S. Environmental Protection Agency (EPA) represented by its Office of Water,
Mexico's  Secretariat of the Environment Natural Resources and  Fisheries (SEMARNAP)
represented  by its National Water Commission  (CNA),  International Boundary and Water
Commission (E3WC), Border Environment Cooperation Commissi9n (BECC), and the North
American Development Bank (NADBank). EPA has and continues to participate with the other
organizations to achieve the goal of improving surface water quality and protecting public health in
the border area. Their authority and responsibilities fall within the scope of the following treaties.

2.1    La Paz Accord

       In 1983 in La Paz, Baja California Sur, Mexico, 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, commonly referred to as the La Paz Accord was signed. It
established a framework for cooperation between the U.S. and Mexico to prevent and eliminate
sources of air, water, and land pollution along the border. Work activities under the La Paz Accord
are coordinated by EPA and SEMARNAP.  The 1983 La Paz Accord defined the 2100 mile (3200
km) stretch of borderland and established the border zone within 62 miles (100 km) on either side
of the U.S.-Mexico border.

       EPA was established in 1970 as an independent agency of the Executive Branch of the U.S.
Government for protecting and regulating use of the nation's land, air and water resources. EPA
Water Programs operate under the Clean Water Act (CWA) and the  Safe Water Drinking Act.
Under Title II of the CWA, Congress authorized the appropriation of funds to plan, design, and
construct municipal wastewater treatment plants in the U.S.  Over the last several years, EPA has
received appropriations for construction of water and wastewater infrastructure along the border.
Initially, this funding was focused on projects developed with the assistance of the IBWC.

       The Water Quality Act of 1987 constitutes the most comprehensive amendments to the Clean
Water Act since its enactment in 1972. Among their many provisions, the 1987 Amendments
authorized the State Revolving Loan program, along with a phase out the Construction Grants
Program, to increase the sharing of the construction costs by local communities. However, in these
Amendments,  Congress  also included a  specific authorization dealing  directly  with border
environmental issues in SanDiego, California and Tijuana, Mexico border area. EPA's Construction
Grants Program and its successor, the Clean Water State Revolving Fund (CWSRF) Program, have
provided $67 billion in financial assistance to help communities improve local water quality,
primarily by building or upgrading municipal wastewater treatment plants and sewer systems.

       Section 510 of the Water Quality Act of 1987, as revised, provided EPA the authority for
the construction of a25 mgd secondary wastewater treatment facility in the amount of $23 9.4 million
to serve the cities of San Diego and Tijuana.

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      More recently, a large portion of the border infrastructure construction funds has been placed
in the Border Environmental Infrastructure Fund (BEIF). The North American Development Bank
(NADBank) acts as EPA's agent for disbursement of BEIF funds as grants for needs that cannot
otherwise be fully met by a combination of NADBank loans or Mexican government grants, State
and local government or private sector resources.

      SEMARNAP was created in 1994 to organize Mexico's environmental policies, programs
and fiscal resources into a single federal agency, whose functions are similar to their U.S.
counterpart.   SEMARNAP has the responsibility to protect, conserve, regulate, and promote
environmental resources hi cooperation with State and Municipal authorities, other Federal agencies,
and  individuals to implement  state environmental policies  in accordance  to the National
Environmental  Policy.  SEMARNAP  manages  the  Mexican federal funding support  for
environmental infrastructure through grant-type subsidies.

        EPA  designated its Office of Water and  SEMARNAP designated its National Water
Commission (CNA) to lead their respective agencies on water matters.

      In 1993, the U.S. and Mexico announced an interim target of $700 million each in federal
grants for planning, design, and construction of water and wastewater facilities over 7 to 10 years.
The intent of this grant funding was to make projects affordable by using grants to augment debt
capital.

2.2   NAFTA

       Although primarily a trade agreement, the November 1993  North American Free Trade
Agreement (NAFTA) was supplemented with specific environmental subagreements which pro vide
border communities a greater role in determining and fulfilling their environmental protection needs.
These provisions included the North American Agreement on Environment Cooperation (NAAEC),
which is to be implemented by the Commission on Environment Cooperation (CEC), as well as the
Border Environment Cooperation Commission and the North American Development Bank. CEC,
BECC and NADBank are international organizations intended to implement certain environmental
aspects  of the agreement in communities on both sides of the border.

       The BECC, located in Ciudad Juarez, Chihuahua, works with state and local governments
to provide financial and technical assistance for  development of projects dealing with water,
wastewater, and municipal solid waste needs. BECC certification is required for a project to be
eligible for financing from the NADBank, which arranges  for public and private investment.
Certification is based on a set of environmental, health, technical, financial, community participation
and sustainable development criteria through a process that includes extensive public participation.

        The NADBank, based hi San Antonio, Texas, was created to serve as a financial partner and
 catalyst in financing construction of BECC- certified environmental infrastructure  projects.
NADBank's capital consists of $3 billion, contributed equally by the U.S. and Mexican governments.

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NADBank functions as a financial broker, not only lending its own resources, but arranging loans
and grants from others. NADBank administers EPA's Border Environment Infrastructure Fund
(BEIF) as part of its duties to supplement its loan and guaranty programs. BEIF funds are to be used
as a funding source last resort to make projects viable and affordable for border communities.
Currently, each dollar of EPA's BEIF funding has leveraged more than two  dollars from other
sources.

2.3    Other Border Relationships

       The International Boundary and Water Commission (IBWC), consisting of U.S. and Mexican
Sections, has expanded binational cooperation under the La Paz Accord, having executed a series
of subagreements under their enabling treaties for projects to protect the environment and public
health along the border through construction and/or upgrades of water and wastewater infrastructure.

       The George E. Brown U.S.-Mexico Foundation for Science (FUMEC) coordinates, promotes,
follows up, and evaluates actions aimed at the improvement of scientific and educational cooperation
between Mexico and the United States, complementing the tasks of other public and private
academic and research institutions in both countries. Currently FUMEC is implementing a Training,
Certification and Technical Assistance Program (SCCAT) for the management of water  and
wastewater projects along the Border area with an EPA funding of $3.5 million has been provided
to FUMEC, of which $2.0 million was used to establish an endowment and $1.5 million for other
purposes.

       There are a total often border states which consist of four U.S. Border States (California,
Arizona, New Mexico and Texas) and six Mexican States (Baja California, Sonora, Chihuahua,
Coahuila, Nuevo Leon and Tamaulipas.

2.4    Major Data Sources

       The surface water quality sampling data obtained for this report was provided by the U.S.
Geological Survey (USGS), Texas  Natural Resource Conservation Commission (TNRCC),
International Boundary Water  Commission (IBWC),  New Mexico  Environment Department
(NMED), Arizona Department  of Environmental Quality (ADEQ), City of San Diego, and the
California Regional Water Quality Control Board (CRWQCB) San Diego Region.

       The U.S.Center for Disease Control (CDC), Texas County Health Departments and the Pan
American Health Organization (PAHO) provided the public health data cited in this report.

2.5    Public Health

       The Center for Disease Control  (CDC) maintains  a database of waterborne disease
occurrences that correlates the cause  of waterborne disease with acute gastrointestinal illnesses.
Agents which cause the highest incidence of infection are bacterial agents including Shigella,
protozoan, including Entamoeba histolytica, and viruses including Hepatitis A.  The selected
waterborne diseases are reportable infectious illnesses with clear associations to contaminated water,
primarily by fecal contamination.

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2.5.1   Description of Illnesses

       Amebiasis and Shigellosis both result in severe debilitating dysentery and prostration,
whereas Hepatitis A symptoms are nausea, diarrhea, abdominal cramps, fever, and chills, and
sometimes jaundice.

       Entamoeba histolytica, the causative agent of amoebic dysentery or Amebiasis, is the only
pathogenic amoeba found in the human intestine. E. histolytica is transmitted between humans
through the ingestion of cysts.  Some forms of amoebae can infect a person through skin contact with
infected water, including swimming.  These forms can also infect the blood, brain and spinal cord
of a human. The more common severe dysentery can be recurrent.

       Shigellosis is also known as bacillary dysentery, which produces an unusually virulent toxin.
This illness is a clear indicator of lack of treatment facilities for human waste in the border region
because the pathogenic bacilli reside only in the intestines of humans, apes, and monkeys.  The
Shigella bacteria proliferate to immense numbers in the small intestine,, then they  produce tissue
destruction and scarring in the large intestine. The ulcerations in the intestinal mucus cause severe
diarrhea with blood and mucus in the stools, and infected people can have as many as 20 bowel
movements a day, resulting in dehydration. Health care (antibiotics and electrolyte replacement) is
critical to avoid fatalities. Where good health care is not available, morbidity rates of those infected
with the Shigella bacillus can approach 20 percent, with  infants and young children especially
vulnerable.

       Hepatitis A has other modes of transmission in addition to water, which include transmission
through contaminated food. Hepatitis A rates may decline through public health education programs
that teach people sanitation before handling food. Therefore, declines in infectious disease rates may
or may not be directly related to new wastewater treatment plants. However, these  investments in
public health education should, in time, directly improve public health. Hepatitis A typically enters
the body orally, multiplies in the digestive tract, and spreads to the liver, kidneys, and spleen. The
virus is found in the feces and is present in greatest numbers before symptoms are present. For this
reason, a food handler responsible for spreading the Hepatitis A virus may not feel ill at the time.
Additionally, the virus is capable of surviving outside the body for several days on surfaces such as
cutting boards.  Hepatitis A  is resistant to chlorine at levels normally found in tap  water used.
Another common mode of transmission is in shellfish, especially raw shellfish.

       The pathogen that causes Typhoid Fever is found only in the feces of human beings. The
characteristics of high fever and constant headaches are followed by diarrhea. In severe cases, there
can be perforation of the intestinal wall. The mortality rate in areas with good health  care is only one
to two percent, but left untreated, mortality can be as high as ten percent.  Recovered patients can
remain carriers and continue to transmit the infection indefinitely.

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2.5.2   Remedial Progress
       Even with the progress that has been and is being made, available public health data for the
border area indicate high levels of Amebiasis, Shigellosis (amoebic dysentery), Hepatitis A, and
other waterborne diseases that can be transmitted by use of, or contact with, untreated or poorly
treated drinking water and wastewater. Disease rates are higher hi the U.S. border area than in most
other areas of the United States.

        An outbreak of a disease on one side of the border threatens the other side because of
migration of people across the border for a variety of reasons such as visiting family and friends,
seeking employment, and/or conducting business on the other side. Therefore, there are some
commonalities shown in the health data. Analysis of these data shows there is a demonstrated record
of success hi improving public health through the completion of wastewater infrastructure projects
at the South Bay International Wastewater Treatment Plant (SBIWTP) as indicated on Figure 3-4
by a decrease hi fecal coliform concentrations.  Moreover, the waterborne disease rates for the San
Diego County decreased with the exception of Typhoid Fever. There may be a relationship between
the decrease of Amebiasis, Hepatitis A, and Typhoid Fever in the Nogales area and construction of
the Nogales International Wastewater Treatment Plant.  Generally the level of drinking water and
wastewater treatment is less adequate as a general matter along the border compared with the rest
of the U.S.

       Table 2-1 indicates that the current incidence rates of disease are higher on the U.S.-Mexico
border than the rest of the U.S.

Table 2-1.  Comparison Between U.S.-Mexico Border And U.S.-Nationwide Waterborne
            Disease Rates (1998). (Incidences per 100,000 People)
Disease
Amebiasis
Hepatitis A
Shigellosis
Typhoid Fever
US Border
Rates
1.4
37.1
35.3
0.4
Mexican Border
Rates
798.8
50.1
No Data
Available
36.1
US Nationwide
Rates
1.4
12.6
10.9
0.2
Reference: Pan American Health Organization
website http://www.fep.paho.org/healthprofiles

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3      The Watersheds of the Borderlands

3.1    Watershed Basins

       The U.S.-Mexico border area is located within seven major surface watershed basins
stretching from the Pacific Ocean to the Gulf of Mexico. Each, with one exception is a major water
body and they are called the Pacific Coastal, New River, Gulf of California Coastal, Colorado River,
Northwest  Chihuahua, Rio  Grande, and Gulf of Mexico  Coastal Basins.   From the water
environment perspective, each basin is uniquely defined by its geography, hydrology, water quality,
public health and existing water and wastewater infrastructure. A U.S.-Mexico Watershed Basins
Map is shown on Fig. 3-2.

3.2    Population of the Borderlands

       Communities within a watershed basin are interdependent, with the condition of the
waters leaving one community potentially affecting the water supply of its neighbor. While the
water protection standards set by the two governments for their communities may differ in their
form, considerable work has been done by the regulatory agencies to make them complementary
in their effect. The total border population is about 12.6 million and is expected to increase'to
about 21 million in the next two decades, based on estimates presented below.  Fig 3-1 shows the
population distribution by basin.  Growth along the U.S.-Mexico border has increased concerns
for environmental and public health issues, including the ability to provide water and wastewater
infrastructure for its residents and visitors.
                                | • Year 2000 BYear 2020
            Pacific
            Coastal
New River   Gulf of   Colorado Northwest Rio Grande   Gulf of
         California   River   Chihuahua            Mexico
          Coastal                               Coastal
               Watershed Basins
                   Figure 3-1.  U.S-Mexico Border Population by Basin.

-------
                                       1
                                       s
10

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3.3    Pacific Coastal Basin

3.3.1  Geography

       The Pacific Coastal Basin is located along  the western coast  of California and Baja
California. More than 4 million people live here, primarily in the sister cities of San Diego and
Tijuana. The basin, which is about 50 miles (80km) wide, extends from Lake Elsinore in Riverside
County, California to the city of Ensenada, Baja California and includes the Peninsula and Sierra
Juarez mountain ranges. A satellite image of this portion of the border area is shown in Fig.3-3.
                    FIGURE 3-3.  Satellite Image of partial US-Mexico border
                                 looking east of the Pacific Coastal Basin. Gulf
                                 of California shown center right.
 3.3.2  Hydrology

        The Pacific Coastal Basin drains approximately 7,650 square miles (19,800 sq. km), with
 about half of the drainage area in California and half in Baja California.

        The basin has a very dry, semiarid climate with few fresh water sources. Flow in this basin
 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. Most of these streams are not perennial because of severe
 drought conditions in the area. The Tijuana River, which drains 1,275 square miles of the basin, is

                                             11

-------
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.

3.3.3  Water Quality

       One major water quality concern in the Pacific Coastal Basin focuses on fecal coliform and
dissolved oxygen levels. Water quality monitoring stations for the Pacific Coastal Basin has been
established along the Pacific Coast from Punta Bandera or near the San Antonio de los Buenos
wastewater treatment plant outfall north to Carnation Street/Camp Surf at Imperial Beach and at the
ocean outfall to the South Bay International Wastewater Treatment Plant (SBIWTP). Start-up of the
SBIWTP with advanced primary treatment and discharge has decreased concentrations of fecal
coliform bacteria in the Pacific Ocean as indicated in Fig. 3-5. Table 3-1 [Figure 3-4] shows that
for receiving waters monitoring in the Pacific Coastal Basin, fecal coliform measurements along the
shore remain extremely high, with concentrations consistently exceeding 200 colonies/100 ml. The
IB WC and Hie State of California in its National Water Quality Inventory Section 305(b) Report and
the City of San Diego have identified fecal coliform. as a concern hi the Tijuana River, indicating that
more work needs to be done to control unregulated discharges to the river. Conditions at several of
the water quality monitoring locations shown, exceed U.S. surface water quality standards.
Another  water quality concern  in  the Pacific Coastal  Basin results from soil erosion and
sedimentation due to increases in population growth, urbanization, and unregulated development.
Due to these conditions, the estuaries and wetlands have been reduced from 20 to 40 percent of their
original area.  The Tij uana River National Estuarine Research Reserve is the most important estuary
in the Pacific Coastal Basin, and an erosion control program has been implemented to ameliorate
these problems.
                                             12

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Table 3-1 Comparison of Surface Water Quality Standards with Sampling Data for the Pacific
Coastal Basin.
Sampling
Station
Number







S-l



S-2

S-3

S-4


S-5


S-6

S-7

S-7a

S-8


S-9

S-10

S-ll

S-12
Water
Quality
Monitoring
Locations






San Antonio de
los Buenos
WWTP Outfall
Pipe, MX
ElVigia,MX

Fracc. Playas de
Tijuana, MX
North And South
of Mouth of
Tijuana River
Shoreline atmouth
of Tijuana
River.U.S.
End of Seacoast
Dr, U.S. side
Hollister Bridge,
U.S. side
Dairy Mart
Bridge, U.S. side
Silver Strand State
Beach, N. Fence
Line
Hotel Coronado,
U.S. side
Terminus
Monument Road
3/4 mile north of
Tijuana River
Camp Surf, U.S.
side
U.S. Standards



Fecal
Coliform
Colonies
/100ml


200



200

200

200


200


200

200

200

200


200

200

200

200
Dissolved
Oxygen
mg/l



6.0'



6.0

6.0

6.0


6.0


6.0

6.0

6.0

6.0


6.0

6.0

6.0

6.0
Sampling Data



Fecal
Coliform
Colonies/
100ml
Geometric
Averages
96



363

427

462


2319


354

440

670

25


21

469

471

275
Dissolved
Oxygen
mg/l
Geometric
Averages

No Data
Available


No Data
Available
No Data
Available
No Data
Available

No Data
Available

No Data
Available
No Data
Available
No Data
Available
No Data
Available

No Data
Available
No Data
Available
No Data
Available
No Data
Available

Reporting
Agency and
Time Frame



rowc
93-98


IBWC
93-98
IBWC
93-98
IBWC
93-98

IBWC
93-98

IBWC
93-98
San Diego
99-00
San Diego
99-00
IBWC
93-98

IBWC
93-98
IBWC
93-98
IBWC
93-98
IBWC
93-98
                                         15

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3.3.4  Public Health Conditions
       The health data presented in Table 3-2 are for the four major waterborne diseases which have
a direct relation to the surface water quality. The analyzed periods are from 1988-1998 because these
are the periods which represent increases and decreases which relates to the building of infrastructure
facilities along the border.

       Tijuana's disease rates are higher than in San Diego County; however, Tijuana's disease rates
were lower than those of most other Mexican border communities, as indicated in Table 2-1.

Table 3-2. Reported Waterborne Diseases in the Pacific Coastal Basin
           (Incidences per 100,000 People)
Pacific
Coastal
Basin


U.S.
Counties
San Diego
County
Mexico
Cities
Tijuana

Amebiasis

1988



1.4


639.4
1998



1


4875
%
Chg.


-29


662
.
Hepatitis A

1988



24.3


43.9
1998



15.8


113
%
Chg.


-35


157

Shigellosis

1988



25.3


11.0
1998



10.1


107
%
Chg


-60


873

Typhoid Fever

1988



0


10.5
1998



0.3


36.0
%
Chg.


—


243
Reference: Pan American Health Organization
website http://www.fep.paho.org/healthprofiles
3.3.5   Existing Water and Wastewater Infrastructure

        Descanso, California. Water supply is provided from wells with a high iron and manganese
content through an aging water distribution system. The community wastewater is currently treated
by individual septic tanks.

        Ensenada, Baj a California. Water supply is provided from a surface impoundment and wells.
The water distribution system covers over 98 percent of the city. Wastewater is collected from about
79 percent of the city and is treated by a 20 mgd oxidation ditch ( EPA has not funded infrastructure
hi Ensenada).

        San Diego, California.  Water  supply -is obtained from the  Colorado River and some
independent wells which serve the entire county. Wastewater is collected and treated from most of
the city and county by the Metropolitan Wastewater Department, with some jurisdictions providing
for their own collection. The City treats its wastewater in its 140 mgd Point Loma advanced primary
wastewater treatment plant with ocean discharge.  San Diego is currently constructing additional'
                                           16

-------
wastewater treatment capacity. A water reclamation plant has been completed for the North City area.

       Tecate, Baja California. Water supply is obtained from the Colorado River and local wells,
serving about 95 percent of the city. Wastewater is collected from about 84 percent of the city and
treated by trickling filters. The needs of the adjacent small community of Tecate, California are not
known.

       Tijuana, Baja California. Water supply is from a surface impoundment on the Tijuana River,
augmented through an aqueduct from the Colorado River, and serves the entire city. Wastewater is
collected from over 60 percent of the city and is treated at either the southerly San Antonio de los
Buenos wastewater treatment plant or at the new South Bay International Wastewater Treatment Plant
(SBIWTP) in the Tijuana River Valley, both with ocean discharge. The latter was funded in large part
by EPA and the Mexican government. The SBIWTP and ocean outfall are shown on Figures 3-6,3-7,
3-8, and 3-9.  The SBIWTP  is currently operating at the advanced primary level. The San Antonio
plant and its influent pumping station are currently being rehabilitated with construction of a second
influent pumping station underway, which was also funded by EPA.
  FIGURE 3-6.    Completed Advanced Primary     FIGURES-?. Construction of Ocean Outfall.
  Wastewater Treatment Plant (IWTP) in San Diego,
  California
                                            17

-------
Figure 3-8. Installation of the 12 Foot Diameter
           Outfall for IWTP.
Figure 3-9 Construction  of headworks and odor
control building at the International Wastewater
Treatment Plant.
                   18

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3.4     New River Basin

3.4.1    Geography

        The New River Basin extends north from the northeast section of Baja California to
southeastern California, an area of approximately 7,500 square miles (19,425 sq. km). The basin is
enclosed by the Chocolate and Santa Rosa mountain ranges that separate it from the Colorado River
and Pacific Coastal Basins located to the east and the west, respectively. At the center of the basin
is the flat, fertile Imperial/Mexicali Valley which contains the region's agricultural communities.
There are several urban areas in the basin including the sister cities of Mexicali, Baja California, and
Calexico, California.  A satellite image in Figure 3-10 shows the New River Basin including the
Imperial / Mexicali Valley with the  Salton Sea in the foreground..
                  Figure 3-10. Satellite image looking south showing the New River
                             Basin with the Salton Sea.
                                             19

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3.4.2   Hydrology

       The primary water bodies in the New River Basin are the New and Alamo Rivers, which flow
north from Mexico into a highly saline water body over 200 feet below sea level known as the Salton
Sea. The Salton Sea was created in 1905 when the Colorado River breached an irrigation canal
during severe floods and filled a natural depression between the Imperial and Coachella Valleys. The
New River receives most of its flow in the U.S. from the All American Canal and in Mexico from the
Alamo Canal. Figure 3-11 shows the Salton Sea at low water stage.
                                   FIGURE 3-11. Salton Sea.
                                          20

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3.4.3   Water Quality

       Currently, the New River is considered to be the most polluted water course in the United
States. Since 1985, water quality samples have indicated water quality problems in the basin.  The
1999 State of California National Water Quality Inventory Section 305(b) report identifies bacteria
and sedimentation/siltation as two water quality concerns in the New River Basin.

       High levels  of fecal coliform bacteria indicate contamination by sewage.  The current
California water quality criterion for fecal coliform bacteria is 200 colonies/100 ml for waters used
for contact recreation such as swimming or bathing. Fecal coliform concentrations are several orders
of magnitude greater than this limit and average almost 461,665 colonies per 100 ml in the New
River at the Border.  Table 3-3 Figure 3-12 and contains sampling stations and data  and applicable
water quality criteria for various locations on the New River.
Table 3-3.  Comparison of Surface Water Quality Standards with Sampling Data for the
            New River Basin.
Station
Number







1


2



3


4





5


Water
Quality
Monitoring
Stations






Alamo River at
Delta into Salton
Sea
New River at
outlet (into Salton
Sea) near
Westmorland, CA
Alamo River at
Int. Border near
Calipatria, Ca
New River
upstream of
Discharge Canal at
Mexicali



New River at
International
Border

U.S. Standards

Fecal
Coliform
Colonies
/100ml



200


200



200



*30,000




No Data

Dissolved
Oxygen
mg/I




5.0


5.0



5.0



No Data




5.0


Sampling Data

Fecal
Coliform
Colonies
/100ml
Geometric
Average

No Data


No Data



35



461,665




No Data

Dissolved
Oxygen
mg/1
Geometric
Average


No Data


No Data



5.8



No Data




2.6

Reporting
Agency and
Time Frame




EPA


uses


USGS/CRW
QCB
88-97
IBWC
88-97
*Minute 264
US-
Mexican
1944 Water
Treaty.
IBWC
88-97

                                            21

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22

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3.4.4  Public Health Conditions

       While the New River Basin has some of the worst water quality conditions hi the U.S., recent
wastewater infrastructure investments in the basin, such as improvements to Mexicali's sanitary
sewers, can be correlated with the 1988-1998 decline hi Amebiasis, Shigellosis, and Hepatitis rates
in Imperial County, California, as indicated in Table 3-4. No incidences were reported for Typhoid
Fever.

Table 3-4.Reported Waterborne Diseases in the New River Basin
          (Incidences 100,000 People )
New
River
Basin


U.S.
Counties
Imperial
County
Mexican
Cities
Mexicali

Amebiasis

1988



1



544
1998


,
0



1910
%
Chg.


-100



251

Hepatitis a

1988



19



34.2
1998



16



154
%
Chg.


-16



350

Shigellosis

1988



63.7



10.6
1998



13.2



18
% •
Chg.


-79



70

Typhoid Fever

1988



0



20.6

1998



0



107

%
Chg.


0



419
 Reference: Pan American Health Organization
 website http://www.fep.paho.org/healthprofiles.

 3.4.5   Existing Water and Wastewater Infrastructure

        Blythe, California. Water supply is obtained from wells containing high concentrations of iron
 and manganese. The city provides for wastewater collection and treatment.

        Brawley, California.  The city operates a 1.7 mgd water treatment plant. The wastewater
 treatment plant consists of primary clarifiers, aerated lagoons and sludge digesters. EPA has provided
 funding for the water treatment plant.

        Calexico, California.  Water supply is obtained from the Colorado River and it is treated hi
 a 10 mgd water treatment plant. Treatment of the wastewater is provided by a 2.1 mgd capacity plant.
 Both facilities are being expanded and EPA has provided funding for the water treatment plant

        Heber, California. The city has an existing water treatment plant with a capacity of 1.7 mgd.
 The water distribution system and wastewater collection system are being upgraded with funding
 participation from EPA.
                                             23

-------
       Mexicali, Baja California.  Water supply is obtained its from sources connected to the
Colorado River. The water treatment plant serves 98 percent of the city. Wastewater collection and
treatment is performed by stabilization ponds located in two service areas. The Mexicali I area is 96
percent sewered and Mexicali II is 80 percent sewered. The two systems treat almost 100 percent of
the service area. EPA is participating in the funding of the improvements.

       Palo Verde, California.  Water is obtained from municipal wells.  Wastewater is treated by
individual septic tanks.

      Salton, California. No information on water supply was provided. Wastewater is treated by
stabilization/percolation ponds which are reported to produce high total dissolved solids in the
groundwater.

       Seeley, California. Water and wastewater infrastructure information was not provided.
                                             ?
       Westmorland, California. Municipal water supply is obtained from Brawley, but there is no
additional information about the distribution system. Wastewater is treated by stabilization ponds.
EPA is participating in the funding of replacement of the existing wastewater treatment facility with
an oxidation ditch facility.

3.5    Gulf of California Coastal Basin

3.5.1   Geography

       The Gulf of California Coastal Basin, which has an area of approximately 5,800 square miles
(15,000 sq. km) covering portions of the states of Baja California, Arizona, Sonora and Chihuahua
as indicated on Fig. 3-13, consisting of horseshoe-shaped 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 Basin extends to the eastern part of Baja
California and the north and northwest parts of Sonora. The principal communities in this basin are
the cities of Caborca, Magdalena de Kino  and Puerto Penasco located in the State of Sonora in
Mexico, Lukeville and Douglas in the State of Arizona.


3.5.2   Hydrology

       The major surface waters in this basin 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 Gulf of California. At one time, the Colorado delta at the Gulf of California was a vast area of
wetlands and salt flats that covered over 3,800 square miles (4,280 sq. km) and served as an important
estuary. However, this delta region has been altered substantially by human activity. Most notably,
upstream waters have  been drawn off and diverted for municipal and industrial use,  and  for
agricultural irrigation. Presently, there is little perennial flow in the lower Colorado River, most of
the water that the  delta receives coming from agricultural drainage from the U.S. and Mexico. In
addition, smaller streams drain from the higher elevations to the east and west of the basin and then
flow directly into the Gulf of California.

                                           24

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                                            s
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                                             <
25

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3.5.3  Water Quality

       Most of the water used for agricultural purposes flows back into the river, contributing to high
salinity, solids, and nutrients from agricultural fertilizers. High salinity and solids levels in the Lower
Colorado River are carried into the northern Gulf of California. No water quality data was available
in this basin; no monitoring stations are shown on Fig. 3-13 Gulf of California Basin map.

3.5.4  Public Health Conditions

       Public health data in the Gulf of California Basin within the State of Sonora, Mexico for the
years 1999-2000 is included hi Table 3-5.  It encompassed the communities of Sonoyta, Puerto
Pefiasco, Caborca, Altar, Santa Ana, Magdalena de Kino, Imuris and Bavispe.

                                             !
Table 3-5.  Reported Waterborne Diseases in The Gulf of California
            Coastal Basin. (Incidences  per 100,000 People )
Gulf of
California
Coastal
Basin
Mexican
States
Sonora

Amebiasis

1999

23,708
2000

22,747
%
Chg.
-4

Hepatitis A

199
9
196
2000

86
%
Chg.
-56

Shigellosis

1999

44
2000

68
%
Chg
55

Typhoid Fever

1999

1
2000

3
%
Chg
200
Reference: Pan American Health Organization
website http://www.fep.paho.org/healthprofiles.

3.5.5  Existing Water and Wastewater Infrastructure

       Altar, Sonora.  Water supply is obtained from seven wells which provide service for 92
percent of the service area and the remaining population is served by water trucks.  The wastewater
collection and an oxidation pond treatment system serves for about 70 percent of the service area.

       Bavispe, Sonora. Water supply is obtained from seven wells providing service for 96 percent
of the service area. Wastewater collection is provided for about 77 percent of the service area with
wastewater treatment provided by a stabilization pond.

       Caborca, Sonora.  Water supply serves 97 percent of the city from 8 foot deep wells and a
water treatment plant with chlorination facilities. The wastewater collection system covers 92 percent
of the city with the remaining population served by septic tanks and privies. Wastewater is treated
in a stabilization pond.
                                            26

-------
       Imuris, Sonora. Water supply is obtained from wells serving about 96 percent of the service
area. Sewer lines have been installed in about 75 percent of the community, but only 40 percent are
connected.  Wastewater treatment is achieved by oxidation ponds.


       Magdalena de Kino, Sonora. Water supply is obtained from wells near the Magdalena River,
with a water treatment facility providing chlorination. The water distribution system serves 98
percent of the city. The wastewater collection system covers 91 percent of the city and wastewater
is treated by a stabilization pond system.

       Puerto Penasco, Sonora.  Water supply is obtained from two well fields some distance from
the city with significant infiltration of sand into the transmission piping.  Wastewater is collected
from 82 percent of the city, and is treated hi an oxidation pond system.

       Santa Ana, Sonora. Water supply is obtained from wells and treated in a water treatment
plant.  Water distribution serves 81 percent and wastewater collection covers 54 percent of the city.
No information on wastewater treatment systems has been reported.

       Sasabe, Sonora. Water is obtained from wells. There is no municipal wastewater collection
or treatment.  Cesspools, septic tanks and privies are widely used.

       Sonoyta, Sonora. Water supply is drawn from wells. A wastewater collection and treatment
system includes a stabilization pond. No information for nearby Lukeville, Arizona is available.

3.6   Colorado River Basin

3.6.1  Geography

       The Colorado River Basin runs from the Rocky Mountains of northern Colorado for 1,200
miles  (1,920 km) to the delta at the Gulf of California as indicated on Fig. 3-14. The river basin
drains approximately 246,000 square miles (637,000  sq. km) which covers the  states of Wyoming,
Utah,  Colorado, Nevada, California, New Mexico and Arizona. The sister city pairs for this basin
are: Yuma, Arizona/San Luis Rio Colorado, Sonora; Nogales, Arizona/Nogales,  Sonora; Douglas,
Arizona/Agua Prieta; Sonora; and Naco, Arizona/Naco, Sonora.

3.6.2  Hydrology

       The Colorado River Basin major waterways are the Colorado River, the Gila River, the Santa
 Cruz River, and the San Pedro River. The Santa Cruz River flow, which drains an area of 8,200
 square miles (21,240 sq. km), originates in Arizona, flows south across the border through the urban
 areas of Nogales, Sonora, and Nogales, Arizona, crossing back into the U.S. flows north into the Gila.
 The San Pedro River flows north across the international boundary before flowing into the Gila.

        The lower Colorado River is the main water supply source for much of the southwestern U.S.,
 as well as for northern Baja California and northwestern Sonora. Current agreements on water usage
                                             27

-------
allot 8.5 million acre-feet per year (105 trillion liters per year) of water to the lower Colorado basin of
the U.S., and 1.5 million acre-feet per year (18.5 trillion liters per year) to Mexico. Several dams and
 reservoirs are used for water storage significantly altering the natural river flow and
reducing it to an ephemeral stream.

       The lower Gila River flows east to west across southern Arizona.  The entire Gila watershed
drains approximately 57,900 square miles before joining the Colorado River near Yuma; 8200 square
miles of this watershed is within the lower Colorado River area. Most of the Gila River is ephemeral
and flows only when it rains or when water is released from the dams.

3.6.3  Water Qualify

       Water quality problems in the lower Colorado River Basin are due to an increase in sediment,
salinity, and fecal coliform concentrations. High salinity and solids concentrations in the river and its
tributaries are thought to be caused in part by waterdiversion and reuse. Some communities in the basin
discharge untreated or partially treated wastewater into the Colorado River and produce high fecal
coliform concentrations in the basin.

       According to the State of Arizona National Water Quality Inventory Section 305(b) reports, fecal
coliform concentrations have been found to exceed both U.S. and Mexican Standards at several water
quality monitoring stations as indicated in Table  3-6 [Figure 3-14].  For example, fecal coliform
concentrations in the East Nogales Wash, which flows into the Santa Cruz River hi Nogales, Arizona,
has been extremely high, exceeding the State of Arizona and Mexican standards of 200 colonies/100 ml.
Fecal coliform contamination in the  Wash is thought to result from periodic overflows of the sewer
system, which is old and overloaded.
                                             28

-------
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29

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Table 3-6.  Comparison of Surface Water Quality Standards with Sampling Data For The
Colorado River Basin
Station
Number

1
2
3
4
5
6
7
8
9
10
11
Water Quality
Monitoring
Stations

Colorado River at No.
International Boundary
above Morelos Dam
East Nogales Wash at
Morley St
Nogales Wash, at Fire
Station
Gila River at Gillespie
Dam
East Nogales Wash at
U.S. Border
San Pedro River at
Charleston, AZ
San Pedro River at
Highway 92 Palominas
Santa Cruz River at
International Boundary
Santa Cruz River at
Kino Spring location
Whitewater Draw at
Highway 80
Whitewater Draw at
U.S. Border
U.S. Standards
Fecal
Coliform
Colonies/
100ml
. 200
200
200
200
200
200
200
200
200
200
200
Dissolved
Oxygen
mg/1
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
Sampling Data
Fecal Coliform
Colonies/100 ml
Geometric
Average
No Data
52,355
800
1296
No Data
688
323
289
No Data
No Data
788
Dissolved
Oxygen
mg/I
Geometric
Average
8.1
7.2
8.5
76.8
No Data
89.0
8.1
No Data
6.5
8.2
6.0
Reporting
Agencies
and Time
Frame
USER
89-98
ADEQ
86-99
ADEQ
86-87
USGS
88-97
ADEQ
86
USGS
88-93
ADEQ
88-99
ADEQ
90-98
ADEQ
86
ADEQ
87-88
USGS
88-93
                                        30

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3.6.4   Public Health Conditions

       Yuma, Pima, Santa Cruz and Cochise counties in Arizona had very high incidences of Hepatitis
A, and Shigellosis.  Table 3-7 contains incidences for this basin from 1988 to 1998.  Hepatitis A
decreased in Santa Cruz, Yuma and Cochise County , but increased in Pima  County.  Shigellosis
decreased in all four counties, while there were no reported cases of Typhoid Fever.

       In Mexico, gastrointestinal disease is prevalent in the Colorado River Basin, and it is one of the
six leading causes of infant mortality in Nogales and Agua Prieta, Sonora. Public health data for San Luis
Rio Colorado, Nogales, and Agua Prieta indicate that disease rates are higher there than in border counties
hi the U.S.  Between 1988 and 1998, Hepatitis A  rates for Nogales, Agua Prieta, and San Luis Rio
Colorado decreased significantly. Amebiasis rates were also lower in all three cities. Typhoid fever rates
decreased, but Shigellosis rates were not reported.
Table 3-7.  Reported Waterborne Diseases in The Colorado River Basin
            (Incidences per 100,000 People)
Colorado
River
Basin

U.S.
Counties
Vfuma, AZ
Pima, AZ
Santa Cruz, AZ
Cochise County,
AZ
Mexican
Cities
Nogales, SN

A.gua Prieta, SN

San Luis
Colorado, SN
Amebiasis

1988


0
0.5
3.7
0



956

956

787

1998


0
0.6
18.4
9.0



757

63.0

318

%
Chg.


0
20
397
—



-21

-93

-60

Hepatitis A

1988


40.2
22.5
74.4
74.8



54.4

54.4

28.4

1998


25.7
29
42.0
17.8



5.0

5.0

10.0

%
Chg.


-36
29
-44
-76



-91

-91

-65

Shigellosis

1988


25.8
41.3
26.1
11.4



No
Data
No
Data
No
Data
1998


6.0
24.2
23.6
3.6



1.0

1.0

5.0

%
Chg.


-77
-41
-10
-68





—

—

Typhoid Fever

1988


0
0
0
0



2.8

2.8

8.4


1998


0
0
0
0



1.0

0

0


%
Chg.


0
0
0
0



-64

-100

-100

Reference. Pan American Health Organization
website http://www.feD.paho.org/healthproFiles.
                                             31

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3.6.5   Existing Water and Wastewater Infrastructure

       Agua Prieta, Sonora. Water supply is obtained from two water supply wells providing service
to 95 percent of the population. Wastewater collection coverage is about 60 percent which is treated in
an oxidation pond.
•
       Bisbee, Arizona. Water is obtained from two wells.  There is a municipal wastewater collection
system and treatment is by two stabilization pond systems and one trickling filter at three separate
locations.

       Cananea, Sonora.  Water supply is obtained from fourteen wells in El Rio and Ojo de Agua
basins, serving 98 percent of the community. The system had been maintained by a mining company
until the beginning of 1999. Municipal wastewater collection system serves about 98 percent of the
population.  Wastewater is treated by a stabilization pond facility.
                                             t
       Douglas, Arizona. Water supply is provided by two reservoirs with a combined capacity of 5
mgd.  The city provides wastewater collection and treatment at a 2 mgd activated sludge plant

       Naco, Sonora. Water supply is obtained from two wells with provisions for chlorination. The
water distribution system provides service to about 98 percent of the town. Wastewater that is collected
from about 91 percent of the service area is treated in two stabilization ponds. EPA is participating in
the financing for an upgrade of the two-pond system.

       Nogales, Arizona.  Water supply is obtained from wells, one of which has been impacted by
volatile organic compounds. The water distribution system covers the entire service area.  Wastewater
collection and treatment serves 85  percent of the population.  Wastewater treatment is provided by a
package plant and by the Nogales International Wastewater Treatment Plant which is owned jointly by
the city of Nogales and the U.S. Section of the IBWC who also operates the facility.

       Nogales, Sonora. Water supply is drawn from wells which serve 85 percent of the population.
Wastewater collection serves  85 percent of the population.  Wastewater is treated at the Nogales
International Wastewater Treatment Plant through an agreement with IBWC.

       Patagonia, Arizona. Water supply  is obtained from wells.  The city provides wastewater
treatment. EPA is participating hi the funding of improvements to the wastewater treatment facility.

       San Luis, Arizona.  Water supply is obtained from one well. The city provides for wastewater
collection and treatment.

       San Luis Rio Colorado, Sonora.  Water  supply is drawn from 17 wells with provision for
chlorination. The water distribution system serves  97 percent of the community and water trucks
provide for the remainder. The city currently does not have a wastewater treatment facility. Wastewater
collectors serving about 35 percent of the population discharge directly into the Colorado River.

       Somerton, Arizona. Municipal water supply is obtained from wells with disinfection and is
treated for iron and manganese. Wastewater treatment is provided by three stabilization ponds.
                                            32

-------
       Tombstone, Arizona. Municipal water supply is obtained from a reservoir and two wells which
is then conveyed by a 26-mile long aqueduct to the city. Wastewater is treated at an oxidation ditch
facility.

       Willcox, Arizona has a municipal wastewater treatment plant. No information was provided on
water supply.

       Yuma, Arizona.  Municipal water supply is drawn from wells and chlorinated providing service
to 99 percent of the population, with the remainder being served by water trucks.  Wastewater treatment
for the city of Winterhaven, California, and a U. S. Marine Corps base is provided by a 20 mgd city plant.
There are also several private wastewater treatment facilities in the city.

3.7    Northwest Chihuahua Basin

3.7.1   Geography

       The Northwest Chihuahua Basin is ahigh plateau that extends across the continental divide both
in the U.S. and Mexico, covering about 32,000 square miles (83,000 sq. km) in the States of New
Mexico, Chihuahua and Sonora. Cities in the basin include Columbus, New Mexico, and Las Palomas,
Ascension, Janos, andNuevo Casas Grandes hi the State of Chihuahua.

3.7.2  Hydrology

       The Northwest Chihuahua Basin, unlike the other major basins that span the U.S.-Mexico Border
has no perennial streams flowing across it.  Very few perennial streams flow within the basin, which is
considered to be hydrologically landlocked. During wet weather, some transboundary streams such as
Wamels Draw flow for short periods; nevertheless, they do not flow out of the basin before they dry out
and completely disappear.  The basin's only reliable water source is groundwater.  The  four major
groundwater aquifers are the Mimbres, Animas Valley, Playas Valley, and Nutt-Hockett Fig. 3-15
shows a typical watershed.
                        FIGURE 3-15 . Typical watershed basin showing ridges
                        and valleys in the Northwest Chihuahua Basin.
                                             33

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3.7.3   Water Quality

       Since this basin exhibits the dry to semi-dry conditions as shown in Fig. 3-17 and there are no
continually available surface water sources, the quality of water existing in this basin is critically
important When rains create ephemeral flows in dry streambeds, accumulated pollutants are washed
downstream and may enter the groundwater aquifer. Because groundwater is the main water source in
the basin, groundwater pollution is a major concern. Also, groundwater pumping currently exceeds the
estimated replenishment rate. No water quality sampling has been done in this basin; so no monitoring
stations are shown on Fig. 3-17, Northwest Chihuahua Basin map.
                              FIGURE  3-16.  Typical  semi-desert
                              conditions in NW Chihuahua basin.
                                             34

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35

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3.7.4  Public Health Conditions

       Available public health data for Luna, Dofia Ana, and Hidalgo Counties in New Mexico indicate
no reportable cases of Amebiasis, Hepatitis A, Shigellosis or Typhoid Fever in 1998 as indicated on
Table 3-8. There were some reported cases of these diseases in 1988. No available data on incidence
rates exist for the community of Las Palomas, Chihuahua.

Table 3-8.  Reported Waterborne Diseases in the Northwest Chihuahua Basin
            (Incidences per 100,000 People )
Northwest
Chihuahua
Basin


U.S.
Counties
Luna
DoSa Ana
Hidalgo
Mexican
Cities
Las Palomas

Amebiasis

1988



5.7
0
0


No
Data
1998



0
0
0


No
Data
%
Chg.


-100
0
0


No
Data

Hepatitis A

1988



0
15.4
0


No
Data
1998



0
0
0


No
Data
%
Chg.


0
-100
0


No
Data

Shigellosis

1988



17.0
30.8
0


No
Data
1998



0
0
0


No
Data
%
Chg.


-100
-100
0


No
Data

Typhoid Fever

1988



0
0.7
0


No
Data
1998



0
0
0


No
Data
%
Chg.


0
-100
0


No
Data
Reference: Pan American Health Organization
website http://www.fep.paho.org/healthprofiles.

3.7.5 Existing Water and Wastewater Infrastructure

       Ascension, Chihuahua.  Water supply is obtained from five wells, serving about 83 percent of
the community. Wastewater is collected from 44 percent of the community and discharged to an unlined
treatment pond facility.

       Columbus, New Mexico. Water supply is obtained from wells that serve the entire community.
Wastewater treatment is provided by oxidation ponds serving the entire population.

       Janos,  Chihuahua.  Water supply is obtained from three wells, only one of which is fully
operational. Wastewater collection serves 25 percent of the community with an untreated discharge
 to the San Pedro River.
                                            36

-------
      Nuevo Casas Grandes, Chihuahua. Water supply is obtained from wells serving about 97 percent
of the community. Wastewater is collected from 41 percent of the population; no wastewater treatment
available.

      Las Palomas, Chihuahua. Water supply is obtained from wells with a high fluoride content.
Municipal wastewater collection serves about 25 percent of the population; no wastewater treatment is
provided.

      Villa Ahumada,  Chihuahua.   Water  supply serves about 98  percent of the population.
Wastewater collection system serves about 38  percent of the community; no wastewater treatment is
provided.


3.8   Rio Grande Basin

3.8.1  Geography

      The 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 Gulf of Mexico
Coastal Basin covers the delta of the Rio Grande immediately adjacent to the Gulf of Mexico). The Rio
Grande drains an area of approximately 182,215 square miles (471,937 sq. km) 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.  Mountain ranges dominate the landscape, and include the Sierra de la
Ensenada and Huachuca Ranges. Major cities along the lower Rio Grande, which is a part of the U.S.-
Mexico binational boundary include five sister city pairs, which are El Paso, TX/Ciudad Juarez,CH,
Presidio,TX/Ojinaga, CH, Del Rio/Ciudad  Acuna,CO, Eagle  Pass,TX/Piedras  Negras,CO  and
Laredo,TX/Nuevo Laredo,TM.

3.8.2  Hydrology

      The primary water courses in the basin are the Rio Grande and its tributaries, including the Rios
Conchos, Salado, and San Rodrigo in Mexico, and the Pecos and Devil's Rivers hi Texas. On the main
stream are the Amistad and the Falcon Reservoirs.  The Rio Grande, which in Mexico is known as the
Rio Bravo, defines the international boundary from El Paso, Texas/Ciudad Juarez,  Chihuahua, to its
delta on the Gulf of Mexico.

       Most flows in the upper Rio Grande Basin originate from precipitation hi the Rocky Mountains.
Flow contributions into the Rio Grande are from the Guadalupe, Davis, Santiago, and Sierra Madre
Occidental mountain ranges of western Texas and northeast Chihuahua and Coahuila. A hydrographic
feature of the region is the extent of control on the natural flow of the river including dams, reservoirs,
canals and diversions for water supply and flood control.  The water control structures have altered the
river flow in the basin, and have made flow hi the lower Rio Grande dependent on controlled releases
and "return flows" back to the river from agricultural and other commercial water uses.
                                            37

-------
3.8.3  Water Quality

       The Rio Grande is impacted by discharges from communities and industries along its banks and
tributaries and by agricultural runoff as shown on Fig. 3-18. U.S. Colonia communities are located close
to the river and to a public water supply or wastewater systems.
                        FIGURE 3-18. Sewage  discharge  to  a   waterway
                        containing foaming detergents near Rio Grande.
       Fecal coliform bacteria concentrations are a concern in all of the major urban centers. For
instance, fecal coliform concentrations averaged 1,518 colonies/100 ml below Laredo/Nuevo Laredo,
exceeding both Texas water quality standards and Mexican Standards of 200 colonies/100 ml for contact
recreation water.  As indicated on Table 3-9 most of the water quality monitoring stations shown on
Figs. 3-19 and 3-20 met the minimum dissolved oxygen requirement of 5 mg/1.
                                             38

-------
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                              40

-------
Table 3-9  Comparison of Surface Water Quality Standards with Sampling Data for the Rio
Grande Basin
Station
Numbers






1


2



3



4

5



6



7


8


9

11


Water Quality
Monitoring Stations






Rio Conchos 0.2 Km
upstream from mouth
NW of Ojinaga, Mexico
Rio Conchos, 1.5 miles
from confluence with Rio
Grande, near Ojinaga,
Mexico
Rio Grande 0.4 km
upstream from Del
Rio/Ciudad Acufia
International bridge
Rio Grande 1 km
upstream of Eagle Pass
Rio Grande 1.1 miles
downstream of Highway
81 bridge between
Laredo/Nuevo Laredo
Rio Grande 6.4 Km
below Del Rio/Ciudad
Acufia International
bridge
Rio Grande Floodway at
San Marcia, NM

Rio Grande below Rio
Conchos near
Presidio,TX.
Rio Grande at El Paso,
TX Courchesne Bridge
Rio Grande at Laredo
Water Treatment Plant
pump intake

U.S. Standards
Fecal
Coliform
Colonies/
100ml


200


200



200



200

200



200



1000


200


200

200


Dissolved
Oxygen
mg/1



• 5.0


5.0



5.0



5.0

5.0



5.0



6:0


5.0


5.0

5.0



Sampling Data
Fecal
Coliform
Colonies
/100ml
Geometric
Average
No Data


No Data



No Data



705

1518



330



'576


No Data


No Data

105


Dissolved
Oxygen
mg/1
Geometric
Average

7.6


ND



8.2



8.2

11.3



7.7



9.2


11.7


8.0

11.9



Reporting
Agency and
Time
Frame


IBWC
92

USGS



TNRCC
91-92


IBWC
93-98
TNRCC
89-94


TNRCC
88-92


USGS
and
NMWRD
TNRCC
92-98

USGS
92
TNRCC
88-97

                                         41

-------
Table 3-9 Comparison of Surface Water Quality Standards with Sampling Data for the Rio Grande
Basin
Station
Numbers

12
13
14
15
16
17
18
19
20
21
Water Quality
Monitoring Stations

Rio Grande at Nuevo
Laredo at International
Bridge H
Rio Grande at pipeline
crossing upstream from
Falcon Reservoir
Rio Grande below
Amistad Dam near Del
Rio.TX
Rio Grande below
Anzalduas dam near
Reynosa, MX
Rio Grande below
Elephant Butte Dam, NM
Rio Grande below Falcon
dam Near Falcon, TX
Rio Grande below Rio
Conchos, 14.4 km
downstream of
Presidio/Ojinaga
International Bridge
Rio Grande below Rio
Conchos near Presidio,
TX
Rio Grande near El India,
TX (36 miles down from
Eagle Pass)
Rio Grande 14 Km down
of Eagle Pass
U.S. Standards
Fecal
Coliform
Colonies/
100ml
200
200
200
200
1000
200
200
200
200
200
Dissolved
Oxygen
mg/1
,3.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
Sampling Data
Fecal
Coliform
Colonies
/100ml
Geometric
Average
690
10,529.00
No Data
No Date
No Data
No Data
235
No Data
94
623
Dissolved
Oxygen
mg/1
Geometric
Average
8.7
7.3
6.3
No Data
8.9
69.0
No Data
No Data
8.2
7.9
Reporting
Agency and
Time
Frame
USGS 88
TNRCC
USGS
88-98
USGS 93
USGS 93
USGS 92
NMWRD
USGS 99
TNRCC
88-98
USGS
USGS
88-93
TNRCC
88-9
Note: No water quality monitoring station 10 shown . Monitoring station is shown in the Gulf Coastal Basin
                                                    42

-------
3.8.4    Public Health Conditions

        The shared water resources of the Rio Grande and the migration of people across the U.S.-Mexico
Border for personal or business purposes represent a maj or mode of cross-border disease transmission. The
public health conditions in the Texas counties bordering the Rio Grande in 1988 and 1998 are indicated
on Table 3-10.

        Amebiasis rates on the U.S. side of the border have been almost insignificant over a 10 year
period, while the Mexican side has increased at an astonishing rate.

        Hepatitis A is also a problem in the border area.  On the U.S. side of the border, incidence rates
have generally increased over the 10 year period; however, on the Mexican side it has decreased. The 1988
rate of Hepatitis A hi the border area was about three times the average U.S. rate.

        Shigellosis  has increased hi the majority of the U.S. and Mexico border communities.  It is
interesting to note that El Paso had an increase of 63 percent and Ciudad Juarez a 900 percent increase over
a 10 year period.

        Typhoid Fever hi U.S. border communities has been almost eradicated, but Mexico border
communities still have a higher  incidence rate.
                                               43

-------
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                                44

-------
3.8.5    Existing Water and Wastewater Infrastructure
        Alpine, Texas.  Water supply is obtained from wells serving the entire population.  The
community has an existing wastewater treatment plant.

        Alton, Texas. A municipal water, wastewater treatment, and a collection system serve the
community. Improvements are being made with EPA funds.

        Camargo, Tamaulipas.  Water supply is obtained from the Rio Grande without treatment and
from two wells with chlorination to supply over 96 percent of the city. Wastewater collection covers 60
percent of the city, but only 35 percent of the population is connected.  Wastewater treatment is provided
by a stabilization pond.

        China/General Bravo, Nuevo Leon. Water supply is obtained from a surface impoundment with
treatment; 75 percent of China and 96 percent of General Bravo are served. Wastewater collection serves
20 percent of China, but without treatment.

        Ciudad Acufia, Coahuila. Water supply is obtained from the Rio Grande and treated. About 82
percent of the population is served by a water distribution system and the remainder of the population is
served by water trucks. Wastewater is treated by an activated sludge system. Wastewater is collected from
60 percent of the city, the remainder served by septic tanks or cesspool systems. EPA has participated in
funding these facilities and a system-needs study. Figs.  3-21 and 3-22 show the wastewater collection
system under construction.
   Figure 3-21. Sewer Installation in Ciudad Acuna, Coahuila,
            Mexico.
                                              45
                                                              Figure 3-22 Sewer Inspection in Ciudad
                                                                        Acufia, Coahuila, Mexico

-------
        Ciudad Juarez, Chihuahua.  Water supply is obtained from wells which supply the entire
population. Two wastewater treatment plants, named North and South, have been completed and are in
operation. Figs. 3-23 and 3-24 show portions of the wastewater treatment plant under construction. EPA
has participated in funding of improvements to the wastewater collection system and one pump station in
coordination with construction of the treatment plants.
   Figure 3-23.  Pump Station  under
   construction at Ciudad Judrez, Mexico.
Figure 3-24. Wastewater Treatment Plant at Ciudad
Juarez, Chihuahua, Mexico.
         Coyame, Chihuahua.  Water supply is obtained from wells which serve about 90 percent of the
 community. Wastewater collection serves about 25 percent of the population; however, no treatment is
 provided.
         Del Rio, Texas. Water supply is obtained from the San Felipe Springs. The city is served by a
 wastewater collection and treatment system. EPA has participated in the funding of treatment for the water
 supply and improvements to storage and distribution facilities.

         Donna, Texas. Water supply is obtained from the Rio Grande and treated in a 4.5 mgd water
 treatment plant. The entire population and 20 Colonias are served. Wastewater treatment is provided in
 a 2.7 mgd activated sludge plant. EPA has participated in funding replacement of the city water treatment
 plant, as well as water supply  and wastewater collection for the Colonias.  Fig. 3-25 shows a colonia
 housing along the border.
                                              46

-------
                    Figure 3-25. Colonia housing showing privy in the background.

        Eagle Pass, Texas. The city has a water supply system and a request has been received from the
nearby Colonia of Pueblo Nuevo for extending water service, wastewater collection and treatment.

        El Paso, Texas. Water supply is obtained from several well fields and from the Rio Grande. The
surface water is treated in a water treatment facility which serves the entire population, with additional
treatment in the planning stage.  Wastewater treatment is provided by four plants that serve the entire
community, as well as Colonias located adjacent to the city.  EPA has participated in the funding of
planning and construction for water supply improvements for the city and the Colonias.

        Fabens, Texas. Water supply is obtained from wells with a high iron and manganese content.
No information was provided on wastewater treatment.

         Gustavo Diaz Ordaz, Tamaulipas. Water is supplied to 97 percent of the city, the remainder of
the population relying on shallow wells or water trucks for drinking water needs.  Wastewater is collected
from 30 percent of the city and treated in a stabilization pond, with the remainder using septic tanks and
latrines.

         Guadalupe Bravos, Chihuahua. Water  supply is obtained from two wells, with a high total
dissolved solids content. About 50 percent of the population is served by a wastewater collection system;
however, no wastewater treatment is provided.

         Laredo, Texas.  Water supply is obtained from the Rio Grande and treated in two water
treatment plants. Water is distributed to the entire city except to the Colonias, which are served by water
trucks. Wastewater treatment is provided by five plants. A wastewater collection system serves the entire
community. Colonias are served by septic tanks.  Typical Colonias are shown in Figs. 3-26 and 3-27.
                                              47

-------
    Figure 3-26. Colonia Housing along the border.
Figure 3-27 Typical U.S. Colonia..
         Manuel Benavides, Chihuahua.  Water distribution is to about 65 percent of the population.
About 25 percent of the population is served by a wastewater collection system, but without treatment.

         McAllen, Texas. Water supply is obtained from the Rio Grande and the entire population is
served by the distribution system.  Wastewater treatment is performed at two activated sludge plants
having a total capacity of 16 mgd and a wastewater collection system that covers about 90 percent of the
city.

         Mercedes, Texas. Water supply is obtained from a well and the Rio Grande and treated. Water
is distributed to the entire city. Wastewater treatment is provided by an activated sludge plant; wastewater
collection covers 98  percent of the city.   EPA has participated in the funding of water  supply and
wastewater system improvements.

         Mier, Tamaulipas.  Water supply is drawn from Rio Grande and treated. Water is distributed
to 90 percent of the community. Wastewater treatment is provided by an activated sludge plant. Colonias
outside the city are not served by the water and wastewater treatment systems.

         Miguel Aleman, Tamaulipas.  Water is obtained from the Rio  Grande and treated with
distribution to 90 percent of the service area. Wastewater is collected from 80 percent of the population
and treated by stabilization ponds.
                                             48

-------
         Nava, Coahuila. Water supply is obtained from twenty-one wells and distributed to 93 percent
of the population. Wastewater is collected from about 27 percent of the service area, including Estacion
Rio Escondido and La Sauceda, but with no treatment.

         Nueva Ciudad Guerrero, Tamaulipas.  Water supply is drawn from Falcon Reservoir and
distributed to about 90 percent of the population.  Wastewater is collected from about 61 percent of the
population and the treatment system is an Imhoff tank, which is currently out of service.

         Nuevo Laredo, Tamaulipas.  Water supply is obtained from the Rio Grande, treated by two
plants and distributed to about 90 percent of the city. Wastewater is collected from about 85 percent of
the population and treated by an activated sludge plant.  EPA has participated in the funding of facilities
and a system-needs study.

          Ojinaga, Chihuahua. Water supply is obtained from six wells and distributed to 98 percent of
the population.  Wastewater is collected from 55 per cent of the population and treated in an oxidation
pond facility.

          Piedras Negras, Coahuila.  Water supply is obtained from the Rio Grande  and  treated.
Wastewater is collected from the entire city and treatment is provided in a stabilization pond. EPA has
participated in the funding of facilities and a system-needs study.

          Presidio, Texas.  The city has a municipal water supply and distribution system. Wastewater
is collected and pumped to stabilization ponds for treatment.

          Reynosa, Tamaulipas. Water supply is obtained from the Rio  Grande, treated by two water
treatment plants and distributed to approximately 93 percent of the city. Wastewater is collected from 70
percent of the population and treated, but there are two untreated discharge points. EPA has participated
in the funding of some facilities and a needs study, as well as the construction of improvements to the
wastewater treatment and collection system.

          Rio Bravo, Tamaulipas. Water is obtained from the Rio Grande and treated.  Distribution is to
about 95 percent of the community. Wastewater  collection serves 50 percent of the population and
treatment is provided by an activated sludge plant.  Nearby Colonias are not served.

          Rio Grande, Texas. The city has a municipal water supply, treatment and distribution system,
as well as a wastewater collection and treatment system.

          Roma, Texas. Water supply is drawn from the Rio Grande, with 1.5 mgd of treatment capacity.
Wastewater is collected from about 25 percent of the population and treated at an activated sludge plant.
EPA is participating hi funding of a new wastewater treatment plant and of water distribution and
wastewater collection for Colonias.
                                              49

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         Sanderson, Texas.  Water is supplied to the entire community. Wastewater is treated in septic
tanks and cesspools.

         Weslaco, Texas. No information was provided on the water supply. Wastewater treatment
exists, but further information was not provided.

         Zaragoza, Coahuila.  Water supply is obtained from eight wells, treated and distributed to 86
percent of the population. There is no wastewater treatment, although collection covers 75 percent of the
community and 41  percent is served.
3.9
Gulf of Mexico Coastal Basin
3.9.1     Geography

         The Gulf of Mexico Coastal basin is defined as the delta area between Brownsville and
Matamoros and the coastline along these two cities which drains directly into the Gulf of Mexico.

         The major cities are Matamoros and Valle Hermoso in Tamaulipas, Mexico, and Brownsville,
Texas, as shown in Fig 3-27.

3.92     Hydrology

         The Rio Grande in the Gulf of Mexico Coastal Basin widens into a flood plain area near the
sister cities of Brownsville, Texas, and Matamoros, Tamaulipas. The river flows through wetlands, salt
marshes and open waters until it finally reaches the Laguna Madre and drains into the Gulf of Mexico

3.9.3     Water Quality

         Water quality in the Gulf of Mexico Coastal Basin is impacted by increasing population growth,
urbanization, and industrialization, which will place a high demand on the water resources available in the
basin.

         High concentrations of  solids and other substances  are  related to industrial,  pollution;
bacteriological contamination is due to raw or partially treated sewage discharges. As indicated in Table
3-11, fecal coliform concentrations in Brownsville below El Jardin Pumping Station exceeded Texas water
quality criteria of 200 colonies/100  ml for contact recreation, as well as Mexican standards.
                                             50

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                                               o
                                               I
                                               GO
                                               •g
                                               I
                                               o
                                               I
                                               £

                                               I
                                               •I
                                                «

                                               3
                                                CO
                                                «
                                                O
                                               U
                                                S
                                               '8
                                                O
                                               Sa
                                               O

51

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Table 3-11 Comparison of Surface Water Quality Standards with Sampling Data for Ghilf of
           Mexico Coastal Basin.

Station
Numbers


1



Water
Quality
Monitoring
Stations


Rio Grande
near
Brownsville
below Jardin
Pumping
Station

U.S. Standard
Fecal
Coliform
colonies/
100ml

200



Dissolved
Oxygen
mg/1

5.0'




Sampling Data
Fecal
Coliform
colonies/
100ml
Geometric
Average
1574



Dissolved
Oxygen
mg/I
Geometric
Average
7.70



Reporting
Agencies
and Time
Frame

USGS
88-95



3.9.4    Public Health Conditions

        Incidence rates in 1988 and 1998 for Amebiasis, Hepatitis, Shigellosis and Typhoid Fever for
Cameron County, Texas and Matamoros, Tamaulipas are indicated on Table 3-12 below.

Table 3-12 Reported Waterborne Diseases in the Gulf of Mexico Coastal Basin
           (Incidences per 100,000 people)
Gulf of
Mexico
Coastal
Basin

U.S.
Counties
Cameron
County/DC
Mexican
Cities
Matamoros,
TM

Amebiasis

1988


14.2


1029
1998


6.1


2477
%
Chg.


-57


141

Hepatitis A

1988


22.8


50
1998


66.5


332
%
Chg.


1916


564

Shigellosis

1988


19.7


16.1
1998


41


24
%
Chg.


108


49

Typhoid Fever

1988


0.8


22
1998


0.6


40
%
Chg.


-25


82
Reference: Pan American Health Organization
website http://www.fep.paho.org/healthprofiles.
                                             52

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I   3.9.5    Existing Water and Wastewater Infrastructure

I           Brownsville, Texas.  Water supply is obtained from the Rio Grande, treated in two water
     treatment plants and distributed to the entire city. Wastewater is collected and treated by two activated
     sludge plants with a total capacity of 22.8 mgd. EPA has participated in the funding of planning for water
     supply improvements.

             Matamoros, Tamaulipas. Water supply is obtained from the Rio Grande, treated in four water
     treatment plants with about 32 mgd total capacity and distributed to 90 percent of the city. Wastewater
     is conveyed untreated in open channels through the Laguna Madre to the Gulf of Mexico. Collector
     sewers serve 85 percent of the city. EPA has participated in funding some facilities and system-needs
     study.

             Valle Hermoso, Tamaulipas.  Water supply is obtained from  the Rio Grande, treated and
     distributed to approximately 98 percent of the city. Wastewater is conveyed by open channels through
     agricultural fields and the Laguna Madre to the Gulf of Mexico. Wastewater is collected from 55 percent
     of the city, but no treatment is provided. The remaining wastewater is treated by septic tanks or latrines.
                                                   53

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4        Current Water and Wastewater Infrastructure Needs

         While many U.S.-Mexico border communities are currently  addressing their water and
wastewater infrastructure needs, there is still much work to be done hi order to provide adequate human
health and environmental protection. Water supply and wastewater treatment infrastructure in the border
area, as is the case elsewhere, varies from community to community.  There are systems which have
capacity to serve essentially the entire populace and those without significant public systems, in which case
individual homes and commercial/industrial facilities hi the community have made their own provision
for service. Financial supplements to limited local budgets are necessary to expedite the resource-intensi ve
building, expansion or rehabilitation of water treatment plants, water distribution networks, wastewater
treatment plants and sewer systems.

         The needs are not only for the people now living in the border area, but to keep up with the
growth of the communities. For that reason, the current needs have been estimated for two different time
frames. The Near-term needs are those that the communities have identified as essential to provide or
maintain  adequate service for the populace today.  Long-term needs are those that, while they should be
started as soon as possible, are based on the commonly used public works planning period of 20 years to
provide for the additional burden of maintaining service into the future.

         Near-term needs descriptions and projections for these endeavors have been taken from
individual community profiles developed at the BECC by the Project Managers, under the direction of the
Technical Director, who are in direct contact with local government officials. In some cases, the Near-
term needs are not hi the profiles.  Because these profiles generally reflect a known deficiency or potential
health or environmental hazard, the near-term is considered the time frame within which municipal
officials can implement a project development process. That is, the Near-term needs estimate represents
a two to  three year time frame within which it is reasonable to  expect a community to complete its
program, but many can be expected to be completed sooner and others will undoubtedly require a longer
period to reach completion.  Projects which have been certified by the BECC, are being readied for
construction and have already identified financing are not included as Near-term needs in the tables 4-1
thru 4-7.

         Long-term water and wastewater infrastructure needs have been estimated from the projected
Year 2020 populations of the watersheds and generally consist of substantial rehabilitation of the existing
systems where available as well as addition of capacity to provide for population growth. The 20-year
planning  horizon is common hi long-range public works management plans, but many factors would affect
the actual pace of development used in the long-range estimates. Allowance has been made for the value
of portions of existing facilities that should remain serviceable in 20 years, mitigated by the cost of
rehabilitation to include them in upgrades  where possible.

         The EPA Drinking Water Needs  Survey and Clean Water Needs Survey cost curves were used
to calculate the Year 2020 needs for water  supply filtration plants and distribution lines and wastewater
treatment plants and collection systems respectively. Development of impoundments, reservoirs  and
aqueducts are not included hi the estimates  for water supply. Wastewater treatment facility estimates are
based on  stabilization pond technology unless there is an existing plant utilizing another technology. The
long-term estimates are for  service to  the  entire estimated population  of the  community  and, for
wastewater treatment, attainment of secondary treatment. Within each watershed, extension of the needs
identified hi the profiles have been supplemented with estimates based on the population of areas outside
of identified communities.


                                             54

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4.1
Pacific Coastal Basin
         Descanso, California.  Improvements to the municipal water supply and treatment system
include the replacement of obsolete water distribution lines, construction of a new storage tank and
installation of filtration units at the three water supply wells. A municipal wastewater treatment plant and
collection system might be expected to be constructed in the future.

         Ensenada, Baj a California. Improvements to the water and wastewater systems may include the
possibility of water reuse.

         Tecate, Baja California.  Water  distribution system and wastewater collection system may
expand to the entire city as well as upgrading of the existing wastewater treatment plant.

         Tijuana, Baja California. A significant portion of the wastewater collection system is in need
of replacement.

         San Diego County, California. Other near-term needs include improvements to the water supply
system in the Sweetwater District.

               Table 4-1 Near-and Long-term Needs in the Pacific Coastal Basin
Community
Descanso, CA
Ensenada, BC
San Diego, CA
Tecate, BC
Tijuana, BC
Unincorporated and
Other Areas of San
Diego County, CA
Total
Year 2000
Population
900
325,000
1,248,200
74,500
1,260,100
1,421,900

4,330,600
Year 2020
Population
1,100
617,300
1,496,900
134,300
2,676,700
1,693,000

6,619,300
Near-term
Capital Cost
(Smillions)
2
10
0
9
7
93

121
Long-term
Capital Cost
(Smillions)
2
145
127
46
402
103

825
                                              55

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4.2
New River Basin
         Blythe, California. The community is considering a centralized water production and treatment
facility. Water mains are envisioned to serve the nearby areas of Ripley and Mesa Verde.

         Brawley, California.  The community  has received a notice  of non-compliance from the
California Regional Water Resources Control Board mandating the upgrade and expansion of its existing
wastewater treatment plant. The city is also considering replacement of water supply piping foradditional
capacity and improvements to the wastewater collection system and pumping stations.
plants.
         Calexico, California. The community is expanding the existing water and wastewater treatment
         Heber, California. The community expects to complete improvements to and expand the
existing water treatment plant and wastewater collection system.

         MexicaH, Baja California. The community needs to identify, evaluate and select alternatives
for wastewater treatment using natural systems for four communities in the Mexicali Valley.  The
feasibility for water reuse could be included in the evaluation.

         Palo Verde, California. The community needs to develop a wastewater facility plan for possible
construction of a wastewater collection system and treatment plant to replace individual septic tanks.

         Salton, California. The community is considering rehabilitation of its wastewater collection
system and replacement of its wastewater treatment plant.

         Seeley, California. The community needs to evaluate its water supply and wastewater systems.

         Westmorland, California. The community  is to complete a replacement of its wastewater
treatment plant.
                                              56

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                Table 4-2 Near and Long-term Needs in the New River Basin.
Community
Blythe, CA
Brawley, CA
Calexico, CA
Heber, CA
Mexicali, BC
Palo Verde, CA
Salton, CA
Seeley, CA
Westmorland, CA
Unincorporated and
other Areas of Imperial
County, CA
Total.
Year 2000
Population
. 14,200
24,000
28,500
3,600
794,400
13,900
. 500
500
1,900
91,700
973,200
Year 2020
Population
26,700
44,900
53,500
6,700
1,233,000
26,100
1,000
900
3,500
171,900
1,568,200
Near-term
Capital Cost
(Smillions)
12
14
0
0
4
2
3
6
0
No Data
41
Long-term
Capital Cost
($millions)
15
18
32
4
85
20
2
2
3
27
208
4.3
Gulf of California Coastal Basin
         Altar, Sonora.  The community needs to expand its water distribution system to serve the
balance of the city, provide chlorination, refurbish all water supply production wells and expand the
delivery system to adjacent areas.  It also needs to expand the wastewater collection system to provide
city wide service and to expand and rehabilitate the existing oxidation pond.

         Bavispe, Sonora. The community needs to upgrade or replace its water supply production wells
and its water distribution facilities, expand its wastewater collection system and provide additional
treatment capacity.

          Caborca, Sonora. The community needs to rehabilitate its public water distribution system.

          Imuris, Sonora. The communLty needs to rehabilitate and upgrade its water supply production
wells and expand the water distribution system, rehabilitate or replace the wastewater collection lines and
upgrade the wastewater treatment plant.

          Magdalena de Kino,  Sonora.  The  community needs to improve its water and wastewater
systems.

                                              57

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         Puerto Penasco, Sonora. The community has short-term needs to improve its water system,
expand and rehabilitate its wastewater system.  This  will require the expansion of the wastewater
collection system, the wastewater treatment plant and the water distribution system.

         Santa Ana, Sonora. The community needs to construct a wastewater treatment plant, expand
the wastewater collection system and make improvements to the potable water system.
         Sdsabe, Sonora.  The community needs to construct a wastewater collection and treatment
system.
         Sonoyta, Sonora.  The community needs to make improvements to the public water supply
system and to the wastewater collection and treatment facilities, including rehabilitation and expansion.
Lukeville, Arizona, is an adjacent small community of less than 100 people and its needs estimates are
included with those of Sonoyta.

          Table 4-3 Near and Long-term Needs in the Gulf of California Coastal Basin
Community
Altar, SN
Bavispe, SN
Caborca, SN
Imuris, SN
Magdalena de Kino, SN
Puerto Peffasco, SN
Santa Ana, SN
Sasabe, SN
Sonoyta, SN/Lukeville, AZ
Total
Year 2000
Population
7,900
2,000
70,900
12,400
42,900
39,500
13,400
1,400
16,500
206,900
Year 2020
Population
11,500
3,500
100,800
22,200
76,500
49,900
23,900
2,500
29,500
320,300
Near-Term
Capital Cost
(SMillions)
No Data
1
No Data
1
5
12
4
1
2
26
Long-Term
Capital Cost
(SMillions)
7
4
45
17
30
21
20
3
15
162
                                            58

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4.4
Colorado River Basin
         Agua Prieta, Sonora.  The community needs rehabilitation of its water distribution system,
expansion of its water storage capacity and expansion of both the wastewater collection system and
treatment plant.

         Bisbee, Arizona.  The community needs improvements to the wastewater collection system
including correction of excessive inflow and infiltration in two areas and treatment facilities.

         Cananea, Sonora. The community needs to create a public water utility, install water meters,
increase water  storage  capacity, expand water  distribution.and wastewater collection systems and
rehabilitate its wastewater treatment facilities.
                                              i

         Douglas, Arizona. The community needs to upgrade its water supply and wastewater systems.

         Naco, Arizona/Sonora.  Additional needs information  for this community was not made
available.

         Nogales, Arizona. The community needs to upgrade its water distribution system, wastewater
collection system and its share of the international wastewater treatment plant.

         Nogales, Sonora. The community needs to upgrade municipal water supply and distribution,
wastewater collection and its share of the international wastewater treatment plant.

          Patagonia, Arizona. The community needs to upgrade its wastewater treatment plant because
of upcoming revision of effluent limits and to rehabilitate its wastewater collection system to reduce
excessive inflow and infiltration.

          San Luis, Arizona.  The community needs to increase its water supply and storage capacity as
well as rehabilitate its wastewater collection system.

          San Luis Rio Colorado, Sonora. The community needs to provide a wastewater treatment plant,
expand its wastewater collection system and upgrade its water system.

          Somerton, Arizona. The community needs additional wastewater treatment plant capacity as
well as replacement of undersized and deteriorating asbestos cement water mains and obsolete water
meters.

          Tombstone, Arizona.  The community needs improvements to its water supply and distribution
system, expansion of the wastewater collection system and upgrading of its wastewater treatment plant.

          Willcox, Arizona. The community needs to upgrade its wastewater treatment plant.

          Yuma,  Arizona.  The community needs to extend its  water distribution and wastewater
collection systems.
                                              59

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Table 4-4 Near- and Long-term Needs in the Colorado River Basin.
Community
AguaPrieta,SN
Bisbee, AZ
Cananea, SN
Douglas, AZ
Naco, AZ/SN
Nogales, AZ/SN
Patagonia, AZ
San Luis, AZ
San Luis Rio
Colorado, SN
Somerton, AZ
Tombstone, AZ
Willcox, AZ
Yuma,AZ
Unincorporated and
Other Areas of
Cochise County,
AZ
Unincorporated and
Other Areas of
Pima County, AZ
Unincorporated and
Other Areas of
Santa Cruz County,
AZ
Unincorporated and
Other Areas of
Yuma County, AZ
Total
Year 2000
Population
76,400
6,400
31,900
15,500
6,300
183,500
1,000
14,100
157,300
7,300
1,500
3,800
63,800
71,900

743,500

19,400

60,000

1,463,600
Year 2020
Population
198,400
8,500
44,000
20,600
8,500
337,400
1,700
19,500
272,400
10,100
2,000
5,000
88,200
95,500

980,200

32,300

83,000

2,207,300
Near-term
Capital Cost
(Smillions)
3
10
3
10
No Data
55
2
2
17
3
5
2
72
No Data

No Data

No Data

No Data

184
Long-term
Capital Cost
(Smillion)
73
4
16
6
4
82
2
7
92
4
2
3
21
19

75

10

18

438
                            60

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4.5
Northwest Chihuahua Basin
         Ascension, Chihuahua. The community needs to upgrade or replace its water distribution and
storage system, expand its wastewater collection system and provide for wastewater treatment facilities.

         Columbus, New Mexico.  The community needs minor improvements at its municipal wells
and completion of the third phase of its wastewater treatment plant.

         Janos, Chihuahua. The community needs to rehabilitate and upgrade the municipal wells and
water distribution system and to provide a wastewater treatment plant.

         Nuevo Casa Grandes, Chihuahua. The community needs to expand and upgrade its water
supply and distribution system and provide a wastewater treatment plant.

         Palomas, Chihuahua.  The community needs to rehabilitate or replace its water supply and
distribution  system  as well as upgrade or replace the wastewater  collection system and provide a
treatment plant.

         Villa Ahumada, Chihuahua.  The community needs to rehabilitate and upgrade the water
distribution  system, expand wastewater collection to the entire community and provide a wastewater
treatment plant.

Table 4-5  Near- and Long-term Needs in the Northwest Chihuahua Basin.
Community
Ascensi6n, CH
Columbus, NM
Janos, CH
Nuevo Casas
Grandes, CH
Las Palomas, CH
Villa Ahumada, CH
Unincorporated and
Other Areas of
Hidalgo County, NM
Unincorporated and
Other Areas of Luna
County, NM
Total
Year 2000
Population
23,400
1,000
11,100
67,800

7,200
13,600
5,900

25,800
155,800
Year 2020
Population
42,300
1,700
14,100
128,700

14,700
25,700
6,800

41,400
275,400
Near-term
Capital Cost
(Smillions)
2
1
No Data
No Data

No Data
2
No Data

No Data
5
Long-term
Capital Cost
(Smillion)
26
3
11
55

11
19
4

12
141*
 * Value is different than in the Status report ( Summary Report) EPA -832-R-00-007 Page 6 published May 2000 because
 the report was preliminary.
                                              61

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4.6
Rio Grande Basin
        Alpine, Texas. The community needs to upgrade its water supply production wells, storage
capacity and water distribution system. The wastewater treatment plant needs to be upgraded and a new
interceptor line provided.

        Alton, Texas. The community needs to expand its water distribution system. An alternative
is being considered for connecting its system to the McAllen municipal water supply system.

        Camargo, Tamaulipas. The community needs to upgrade its wastewater collection system.

        China/General Bravo, Nuevo Leon. The community needs to expand its wastewater collection
system and provide wastewater treatment.

        Ciudad Acuna, Coahuila. The community has a wastewater treatment plant under construction
and needs to upgrade its wastewater collection system.

        Ciudad Juarez, Chihuahua. The community needs to expand both the water
and the wastewater systems to serve the metropolitan area.

        Coyame, Chihuahua. The community needs to rehabilitate and upgrade its water supply and
distribution system and provide a wastewater treatment plant.

        Del Rio, Texas. The community is rehabilitating its water storage and distribution system, water
supply wells and pumping station.
        Donna, Texas. The community is replacing and upgrading the existing wastewater collection
system.
        Eagle Pass, Texas. The community needs to upgrade its water distribution system and may
consider expanding it to serve neighboring Pueblo Nuevo, Texas. The existing wastewater treatment
plant needs to be upgraded or replaced and extension of the collection system to Pueblo Nuevo may be
considered.

        El Paso, Texas. The community needs to include long-term planning for water supply.

        Fabens, Texas.  The community needs to install a water treatment system for high iron and
manganese removal.
        Gustavo Diaz Ordaz, Tamaulipas. The community needs to upgrade its wastewater collection
system.
        Guadalupe Bravos, Chihuahua.   The  community needs  to  provide  for  water  system
improvements, wastewater treatment and expansion of its wastewater collection system.
                                            62

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        Laredo, Texas. The community is considering expansion of its water distribution and
wastewater collection systems for nearby Colonias.

        Manuel Benavides, Chihuahua. The community needs to and upgrade and expand its water
distribution system, expand its wastewater collection system and provide for wastewater treatment.

        McAllen, Texas. The community needs to expand its wastewater collection system including
service to Colonias outside of the city limits.

        Mercedes, Texas. The community may need to  expand its wastewater treatment plant and
collection systems.

        Mier, Tamaulipas. The community needs to rehabilitate and expand its water treatment plant.

        Miguel Aleman, Tamaulipas. The community needs to extend its wastewater collection system
and upgrade its treatment facilities.

        Nava, Coahuila. The community needs to upgrade its water supply and distribution system,
including additional storage, to improve and expand the wastewater collection system and to provide a
wastewater treatment plant.  The community of Estacion Rio Escondido needs upgrading of the water
supply system. Provisions of water supply and wastewater collection system is being considered for the
community of La Sauceda.

        Nueva Ciudad Guerrero, Tamaulipas. The community needs to expand its wastewater collection
and provide an operational wastewater treatment facility.

        Nuevo Laredo, Tamaulipas.  The community needs to upgrade its water distribution and
wastewater  collection systems.  Correction of Inflow/Infiltration problems is being considered for
improving its wastewater collection system

         Ojinaga, Chihuahua. The community needs to construct a water distribution system and storage
facilities, upgrade wastewater treatment and expand its wastewater collection system.

         Piedras  Negras, Coahuila.  The community plans to upgrade or  replace its  wastewater
 stabilization ponds with an activated sludge system as  well as to upgrade and extend the wastewater
 collection system.

         Presidio, Texas. The community needs upgrading or replacement of its wastewater treatment
 plant.

         Reynosa, Tamaulipas.  The community needs to upgrade part of its water supply system and
 upgrade and expand its wastewater collection system. Bioremediation of Laguna La Escondida, is being
 considered as well as the development of a treated wastewater sludge management plan.
                                             63

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         Rio Bravo, Tamaulipas.  The community needs to upgrade its water treatment plant and is
considering extension of wastewater collection to a nearby Colonia.

         Rio Grande, Texas.  The community is considering water treatment plant upgrading and
expansion of the wastewater collection system to a Colonia.

         Roma, Texas.  The community is making water and wastewater improvements including
extension of service to a Colonia.

         Sanderson, Texas. The community is considering wastewater collection and treatment facilities.

         Weslaco, Texas. The community needs upgrading of its wastewater collection and treatment
systems, with possible extension of service to a Colonia.

         Zaragoza, Coahuila. The community needs to upgrade its water distribution system and provide
for adequate storage capacity. Wastewater needs include expansion of the wastewater collection system
to the full service area and provision of a wastewater treatment plant.
                                             64

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Table 4-6 Near - and Long-term Needs in the Rio Grande Basin
Community
Alpine, TX
Alton, TX
Camargo, TM
China/General Bravo, NL
Ciudad Acufia, CO
Ciudad JuSrez, CH
Coyame, CH
Del Rio, TX
Donna, TX
Eagle Pass, TX
El Paso, TX
Fabens, TX
Guadalupe Bravos, CH
Gustavo Diaz Ord&z, TM
Laredo, TX
Manuel Benavides, CH
McAllen, Texas
Mercedes, TX
Mier, TM
Miguel Aleman, TM
Nava, CO
Nueva Cd Guerrero, TM
Nuevo Laredo, TM
Ojinaga, CH
Piedras Negras, CO
Presidio, TX
Reynosa, TM
Rio Bravo, TM
Year 2000
Population
5,800
4,000
15,800
17,000
81,206
1,239,900 .
2,100
36,100
15,800
30,700
640,000
500
10,300
14,600
189,000
2,100
112,500
15,000
6,500
23,800
24,500
3,900
358,500
24,000
142,300
5,000
533,400
108,400
Year 2020
Population
6,600
7,300
18,900
23,000
294,900
2,395,000
4,000
47,600
28,500
53,500
923,400
700
14,000
13,300
360,500
1,700
202,300
26.,900
7,900
31,500
45,700
4,200
898,000
27,700
270,000
7,400
1,138,000
147,200
Near-term
Capital Cost
(Smillions)
7
No Data
2
2
81
No Data
No Data
0
0
No Data
No Data
No Data
No Data
2
11
No Data
No Data
6
5
4
13
No Data
13
4
58
4
29
5
Long-term
Capital Cost
(Smillions)
2
7
13
17
43
437
4
14
11
15
121
1
12
9
85
2
62
14
7
9
30
3
151
12
80
7
155
55
                             65

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Community
Rio Grande, TX
Roma,TX
Sanderson, TX
Weslaco, TX
Zaragoza, CO
Unincorporated and Other
Areas of Brewster County,
TX
Unincorporated and Other
Areas of Dofia Ana
County, NM
Unincorporated and Other
Areas of El Paso County,
TX
Unincorporated and Other
Areas of Hidalgo County,
TX
Unincorporated and Other
Areas of Maverick
County, TX
Unincorporated and Other
Areas of Presidio County,
TX
Unincorporated and Other
Areas of Starr County, TX
Unincorporated and Other
Areas of Terrell County,
TX
Unincorporated and Other
Areas of Val Verde
County, TX
Unincorporated and Other
Areas of Webb County,
TX
Total
Year 2000
Population
10,400
12,000
1,200
28,900
19,200
2,900
141,600

124,500
484,500
23,500

3,900
54,200
100
10,400

24,400
4,603,900
Year 2020
Population
19,700
22,800
1,100
51,900
39,400
3,200
213,100

179,700
935,600
40,900

5,700
103,.000
100
13,700

46,600
8,656,200
Near-term
Capital Cost
(Smillions)
' 5
0
4
5
4
No Data
No Data

No Data
No Data
No Data

No Data
No Data
No Data
No Data

No Data
264
Long-term
Capital Cost
(Smillions)
17
14
1
28
26
2
32

28
63
12

3
20
1
6

13
* 1,644
* Value is different than in the Status report (Summary Report) EPA -832-R-00-007 Page 6 published May 2000 because
the report was preliminary.
                                                    66

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4.7
Gulf of Mexico Coastal Basin
         Brownsville, Texas.  The community proposes to build a reverse osmosis system to treat
wastewater to "bottled water" quality for use by the Port of Brownsville and nearby industries.

         Matamoros, Tamaulipas. The community needs to rehabilitate or replace its wastewater collection
system and complete the construction of a wastewater pump station.

         Valle Hermoso, Tamaulipas.  The community needs to upgrade  its water distribution and
wastewater collection system as well as to provide for a wastewater treatment plant.

           Table 4-7 Near-and Long-term Needs in the Gulf Of Mexico Coastal Basin
Community
Brownsville, TX
Matamoros, TM
Valle Hermoso, TM
Unincorporated and
Other Areas of
Cameron County, TX
Total
Year 2000
Population
145,600
427,700
60,100
202,400
835,800
Year 2020
Population
227,200
736,900
83,200
315,800
1,363,100
Near-term
Capital Cost
(Smillions)
34
6
10
No Data
50
Long-term
Capital Cost
(Smillions) .
128
181
38
39
?? ,
 * Value is different than in the Status Report ( Summary Report) EPA -832-R-00-007 Page 6 published May 2000 because the
 city of Reynosa was originally included in the Gulf of Mexico Coastal basin due to changes in the limits of the watershed basin.
                                                67

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5       Accomplishments

        The EPA role in the funding of water and wastewater infrastructure projects in the U.S. - Mexico
Border for communities was initially in cooperation with the IB WC and more recently with the NADBank.
In addition, EPA has funded an infrastructure Project Development Assistance Program (PDAP), the
development of programs by the George E. Brown U.S.-Mexico Foundation for Science (FUMEC), as well
as assistance to border tribal governments in order for them to  accomplish the same result as the
communities. The EPA financial commitments to date for these needs are shown hi Table 5-1.
Table 5-1.  Current EPA Participation, in U.S.-Mexico Border Infrastructure Needs
Basins
Pacific Coastal Basin *
New River Basin
Gulf of California Coastal
Basin
Colorado River Basin
Northwest Chihuahua Basin
Rio Grande Basin
Gulf of Mexico Coastal Basin
PDAP
FUMEC
Tribal
Total
Total Project
Value
( In $ Millions)
190
113
0
60
0
445
7
37
852
EPA Share
( In $ Millions )
86
58
None
20
None
120
7
37
328
5.1
    * Does not include IWTP prior to Fiscal Year4995.

BEIF
        EPA currently places its grant funds into the Border Environment Infrastructure Fund
(BEIF) account at the NADBank for assistance in making jointly-funded projects viable and affordable for
border communities. The Bank administers grant resources provided by EPA as its share of construction
costs directly as capital cost contributions, as transition payments, or both. It should be noted that EPA
funding eligibility criteria require the requesting community to seek out available funding from all other
sources before a contribution is made from the BEIF account. In addition, the EPA share of BEIF-funded
projects in Mexico require an equal match of Mexican grant funds.
                                            68

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5.2
PDAP
        PDAP funding is used for providing grants for preliminary engineering and design studies by
many communities which would not otherwise be able to prepare these for the detailed application for
BECC certification. Activities include project-specific capacity building to address certification criteria,
preliminary engineering studies, environmental assessments, technical and economical feasibility studies,
project management studies, preliminary design, and development of operation and maintenance plans.
5.3
 FUMEC
         The FUMEC has begun its pilot programs for inventorying available human resources and
developing training programs in areas where the human resource inventories show that there is a need.

5.4      Border Tribal Assistance

         Border tribal governments for recognized  U.S. tribes with lands in the border area receive
infrastructure funding directly or through the Indian Health Service.
                                               69

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6.      Future of Water Infrastructure Management in the Border Area

       After many years of growth in the border area spurred on by an agreeable climate and
employment opportunities, the need for binational federal attention on protection of water quality
and its effect on public health was recognized and the first steps taken.  The La Paz Accord, signed
in 1983 and the NAFTA side agreements, followed by creation of new binational infrastructure
development institutions and appropriations from the Mexican and U.S. governments, have had a
significant impact on the lives of those who  live and work in the border area by protecting public
health and improving surface water quality.

       New long-term integrated planning mechanisms have been created and supported for the
water infrastructure needs of the communities. Oversight, assistance in technology-sharing and
funding, enhanced public participation in local governmental decisions and encouragement of
binational communities to work out solutions based on the needs of all have been established.

       At this time, at least 9 percent of the border populace is still without public water supply, as
much as 23 percent are without wastewater  collection and up to 40 percent without treatment of
wastewater. The watersheds still need improvements in environmental and public health safeguards.
Each community is making progress  according to its own needs and abilities, but the work is
considerably less than complete.

6.1    Summary of Near- and Long-Term Water and Wastewater Infrastructure Needs

       Across all seven watershed basins, the estimated water supply and wastewater treatment
infrastructure capital needs for communities and recognized tribes under consideration through the
year 2020 in the U.S. part of the border area are estimated at $1.7 billion and for Mexico at $2.8
billion. The binational total of $4.5 billion is in addition to the current commitments shown in Table
5-1.

       These needs are summarized by watershed basin in Table 6-1, with a breakdown between
those in the U.S. and those in Mexico.
                                          70

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Table 6-1 Summary of Near- and Long-term Water and Wastewater Infrastructure Needs.
Basin

Pacific Coastal
New River
Gulf of
California
Coastal
Colorado River
NW Chihuahua
Rio Grande
Gulf of Mexico
Coastal
Total
Near-term Needs (Smillions)
U.S.
95
37
0


133
1
42
34

342
Mexico
26
4
26


51
4
222
16

349
Total
121
41
26


184
5
264
50

691
Long-term Needs (Smillions)
U.S.
232
123
0


216
19
517
229

1336
Mexico
593
85
162


222
122
1065
219

2468
Total
825
208
162


438
* 141
* 1644
*386

3804
6.2    EPA and Other Needs Estimates

       A number of the border institutions, including the BECC and NADBank have made needs
estimates for border water infrastructure development and those have been compared to the ones
presented here. The results, as expected, are closely comparable because the same existing facilities
and future population information were utilized for all the estimates. These population estimates
were taken from the January 22,  1999, draft of a paper entitled Population and Economics on the
US-Mexico Border: Past, Present and Future by James Peach, Professor of Economics and
International Business, and James Williams, Professor of Sociology, both of New Mexico State
University.
                                          71

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6,3    Next Steps

       As part of the NAFTA negotiations, the U.S. and Mexican governments each pledged $700
million in grant funding to help make projects affordable hi the border communities.  EPA has
received $550 million of these funds in appropriations to date (including FY 2001) which are being
committed on both sides of the border. Mexican projects with an EPA share must provide a U.S.
benefit. Based on these current estimates, the $700 million target from each nation will not complete
the construction or upgrading of all communities water and wastewater facilities.

       Expectations are that the border area communities will make progress  on building the
institutional capacity to operate, maintain, repair and build up the financial reserves to upgrade and
enlarge their water  supply and wastewater treatment facilities over the next 20 years.  Each
community would be expected to proceed on its own schedule related to the size and condition of
existing facilities, other municipal priorities and the local economic situation.

       Currently, funding for U.S. Border projects consist of community resources, borrowing from
the NADBank or a State Revolving Funds and subsidies or grants from state and federal, sources.
The terms of each financing package are researched, analyzed and negotiated by the Bank. It is the
expectation of both  CNA and EPA that the communities will approach self-sufficiency as then-
institutional capacity increases, that rates and general fund allowances will rise to total operating and
maintenance costs and that the work to build a complete modern infrastructure system for the
existing populace will continue even after support from the federal agencies will have been
completed. However, the regulatory roles which are now apart of the responsibilities of both federal
agencies  will continue hi order to ensure that each border community operates  its facilities
adequately with its own resources, but it will take time, for this capability to develop. The U.S. and
Mexican governments must determine how long and to what level to continue the current program
to provide for the remaining existing needs and for development of future capacity.
                                          72

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7.     Information Resources

      This publication is produced by the Office of Wastewater Management (OWM) and is
available free of charge, to the end of supply, from the following source:

U.S. EPA Headquarters
Office of Water Resource Center (RC-4100)
1200 Pennsylvania Avenue, Ariel Rios Building
Washington, D.C. 20460
Tel. (202) 260-7780 Fax (202) 260-0386  e-mail center water-resource@epa.gov

Publication can be downloaded from the EPA internet website : .
http//www.epa.gov/owm/mexican.htm
References

1.     Arizona Department of Environmental Quality, 1994. Arizona Water Quality Assessment,
       1994.
2.     Arizona Department of Environmental Quality, 1998. Internal Memorandum from Mario
       Castaneda, Water Border Technical Coordinator, to Wayne Hood, Section Manager, Hydro
       logic Support and Assessment Section, November 16, 1998.  Subject: Northeast Sonoran
       Water Quality Monitoring Project.
3.     Arizona Department of Environmental Quality, 1998. Arizona Water Quality Assessment,
       1998, Volume I - Assessment Process and Analysis.
4.     Arizona Department of Environmental Quality, 1998. Arizona Water Quality Assessment,
       1998, Volume II - Assessment Data and Standards.
5.     ArizonaDepartment of Environmental Quality, 1999. Arizona Department of Environmental
       Quality Fixed Station Network Sampling Plan.
6.     Gobierno del Estado de Baja California, Mexico, 1993. Feasibility Study - Implementation
       Program, Environmental Improvement Project for Tijuana River Area III. In consultation
       with Chuo Kaihatsu Corporation and Black & Veatch International.

 7.     City of San Diego Water Quality Report 1995-1999.
 8.     California State Water Resources Control Board,  1994.  Water Quality Control  Plan:
       Colorado River Basin - Region 7.
 9.     California State Water Resources Control Board, 1994.  Water Quality Control  Plan:
       Colorado River Basin - Region 9.
 10.   California State Water Resources Control Board,  1999. 1998 California 305(b) Report on
       Water Quality.
 11.   International Boundary and Water Commission, 1994. Binational Study Regarding the
       Presence of Toxic Substances hi the Rio Grande/Rio Bravo and its Tributaries Along the
                                          73

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       Boundary Portion Between the United States and Mexico.
 12.    International Boundary and Water Commission, 1999. Internet site at [http://www.ibwc.gov],
       accessed November 1999.
 13.    New Mexico Water Quality Control Commission, 1998. Water Quality and Water Pollution
       Control in New Mexico, 1998. NMED/SWQ-98/4.
 14.    Pan American Health Organization 2000. Internet site at
       [htpp://www.fep.paho.org/healthprofiles]
 15.    Peach, James, and James Williams, 1999. Population and Economic Dynamics on the U.S.-
       Mexico Border: Past Present and Future. Draft.
 16.    San Diego State University  Center  for Inland  Waters,  1999.    Internet  site at
       [http://www.sci.sdsu.edu/salton/SaltonBasinHomePage.html], accessed November, 1999.
 17.    Texas Natural Resources Conservation Commission, 1994.  Regional Assessment of Water
       Quality in the Rio Grande Basin, Including the Pecos River, the Devils River, the Arroyo
       Colorado, and the Lower Laguna Madre. Prepared by the Watershed Management Division
       under authorization of the Texas Clean Rivers Act.
 18     U.S. Department of Health and Human Services, 1996. The New River Petitioned Public
       Health Consultation. Internet site at
       [http://www.sci.sdsu.edu/salton/NewRiverPPHCons.html ],  accessed November, 1999.
 19.    U.S. EPA, 1995.  Draft U.S./Mexico Border Environmental Report: Surface Water Quality.
20.    U.S. EPA, 1996.  Binational Toxic Substances Study: New and Lower Colorado Rivers.
21.    U.S. EPA, 1996. U.S./Mexico Border XXI Program Framework Document. EPA 160-R-96-
       003.
22.    U.S. EPA, 1996. U.S./Mexico Border XXI Program 1996 Implementation Plans. EPA 160-
       R-96-004.
23.    U.S. EPA, 1997.  The Index of Watershed Indicators.  EPA 841-R-97-010.
24.    U.S. EPA, 1997.  U.S./Mexico Border Watersheds Report Summary.
25.    U.S. EPA, 1998.  U.S./Mexico Border XXI Program 1997-1998 Implementation Plans and
       1996 Accomplishments Report.  EPA 160-R-98-001.
26.    U.S.EPA, 1998. U.S./Mexico Border XXI Program 1998 Implementation Plans. EPA 160-
       R-98-003.
27.    U.S. EPA, 1998. ColoniaFact Sheet. Internet site at [http://www.epa.gov/owni/clnfcts.pdfl,
       accessed November, 1999.
28.    U.S. EPA, 1999.  Border XXI Water Work Group Progress Report 1995-2000.
29.    U.S. EPA 2000. Status Report on the Water and wastewater Infrastructure Program for the
       U.S.-Mexico Borderlands. EPA-832-R-00-007
30.    U.S. Geological  Survey, 1999. National Water Quality  Assessment Program,  Central
       Arizona Basins. Internet site at [http://wwwdaztcn.wr.usgs.gov/cazb-Surface-water.html],
       accessed November, 1999.
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