Border
Environment Cooperation Commission
Construction of the
Wastewater System for El Paso County Tornillo Water Improvement District
(EPCTWID)
(Tornillo, Texas)
Human
Health and the Environment
Technical Feasibility and Project Management
1. Type of Project. The proposed project falls under the BECC priority area of wastewater
treatment. The community of Tornillo
does not have sanitary sewer service. Sewage
is disposed using various onsite systems.
Many of these on-site systems are substandard and failing. This project will provide wastewater
collection and treatment facilities for the community of Tornillo. The EPCTWID (Tornillo District) is the project
sponsor.
2. Location of Project. The project is located in the unincorporated community of Tornillo,
Texas approximately 32 miles southeast of the City of El Paso approximately 2
miles north of the Rio Grande River.
The proposed project is within the 62-mile limit from the border that
the BECC requires for certification of a project.
Tornillo
3.
Description of Project and Tasks.
Background - The EPCTWIDs wastewater
facility plan was originally developed in 1996 as a Phase I Study under Texas
Water Development Boards (TWDB) Economically Distressed Areas Program
(EDAP). The plan provided for
wastewater collection and treatment facilities to serve the older, more densely
developed area of Tornillo. The plan
was amended twice in 2000 to provide a more effective system and extend the
population and flow projections to the year 2020.
In
early 2001, the former directors of the utility, the Tornillo Water Supply
Corporation, requested assistance from the BECC to amend the facility plan to
include eight adjacent, EDAP ineligible areas and to certify the overall
project for future financing by the North American Development Bank
(NADB). The current design project is a
joint TWDB and BECC funded effort.
Construction funding support is proposed to be proportioned between TWDB
and the NADB based on the portion of total flow generated from EDAP eligible
areas and from the EDAP ineligible areas, respectively.
Original and Expanded Project Area
-
The original project area is centered on the older, developed areas of the
Tornillo; i.e., areas that are EDAP eligible.
The expanded areas include seven platted and partially developed subdivisions,
and one centrally located un-platted/undeveloped area that is a candidate for
future development.
Population Projections - Table 1 shows the population projections for the project. All of the new subdivisions are projected to attain build-out by about 2010. This is shown graphically in the table where shading indicates build-out population in particular years.
Table 1: Population Projections
Areas / Subdivisions |
Occupied Lots |
Population |
||||
2001 |
2005 |
2010 |
2015 |
2020 |
||
Original Project, Adjusted 1 |
--- |
1,540 |
1,828 |
2,241 |
2,657 |
3,4892 |
Expanded Areas: |
||||||
Drake No.
2 |
50 |
200 |
216 |
216 |
216 |
216 |
Drake No.
3 |
6 |
24 |
27 |
32 |
32 |
32 |
Drake No.
4 |
49 |
196 |
223 |
232 |
232 |
232 |
Drake No.
5 |
97 |
388 |
441 |
508 |
508 |
508 |
Drake No.
6 |
72 |
288 |
328 |
364 |
364 |
364 |
Drake No.
7 |
68 |
272 |
309 |
363 |
364 |
364 |
Ranchitos
Arco Iris |
67 |
268 |
305 |
352 |
352 |
352 |
Proposed Subdivision |
|
|
575 |
676 |
794 |
932 |
TOTALS |
409 |
3,176 |
4,252 |
4,984 |
5,519 |
6,4892 |
1 Population projection adjusted
to reflect current population served by EPCTWID water system
2 Basis of design projections
Flow Projections - Table 2 shows current and projected wastewater flows for the overall system. The average daily flow rate for this system is based on an average per capita wastewater production rate of 91.2 gpcd and four people per household. The system is designed to pass peak flows that are four times the average daily flow rate. The treatment plant peaking factor of 4 is equivalent to the 2-hour peak flow adjustment used in the 1996 Facility Plan and is consistent with the collection system peaking factor.
Table 2 Projected
Wastewater Flows
Flow Parameter |
2001 (MGD) |
2005 (MGD) |
2010 (MGD) |
2015 (MGD) |
2020 (MGD) |
Average Daily Flow (MGD) |
0.29 |
0.40 |
0.46 |
0.51 |
0.59 |
Treatment Plant Design Flow (MGD); PF = 1.24 |
0.36 |
0.49 |
0.57 |
0.63 |
0.73 |
Peak Flow (MGD); PF = 4 |
1.17 |
1.58 |
1.85 |
2.03 |
2.37 |
MGD= Million Gallons per Day
Proposed Collection System
Improvements- The proposed wastewater
collection system is designed to serve both the original and expanded project
areas. It consists of 78,087 LF of
gravity sewer ranging from 6 to 18-inches in diameter, 500 LF of 12-inch
diameter force main, 239 manholes, and one 1,650-gpm-sewage lift station.
Proposed Wastewater
Treatment Plant- The proposed wastewater treatment plant is a 734,000 gpd
capacity, extended aeration, oxidation ditch type based treatment system
located at the intersection of Henderson Road and Tornillo Drain. The facility consists of an influent pump
station, screenings and grit removal, an extended aeration facility (oxidation
ditch type), a secondary clarifier, chlorination facilities, sludge dying beds,
and a 200 ft. outfall line to Tornillo Drain.
The project is planned for completion in 2005. Based on population and flow projections, in 2005 approximately 43 percent of the flow will be generated from the EDAP eligible area of the project and 57 percent from EDAP ineligible areas.
4. Compliance with international Treaties and Agreements. The implementation of this project will comply with all the current International Treaties and Agreements between the United States of America and Mexico that are related to environmental problems along the international border.
II.
Human Health and the Environment
1. Human Health and Environment. Diseases generally associated with developing countries have been problematic in colonia communities on the U.S. side of the Texas/Mexico border due to poor health care and groundwater contamination. Human health is impacted by environmental infrastructure deficiencies. Municipal water and wastewater systems are typically limited, being undersized and sub-standard in these border communities. This contributes to high rates of disease in the border region. Texas counties bordering Mexico have waterborne disease rates often two to three times greater than the statewide average.
Many of the existing sewage
disposal systems in the unincorporated community of Tornillo do not comply with
the El Paso County requirements for construction and operation of on-site
sewage systems. Over 80% of septic
tanks in the area are currently not registered with the county, according to a
Tornillo District representative. These
regulations prohibit use of septic tank systems on lots of less than one-half
acre in size.
Many of the homes in the
older areas of Tornillo use cesspools, constructed of a cinder block or
brick. A small percentage of homes
dispose wastes directly onto the ground or into irrigation canals. Any of the systems relying on soil absorption
will continually fail due to the characteristics of the soil that do not favor
such activity. High groundwater table
in some of the project areas accentuate the shortage of absorption capacity. Ponding of effluent in yards and alleys can
be a common occurrence. These practices
contribute to groundwater and surface water contamination.
The
proposed wastewater collection and treatment system will provide a modern,
centralized, compliant resource for the communitys sewage disposal. In properly handling wastes, issues
resulting from substandard on-site systems, such as surface ponding and direct
discharge into waterways, will be eliminated.
After-effects such as illness from water-borne diseases and groundwater
and soil contamination will be prevented.
2. Environmental Assessment: The original Environmental Information Document was prepared in December 1997 by Blanton and Associates, Inc., Hicks and Company and Michael Sullivan and Associates, Inc. consultants. It was revised in early 2001 to include the expanded area. This assessment concludes that there are no negative long-term impacts expected as a result of this project. EPA issued a Finding of No significant Impact (FNSI) on December 26, 2001, and the NEPA process has concluded.
An
evaluation of environmental impacts associated with the revised wastewater
improvements determined that environmental impacts would be minimal and
consistent with impacts of the 1997 Project, provided that mitigate measures
regarding erosion control during and after construction are followed.
The
majority of the pipeline work associated with the proposed projects will be
placed within the existing right-of-way of dedicated public streets and
irrigation canals. No significant
landform alterations are expected to be necessary for the construction of the
proposed collection system. No soils
classified as Prime Farmlands occur within the proposed project area.
3. Compliance with Environmental and Cultural Resources Law and
Regulations. The planning and design of the proposed wastewater
collection and treatment system comply with all applicable environmental and
cultural laws and regulations. The new
wastewater collection system will meet TNRCC and EPAs regulations.
1.
Appropriate Technology. The Tornillo wastewater facility plan was originally developed in
1996 for the project through TWDB funds.
The facility plan included a planning horizon of 20 years and included
modeling of the proposed wastewater system for average demands and peak demands
to determine the appropriate phasing of the proposed infrastructure for the
immediate needs, 2010 needs, and 2020 needs.
The average per capita residential production used was 91.2 gpd for
wastewater. The facility plan also
contained various alternative analyses whereby the selected alternative was the
most cost effective and provided ease of operation. The following summarizes
the alternative analyses:
Wastewater Treatment System
Wastewater Collection
§
Minimum gravity sewer line size shall be 6 inches
in diameter.
§
Sewers shall be designed and constructed with
sufficient slope to give a velocity when flowing full of no less than 2 feet
per second (fps) and no greater than 10 fps.
§
The minimum Mannings n factor for design of
sewer lines shall be 0.013.
§
Sewer lines shall be laid at grades within the
minimum and maximum slope criteria delineated in the TAC.
§
Minimum cover for gravity sewer lines and force
mains is 5 feet.
§
Sewer
force mains shall be designed and constructed so that flow velocities range
between 3 and 5 feet per second at lift station firm pumping capacity.
Hydraulic Analysis. The system is designed to pass peak flows that are four times the
average daily flow rate. The average
daily flow rate for this system is based on an average per capita wastewater
production rate of 91.2 gpcd and four people per household. Wastewater contributions are primarily
residential but also include schools, and limited light industrial and
commercial. Current and projected
wastewater flows for the overall system are shown below. The year 2020 flows are the basis for the
plant design, as illustrated in the Facility
Plan Amendment No. 3, PSC, May 2002.
Wastewater
Treatment. Tornillo currently does not have a wastewater treatment system. Individual
on-site facilities serve as the only means of treatment. The proposed plant is
a 734,000 gpd, extended aeration, oxidation ditch based wastewater treatment
plant located at the intersection of Henderson Road and Tornillo Drain. The facility consists of an influent pump
station, screenings and grit removal, an oxidation ditch, a secondary
clarifier, chlorination facilities, sludge dying beds, and a 200 ft. outfall
line to Tornillo Drain.
Design Flows/Characteristics. Table 3-3 lists the population and influent flow and load projections that serve as the basis for design for the WWTP. The plant and its unit processes are to be designed to treat a 2020 projected design flow of 0.73 MGD and to hydraulically process a 2020 projected 2-hour peak flow of 2.37 MGD.
Table 3-3. Flow Characteristics
Design Year |
2020 |
Population |
6,489 |
Average
Daily Flow, MGD |
0.59 |
30-d
Wet Weather Flow, MGD 1 |
0.73 |
2-Hour
Peak Flow, MGD 2 |
2.37 |
BOD5,
mg/L 3 |
200 |
BOD5,
lb/d |
990 |
TSS,
mg/L 3 |
200 |
TSS,
lb/d |
990 |
System
Description. The collection system consists of 78,087 feet
of gravity sewer ranging from 6 to 18-inches in diameter, 500 feet of 12-inch
diameter force main, 239 manholes, and one 1,650 gpm sewage lift station.
Three main interceptors
(labeled Interceptors I, II, and III) serve the system.
§
Interceptor
I conveys the flow from the northwest part of the planning area including Drake
Subdivision Units 5, 6, and 7 as well as the partially developed 58 acre tract
near the intersection of Henderson Rd. and the Alamo Alto Drain.
§
Interceptor
II conveys the flow from Drake Subdivision Unit 4 in the northeast part of the
project area down the existing facility plan line in Highland Street to
Interceptor III at O.T. Smith Rd.
§
Interceptor
III transmits flow from Drake Subdivision Units 1, 2, and 3 via residential
streets in the north central part of the project area, to O.T. Smith Rd., and
to the lift
station on Henderson Rd. The downstream reaches of Interceptors I and III carry the
incremental flows from the EDAP eligible areas.
§
The
lift station lifts the total flow to a gravity sewer line located south of
Tornillo Canal on Henderson Rd. This
line carries these flows to the WWTP at Henderson Rd. and Tornillo Drain.
§
Sewer
depths range from five feet at upstream manholes to 24.5 feet at Alamo Alto
Drain and Tornillo Canal.
2. Operation and Maintenance Plan. The Tornilllo District will get a comprehensive Operation and
Maintenance Plan. The contractor for
the wastewater treatment plant project will be required to provide an operations
manual and training associated with the equipment.
3. Compliance with applicable design norms and regulations. This project complies with
applicable design standards and regulations that are required by the state of
Texas and County of El Paso.
IV. Financial Feasibility and Project Management
1. Financial Feasibility.
The project has a total project cost is $12,743,402. The following table illustrates the details of the estimated project cost.
Project Cost Summary
Item |
Total Project |
EDAP
Eligible |
EDAP
Ineligible |
Construction |
|
|
|
Wastewater Collection System |
$8,234,330 |
$3,540,762 |
$4,693,568 |
Wastewater Treatment Plant |
$3,066,802 |
$1,304,580 |
$1,762,222 |
Sub-Total Construction |
$11,301,132 |
$4,845,442 |
$6,455,790 |
Land and Easement Acquisition |
|
|
|
Crossing Permit Acquisition |
$3,000 |
$3,000 |
$0 |
Land for Lift Station |
$9,960 |
$9,960 |
$0 |
Land for WWTP |
$105,000 |
$105,000 |
$0 |
Sub-Total Land and Easement |
$117,960 |
$117,960 |
$0 |
Engineering and Administration |
|
|
|
Design Phase Services |
$779,300 |
$335,099 |
$444,201 |
Construction Inspection & Legal |
$436,780 |
$187,815 |
$248,965 |
Management & Administration |
$108,130 |
$46,496 |
$61,634 |
Sub-Total Engineering Services |
$1,324,210 |
$569,410 |
$754,800 |
GRAND TOTAL |
$12,743,402 |
$5,532,812 |
$7,210,590 |
The following
table summarizes the financial structure of the project.
Source |
Amount |
BEIF-NADB (Grant) |
$5,255,441 |
TWDB (Grant) |
$5,334,961 |
TWDB (Loan) |
$164,000 |
NADB Loan (Low Interest) |
$1,500,000 |
BECC (Grant) |
$489,000 |
Total |
$12,743,402 |
Additionally, Transition
Assistance from the BEIF program is included to allow for the gradual increase
in the rates. The Transition Assistance
is not a project cost and therefore is not listed in the above financial
structure.
Source |
Amount |
Transition Assistance (BEIF Grant) |
$425,621 |
2. Rate Model:
The
average monthly rate for water is $26.0.
A starting rate of about $48.00, for the combined water and sewer rate, will
be needed for the project. In order to increase the rate in a gradual manner
transition assistance from the BEIF program is needed in the amount of $425,621
over a seven year period to reach a combined rate of $62.00.
3. Project Management. The existing organizational structure of a General Manager, an
Operations Department, and an Administrative Department will be increased by
two new employees to operate the proposed expanded infrastructure.
1. Comprehensive Public Participation
Plan: The
Tornillo Water Supply Corporation and the project steering committee submitted
a public participation plan to the BECC on October 14th and approved
by BECC on October 15th, 2001. The plan comprises the development of
a steering committee, meeting local organizations, providing project
information to the public, holding public meetings and submitting a final
report for the project. Activities
carried out in fulfillment of the plan are presented below.
2. Steering Committee: The committee is formed with: Estela Pacheco,
President; Edis Delgado, resident; Norma Morales, resident; Sebastian
Hernandez, resident; and Ofelia Bosquez and Jose Rodriguez of the Tornillo
Independent School District; and Laurencio Bosquez, business owner
3. Local Organizations: Organizations and groups
contacted include the Tornillo Independent School District; local churches;
County Commissioner; the Volunteer Fire Department; Wenchos Gas and Food Mart;
Lupitas Grocery Store; Tornillo Trading Post; Flamingos Dance Hall; San Jose
Bakery; Tornillo Parent Teacher Organization; Guitierrez Septic Tank; Elias
Welding Shop; Gardeas Well Service; Archuletas Farm Equipment; Tornillo
Dollar Store and Marias Beauty Shop. Javier Escalante, Tornillo Water Supply
Corporation; Francelia Vega, technical secretary; Mike Pink and Horacio Juárez,
engineering consultants form the technical work group.
4. Public Information: The Facility Plan was available at the Tornillo
Water Supply Corporation offices and at Wenchos Gas and Food Mart after hours.
Immediately prior to the first public meeting, door-to-door visits were carried
out by steering committee and the volunteer fire department to deliver
bilingual fact sheets and carry out a survey. Public meeting notices were also
sent via the water bill to all customers and followed up via phone calls.
During these visits 137 surveys were completed resulting in 129 supporting the
proposed project and 4 against with 4 no answers. The public meeting notices were
also posted in El Paso Times and The Courier, a local newspaper.
5. Public Meetings: The first public meeting
was held on November 15, 2001 at the High School. Approximately 200 people were
present. The second public meeting was held on July 25,2002 at the local High
School. Approximately 110 people attended the meeting. Survey results at the
meeting showed 106 in support of the rate increase and3 against.
1. Definition and Principles
Principle 1: The project will improve the quality of life for residents of the Town of
Tornillo by providing safe, desirable wastewater collection and treatment for current and future residents.
Principle 2: The proposed project includes changes to the system that would insure the protection of human health and the environment with population changes projected through the year 2020. Development in the Town of Tornillo will be hindered without implementation of the proposed wastewater system, putting the socioeconomic well-being of the community, already poor, at further risk. The existing wastewater infrastructure of on-site systems is not safe and can not sustain the projected population increase.
Principle 3: An Environmental Information Document was prepared documenting the development of alternatives and which included the consideration and analysis of environmental issues. Environmental protection is integral to the project.
Principle 4: Stakeholders have been involved and have had the opportunity to participate in the decision-making process. This not only includes the local residents, but also local, regional, state, and federal agencies with statutory interest and standing in the issues at hand.
2. Institutional and Human Capacity
Building.
The Tornillo District currently does have the basic institutional and human capacity to operate and maintain the proposed improvements. However, it will need an additional two employees to operate the proposed improvements.
· The District will be upgrading its existing operation and maintenance plan, and the safety and contingency plan to include the new facilities.
· The District has also implemented a plan to encourage the current employees to seek the highest level certification possible.
· The Districts Board of Directors have set the goal for all operators to obtain a minimum Class C license.
· The Districts Board of Directors has approved monetary incentives and will pay all expenses for employees to attend seminars and courses out of town to obtain certification.
3. Conformance with Applicable Local/Regional Conservation and Development
Plans.
The project is in conformance with the State Implementation Plan (SIP) for the County of El Paso, with Section 208 of the Clean Water Act of 1977, and with the Water Quality Management Plan developed by the Texas Water Development Board, the TNRCC and the Rio Grande Council of Governments.
4. Conservation of Natural Resources.
The proposed wastewater system will result in natural resource protection and conservation of water resources. Contamination of groundwater and soil will be prevented through centralized control of operations and maintenance for the community sewage disposal system. Additionally, controlled discharge of treated wastewater will contribute water volume to irrigation sources that was formerly lost in the form of evaporation and/or percolation.
5. Community Development.
The implementation of this project is crucial for community development. A wastewater collection and treatment system is important for the safe existence of current and future population.
The County of El Paso is planning to expand the nearby existing Fabens International Port of Entry from two lanes to four, more than doubling the width of the bridge from 60 feet to 150 feet. Without the proposed improvements to the wastewater system, the projected economic development from the expansion of the bridge may not occur, because new businesses will be unable to locate within the boundaries of the Tornillo District.