Work Plan for the Implementation of
Water Supply and Hydroelectric Power Generation System, Finca Manhattan, Cabo
Matapalo, Costa Rica
By:
Osa Water Works, S.A.
January
29, 2002
A hydrological resources report describing recommended installations for
Finca Manhattan was presented on January 13, 2002.
A second report detailing water quality was presented on January 19,
2002. This final engineering work
plan contains a description of the proposed installations, time frames for the
completion of project components, and line-item costs of the different project
elements.
Hydroelectric
Power Generation System.
The seasonal hydroelectric power generation system under proposal is to
consist of the following components: 1)
two coffer dams; 2) two
infiltration galleries; 3) 3” and
4” Schedule 80 PVC hydro pipeline; 4) air evacuation valves as needed; 5)
ball-valve controls; 6) Harris DC Pelton wheel with electrical couplings
integrated into a service electric systems to be located in the power systems
bodega, described below. A conceptual diagram showing piping run distances and other
relevant system information is given in Figure 1.
Power
Systems Bodega
A
steel-reinforced, soundproof concrete block structure measuring 4 meters by 9
meters will be constructed to house all of the electrical power systems.
A floor plan of this power systems bodega is shown in Figure 2.
This bodega will be compartmented into four rooms.
The Pelton room will house the Pelton wheel assembly and valving and
discharge water directly back into the stream.
The generator room will house the new 12 kW natural gas generator already
on site as well as the reconditioned 10 kW diesel generator previously used for
Bahía Esmeralda power generation needs. The
battery room will contain the batteries used by the hydro and solar power
generation systems. The control
room will contain 4 Trace inverters, 2 of which are already on site, and the
necessary switching and safety systems. A
1.5 meter rollup door will be deployed as a service entrance, opening into the
Generator Room. The main entrance,
a conventional steel door, will open into the Control Room.
The array of 16 solar panels with two passive tracker units will be
mounted on the roof of the structure.
Integrated
Water Supply.
The potable water supply system will include four project elements:
1) remodeling of the spring
water intake to exclude river water; 2)
1” pipeline from the Bahía distribution tank to the 35,000 gallon tank at
Casa Verde; 3)
replacement of Bahía polyethylene piping with 1” PVC pipeline; 4)
Installation of a water filtration system for Casa Verde.
The potable water for Bahia Esmeralda and the cuidador houses will be
derived from the sealed spring box to be installed.
A full water quality analysis of this spring water will be performed in
order to determine if water purification will be required to ensure potability.
We anticipate that this spring source will be fully potable and not
require any treatment. However, if
this is not the case, a filtration system would need to be designed and
implemented at a later date.
The
filtration system (10-15 gallon per minute) will consist of the following
modules: 1) a primary
filter for the removal of large suspended sediment;
2) ultraviolet bacterial disinfection unit; 3) secondary particulate filtration; and 4) granular activated carbon filter for the removal of
organic compounds. This will ensure
high-purity drinking water for Casa Verde and both satellite houses.
Irrigation
water will be supplied by the 35,000 gallon water tank located at Casa Verde. It will derive water from three sources:
1) rain water capture;
2) the spring;
and 3) the lower well. Project
elements associated with supplying the tank with well water include 1) the
deployment of a submersible pump; 2)
1” PVC pipeline from the lower well to the storage tank; and 3) a 2” main
pipeline running from Casa Verde to the Matapalo road.
This irrigation system will deliver high water pressure for excellent
sprinkler irrigation throughout the property.
Wiring
A conceptual diagram of the wiring network is given in Figure 3
This wiring network is necessary to supply AC power to Casa Verde, Bahía
Esmeralda, and the well house. Additional
wiring is included to enable a float-switch activated control of the well pump
for full automation. This
electrical wiring system is engineered for the highest performance, given the
versatility of the power systems bodega’s three separate energy sources.
Time Frame
Project elements are shown in Table 1 below with the time frames for
completion of each project element shown.
Work can begin upon receipt of a deposit.
Table 1. Time
frame for the completion of project elements.
X=Work Crews; O=OWW
Budget
Costs associated with the project elements are shown in Table 2.
The bid for the entire project is $71,200.
This includes the cost of demolition of existing water tank and removal
of debris. In the event the
decision is made not to remove the existing tank, then a deduction of $2,000
will be made from the overall bid.
Table
2. Line
Item Costs of Project Elements
A deposit of $65,000 will be required to begin construction.
This includes the cost of the water quality, engineering and design
completed, the cost of all materials, half of the labor contract, and half of
the OWW installation and oversight fee. The
balance of $6,200 will be due upon completion of the project and final smoke
testing.
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