Border Environment Cooperation Commission
South
Central Regional Wastewater Collection and Treatment System Vado, Del Cerro, La
Mesa, San Miguel, Berino, and Chamberino Communities in
Doña Ana
County, New Mexico
1.
Type of Project.
The project consists of construction of a wastewater
collection system and wastewater treatment plant to serve six unincorporated
communities in Doña County, New Mexico.
2. Location
of Project. The
communities of Vado, Del Cerro, La Mesa, San Miguel, Berino, and Chamberino are
located approximately 13 to 18 miles south-southeast of Las Cruces, New Mexico
and 27 miles north of the U.S.
Mexico Border. The project area
begins 12 miles south of Las Cruces along Highway 128 and extends to about 10
miles south. The project will serve a
2000 population of 9,140 and a 2020 population of 17,400. It is anticipated these areas will continue
to grow at variable rates but generally consistent with the overall border area
of 4%-6% in the beginning of the planning period and reduced to 3% by the end
of the planning horizon. The following
figure Illustrates the project are, mainline connections, and treatment plant
site.
3. Description
of Project and Tasks.
All of the six communities at
present do not have any form of wastewater collection and treatment system
other than on-site disposal systems.
The on-site disposal systems include individual septic tanks with leach
fields, or cesspools.
In order to address
this lack of wastewater service, the proposed project will include providing
service to the residents through 4-inch diameter hook-ups connected directly to
each customers plumbing system. The
wastewater will be collected by a conventional gravity sewer system from all
six communities and conveyed through a forcemain located at varying distances
to the wastewater treatment plant located in approximately the center of the
planning area. The proposed wastewater
treatment system includes an activated sludge type treatment process
(sequencing batch reactor), ultraviolet disinfection to treat a volume of 1.05
mgd, which will be expanded in a second phase in the year 2009 to 2.1 mgd to
meet 2020 demands. The treated effluent
from the wastewater treatment facility will be discharged to the Rio Grande and
meet the NPDES (National Pollutant Discharge Elimination System) standards of
less the 30 mg/l of biochemical oxygen demand, 30 mg/l of total suspended
solids, 20 mg/l of nitrogen, and 500 organisms/100 ml of total coliform.
The wastewater sludge will be
transported to the solid waste landfill located west of Las Cruces after proper
treatment, which includes aerobic digestion and mechanical dewatering. Additionally, the standard per capita
wastewater flow for residential of 85 gallons per capita was used.
A summary of the
components are addressed below:
Collection
and Conveyance System:
·
301,800 lf PVC
gravity sewer line and corresponding manholes
o
93,000 lf for Vado
and Del Cerro
o
163,000 lf for La
Mesa and San Miguel
o
26,000 lf for Berino
o
19,000 lf for
Chamberino
·
20 lift stations
·
78,100 lf of 8 to
16-inch forcemains
·
2,200 hook-ups
Treatment
System (2.1 MGD)
·
Headworks with Bar
Screen and Grit Removal
·
Phase I Sequencing
Batch Reactor with a capacity of 1.05 MGD
o
2 SBR Basins
·
Phase II Sequencing
Batch Reactor with a capacity of 1.05 MGD
o
2 SBR Basins
·
Aerobic Digester
·
10 Acres of Land
Effluent
Disposal System:
·
One UV disinfections
unit
·
400 lf of 24-inch
diameter gravity discharge line to Rio Grande
Sludge
Disposal System:
·
Aerobic Digestion
with Belt Press Mechanical Dewatering
4. Compliance with international
Treaties and Agreements. The
project sponsor submitted a statement that the project complies with the rights and obligations
established in applicable treaties and agreements
1.
Human Health and Environment. Rapid, unplanned urban growth has occurred
in much of the South Central region.
Growth and construction in the area is essentially unregulated. Vado, Del Cerro, the surrounding area -
termed Vado 4, La Mesa, San Miguel, Berino, and Chamberino have been designated
as colonias by Doña Ana County. The
current poor conditions of this area are expected to get worse as the unchecked
expansion continues.
Many of the residential
lots are landlocked, and some contain five or six mobile homes on one acre. Wastewater is treated by on-site systems
including septic tanks and cesspools. The density of septic tanks and cesspools
is increasingly rapid. Field
observation indicates that some sewage is allowed to run into the ground with
no treatment.
Because of the shallow groundwater table (five to
ten feet below the surface), there exists a greater potential for groundwater
contamination. Furthermore, the high density of homes combined with a prominent
layer of poorly draining soil causes frequent surfacing of contaminated water
and is an immediate threat to public health.
Rodents and insects are attracted into the area, and children who enjoy
playing in water puddles after rainstorms can stray into contaminated water. The intent of this project is to address the
existing threat to public health and groundwater contamination, and to avoid
such threats in the future.
Hepatitis
A is a liver disease associated with unsanitary disposal of sewage and
inadequate or contaminated water supplies.
The incidence rate of Hepatitis A for Dona Ana County was 36.2 cases per
100,000 persons in 1997, which is over 79% higher than for the State of New
Mexico. The baseline value in 1994 for
Hepatitis A was 16 cases per 100,000 persons in New Mexico. In addition, the number of cases of Shigella
in Dona Ana County is 12% higher than for the rest of the State. Shigellosis often results from poor
sanitation, lack of water/wastewater facilities, contaminated water and food
and is common is colonias areas.
2. Environmental Assessment. Previously, the Facilities Plan documents prepared
for each community in 1994 were approved and Findings of No Significant Impact
(FONSI) were issued for Vado/Del Cerro, La Mesa/San Miguel, and Berino. These Facility Plans recommended wastewater
treatment plants for each community.
Regionalization of the treatment facility and relocation of the
treatment site required revision of the Facilities Plans. The New Mexico Environment Department (NMED)
and Taschek Environmental Consulting completed a new Environmental Information
Document (EID) of the new, regional treatment facility site and produced a
draft Environmental Assessment (EA) for the entire South Central Regional
system which includes all six communities of Vado, Del Cerro, La Mesa, San
Miguel, Berino, and Chamberino. This
draft EA was submitted jointly by NMED/Dona Ana County to EPA at the end of
March 2001. It is anticipated that a FONSI for the South Central Wastewater
System will be issued by early May 2001. The EA and FONSI will be available for
public review and comment through early June 2001.
3. Compliance with Environmental and Cultural Resources Law and
Regulations. As part of the environmental review, the EID
considered any and all crosscutting environmental and cultural/historical laws,
Executive Orders and regulations, including among others, Significant, Unique
or Important Farmlands, National Natural Landmarks, Wilderness Protection, Wild
and Scenic Rivers, Wetlands Protection, Floodplain Management, Fish and
Wildlife Protection, Endangered Species Protection, Historical, Architectural,
Archeological, and Cultural Sites, Air Quality, and Environmental Justice. The project is in compliance with all
applicable environmental and cultural resource laws and regulations, assuming all
future consultation, mitigation, and observance of restrictions are
followed. In the development of
environmental documentation for this project, an Archeological Survey and a
Biological Assessment were completed for the project area.
A Class III (100%) ground coverage archeological
survey was conducted in January 2000.
Only one artifact, a piece of historic glass, was recorded during the
survey. No impacts to cultural resources
are anticipated as a result of this project.
The complete archaeological report has been submitted to the State
Historic Preservation Officer for review and concurrence. In addition, the new
Section 106 regulations for Native American/Tribal consultation have been
concluded. No issues of concern were
raised by the Mescalero Apache.
A Threatened and Endangered Species Survey (TES)
was completed in January 2000. Although
a wide range of threatened and endangered species could potentially occur
within the project area, only a loggerhead shrike (a candidate for listing for threatened
status with USF&W) was observed during this field survey. The project is not expected to have any
significant impact on threatened or endangered species in the area.
1. Appropriate Technology.
In 1994, Doña Ana County through a New Mexico
Environment Department completed four wastewater facilities plans for these six
communities. At such time Vado and Del
Cerro were grouped together and La Mesa and San Miguel were as well. These facility plans recommended four
wastewater treatment plants. In 1999,
through the BECC technical assistance program, several studies were completed
which concluded that it would be more cost-effective to have regional
wastewater treatment facility that would treat all of the flow for the six communities. Additionally a study for selection of the
site was completed which included the evaluation of seven sites. Each of these studies included a planning
horizon of 20 years and completed the following alternative analysis:
·
Wastewater Collection
Alternatives: Four alternatives were
analyzed which include the small-diameter variable-slope sewers, vacuum sewer
system, pressure grinder pump system, and the selected alternative of a
conventional gravity system.
·
Wastewater Treatment
Alternatives: Five alternatives were
analyzed which include an oxidation ditch system, trickling filter system,
contact stabilization system, wetlands facility, and the selected alternative
of the activated sludge utilizing a sequencing batch reactor configuration.
·
Disinfection: Three alternatives were analyzed which
include gas chlorination, on-site generation of chlorine, and the selected
alternative of ultra-violet disinfection.
·
Effluent Disposal
Alternatives: Three effluent disposal
alternatives were analyzed which include a surface irrigation, wetlands
disposal and the selected alternative of discharge to the Rio Grande.
·
Sludge
Management: four dewatering
alternatives were analyzed which include three types of drying beds and the
selected alternative of mechanical dewatering.
·
Site for WWTP: Seven sites were analyzed.
The alternatives discussed
above were ranked based on reliability, reduction of energy use, water supply
implication, process complexity and appropriateness, environmental impacts, and
implementability. The selected
alternative and the best alternative was selected used on a combination of
these criteria, lowest initial investment and lowest operation and maintenance
cost during the planning period.
Additionally, the owner of the site for the wastewater treatment plant
is a willing seller.
2. Operation and
Maintenance Plan. New
Mexico Environment Department requires that a project plan of operation be
prepared during the construction phase as well as an O&M manual for the
lift station and wastewater treatment plant.
After approval of the manuals an operator training course will be
conducted as the facility is coming on-line.
Additionally, a monitoring period of one year is required; quarterly
project performance reports will be completed.
3. Compliance with applicable design
norms and regulations. This
project is compliance with applicable design standards and regulations, which
are required, by the New Mexico Water Quality Control Commission and NMED
Groundwater Bureau.
Financial Feasibility and Project Management
1. Financial
Feasibility.
The
project has a total project cost of
$28,421,700, which includes $3,300,000 for hookups and $1,900,200 for
expansion of the wastewater treatment plant in 2009. The following table illustrates the details of the estimated
project cost.
|
|
PROJECT AREA |
|||||||||||
ITEM |
Total Project |
Vado/ Del Cerro |
La Mesa/ San Miguel |
Berino |
Chamberino
a |
||||||||
Collection
(lf) |
301,000 |
93,000 |
163,000 |
26,000 |
19,000 |
||||||||
Conveyance
(lf) |
78,100 |
16,000 |
11,100 |
24,000 |
27,000 |
||||||||
Lift
Stations |
Aprox 20 |
7 |
Aprox 12 |
1 |
2 |
||||||||
Initial
Phase Treatment Capacity (mgd) |
|
1.05 |
Included in Vado/Del Cerro |
Included in Vado/Del Cerro |
Included in Vado/Del Cerro |
||||||||
Phase 1 Treatment Capacity
(mgd) |
|
2.1 |
|||||||||||
Planning
Phase |
|
|
|
|
|
||||||||
Facility Planning |
$547,800 |
$173,500 |
$224,300 |
$93,800 |
$56,200 |
||||||||
NMGRT@5.8125% |
$31,800 |
$10,000 |
$13,000 |
$5,500 |
$3,300 |
||||||||
Total Planning Phase |
$579,600 |
$183,500 |
$237,300 |
$99,300 |
$59,500 |
||||||||
Initial Phase (Existing Need)
- Collection, Conveyance, Treatment, and Hook-Up Construction |
|||||||||||||
Collection |
$11,138,000 |
$3,245,000 |
$4,339,000 |
$1,840,000 |
$1,714,000 |
||||||||
Conveyance (incls. Lift
Stations) |
$2,820,000 |
$250,000 |
$491,000 |
$725,000 |
$1,354,000 |
||||||||
Treatment |
$2,717,800 |
$2,717,800 |
NA |
NA |
NA |
||||||||
Total Construction |
$16,675,800 |
$6,212,800 |
$4,830,000 |
$2,565,000 |
$3,068,000 |
||||||||
Engineering/Management |
$2,467,000 |
$1,019,100 |
$555,900 |
$391,800 |
$500,200 |
||||||||
Land Acquisition |
$310,000 |
$110,000 |
$50,000 |
$70,000 |
$80,000 |
||||||||
Contingency |
$1,945,300 |
$734,600 |
$543,600 |
$302,700 |
$364,800 |
||||||||
Taxes |
$1,243,800 |
$469,400 |
$347,600 |
$193,500 |
$233,300 |
||||||||
Subtotal: |
$22,641,900 |
$8,545,500 |
$6,627,100 |
$3,523,000 |
$4,246,300 |
||||||||
Hook-Up Costs |
$3,300,000 |
$1,500,000 |
$1,140,000 |
$420,000 |
$240,000 |
||||||||
Total Initial Phase: |
$25,941,900 |
$10,045,500 |
$7,467,100 |
$3,943,000 |
$4,486,300 |
||||||||
Phase 1 - Wastewater Treatment
Plant Expansion |
|||||||||||||
Construction |
$1,500,000 |
$1,500,000 |
|
|
|
||||||||
Engineering/Management |
$150,000 |
$150,000 |
|
|
|
||||||||
Land Acquisition |
$0 |
$0 |
|
|
|
||||||||
Contingency |
$145,800 |
$145,800 |
$0 |
$0 |
$0 |
||||||||
Taxes |
$104,400 |
$104,400 |
$0 |
$0 |
$0 |
||||||||
Total Phase 1 |
$1,900,200 |
$1,900,200 |
$0 |
$0 |
$0 |
||||||||
TOTAL ALL PHASES: |
$28,421,700 |
$12,129,200 |
$7,704,400 |
$4,042,300 |
$4,545,800 |
||||||||
The project has
received $12.5M in funding from BECC for facility planning and final design and
New Mexico Environment Department through the EPA funded Colonias Program for
construction. The remaining unfunded
portion of $16.0M will be funded through a combination of BEIF, rate structure,
and loan funds. Additionally, in order
to maintain the proposed rate structure transition assistance of $838,544 is
also included. The following table summarizes the financial structure of the
project.
|
|
PROJECT
FUNDING |
|||
ITEM |
Total Project Costs |
USEPA Colonias (Grant) |
BECC TA Funds (Grant) |
NM State Revolving Loan Fund
(Loan) |
BEIF Funds (Grant) |
Planning Phase
|
|
|
|
|
|
Facility
Planning |
$579,600 |
$367,500 |
$212,100 |
$0 |
$0 |
Total
Planning Phase |
$579,600 |
$367,500 |
$212,100 |
$0 |
$0 |
Initial
Phase (Existing Need) |
|
|
|
|
|
Engineering/Management
(through bidding) |
$2,871,534 |
$2,070,534 |
$800,900 |
$0 |
$0 |
Construction,
land, contingency, and taxes |
$19,770,466 |
$9,050,566 |
$0 |
$2,800,000 |
$7,919,900 |
Subtotal |
$22,641,900 |
$11,121,100 |
$800,900 |
$2,800,000 |
$7,919,900 |
Hook-Up Construction |
$3,300,000 |
$0 |
$0 |
$0 |
$3,300,000 |
Total Initial Phase w/Hook-ups
|
$25,941,900 |
$11,121,100 |
$800,900 |
$2,800,000 |
$11,219,900 |
TOTAL (Including Planning) |
$26,521,500 |
$11,488,600 |
$1,013,000 |
$2,800,000 |
$11,219,900 |
Phase 1 WWTP Expansion |
|
|
|
|
|
Engineering/Management |
$150,000 |
To Be
Determined |
|||
Construction, contingency, taxes |
$1,750,200 |
||||
Total
Phase 1 |
$1,900,200 |
|
|
|
|
TOTAL
ALL PHASES |
$28,421,700 |
$11,488,600 |
$1,013,000 |
$2,800,000 |
$11,219,900 |
Transition Funds |
$838,544 |
$0 |
$0 |
$0 |
$838,544 |
2. Rate
Model: There are currently no wastewater facilities serving this area and
therefore no historic fee/rate schedules.
The financial model shows an initial user fee of $21.00 per residential
connection per month, billed as a fixed rate.
It is anticipated that the user fees will initiate in FY 2002. In FY 2005 the user fee will be increased to
$22.00, in FY 2007 to $23.00 and in FY 2008 to $24.00. The financial model also illustrates in each
year revenues are sufficient to offset expenses, with the cumulative total
funds from all sources building each year.
Included in the expenses is a repair/replacement line item that builds
at a rate of 10 to 20% of the total operations and maintenance expenses for
that year. The percentage increases as
the utility ages.
3 Project Management. Organizationally, the utility will be managed by
County staff and operated by one or more contract operations companies. Initially, the County utility staff will
include a Utility Administrator, Assistant Utility Administrator, Financial
Specialist, General Foreman, Utility Operations, Senior Secretary/Administrative
Assistant, Customer Service Manager, and Project Manager. Key support personnel will include field
coordinator and various field personnel.
Other support will come from personnel in various County
departments.
1. Comprehensive Public Participation Plan. The objectives of the Comprehensive Public
Participation Plan (Plan) are to ensure that the community understands and
supports the environmental, health, social, and financial benefits and costs of
the project, as well as any changes in user fees. Such Plan includes the
following elements required for certification in public participation:
development of a steering committee, meeting local organizations, development
of a public information campaign, and public meetings. The activities carried out thus far related
to this Plan are summarized below.
2. Steering Committee: Three steering committees were formed for this project. One committee
was formed for the colonias of Vado, Del Cerro, San Miguel and La Mesa. Other
committees were formed in Chamberino and Berino. This last steering committee
was reactivated from the Berino project certified in 1998. The committees participated in the
development of the public outreach campaign and public meetings. These
committees met sixteen times to follow up on the public process.
3. Local Organizations: Meetings were held with a several local organizations to present the
project and solicit support for and understanding of the project. These
organizations include: Colonias Development Council; the Vado, Mesquite, Alto
de las Flores, La Mesa, Berino, and Desert Sands Mutual Domestic
Water Consumers Associations; Berino Mutual Sewage Works Association; Anthony
Water and Sanitation District; Chamberino Water Board; Tierra del Sol; Border
Health Office; Gadsden Independent School District; La Clinica de la Familia;
International Boundary and Water Commission; Southwest Environmental Group;
Rural Community Assistance Foundation and Elephant Butte Irrigation District
4. Public
Information: Project
information, such as the Facility Plan and project fact sheets were available
in several locations throughout the colonias, such as the Mutual Domestics;
Post Offices, local Churches; Senior Centers; Health Centers; and Fire
Stations. Other outreach methods were determined by each steering committee
that included mailers, flyers, neighbor meetings, door to door notification of
the public meetings and poster signs were posted at frequently used areas.
Notices for public meetings were posted in Las Cruces Sun News, in the water
bills and local television.
5. Public Meetings: From
April 1999 to January 2001 ten public meetings were held, in addition to
County Commissioners public meetings. Several of them were held in conjunction
with NEPA required meetings. In the final public meeting that took place on
January 31, 2001 96% of those surveyed supported the project and proposed rate
structure.
1. Definition
and Principles The proposed project complies
with BECCs definition of Sustainable Development: Conservation oriented
social and economic development that emphasizes the protection and sustainable
use of resources, while addressing both current and future needs, and present
and future impact of human actions.
The project is in
general compliance with the definition as follows:
·
Social impacts are positive because the colonia properties are added to
the tax base of the area, allowing for increased social services and
improvements to schools.
·
It has a positive economic impact because it will strengthen property
values. Increased value will mean better chances for homeowners to access
credit, improve their lives, and increase their net worth.
·
It improves the impact of current human activity on the environment
while at the same time eliminating further degradation to the environment.
·
It has been developed with protections for water resources, floodplains,
cultural resources, and threatened, endangered and protected species.
·
It addresses current need for services in the rural communities outside of the
city limits, and incorporates modest historical expectations for growth. Future
growth can be managed and regulated by the county-wide wastewater utility.
Principle 1: The project is centered on the needs
of the residents of the communities of Vado, Del Cerro, La Mesa, San Miguel,
Berino and Chamberino, in Dona Ana County, New Mexico.
Principle 2: The rights of the residents to
adequately raise their standard of living and develop their properties are
recognized and underlie the reasons for undertaking the project.
Principle 3 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. This project is one of several in the southern New
Mexico region and is a component of the Countys commitment to regional
planning. This is a significant
development in the planning necessary to successfully address emerging
infrastructure needs and is a basic component of sustainable development. Dona Ana County has begun the process of
strengthening its institutional infrastructure. A significant amount of technical and managerial training and
development will be directed into the area.
Operations and personnel will receive extensive training on equipment
and environmental issues.
3. Conformance with Applicable Local/Regional
Conservation and Development Plans.
The project conforms to the
following local and regional plans:
·
Dona Ana County Comprehensive Plan, 1994
·
Dona Ana County Wastewater Facilities Plan, 1997
·
Dona Ana County Resolution 96-36, passed May 14, 1996
4. Conservation of Natural
Resources.
The project will
eliminate the inadequate on-site wastewater disposal systems currently used in
the project area as sources of potential ground and surface water
contamination. Protection of the Rio
Grande as a source of water for neighbors to the south, including El Paso, is
enhanced. The County is developing a
series of comprehensive ordinances to address statutory requirements of the
Clean Water Act and its related laws.
These ordinances have been drafted and are structured on EPA model
ordinances.
Dona Ana County participates in local and regional
water conservation programs and efforts.
The Countys leadership is committed to developing water conservation
goals and policies as part of its water management program. Reuse alternatives have been considered in
planning for all facility development.
Appropriate alternatives will be implemented to support each facilitys
capacity and water management program goals.
Also, it is recognized that legal/institutional capacities and economic
incentives must exist if water users are to significantly conserve water. Dona Ana County is committed to developing
these policies and assisting the community water providers for similar policy
development.
5.
Community Development.
Through
the development of this project and the close working relationships developed
with the community members, individuals have realized the importance of
addressing environmental issues as a community. This has fostered and strengthened the existing community groups,
empowering them to take action on their own behalf. A number of private nonprofit agencies and task forces have
banded together to advocate infrastructure development in the unincorporated
colonias areas. The Colonias
Development Council, an independent community organization of over 15
government and private agencies, has applied for a grant from the U.S.
Department of Housing and Urban Development.
By providing the integral infrastructure of sewer collection and
treatment, the planning area will appear more attractive and inexpensive for
new community services, such as schools, churches, and recreational facilities,
encouraging them to move into the area.
1. Leedshill Herkenhoff, Inc., Chamberino
Wastewater Facility Plan, Doña Ana County, New Mexico, Vol. I & II ,
October 1996
2. Molzen-Corbin & Associates, Berino and
Montana Vista Wastewater Facilities Plan Amendment to Berino Wastewater
Facility Plan, September 1998.
3. Molzen-Corbin & Associates, Berino and
Montana Vista Wastewater Facilities Plan Amendment No. 2 to Berino Wastewater
Facilities Plan, January, 2001.
4. Souder, Miller & Associates, Revised
Facility Plan &
Environmental Information Document for the La Mesa/San Miguel Wastewater
Project, October 2000.
5.
Wilson & Company,
Wastewater Collection System for Vado/Del Cerro and Wastewater Treatment Facilities
for Vado/Del Cerro/La Mesa/San Miguel, March 2000.
6.
Taschek
Environmental Consulting, Environmental Information Document for the South
Central Regional Wastewater Treatment System, Doña Ana County, New Mexico.
7.
Taschek Environmental
Consulting, Endangered Species and General Biological Survey Report, South
Central Regional Wastewater Treatment System, January 2001.
8.
Taschek Environmental
Consulting, A Cultural Resource Survey of Proposed Location for a Wastewater
Treatment Plant, Discharge Area, and Force Main Line, and a Reconnaissance of
Historic Period Buildings in the Communities of Vado/Del Cerro, Berino,
Chamberino, La Mesa, and San Miguel, Doña Ana County, New Mexico, January,
2001.