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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
in 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
Qncidences per 100,000 People )

Colorado Amebiasis Hepatitis A Shigellosis Typhoid Fever
Basin °

Che 1988 | 1998 | | 1988 | 1998 | | 1988 | 1998 | °°

1988 | 1998 Chg. Chg. Chg.

US.
Counties

: Az 0 0 0 40.2 | 25.7 | -36 | 25.8 6.0 “77 0 0 0

ima, AZ 0.5 0.6 20 22.5 29 29 413 | 24.2 | -41 0 0 0
|" Cruz, AZ 3.7 18.4 | 397 | 74.4 | 42.0 | -44 | 26.1 | 23.6 | -10 0 0 i)

‘ochise County,| 0 9.0 -- | 74.8 | 17.8 | -76 114 | 3.6 -68 0 0 0
JAZ .

Mexican
Cities

logales, SN 956 757 21 54.4 5.0 91 No 1.0 _ 2.8 10 ~64
Data

Agua Prieta,SN | 956 | 63.0 -93 54.4 5.0 -91 No 1.0 _ 2.8 0 “-100
Data

San Luis 787 318 -60 28.4 | 10.0 -65 No 5.0 _ 8.4 0 -100
powee SN Data
— — — oe — oe ee

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



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 Pefiasco, 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 in 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.

Sdsabe, 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


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
tates 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 Amebiasis Hepatitis A Shigellosis Typhoid Fever
Basin
1988 | 1998 | % 1988 | 1998 % 1988 | 1998 % 1988 | 1998 %
Chg. Chg. Chg. Chg,
US,
Counties
Luna 5.7 0 -100 0) 0 0 17.0 0 -100 0 0) 0
Dofia Ana 0 0 0 15.4 0 -100 | 30.8 0 -100 | 0.7 0 -100
| Hidalgo 0 0 0 0 0 0 0 0 0 0 0 0
Mexican
Cities
Las Palomas No No No No No No No No No No | No No
Data | Data | Data | Data | Data | Data | Data | Data | Data | Data | Data | 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



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 (BWC), Border Environment Cooperation Commission (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 It 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 San Diego, 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 ofa25 mgd secondary wastewater treatment facility in the amount of $239.4 million
to serve the cities of San Diego and Tijuana.



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.



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 Figure 3-24. Wastewater Treatment Plant at Ciudad
construction at Ciudad Judrez, Mexico. Judrez, 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
a2.7 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 .



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Sanderson, Texas. Waiter 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.



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 in 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 in the community have made their own provision
forservice. Financial supplements to limited local budgets are necessary to expedite the resource-intensive
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 in 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 in 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 in 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 in the profiles have been supplemented with estimates based on the population of areas outside
of identified communities.



Table3-9 Comparison of Surface Water Quality Standards with Sampling Data for the Rio Grande
Basin

Station | Water Quality
Numbers | Monitoring Stations

US. Standards Sampling Data

Fecal Dissolved Fecal Dissolved Reporting
Coliform Oxygen Coliform Oxygen Agency and
Colonies/ mg/l Colonies mg/l Time

100ml 100m! Geometric Frame
Geometric Average :

Average

Rio Grande at Nuevo 5. 690 . USGS 88
Laredo at International
Bridge II

Rio Grande at pipeline . 10,529.00 . TNRCC
crossing upstream from USGS
Falcon Reservoir 88-98

Rio Grande below ; , USGS 93
Amistad Dam near Del :
Rio, TX

Rio Grande below 5 USGS 93
Anzalduas dam near
Reynosa, MX

Rio Grande below 5 .! » | USGS 92
Elephant Butte Dam, NM. NMWRD

Rio Grande below Falcon 5 . USGS 99
dam Near Falcon, TX

Rio Grande below Rio 5 TNRCC
Conchos, 14.4 km 88-98
downstream of
Presidio/Ojinaga
International Bridge

Rio Grande below Rio
Conchos near Presidio,
TTM

Rio Grande near El India,
TX (36 miles down from
Eagle Pass)

Rio Grande 14 Km down
of Eagle Pass

Note: No water quality monitoring station 10 shown . Monitoring station is shown in the Gulf Coastal Basin



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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.

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 in 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



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 Estacién 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


3.6 Colorado River Basin ..... 0... cece cece eee eee ene en ee eees 27
3.6.1 Geography

3.6.2 Hydrology .... » 27-28

3.6.3 Water Quality 0.0.2... cece eee ee eee eee 28-30

3.6.4 Public Health Conditions ............--eee eee 31

3.6.5 Existing Water and Wastewater Infrastructure . 32-33
3.7 Northwest Chihuahua Basin .......... 0 sce eee cence eee e eee 33

3.7.1Geography

3.7.2Hydrology

3.7.3 Water Quality ... 34-35

3.7.4 Public Health Conditions...............0. 000s 36

3.7.5 Existing Water and Wastewater Infrastructure . .36-37
3.8. Rio Grande Basin 20... . 0. 0c cece cece eee eee eee e een ence 37

3.8.1 Geography . .
3.8.2 Hydrology ....

3.8.3 Water Quality .

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 .......6. 6.6 e cence eee erences 50

3.9.1Geography ..
3.9.2 Hydrology ....

3.9.3 Water Quality .......... .
3.9.4 Public Health Conditions .............--+se0 52
3.9.5 Existing Water and Wastewater Infrastructure ... . 53
Current Water and Wastewater Infrastructure Needs ..............-+- 54
4.1 Pacific Coastal Basin ...... 0... cece cece eee cece eee eee eee 55
4.2 New River Basin ..... 0... cee cece eee cece eee tere en eeee 56-57
4.3 Gulf of California Coastal Basin ...........1 ee eee eee eee 57-58
4.4 Colorado River Basin......... «. 59-60
4.5 Northwest Chihuahua Basin ........ 60.2 eee e cece eee eee es 61
4.6 Rio Grande Basin ....... 0.6.0 cece cece e eee e nee e ne nees 62-66
4.7 Gulf of Mexico Coastal Basin .......... eee cece eee eee e eee 67
Accomplishments ............ 00 eects eee eee eee e eee e tne n ee een ees 68
5.1 BEIF ... 68
5.2PDAP .. ... 69
5.3 FUMEC .........-0000- .. 69
5.4 Border Tribal Assistance ......... 06. e eee e eee eee e ence ee ees 69
Future of Water Infrastructure Management in the Border Area ........ 70
6.1 Summary of Near-and Long-Term Needs :
6.2 EPA and Other Needs Estimates .......
6.3 Next Steps 26... cece eee cece eee nent e neta en eee
Information Resources 2.1.0.0... 00. c cece cece eee eee e cence eens 73

TAReferences 6... eee eee ee tenn e eee e eee nnn 73-74

iii



Community Year 2000 Year 2020 Near-term Long-term
Population Population Capital Cost Capital Cost
(Smillions) (Smillions)

Rio Grande, TX 10,400 19,700 5
Roma, TX 12,000 22,800 0
Sanderson, TX 1,200 1,100 4
5
4

17

Weslaco, TX 28,900 51,900
Zaragoza, CO 19,200 39,400

Unincorporated and Other 2,900 . 3,200 No Data
Areas of Brewster County,
TX

Unincorporated and Other 141,600 213,100
Areas of Dofia Ana '
County, NM

Unincorporated and Other 124,500 179,700
Areas of El Paso County,
TM

Unincorporated and Other * 484,500 935,600
Areas of Hidalgo County,
TX

Unincorporated and Other 40,900
Areas of Maverick
County, TX

Unincorporated and Other 5,700
Areas of Presidio County,
TX

Unincorporated and Other 103,.000
Areas of Starr County, TX

Unincorporated and Other 100
Areas of Terrell County,
TM

Unincorporated and Other 10,400 13,700
Areas of Val Verde .
County, TX

Unincorporated and Other 24,400 46,600
Areas of Webb County,
TX

Total 4,603,900 8,656,200
SE EEE En

* 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.



Community

Year 2000
Population

Year 2020
Population

Table 4-6 Near - and Long-term Needs in the Rio Grande Basin

Near-term
Capital Cost
(Smillions)

Long-term
Capital Cost
(Smillions)

Alpine, TX
| Alton, TX

Camargo, TM
| China/General Bravo, NL
Ciudad Acufia, CO

| Ciudad Juarez, CH

Coyame, CH.

| Del Rio, TX

Donna, TX

| Eagle Pass, TX

El Paso, TX

| Fabens, TX

Guadalupe Bravos, CH

| Gustavo Diaz Ordéz, TM
Laredo, TX

Manuel Benavides, CH

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

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

7

No Data

81
No Data
No Data

No Data

No Data
No Data
No Data
2
il

No Data

2

7
13
17
43

437

14
1
15

121

McAllen, Texas 112,500 202,300 No Data 62
Mercedes, TX. 15,000 26.,900 6 14
Mier, TM 6,500 7,900 5 7
Miguel Aleman, TM 23,800 31,500 4 9
Nava, CO 24,500 45,700 13 30
Nueva Cd Guerrero, TM 3,900 4,200 No Data 3
Nuevo Laredo, TM 358,500 898,000 13 151
Ojinaga, CH 24,000 27,700 4 12
Piedras Negras, CO 142,300 270,000 58 80
Presidio, TX 5,000 7,400 4 7
Reynosa, TM 533,400 1,138,000 29 155
Rio Bravo, TM 108,400 147,200 5 55

65



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 IBWC 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 in Table 5-1.

Table 5-1. Current EPA Participation in U.S.-Mexico Border Infrastructure Needs

. Total Project EPA Share
Basins Value (In $ Millions )
(In $ Millions)

Pacific Coastal Basin * 190 86
New River Basin 113 58
Gulf of California Coastal

‘, 0 None
Basin
Colorado River Basin 60 20
Northwest Chihuahua Basin. 0 None
Rio Grande Basin 445 120
Gulf of Mexico Coastal Basin 7 7
PDAP
FUMEC
Tribal 37 37
Total 852 328

* Does not include IWTP prior to Fiscal Year-1995.
5.1 BEIF

EPA currently places its grant funds into the Border Environment Infrastructure Fund
(@EIF) 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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Pacific Coastal Basin

3.3

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
Judrez 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



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
Wastewater Treatment Plant (IWTP) in San Diego,
California

FIGURE 3-7. Construction of Ocean Outfall.



@Average 1993-1998

Average 1999

WOOL/Satuojoo

sag
durwg oo.yg won eusey

soapy Busnfiy so wow
yur 8 50 syzanoy-o0ry,

puoy juounuow smumusay,

Jes
Pp ‘aay ‘opeuor0g [0H

Our] 9008 “N
‘yovag amg puesig <9ANS

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sary suen{iy,
40 NOW I susfa404S

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awou oujfazous
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euvnly ap svi -298.y

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aBreyosd ELA AL
souang soj ap oyuoqwy tes
pouyp.oys wapusg Byung

2
Figure 3-4, Average Fecal Coliform Concentration Before and After Start-Up of the International Wastewater Treatment Plant and Ocean



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 in Table 3-5. It encompassed the communities of Sonoyta, Puerto
Peiiasco, 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 beac, sae . . .

Coastal Amebiasis Hepatitis A Shigellosis Typhoid Fever

Basin

Mexican 1999 2000 % ; 199 | 2000 % 1999 | 2000 % 1999 | 2000 %

States Chg. | 9 Chg. Chg Chg

Sonora 23,708 | 22,747 4 196 86 -56 44 68 55 1 3 200
= a

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



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 in 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 in 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 in 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)

US Border Mexican Border US Nationwide
Rates Rates Rates

Disease

Amebiasis 14 798.8 14

Hepatitis A 37.1 50.1 12.6

Shigellosis 35.3 No Data 10.9
Available

Typhoid Fever 0.4 36.1 0.2

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



All

Community

Gulf of Mexico Coastal Basin

Year 2000
Population

Year 2020
Population

Near-term
Capital Cost
(Smillions)

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

Long-term
Capital Cost
($millions) .

Brownsville, TX

Matamoros, TM.

Valle Hermoso, TM

Unincorporated and
Other Areas of
Cameron County, TX

145,600
427,700
60,100
202,400

227,200
736,900
83,200
315,800

34
6
10

128
181
38
39

Total

835,800

1,363,100

* 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.


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

Water
Station Quality .
Numbers | Monitoring U.S. Standard Sampling Data
Stations
Fecal Dissolved Fecal Dissolved Reporting
Coliform Oxygen Coliform Oxygen Agencies
colonies/ mg/l colonies/ mg/l and Time
100ml 100mI Geometric Frame
Geometric Average
Average
1 Rio Grande 200 5.0° 1574 7.70
near
Brownsville
below Jardin
Pumping
Station
on

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
(ncidences per 100,000 people)

Gulf of
Mexico
Coastal
Basin

Amebiasis : Hepatitis A Shigellosis Typhoid Fever

% | 199g | 1998 | % | 1988 | 1998 | | 1988 | 1998 | °

1988 | 1998 | Chg. Chg. _| che. Chg, |

US.
Counties
Cameron

County,TX
Mexican
Cities

Matamoros, 1029 | 2477 | 141 | 50 | 332 | 564 | 161 | 24 | 49 | 22 40 2 |

14.2 6.1 57 22.8 | 66.5 | 1916 | 19.7 Al 108 0.8 0.6 25

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

52





3.4.4 Public Health Conditions

While the New River Basin has some of the worst water quality conditions in 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 in 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 )

River Amebiasis Hepatitis a, Shigellosis Typhoid Fever

1988 | 1998 % 1988 | 1998 % 1988 | 1998 % «| 1988 | 1998 | %
Chg. Chg. Chg. Chg.

Counties

Imperial 1 0 -100 19 16 -16 63.7 | 13.2 -79 0 0 0
County |

Mexican
Cities

Mexicali | 544 | 1910 } 251 34.2 154 350 10.6 18 70 20.6 107 | 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 ofiron
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 in
a 10 mgd water treatment plant. Treatment of the wastewater is provided by a2.1 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.



Colorado River Basin

4.4

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.

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.


45 Northwest Chihuahua Basin

Ascensién, 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.

eG—veere
Community Year 2000 Year 2020 Near-term Long-term
Population Population Capital Cost Capital Cost
($millions) (Smillion)
Ascensién, CH. 23,400 42,300 2 26
| Columbus, NM 1,000 1,700 1 3
Janos, CH 11,100 14,100 No Data il
| Nuevo Casas 67,800 128,700 No Data 55
Grandes, CH .
Las Palomas, CH 7,200 14,700 No Data li
| Villa Ahumada, CH 13,600 25,700 2 19
Unincorporated and 5,900 6,800 No Data 4
Other Areas of
Hidalgo County, NM
Unincorporated and 25,800 41,400 No Data 12
Other Areas of Luna
| County, NM.
Total 275,400 141*

* 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



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

Ciudad Juaréz, 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



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



63 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 in 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 their
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 a part of the responsibilities of both federal
agencies will continue in 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



Rio Grande Basin Map Water Quality Monitoring Stations
(Southeast Section) 2.0.2... . eee cence eee teeter enn n eee e seen ees 40

3-21 Sewer Installation in Ciudad Acufia, Coahuila, Mexico .........--e+eeeeee 45
3-22 Sewer Inspection in Ciudad Acufia, Coahuila, Mexico ........-.+++++ esses 45

3-23 Pump Station under Construction at Ciudad Judérez Wastewater
Treatment Plant 2.2.0.0... cece cece rere renee eee e ene n ener eees 46

3-24 Ciudad Juarez, Chihuahua Wastewater Treatment Plant under

3-25 Colonia Housing with Privy in Background ........--.- eee eee e errr eee 47
3-26 Colonia.housing along the border >......- +. see cece cece eect erect ene neee 48
3-27 Typical U.S. Colonia ..... 0.6.06 e cee cence ee teen teen ete eee n eens 48

3-28 Gulf of Mexico Coastal Basin Map with Water Quality
Monitoring Stations . 0.0.6.6. seen eee e eee ene ence renee een tes 51



Figure No.

3-11
3-12
3-13

3-14

3-15

3-16
3-17

3-18

3-19

LIST OF FIGURES

Title . Page
U.S.-Mexico Border Population by Basin ......... 0... cece eee cece cence 9
U.S.-Mexico Watershed Basins Map ........ 00. cece eect e eee nee eeeenee 10
Satellite Image of Partial U.S. Mexico Border 2.6... 6. ees eee cence eee e eee il
Average Fecal Coliform Concentration Before and After Start-Up

of the International Wastewater Treatment Plant and Ocean Outfall ......... 13
Pacific Coastal Basin Map with Water Quality Monitoring Stations ......... 14
Completed Advanced Primary Wastewater Treatment Plant

(IWTP) San Diego, CA... 6... cece cece cece eee een n cence eens 17
Construction of Ocean Outfall ... 0.0... cece cece eee e eect eee rere nee 17
Installation of 12 foot diameter outfall forIWTP .......... 06sec eee eee ee 18
Construction of Headworks and Odor Control Building at the IWTP......... 18
Satellite Image showing the New River Basin with the Salton Sea........... 19
Salton Sea... eee cence nent e nen eee e nen ennees 20
New River Basin Map with Water Quality Monitoring Stations ............ 22.
Gulf of California Coastal Basin Map ........ 00. ccc e eee e cece eee eeeeees 25

Colorado River Basin Map with Water Quality Monitoring
BSS (0) 5S SY 29

Typical Watershed Basin showing Ridges and Valleys in the

N.W. Chihuahua Area 0.6... ccc ccc cee cee eee eee e ne en ne eneees 33
Typical Semidesert Conditions in the Chihuahua Area .........-.+- 00000 34
Northwest Chihuahua Basin Map ........ 00sec e cece cece ence en eees 35

Sewer Discharge to a Waterway containing Foaming Agents
near the Rio Grande 2.0.0... ccc cece cece enn n enn eneeee 38

Rio Grande Basin Map Water Quality Monitoring Stations
(Northwest Section) 2... 6... cece cence eee eee nee eee een teen eeee 39

iv



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.

ByYear 2000 GYear 2020

10
9 BZ
2 8
S$ 7 6.6
eel F
5
& 4 | =
g 3 —
3 2 4.6 4.522 14
2 7; 03 ] 08
4 . ~ -
ra HE =
Pacific NewRiver Gulf of Colorado Northwest RioGrande Gulf of
Coastal California River Chihuahua “Mexico
Coastal Coastal

Watershed Basins

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

9





Boundary Portion Between the United States and Mexico.

International Boundary and Water Commission, 1999. Internet site at [http://www.ibwe.gov],
accessed November 1999. .

New Mexico Water Quality Control Commission, 1998. Water Quality and Water Pollution
Control in New Mexico, 1998. NMED/SWQ-98/4.

Pan American Health Organization 2000. Internet site at
[htpp://www.fep.paho.org/healthprofiles]

Peach, James, and James Williams, 1999. Population and Economic Dynamics on the U.S.-
Mexico Border: Past Present and Future. Draft.

San Diego State University Center for Inland Waters, 1999. Internet site at
[http://www.sci.sdsu.edu/salton/SaltonBasinHomePage.html], accessed November, 1999.

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.

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.

U.S. EPA, 1995. Draft U.S./Mexico Border Environmental Report: Surface Water Quality.
U.S. EPA, 1996. Binational Toxic Substances Study: New and Lower Colorado Rivers.

U.S. EPA, 1996. U.S./Mexico Border XXI Program Framework Document. EPA 160-R-96-
003.

U.S. EPA, 1996. U.S./Mexico Border XXI Program 1996 Implementation Plans. EPA 160-
R-96-004.

U.S. EPA, 1997. The Index of Watershed Indicators. EPA 841-R-97-010.
U.S. EPA, 1997. U.S./Mexico Border Watersheds Report Summary.

U.S. EPA, 1998. U.S./Mexico Border XXI Program 1997-1998 Implementation Plans and
1996 Accomplishments Report. EPA 160-R-98-001.

U.S. EPA, 1998. U.S./Mexico Border XXI Program 1998 Implementation Plans. EPA 160-
R-98-003.

U.S. EPA, 1998. Colonia Fact Sheet. Internet site at [http://www.epa.gov/owm/clnfcts.pdf],
accessed November, 1999.

U.S. EPA, 1999. Border XXI Water Work Group Progress Report: 1995-2000.

U.S. EPA 2000. Status Report on the Water and wastewater Infrastructure Program for the
U.S.-Mexico Borderlands. EPA-832-R-00-007

US. 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.



Coastal Basin.

Sampling Water
Station Quality
Number Monitoring

Locations

U.S. Standards

Table 3-1 Comparison of Surface Water Quality Standards with Sampling Data for the Pacific

Sampling Data

Fecal Dissolved Fecal Dissolved Reporting
Coliform Oxygen Coliform Oxygen Agency and
Colonies mg/l Colonies/ mg/l Time Frame

/100mI 100mI Geometric

Geometric Averages
Averages

San Antonio de
los Buenos
WWTP Outfali
Pipe, MX

$-2 El Vigia, MX 200

of Tijuana
River,U.S.

8-6 End of Seacoast 200
Dr, U.S. side
S-7 Hollister Bridge, 200

US. side

S-7a Dairy Mart 200
Bridge, U.S. side

S-8 Silver Strand State 200
Beach, N. Fence
Line

8-9 Hotel Coronado, 200
US. side

S-10 Terminus 200
Monument Road.

S-11 3/4 mile north of 200
Tijuana River

S-12 Camp Surf, U.S. 200
side

8-3 Frace. Playas de 200
Tijuana, MX

S-4 North And South 200
of Mouth of
Tijuana River

$-5 Shorelineatmouth | 200

6.0

6.0

6.0

6.0

6.0

6.0

6.0

6.0

6.0

6.0

6.0

6.0

96

363

427

462

2319

354

440

670

25

21

469

47

275

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

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



P33 United States Office Of Water (4204-M) EPA-832-R-00-001
SEPA Environmental Protection Agency . January 2001

STATUS REPORT ON THE
WATER-WASTEWATER
INFRASTRUCTURE

PROGRAM FOR THE
US-MEXICO BORDERLANDS



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/l.

38



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 in 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, Mexicali, 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 Judrez. Both are completed and in operation
additionally, eleven other projects in the basin are in 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 in near-term needs is estimated at $691 million,
divided as follows: $342 million in the U.S. and $349 million in 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.



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 (SEMARNAP), through
its National Water Commission (CNA), Border Environment Cooperation Commission (BECC),
North American Development Bank (NADBank) and International Boundary Water Commission.
(IBWC). 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 ahd 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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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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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 Water
Number Quality a
Monitoring U.S. Standards Sampling Data
Stations
Fecal Dissolved Fecal Dissolved Reporting
Coliform Oxygen Coliform Oxygen Agency and
Colonies mg/l Colonies mg/l Time Frame
/100m1 /100m1 Geometric
Geometric Average
Average |
1 Alamo River at
Delta into Salton 200 5.0 No Data No Data EPA
Sea
2 New River at |
outlet (into Salton | 499 5.0 NoData | No Data usGs
Sea) near
Westmorland, CA
3 Alamo River at USGS/CRW |
Int. Border near 200 5.0 35 5.8 QCB
Calipatria, Ca 88-97
4 New River IBWC
upstream of 88-97
Discharge Canal at *Minute 264
Mexicali *30,000 No Data 461,665 No Data US-
Mexican
1944 Water
Treaty.
* [International we
88-97
Border No Data . 5.0 No Data 2.6

21



Puerto Pefiasco, 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 Year 2000 Year 2020 Near-Term Long-Term

Population Population Capital Cost Capital Cost

($Millions) ($Millions)
Altar, SN 7,900 11,500 No Data 7
Bavispe, SN 2,000 3,500 1 4
Caborca, SN 70,900 100,800 No Data 45
Imuris, SN 12,400 22,200 1 17
Magdalena de Kino, SN 42,900 76,500 5 30
Puerto Pefiasco, SN 39,500 49,900 12 21
Santa Ana, SN 13,400 23,900 4 20
Sdsabe, SN 1,400 2,500 1 3
Sonoyta, SN/Lukeville, AZ. 16,500 29,500 2 15

| Total 206,900 320,300 26

58



Table

2-1

3-6

3-7

3-8

3-9

3-10

3-11

3-12

4-1

4-2

4-3

LIST OF TABLES
Title Page

Comparison between US-Mexico Border and US Nationwide
Waterborne Disease Rates ..... 0... cece cece eee cece crete ences eens 8

Comparison of Surface Water Quality Standards with Sampling

Data for the Pacific Coastal Basin ........ 0. cece eee cece cece ene eeees 15
Reported Waterborne Diseases in the Pacific Coastal Basin
Cncidences per 100,000 People) ......... cece eee eee e cnet cence ene 16
Comparison of Surface Water Quality Standards with Sampling

Data for the New River Basin ......... 0... c cece cece eect eee ee eens 21
Reported Waterborne Diseases in the New River Basin
Cncidences per 100,000 People) ....... 0. . cece eee cere eee ene e ene eee 23
Reported Waterborne Diseases in the Gulf of California Coastal Basin

(incidences per 100,000 People) ........ 0... cece cece e cence cece eneeee 26
Comparison of Surface Water Quality Standards with Sampling
Data for the Colorado River Basin ....... 0... c cece cece ence ence eeenee 30
Reported Waterborne Diseases in the Colorado River Basin

(incidences per 100,000 People) ........ 0... cece cece cence cece eee eee 31
Reported Waterborne Diseases in the
Northwest Chihuahua Basin (Incidences per 100,000 People) .............. 36
Comparison of Surface Water Quality Standards with
Sampling Data for the Rio Grande Basin ............ 2.0 0e eee e eevee 41-42
Reported Waterborne Diseases in the Rio Grande Basin

(Incidences per 100,000 People) ........... cc cece ee cece eee neces 44
Comparison of Surface Water Quality Standards with

Sampling Data for the Gulf of Mexico Coastal Basin ...........--0.000005 52
Reported Waterborne Diseases in the Gulf of Mexico Coastal Basin
(incidences per 100,000 People) ...... 0... cece eee eee ence eee neces 52
Near-and Long-Term Needs in the Pacific Coastal Basin .................. 55
Near- and Long-Term Needs in the New River Basin ............0.2-00005 57
Near- and Long-Term Needs in the Gulf of California Coastal Basin......... 58



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
IBWC and the 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 in 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 Tijuana 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.



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 Estacién
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 in funding of a new wastewater treatment plant and of water distribution and
wastewater collection for Colonias.



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. Arizona Department of Environmental Quality, 1999. Arizona Department ofEnvironmental
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 in the Rio Grande/Rio Bravo and its Tributaries Along the

BB


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.

Calexico, California. The community is expanding the existing water and wastewater treatment
plants.

Heber, California. The community expects to complete improvements to and expand the
existing water treatment plant and wastewater collection system.

Mexicali, 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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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.



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

Station Water Quality : Sampling Data
Number Monitoring
Stations

Fecal Dissolved Fecal Coliform Dissolved Reporting
Coliform Oxygen Colonies/100 mi Oxygen Agencies
Colonies/ mg/l Geometric mg/l and Time

100ml Average Geometric Frame
Average

Colorado River at No. | . 200 . No Data 8.1 USBR
International Boundary 89-98
above Morelos Dam

East Nogales Wash at . . ADEQ
Morley St 86-99

Nogales Wash at Fire x . ADEQ
Station 86-87

Gila River at Gillespie x x USGS
Dam 88-97

East Nogales Wash at . ADEQ
US. Border 86

San Pedro River at ‘ . USGS
Charleston, AZ 88-93

San Pedro River at . . ADEQ
Highway 92 Palominas 88-99

Santa Cruz River at x ADEQ
Intemational Boundary 90-98

Santa Cruz River at x . ADEQ
Kino Spring location 86

Whitewater Draw at 6 . ADEQ
Highway 80 87-88

Whitewater Draw at . .! USGS
U.S. Border 88-93



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 Acujfia, Coahuila,
Mexico.

Figure 3-22 Sewer Inspection in Ciudad

Acufia, Coahuila , Mexico
4S



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



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.



Table 4-2 Near and Long-term Needs in the New River Basin.

De |
Community Year 2000 Year 2020 Near-term Long-term
Population Population Capital Cost Capital Cost
(Smillions) (Smillions)

Blythe, CA . 14,200 26,700 12 15

Brawley, CA 24,000 44,900 14 18
Calexico, CA 28,500 53,500 32
Heber, CA 3,600 6,700 4
Mexicali, BC 794,400 1,233,000 85
Palo Verde, CA 13,900 26,100 20
Salton, CA 500 ~ 1,000 2
Seeley, CA . 500 900 2
Westmorland, CA 1,900 3,500 3

Unincorporated and 91,700 171,900 27
other Areas of Imperial
County, CA

Total, 973,200 1,568,200

_— |

43 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
citywide 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 community 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.

37



TABLE OF CONTENTS

Sections
FXO) <0) 0922 i
Table of Contents . . ii
Figures .......... an
1:1) (CS
Executive Summary 1-2
1 Introduction ......... 0.00. c ccc c ccc e ce eee e cence eee en enone 3
2 The Border Team at Work . 4
2.1 La Paz Accord ............ 0. eee 5
2.2 North American Free Trade Agreement -6
2.3 Other Border Relationships .......... +6
2.4 Major Data Sources ..... .6
2.5 Public Health .............00000008 6
2.5.1 Description of Illnesses . 27
2.5.2 Remedial Progress 2.0.00... eee eee eee eee eee 8
3 The Watersheds of the Borderlands .............. 0.0.2 c sees cece enone 9
3.1 Watershed Basins ............ 9-10
3.2 Population of the Borderlands .......... 0... 0s cece eee e ee eee 9
3.3 Pacific Coastal Basin ......... . ll

oenel
Tet

3.3.1 Geography ....
3.3.2 Hydrology ....

3.3.3 Water Quality oe oe. 13-15

3.3.4 Public Health Conditions .............0..000e 16

3.3.5 Existing Water and Wastewater Infrastructure . 16-18
3.4 New River Basin «0.0... 0 cece cee cece ence een ener ens 19

3.4.1 Geography . . 19

3.4.2 Hydrology .... 22.20

3.4.3 Water Quality ..... «+. 21-22

3.4.4 Public Health Conditions.................0006 23

3.4.5 Existing Water and Wastewater Infrastructure . 23-24
3.5 Gulf of California Coastal Basin. ......... 0... c eee eee eee eee 24

3.5.1 Geography ..

3.5.2 Hydrology ..

3.5.3 Water Quality :

3.5.4 Public Health Conditions ................0086 26

3.5.5 Existing Water and Wastewater Infrastructure . 26-27

ii



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 Acufia,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 in 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 Juaréz, Chihuahua, to its
delta on the Gulf of Mexico.

Most flows in the upper Rio Grande Basin originate from precipitation in 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 in the lower Rio Grande dependent on controlled releases
and "return flows" back to the river from agricultural and other commercial water uses.

37



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Table 4-4 Near- and Long-term Needs in the Colorado River Basin.

Year 2000 Year 2020 Near-term Long-term
Community Population Population Capital Cost Capital Cost
(Smillions) (Smillion)
Agua Prieta, SN 76,400 198,400 3 73
Bisbee, AZ 6,400 8,500 10 4
Cananea, SN 31,900 44,000 3 16
Douglas, AZ 15,500 20,600 10 6
Naco, AZ/SN 6,300 8,500 No Data 4
Nogales, AZ/SN 183,500 337,400 55 82
Patagonia, AZ 1,000 1,700 2 2
San Luis, AZ. 14,100 19,500 2 7
San Luis Rio 157,300 272,400 17 92
Colorado, SN
Somerton, AZ 7,300 10,100 3 4
Tombstone, AZ. 1,500 2,000 5 2
Willcox, AZ. 3,800 5,000 2 3
Yuma, AZ 63,800 88,200 72 21
Unincorporated and 71,900 95,500 No Data 19
Other Areas of
Cochise County,
AZ
Unincorporated and 743,500 980,200 No Data 75
Other Areas of
Pima County, AZ
Unincorporated and 19,400 32,300 No Data 10
Other Areas of
Santa Cruz County,
AZ
Unincorporated and 60,000 83,000 No Data 18
Other Areas of
Yuma County, AZ
Total 1,463,600 2,207,300 184 438

60



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 in 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 provide
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 in 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.



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


3.9.5 Existing Water and Wastewater Infrastructure

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.



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
ofa 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.



Acronyms

Acronyms used in this report are :

(ADEQ)
(BECC)
(BEIF)
(CRWQCB)
(CDC)
(CWA)
(CEC)
(EPA)
(FUMEC)
(BWC)

(WTP)
(mgd)
(CNA)
(NMED)
(NAAEC)
(NADBank)
(NAFTA
(PAHO)
(PDAP)
(SEMARNAP)
(SBIWTP)
(TNRCC)
(FUMEC)
(USBR)
(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



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 Quality

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 in 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



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.



3.3.4 Public Health Conditions

The health data presented in Table 3-2 are for the four major waterborne diseases which have
adirect 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
(ncidences per 100,000 People)

Pacific ‘
Coastal Amebiasis Hepatitis A Shigellosis Typhoid Fever
Basin

1988 | 1998 | % | 1988 | 1998 | % | 1988 | 1998 | % | 1988 | 1998 | %
Chg. Chg. Chi Chg.

US.
Counties
San Diego
County 14 1
Mexico
Cities

-29 24.3 | 15.8 -35 25.3 | 10.1 -60 0 0.3 —

Tijuana | 639.4 | 4875 | 662 | 43.9 113 157 11.0 107 873 10.5 | 36.0 | 243

Reference: Pan American Health Organization
website http://Awww.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, Baja 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
in 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





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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 Pefiasco 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



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, anda 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 a high 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, and Nuevo Casas Grandes in 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



New River Basin

3.4

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.



Introduction

1.

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 in 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 in 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), Nuevo 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, resuilting in a deterioration in
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. :



41 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, Baja 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 Year 2000 Year 2020 Near-term Long-term
Population Population Capital Cost Capital Cost
(Smillions) (Smillions)
Descanso, CA . 900 1,100 2 2
Ensenada, BC 325,000 617,300 10 145
San Diego, CA 1,248,200 1,496,900 0 127
Tecate, BC 74,500 134,300 9 46
Tijuana, BC 1,260,100 2,676,700 7 402
Unincorporated and 1,421,900 1,693,000 93 . 103
Other Areas of San
Diego County, CA
Total 4,330,600 6,619,300 121 825
vx ———— — — —— —



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

" Near-term Needs (Smillions) Long-term Needs (Smillions)

Pacific Coastal
New River 37 4 4l 123 85 208

Gulf of 0 26 26 0 162 162
California
Coastal

Colorado River 133 51 184 216 222 438
NW Chihuahua 1 4 5 19 122 * 141

Rio Grande 42 222 264 S17 1065 * 1644

Gulf of Mexico 34 16 50 229 219 * 386
Coastal

Total 349 691 1336 2468 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



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

Station
Numbers

Water Quality
Monitoring Stations

U.S. Standards

Sampling Data

Fecal Dissolved Fecal Dissolved Reporting
Coliform Oxygen Coliform Oxygen Agency and
Colonies/ mg/l Colonies mg/l Time

100ml /100m1 Geometric . Frame

Geometric Average
Average

1

from confluence with Rio
Grande, near Ojinaga,
Mexico

Rio Grande 1 km
upstream of Eagle Pass

Rio Grande 1.1 miles
downstream of Highway
81 bridge between
Laredo/Nuevo Laredo

Rio Grande at El Paso,
TX Courchesne Bridge

Rio Grande at Laredo
Water Treatment Plant
pump intake

200

200

200

200

5.0

5.0

5.0

5.0

‘705

1518

No Data

105

8.2

11.3

8.0

119

1 Rio Conchos 0.2 Km 200 15.0 No Data 76 IBWC
upstream from mouth 92
NW of Ojinaga, Mexico

2 Rio Conchos, 1.5 miles 200 5.0 No Data ND USGS

3 Rio Grande 0.4 km 200 5.0 No Data 8.2 TNRCC.
upstream from Del 91-92,
Rio/Ciudad Acufia
International bridge

IBWC
93-98

TNRCC
89-94

6 Rio Grande 6.4 Km 200 5.0 330 V7 TNRCC
. below Del Rio/Ciudad 88-92
Acufia International
bridge

7 Rio Grande Floodway at 1000 60 “576 9.2 USGS
San Marcia, NM and
NM WRD

8 Rio Grande below Rio 200 5.0 No Data 11.7 TNRCC
Conchos near 92-98
Presidio, TX.

USGS

TNRCC
88-97



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 major 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 in the border area was about three times the average U.S. rate.

Shigellosis has increased in 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 Juaréz a 900 percent increase over
a 10 year period.

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

43



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
GEIF) 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 (BWC), 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 FUMECis 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 of ten 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 Leén 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 (BWC), 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.