II. Human Health and Environment
1. Human Health/Environmental Needs. The City of Nogales, Arizona proposes to
construct a water supply well to replace Well No. 2 in Meadow Hills, which has
been taken offline from the municipal potable water system. This action was
necessary to minimize the potential for interception of existing groundwater
Volatile Organic Compounds (VOC) pollution. The proposed well will guarantee
the Arizona Department of Water Resources 100-year assured water supply.
The project
will address serious health concerns stemming from a VOC contamination plume
that has been identified near the Meadow Hills well area. Contamination of the
aquifer accessed by the Meadow Hills Well No. 2 includes dichloroethylene
(DCE), dichloroethane (DCA), trichloroethane (TCA), and trichloroethylene
(TCE). The source of this plume has been traced to United Musical Instruments
(UMI), a musical instrument manufacturing company. Contamination of groundwater
was discovered by UMI in 1985 during work on an on-site pond. The site was
previously declared an Arizona Water Quality Assurance Revolving Fund (WQARF)
site. UMI received a Poor Water Quality Permit from ADWR with instructions to
remediate VOC-contaminated groundwater. The groundwater treatment
process for Well No. 2 is an air stripping treatment process that transfers
VOCs from the liquid phase to the gaseous phase. The treated water is then sent
to a lined pond where it is extracted and used for irrigation on the Palo Duro
golf course.
Volatile
Organic Compounds are known carcinogens and allowable levels in drinking water
are extremely low by Arizona State and Federal standards. Administration of
VOCs to mice induces neoplasms in the liver, and TCE has been found to cause
pulmonary adenocarcinomas and hepatocellular carcinomas in mice.
The Arizona
Department of Health Services completed a Community Health Survey in Decmeber
1994 and found that the excess occurrence of Systemic lupus erythematosus (SLE)
and multiple myeloma, and the prevalence of Anti-Nuclear Antibodies (ANA) in
Nogales as compared to Patagonia, a neighboring community, is strong evidence
that adverse health effects have occurred in Nogales. The report states: “The
concordance of these observations is strong evidence that adverse health
effects have occurred in residents of Nogales, Arizona and that these health
effects may be the result of complex environmental exposures to biologic or
chemical agents.”
The proposed
well will supply water to the existing City of Nogales potable water system,
provide consistent water quality and is anticipated to supply a capacity equal
to the capacity of the well replaced.
2. Environmental Assessment.
An environmental assessment (EA) was prepared by the City of Nogales. Since the
project sponsor is not seeking federal funding for the construction of the
well, the environmental review does not need to comply with the National Environmental
Policy Act (NEPA). However, the EA does comply with the Border Environment
Cooperation Commission environmental review guidelines as established in the
Project Certification Criteria. As part of the evaluation, the impacts were
assessed for the following environmental parameters: topography, geology and
soils, climate and air quality, drainage, groundwater resources, and
floodplain. The proposed well site will not have any impacts on the existing
upper aquifer, since it will be over 1,000 ft deep to gauge the aquifer
potential of the deeper sediments that make up the Nogales Formation. The project does not have transboundary
impacts.
3. Compliance with Ecology and Cultural Laws
and Regulations. The environmental assessment presented by
the project sponsor complies with the BECC project certification criteria.
Also, the construction of the well does not present a potential impact to any
environmental resources in the project site.
III. Technical Feasibility
1. Appropriate Technology. The final design for
the construction of the Potrero Well has been finalized. Drilling of the well
is underway. The final design was based on hydrogeologic investigations
performed at the project site. The well is being drilled using reverse
circulatory rotary drilling, a method typically used in the construction of
potable water wells.
The investigation showed that the project site is an
appropriate location for the well and that the aquifer is capable of providing
adequate capacity to replace the Meadow Hills Well No. 2. The factors
considered in the selection of the site include: ease of access, proximity to a
water line serving a nearby reservoir, availability of electrical power,
adequate separation of the well site from sources of contamination of
pollution, easement and land acquisition, and location in relation to the
floodplain. The design of the well includes a 20-foot minimum surface seal,
appropriately sized slotted perforations, sounding, gravel and vent tubes,
concrete pump pedestal, and gravel pack and annular grout seal. The well will
be equipped with a vertical turbine pump and motor and the well site will be equipped with a hydropneumatic
pressure tank with air compressor, sampling taps, air release-vacuum relief
valve, shutoff valves, flow meter, and check valve.
Construction
components and techniques selected for the project have been used on numerous
well sites in Nogales and throughout southern Arizona. The well site will
require minimal operator interaction. Controls will be based on reservoir
level, which is affected by the demand in the system. The system will be tied
into the City’s Supervisory Control and Data Acquisition System (SCADA), which
will allow the remote monitoring, and control of the well operation.
2. O&M Plan. The City
of Nogales water system operation and maintenance program has been established
and is currently used for all wells in the system. The same procedures will be
used for the Potrero Replacement Well. Typical procedures for operation and
maintenance of wells, and other facilities in the water system, are contained
in several manuals prepared by the California State University, Sacramento,
entitled “Small Water System Operation and Maintenance” and “Water Distribution
System Operation and Maintenance.” These manuals provide the basic outline for
the operation and maintenance program followed by the City of Nogales. In order
to provide a summary of the operation and maintenance concerns and procedures
for wells in the City of Nogales water system, the following information is provided,
as outlined in the O&M manuals.
a. Start-up
Operation Plan. Chlorination and new source testing is
required per the ADEQ Engineering Bulleting No. 10. Following satisfactory
compliance with new source testing requirements, ADEQ will grant permission for
the well to be placed in service, at which time the City may begin pumping
water from the well into the water system.
b. Contingency
Plan. Numerous options are available to the City if
unforeseen circumstances affect the operation of the well site. During construction
and during normal operation of the site, onsite personnel and operators must be
aware of unusual conditions or changes in the characteristics of the well, such
as water quality, water production, and operation of the pump and motor. In the
event that there is an unexpected change in the operation of the well, the
exact procedure will depend upon the conditions, and are based primarily on the
operators knowledge of the system. The City of Nogales will respond to
emergency conditions in accordance with the City of Nogales Water Department
Emergency Operations Plan.
c. Safety
Plan. Safety issues are addressed in safety training
provided by the City of Nogales to water system personnel and are discussed
extensively in the O&M manuals. The operation safety program includes such
topics as safe work practices, driving safety, hazardous chemicals, use of
monitoring equipment and protective clothing, slips and falls, handling and
lifting, and electrical safety.
d. Quality
Assurance Plan. All operators have a responsibility to
exercise due care and diligence to protect the water sources in the system,
effectively operate and maintain the facilities, and take corrective action as
necessary to assure that safe and potable water in adequate quantity and
pressure is supplied to the community. All operators will have a working
knowledge of all component parts of the wells and completely understand the
role of each part in the operation of the well.
The well will be checked often enough to assure
that the facilities are receiving proper service, maintenance functions are
performed as needed, facility components are operating properly and capable of
producing safe water, and that the well site is secure. The site will be
inspected visually for condition and proper operation every day. When the
operator enters the well site, a complete visual inspection of the facility
will be made, including listening for any unusual noises and feeling for
vibrations on equipment.
The maintenance of proper records pertaining to
operation and maintenance is critical to the proper operation of a well site.
An operational record will be maintained for the well, and will be completed
each time the operator visits the facility either for routine service or for
other purposes. Items noted in the records will include the date and time of
the service visit, well meter reading, electric power meter reading, oil level,
amount of lineshaft oil added, greasing frequency, air level in the pressure
tank, static water level in the well, and general operation and appearance of
the facility. Some of these data will also be logged automatically by the
telemetry system, which reports directly to the main City of Nogales Water
Department computer.
3. Compliance with applicable
design norms and regulations. The well has been designed and will be constructed in accordance with all
applicable local design regulations and standards, as developed by the Arizona
Department of Environmental Quality and presented in ADEQ Engineering Bulletin
No. 10, “Guidelines for the Construction of Water Systems.
IV. Financial Feasibility and Project Management
1.
Financial
Feasibility.
BECC
prepared a financial analysis for submittal to
the NADB (see Appendix A). The financial analysis includes an evaluation of
cash flow, system revenues, debt service, and capital improvement program. As
part of the investment program, only the construction of the Potrero Well is
considered. Other projects, currently being developed as part of the Water and
Wastewater Master Plan are not being considered as part of the Capital
Improvement Program. These projects will be considered at a later date, once
those projects are proposed for BECC certification. The City of Nogales expects
to pay for the construction of the well with a NADB loan and municipal bonds.
|
Project Cost
|
|
Concept
|
Amount (US$)
|
|
|
|
Engineering and testing
|
216,800
|
|
|
|
BECC Documents
Well construction
|
25,000
629,520
|
|
|
|
Contingencies (10%)
|
87,132
|
|
|
|
Total
|
$958,452
|
|
Current Water Expenses
(Annual)
|
|
Concept
|
Amount (US$)
|
|
|
Water Office
|
1,171,203
|
|
|
|
TOTAL
|
1,171,203
|
|
|
|
|
Financial Structure
|
Source
|
Amount (US$)
|
%
|
|
NADB Value lending program
|
479,226
|
50
|
|
Municipal bonds
|
476,226
|
50
|
|
Total
|
$958,452
|
100%
|
Rate
Model: The
loan will be paid with an increase in new water connection fees. The user fees
will not be increased to service the debt of the loan for the construction of
the well. The City of Nogales is considering a rate increase to pay for other
projects in the Capital Improvement Program. The increase
for the average user will increase a total of $6.71 per month, or 31 percent.
The average water bill assumes a monthly consumption per household of 9,500
gallons per month (at $1.68 per every 1,000 gallons) and a monthly base fee of
$5.60. In the year 2006, the rates will increase an additional 2.3 percent to a
monthly average of $28.97. Currently, the average water bill is $21.60 per
month.
|
SINGLE
FAMILY RATES (US$)
|
|
|
2002
|
2003
|
2004
|
|
Average Monthly Water Bill
|
$
21.60
|
$ 28.31
|
$ 28.31
|
|
|
2005
|
2006
|
2010
|
|
Average Monthly Water Bill
|
$ 28.31
|
$ 28.97
|
$ 28.97
|
2.
Project
Management. The City has adequate personnel to handle the
proposed infrastructure and to respond to any potential emergency that might
arise during operation and maintenance of the project.
V. Public Participation
Comprehensive
Public Participation Plan. The
City of Nogales and the steering committee submitted a public participation
plan (Plan) to BECC on February 6, 2000, which was approved two days
later. The Plan described the step the
committee will take to comply with the objectives of public participation,
identify and meet with local organizations, organize an informational outreach
campaign, hold public meetings and develop and final report documenting public
support for the project.
Steering Committee: The steering
committee was formed on January 5, 2000 and included: Maria Gómez-Murphy, president; Anita Jones, Isabel Leal, Leonor
Sesteaga, Norma Cárdenas, Shirley Macias, Maria Antonieta Pérez and Gloria
Rosas, of the Way of the Heart Promotora Institute of Nogales. The committee
counted with the support and advice of Gerardo Calza,
Engineering Department City of Nogales and Kara Festa, consulting
engineer.
Local Organizations:
The steering committee contacted health groups, social and civic organizations and local churches to present the
project and solicit public support for it.
Public
Information: The certification, environmental and
engineering documents, were available for public review at the public library,
Public Works Department, and Way of the Heart Promotora Institute during and
after work hours and during the public meetings. Four 45-minute radio programs were aired with a broadcast
footprint from the border to Tucson, House to house visits were held in
neighborhoods located near the wellhead such as Meadow Hills, Vista del Cielo
and Monte Carlo, as well as in other neighborhoods in Nogales. Public meeting
notices were published in the Nogales International and a bilingual fact sheet
was developed and handed out to residents.
Public Meetings:
Two public meetings were held per BECC requirements. The first meeting was held on March 6, 2000 at the Way of the
Heart Promotora Institute – Nogales Neighborhood Center. About 50 people
attended the meeting. The second public meeting will take place on May 1st,
2002.
VI. Sustainable Development
1. Definition and Principles. The project complies with BECC’s definition of
Sustainable Development: “An economic and social development based on
the conservation and protection of the environment and the rational use of natural
resources, but considering current and future needs, as well as present and
future impacts of human activities”.
The construction of the well is centered
on providing an improved quality of life for human beings.
The project provides environmental protection
by replacing a contaminated water supply.
Stakeholders for this project include the
Public Works Department, and members of the steering committee that have been
active in the public outreach for the project.
2. Institutional and Human Capacity Building. An aspect of this project that will build
institutional capacity is the creation of reserves for any potential
emergencies.
3. Conformance with Applicable
Local/Regional Conservation and Development Plans. The project is required to comply with the
Arizona Department of Water Resources 100-year assured water supply.
4. Natural Resource Conservation. The
Meadow Hills Well No. 2 is being treated by United Musical Instruments via an
air stripping process that converts volatile organic compounds from liquid to
gaseous phase. The treated water is being used for irrigation of the Palo Duro
golf course.
5. Community Development. Without
a clean water source and an assured 100-year water supply, a number of negative
impacts to the community will continue, hindering community development.
