Border Environment Cooperation Commission
Wastewater Collection and Treatment System for
Salem/Ogaz, Doña Ana County, New Mexico
1. Type of Project. The project consists of construction of a
wastewater collection system and wastewater treatment plant.
2.
Location of Project. The
community of Salem is located approximately four miles northwest of the village
of Hatch in Doña Ana County, New Mexico.
Ogaz is a small subdivision immediately east of Salem. The project is located within the 100 km
border region. The 2000
population of Salem/Ogaz is approximately 1,112 people, and is expected to
reach 2,320 people by the year 2020. To
determine the population a historical growth rate of 4.0% was used and reduced
to 3% by the end of the planning horizon.
3. Description of Project and Tasks.
The community of Salem at present
does 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. Health concerns have been
expressed due to the possible failure of these disposal systems and lack of
adequate area for proper treatment through percolation. Many of these on-site systems are not
properly sized or properly constructed.
As this area continues to develop with on-site disposal systems, not
only is the biological contamination of the groundwater inevitable, but also
nitrogen contamination.
In order to address this lack of wastewater
service, the proposed project will include providing service to the residents
through 4-inch diameter sewer services connected directly to each customers
plumbing system. The wastewater will be
collected by a conventional gravity sewer system and conveyed through a
forcemain located approximately 1.25 miles away to the wastewater treatment
plant. The proposed wastewater
treatment system includes an activated sludge type treatment process (sequencing
batch reactor) at a preferred site located approximately 3/4 mile south of the
community and immediately north of the Rio Grande. 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
organismas/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 air-drying. The capacity
of the treatment facility is 200,000 gallons
per day (gpd) and will meet 2020 demands.
The standard per capita wastewater flow for residential areas of 85
gallons per day was used. Additionally,
this community is predominately residential and there are no significant
commercial, industrial, or agricultural wastewater flow anticipated.
A summary of the components are addressed below:
Collection and Conveyance System:
·
20,700 lf of 8-inch
PVC gravity sewer line
·
65 4 feet diameter
manholes
·
1 lift station
·
6,750 lf of 6
forcemain
·
278 hook-ups
Treatment System (0.2mgd):
·
Headworks with
1-manual bar screen and 1-grit removal chamber
·
2 SBR basins
·
1 aerobic digester
·
3.5 acres of land
Effluent Disposal System:
·
Post-Equalization
basin
·
2- UV disinfections
units
·
300 lf of 8-inch
gravity discharge to Rio Grande
Sludge Disposal System:
·
500 sq ft of concrete
drying beds
·
1,000 sq. ft of asphalt
staging pad
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. The community of Salem at
present does 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. Health concerns have been
expressed due to the possible failure of these disposal systems and lack of
adequate area for proper treatment through percolation. Many of these on-site systems are not
properly sized or properly constructed.
The soils in the area are generally well drained loamy sands, which have
high permeability. Due to the
development density and highly permeable soils, the potential for contamination of the shallow
groundwater is high. As this area
continues to develop with on-site disposal systems, biological and nitrogen
contamination of the groundwater is inevitable.
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: An Environmental Information Document (EID) was developed
in association with the Salem Facility Plan.
After preliminary review by BECC, Dona Ana County and the New Mexico
Environment Department (NMED), a revised EID was submitted to NMED for joint
NMED/Dona Ana County submittal to EPA.
EPA has produced an Environmental Assessment (EA)
based on the EID, the Facilities Engineering Plan, and other available
information. The EA and FONSI (Finding
of No Significant Impact) 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.
A plant and wildlife Threatened, Endangered and
Sensitive (TSE) species survey was conducted in June 2000. The survey consisted of a pedestrian survey
of the project areas. The survey
concluded that the site did not provide suitable habitat for any of the
regional listed threatened or endangered species. The proposed lift station and treatment plant sites appear to
have been or are under cultivation.
Areas where collection pipelines are to be installed have been converted
to residential use. No evidence of any
TSE plants and animals were noted.
A
cultural resource survey was conducted in July 2000. During the survey, no registered properties, standing historic buildings
and archaeological artifact were identified.
The cultural resource survey report recommended that no further culture
resources studies are necessary prior to development of the proposed wastewater
treatment site. Monitoring, however, is
recommended during installation of the wastewater collection pipelines, due to
the presence of multiple archaeological sites in the regional vicinity. Subsurface artifacts may be uncovered during
excavation, and care must be taken not to damage them. The complete cultural resource survey report
was submitted to the State Historic Preservation Office for review and
concurrence. In addition, the new
Section 106 regulations for Native American/Tribal consultation have been concluded. The Mescalero Apache raised no issues of
concern.
1.
Appropriate Technology.
A wastewater facility plan was completed in 2000
for the project through the BECC technical assistance program. The facility plan included a planning
horizon of 20 years and completed the following alternative analysis:
·
Wastewater Collection
Alternatives: Two alternatives were
analyzed which include the septic tank effluent pumping system and the selected
alternative of a conventional gravity system.
·
Wastewater Treatment
Alternatives: Four alternatives were
analyzed which include a stabilization pond system, recirculating sand filter
system, aerated facultative pond, and the selected alternative of the activated
sludge utilizing a sequencing batch reactor configuration.
·
Effluent Disposal
Alternatives: Three effluent disposal
alternatives were analyzed which include an evaporation lagoon, surface
irrigation, and the selected alternative of discharge to the Rio Grande.
·
Sludge
Management: Three alternatives were
analyzed which include accumulation at the bottom of the ponds, disposal in a
County liquid waste facility, and the selected alternative of disposal in a
County Landfill.
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 discharge permit has already been obtained and the
site secured for the plant.
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 manual, 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
in 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 is $2,889,204 which includes $417,000 for
hookups. The following table
illustrates the details of the estimated project cost.
|
Table 1. Wastewater System Components and Estimated Costs |
|
|
Wastewater System Components |
Estimated Cost |
|
Facility
Planning |
$70,703 |
|
Collection
System |
$1,257,684 |
|
20,700 ft of 8 PVC gravity sewer lines with 65-4
diameter manhole, 6,750 ft of 6 pressure lines, One lift station with 2-10 hp submersible pumps rated at
52 feet of Total Dynamic Head @ 235 gpm |
$983,000 |
|
Contingency (10%) |
$98,300 |
|
Administration and
Engineering |
$107,297 |
|
New Mexico Gross Receipt
Tax |
$69,087 |
|
Treatment System |
$901,417 |
|
Headworks with 1-manual
bar screen and 1-grit removal chamber, 2-SBR basins, each at 36x36x14;
3-positive displacement blowers @ 20 hp each; 4-25 tube retrievable fine
bubble diffuser assemblies; 2 floating mixers @ 5 hp each; 2-submersible
sludge pumps at 2 hp each, 1-aerobic digester at
36x20x14; 1-positive displacement blowers @15 hp; 1 fixed coarse bubble
diffuser; 1-floating mixer @ 5 hp and 1-submersible sludge transfer pump @ 2
hp |
$689,000 |
|
Contingency (10%) |
$68,900 |
|
Administration and
Engineering |
$94,000 |
|
New Mexico Gross Receipt
Tax |
$49,517 |
|
Effluent Disposal System |
$90,800 |
|
Post-Equalization basin,
UV disinfection unit, 8 gravity discharge to
Rio Grande, River discharge
structure, Land leasing fee |
$68,000 |
|
Contingency (10%) |
$6,800 |
|
Administration and
Engineering |
$11,000 |
|
New Mexico Gross Receipt
Tax |
$5,000 |
|
Sludge Disposal System |
$151,600 |
|
5,000 sq. ft of concrete
drying bed, 1,000 sq. ft of asphalt
staging pad, ½ yd gas engine bucket
loader with aerator attachment, ½ hp decant return pump |
$113,000 |
|
Contingency (10%) |
$11,300 |
|
Administration and
Engineering |
$19,000 |
|
New Mexico Gross Receipt
Tax |
$8,300 |
|
TOTAL CONSTRUCTION COST |
$2,472,204 |
|
Hook-Up Cost for 278 households at start-up and $1,500 per household |
$417,000 |
The project has
received $1.77M in funding from BECC for facility planning and final design,
New Mexico Environment Department through the EPA funded Colonias Program for
construction, and also a Community Development Block Grant for construction. The remaining unfunded portion of $1.1 will
be funded through a combination of BEIF and loan funds. Additionally, in order to maintain the
proposed rate structure transition assistance of $151,588 will also be provided. The following table summarizes the financial
structure of the project.
|
Financial
Structure of Salem Wastewater Facility |
||||||
|
Description |
Total Cost |
Project Funding |
||||
|
EPA/NMED Funds (Grant) |
BECC Funds (Grant) |
CDBG Funds (Grant) |
NM State Revolving Loan Fund (Loan) |
BEIF Funds (Grant) |
||
|
Planning |
$70,703 |
$0 |
$70,703 |
$0 |
$0 |
$0 |
|
Engineering/ Management |
$244,797 |
$65,500 |
$179,297 |
$0 |
$0 |
$0 |
|
Construction/ Contingency/Tax |
$2,156,704 |
$1,101,500 |
$0 |
$350,000 |
$281,850 |
$423,354 |
|
Total Cost |
$2,472,204 |
$1,167,000 |
$250,000 |
$350,000 |
$281,850 |
$423,354 |
|
Percentage
Funding of Total |
100% |
47% |
10% |
14% |
12% |
17% |
|
Hook-up
Construction |
$417,000 |
$0 |
$0 |
$0 |
$0 |
$417,000 |
|
Total Cost w/
Hook-up |
$2,889,204 |
$1,167,000 |
$250,000 |
$350,000 |
$281,850 |
$840,354 |
|
Percentage
Funding of Total |
100% |
40% |
9% |
12% |
10% |
29% |
|
Transition Fund |
$151,558 |
$0 |
$0 |
$0 |
$0 |
$151,558 |
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.
2.
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: Doña Ana
County and the Salem-Ogaz steering committee developed a public participation
plan that includes per certification requirements the development of a steering
committee, meeting local organizations, development of a public information
campaign, and public meetings.
Activities carried out in fulfillment of this plan are summarized below.
2. Steering Committee: A steering committee came out of the Salem
Organizing Project and consisted of Ruben Nuñez, Martina Rodriguez, Julieta
Gallegos, Antonio Piñeda, Eva Nuñez, and Leticia Carrasco, all residents of
Salem-Ogaz. The committee met six times to follow up on the development on the
public participation project.
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 the Colonias Development Council; Garfield Mutual
Domestic Water Consumers Association; International Boundary Water Commission;
Salem Catholic Church; El Paso Electric; State Land Office and the Elephant
Butte Irrigation District.
4. Public Information: Project information, such as the Facility Plan and Environmental
Information Document were available in
several locations such as the Colonias Development Council (Hatch, NM) and Doña
An County offices in Las Cruces, NM. Public meeting notices were published in
Las Cruces Sun News, local churchs bulletin; Post Office and Garfield Mutual
Domestic office in Salem. Fact sheets were delivered door to door by the
steering committee and mailed by Doña An County to the residents of Salem and
Ogaz.
4.
Public Meetings:
Two public meetings were held.
The first public meeting took place on January 30 and the second meeting on
April 5, 2001. Over
100 people attended these meetings. An
exit survey taken shows that 92% support the project and the 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 countywide wastewater utility.
Principle 1: The project is centered on the needs of the residents of
the communities of Salem and Ogaz 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:
o
Dona Ana County Comprehensive
Plan, 1994
o
Dona Ana County
Wastewater Facilities Plan, 1997
o
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.
Wastewater Facility
Plan Update for Community of Salem, New Mexico, prepared by Bohannan Huston
Inc., March 2001. (This document was
submitted to the Border Environment Cooperation Commission in March 2001).
2.
Environmental
Information Document Wastewater Collection and Treatment Facility Plan Update
for Community of Salem, New Mexico, prepared by Terracon, march 2001. (This document was submitted to the Border
Environment Cooperation Commission in March 2001.)