Las Delicias Water Project: Piping System Design

Report
Las Delicias,
El Salvador
Water Supply Project
Implementation Proposal Phase I
Trip Dates: May 2012
Presented to TAC: March 6, 2012
Presentation Outline
• Overview of Las Delicias Community
• Current Water Supply System and Challenges
• Proposed Improvement to Water System
– Summary of alternative analysis
– Phase I (May 2012)
• New Water Tank at Intermediate Elevation
• New Supply pipeline and distribution pipeline
– Phase II (Fall 2012)
• New pump (or VFD)
• Improvements to distribution system
• Control system improvements and pumping at night
• Logistics and Implementation
Las Delicias, El Salvador
Las Delicias
Las Delicias, El Salvador
• Community Facts
–
–
–
–
–
–
–
–
–
~600 homes, 2700 residents
15 miles NW of San Salvador
On Western Slopes of Volcan San Salvador
Homes Spread Out, but Las Delicias is
Bordered by Several Similar Communities
Water Storage & Piping System installed 20
years ago With Water Delivery by Truck
Well and Pump Installed < 5 years ago
Residents are Poor (<$10/week income)
Community Well-Organized through Adesco
and NGOs (FIAT & FIMRC)
Able to spend about $5 per household on
water each month
Project History
• Project FIAT and FIMRC have been active
in Las Delicias for > 5 years
• Initial Contact with Project FIAT (Dave H.)
January 2009
• Application to EWB-USA
March 2009
• Project Approved
May 2009
• Preliminary Assessment Visit
July 2009
• First Assessment Trip
July 2010
• Second Assessment Trip
November 2011
Map of Las Delicias Water System
DOWNHILL
Current Las Delicias Water Supply & Storage System
• Pump Runs 6 Hours a day 4
days/week  ~ 26 hr/wk.
• Pump flow rate: 175-200 GPM.
Map of current Las Delicias Water System
from ADESCO with approx house locations indicated
260 Homes Served by Tanque 3
291 Homes Served by Tanque 1
DOWNHILL
33 Homes
Served
by Tanque 2
Summary of Existing Water System
OVERALL COMMUNITY OF LAS DELICIAS
# homes =
584
430
# people =
2628
1935
Demand gal/day
65,700
48,375
OVERALL
TRAMO #
Assumptions
4.5 people/house
25 gal/day
175 gal/min
pump rate
in 2011
from 2007 map
# Homes in # Homes in Demand
2011
2007 from gallons
map
2011
1 upper
1 lower
2
2a
2b
2c
3
3a
3b
6 upper
6 lower
6a
10
11
4
5
7 upper
7 lower
8
9
9a
9b
12
Calle Prin Upper
CallePrin Lower
NewNW
NewSW
15
8
48
7
25
9
42
40
18
37
22
6
17
19
13
20
16
42
10
18
2
7
10
22
32
57
44
6
16
14
4
21
42
51
6
27
8
37
46
9
29
14
18
1
9
9
41
1688
900
5400
788
2813
1013
4725
4500
2025
4163
0
675
1913
2138
1463
2250
1800
4725
1125
2025
225
788
1125
2475
3600
6413
4950
Pipe
Diameter
inches
2
2
2
1
2
1
2
1.25
1.25
2
1
1
1.25
1
1
2
2
2
1
2
0.5
1
1
2
2
Distance Supplied
from map by Tanque
meters
# on map
311
710
546
137
421
144
140
298
160
144
492
226
130
342
90
979
429
572
362
455
125
236
232
468
377
via
1
1 1 upper
1 1 upper
12
1 2a
12
1 2 & 1 lower?
13
13
1 CallePrin Upper
1
16
1 CallePrin Upper
1 CallePrin Lower
2
2
3
3 7 upper
3 7 upper
3 7 lower
39
39
3 CallePrin Lower
3 7 lower
3 CallePrin Upper
3 CallePrin Lower
3 CallePrin Lower
CURRENT FROM TANK 1 CURRENT FROM TANK 2 CURRENT FROM TANK 3
# homes =
291 # homes =
33 # homes =
260
# people =
1310 # people =
148.5 # people =
1170
Demand gal/day 32,738 Demand gal/day
3,713 Demand gal/day 29,250
Tank Volume
35,000 Tank Volume
11,000 Tank Volume
25,000
time to fill (h)
3.33 time to fill (h)
18 time to fill (h)
2.38
from well
from spring
from well
Supplied by Tanque 1
Supplied by Tanque 2
Supplied by Tanque 3
TRAMO #
# Homes3
TRAMO #
# Homes5
TRAMO #
# Homes7
from Tank 1
from Tank 2
from Tank 3
1 upper
1 lower
2
2a
2b
2c
3
3a
3b
6 upper
6 lower
6a
10
11
15
8
48
7
25
9
42
40
18
37
0
6
17
19
04
05
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
13
20
0 7 upper
0 7 lower
0
8
0
9
0 9a
0 9b
0
12
0 Calle Prin Upper
0 CallePrin Lower
0 NewNW
0 NewSW
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
16
42
10
18
2
7
10
22
32
57
44
Challenges to Las Delicias Water Supply System
• High electric cost
– Typical ADESCO revenue from water fee
~$2300/mo
– Typical monthly cost for water system
~$2000/mo (mostly electicity ~$1500/mo)
– Pumps run about 26 hr/wk
– Not taking advantage of nightime off-peak
rates
– Power factor on pumps leads to monthly
fine of $50/month.
• Inequitable water distribution
– Some homes report receiving water
<1x/week and low flowrates
– “Valvulero” controls distribution via valves to
zones (“Tramo”) throughout community
– Large number of new homes at low
elevation
• Culture of scarcity where residents hoard
water when it is flowing
• Water Quality:
– Effectiveness of in-line chlorination is not
clear
Electric Bill
Monthly Income for Las
Delicias ADESCO
Water System Expenses
Alternatives Analysis Summary
• Drilling another well ($3500 for hydrogeological study) We
spoke with a hydrologist in country and drilling a new well
at higher elevation is considered to have low probability for
success.
• Solar power for pump (eliminated due to high cost >$50K)
• Additional tank locations (three considered – current
location on public land and co-located with current tank)
Other locations require land purchase which could be costly
and time consuming.
• VFD (variable frequency drive – possibility but must
consider approx. 10% loss in pump efficiency at lower
head)
• New pump for better efficiency at lower head.
Proposed Updates to Las Delicias
Water System
• Objectives
– Utilize existing and new tank at intermediate elevation to supply water to
lower half of Las Delicias with lower pumping head required.
– With new pump (or VFD on existing) and supply line  reduced electricity
costs due to lower head will result in more water for the community.
– Improved distribution system  more equitable water supply to all homes
(especially at lower elevations)
• Phase I (May 2012)
– New Water Tank at Intermediate Elevation
– New Supply pipeline and distribution pipeline
• Phase II (Fall 2012)
–
–
–
–
New pump (or VFD added to existing)
Improvements to distribution piping system
Improving power factor for pump via capacitors to eliminate penalty.
Enabling pumping during nighttime to take advantage of lower rates by adding
a timer circuit to the pump controller. (approx. 20% savings)
Proposed Water Distribution System
117 Homes Served
by Tanque 3
280 Homes Served
by New Tank
33 Homes
Served
by Tanque 2
154 Homes Served by Tanque 1
DOWNHILL
Modified water system
OVERALL COMMUNITY OF LAS DELICIAS
# homes =
584
430
# people =
2628
1935
Demand gal/day
65,700
48,375
OVERALL
TRAMO #
Assumptions
4.5 people/house
25 gal/day
175 gal/min
pump rate
in 2011
from 2007 map
# Homes in # Homes in Demand
2011
2007 from gallons
map
2011
1 upper
1 lower
2
2a
2b
2c
3
3a
3b
6 upper
6 lower
6a
10
11
4
5
7 upper
7 lower
8
9
9a
9b
12
Calle Prin Upper
CallePrin Lower
NewNW
NewSW
15
8
48
7
25
9
42
40
18
37
22
6
17
19
13
20
16
42
10
18
2
7
10
22
32
57
44
6
16
14
4
21
42
51
6
27
8
37
46
9
29
14
18
1
9
9
41
1688
900
5400
788
2813
1013
4725
4500
2025
4163
0
675
1913
2138
1463
2250
1800
4725
1125
2025
225
788
1125
2475
3600
6413
4950
Pipe
Diameter
inches
2
2
2
1
2
1
2
1.25
1.25
2
1
1
1.25
1
1
2
2
2
1
2
0.5
1
1
2
2
Distance Supplied
from map by Tanque
meters
# on map
311
710
546
137
421
144
140
298
160
144
492
226
130
342
90
979
429
572
362
455
125
236
232
468
377
via
1
1 1 upper
1 1 upper
12
1 2a
12
1 2 & 1 lower?
13
13
1 CallePrin Upper
1
16
1 CallePrin Upper
1 CallePrin Lower
2
2
3
3 7 upper
3 7 upper
3 7 lower
39
39
3 CallePrin Lower
3 7 lower
3 CallePrin Upper
3 CallePrin Lower
3 CallePrin Lower
PROPOSED FROM NEW TANK ADJUSTED FROM TANK 1
ADJUSTED FROM TANK 3
# homes =
280 # homes =
154 # homes =
117
# people =
1260 # people =
693 # people =
526.5
Demand gal/day
31,500 Demand gal/day
17,325 Demand gal/day
13,163
Tanks Volume
28,600 Tank Volume
35,000 Tank Volume
25,000
time to fill (h)
2.72 time to fill (h)
3.33 time to fill (h)
2.38
from well
from well
from well
WITH CONNECTION "B"
Supplied by Tanque 1
Supplied by Tanque 3
Accessi Tramo # Homes2
Tramo #2
Homes
Tramo #3
Homes2
ble?2
from
New with
B
0 1 upper
15
0
0
0 1 lower
8
0
0
0
2
48
0
0
0 2a
7
0
0
0 2b
25
0
0
0 2c
9
0
0
0
3
42
0
0
Yes
3a
40
0
0
0
0
Yes
3b
18
0
0
0
0
Yes
6 upper
37
0
0
0
0
Yes
6 lower
0
0
0
0
0
Yes
6a
6
0
0
0
0
Yes
10
17
0
0
0
0
Yes
11
19
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0 7 upper
16
0
0
0 7 lower
42
0
0
0
8
10
0
0
0
9
18
0
0
0 9a
2
0
0
0 9b
7
Yes
12
10
0
0
0
0
0
0
0 Calle Prin Upper
22
Yes
CallePrin Lower
32
0
0
0
0
Yes
NewNW
57
0
0
0
0
Yes
NewSW
44
0
0
0
0
Summary of potential changes in
water distribution system
CURRENT SYSTEM
PROPOSED MODIFICATION
• Storage
•
–
–
–
–
– Tanque 1: 35,000 gal
– Tanque 2: 11,000 gal
– Tanque 3: 25,000 gal
• Pump supplies water to
Tanques 1 & 3 at 175 gpm,
~4 days per week
• Spring supplies water to
Tanque 2 (and other tanques)
• Homes serviced by Tanques
1.
2.
3.
291
33
260
Storage
•
•
•
Tanque 1: 35,000 gal
Tanque 2: 11,000 gal
Tanque 3: 25,000 gal
New Tank (combination): 28,600 gal
Current 65 HP Pump supplies water
to Tanques 1 & 3 at 175 gpm
New 20 HP pump will supplywater
to new tank at 175 gpm with much
lower head and energy savings.
Homes serviced by Tanques
1. 154
2. 33
3. 117
New: 280
New tank reduces demand of water from Tanques 1&2
(which require high head) by roughly 50%
DOWNHILL
Exisiting
11,000
gallon tank
Map of Current Water System
(section relevant for EWB-MAP modifications)
RED lines – supply lines to tank (uphill by pump)
BLUE lines – distributions lines by gravity
A
F
D
E
DOWNHILL
B
C
Proposed update to Water System
(section relevant for EWB-MAP modifications)
RED lines – supply lines to tank (uphill by pump)
BLUE lines – distributions lines by gravity
NEW
TANK
New Tank Design – Location and
Coupling with Old Tank
Design of New Tank – 3D view of
Block/Rebar construction
Tank Design
response to J. Knight concerns
• Concrete block vs poured concrete. Block recommended
by local Structural Engineer (Daniel Rivera).
• Assumed strength of concrete (2000-3000 psi acceptable –
steel strength controls) Local Engineer accepted 3000 psi
concrete although 2000 psi concrete will work as well.
• Tank seal at base of wall – We will look into this in further
detail and will add it if necessary. We will contact seal
manufacturer and seek advice of a water engineer before
making a decision.
• Supply pipes will be connected to both tanks with shutoff
valve to each.
Design of Additional Pipelines for
A
- supplying water to tank
- distributing water
F
D
E
DOWNHILL
B
C
Proposed update to Water System
(section relevant for EWB-MAP modifications)
RED lines – supply lines to tank (uphill by pump)
BLUE lines – distributions lines by gravity
NEW
TANK
Supply Pipe 1 Pipe Profile
Elevation (m)
Road
Crossing
Profile of New Supply Pipe
656
654
652
650
648
646
644
642
640
638 A
636 638
0
NEW
TANK
Road
Crossing
C
B
Elevation:
640 m
651 m
105 m
D
643 m
640 m
240 m
m
50
655 m
100
150
200
Elevation
250
300
350
Distance from Connection to Main Supply Pipe (m)
Tee
connect
to 6”
pipe
Gate
Valve
45°
Elbow
Tee with Manual
Air release valve
Tee with Manual
drain valve
PIPE FITTINGS
90°
Elbow
with
anchor
90° Pipe
Elbow Exit
Gate
90°
Valve Elbow
Estimate of head losses in
supply pipe 1 (smooth PVC)
Item
D_pipe (in)
D_pipe (m)
A (m^2)
A (cm^2)
V (m/s)
Re
f
h_L major (m)
h_L minor (m)
h_L major (% of z)
h_L minor (% of z)
1"
1-1/4"
1-1/2"
2"
2-1/2"
3"
3-1/2"
4"
1.029
1.36
1.59
2.047
2.445
3.042
3.521
3.998
0.026
0.035
0.040
0.052
0.062
0.077
0.089
0.102
5.37E-04 9.37E-04 1.28E-03 2.12E-03 3.03E-03 4.69E-03 6.28E-03 8.10E-03
5.37
9.37
12.81
21.23
30.29
46.89
62.82
80.99
20.50
11.74
8.59
5.18
3.63
2.35
1.75
1.36
5.36E+05 4.05E+05 3.47E+05 2.69E+05 2.26E+05 1.81E+05 1.57E+05 1.38E+05
0.0117
0.0125
0.0130
0.0139
0.0145
0.0153
0.0159
0.0164
3593.8
955.5
267.7
87.7
4667.3% 1240.9%
347.6% 113.9%
454.9
47.0
590.8%
61.0%
137.0
17.1
177.9%
22.2%
58.9
8.4
76.5%
10.9%
20.9
3.5
27.1%
4.6%
10.4
2.0
13.5%
2.5%
5.7
1.2
7.4%
1.5%
4” PVC sufficient to keep major and minor losses to <10% of the
elevation change
Supply Pipe 1 Trenching
• Based on recommendations from EWB Water Resource Guidelines
and advice from Tony Sauder:
– 70 cm trench depth (45 cm depth acceptable except in road crossing) with
pipe buried below 50 cm
– 10 cm bedding (2-12 mm soil) if stones/rocks present in trench
– Back-fill with soil that is free of lumps, from stones (>3 cm), and from
organic matter
– PVC pipe joined in trench and cure for >10 hr prior to pressurizing. Keep
joints exposed to check for leaks. Expansion joints not necessary
– For road crossing, may bury PVC pipe inside steel or concrete pipe (ID >
diameter of PVC joints); final decision to be made in the field after
evaluating potential for erosion
50 cm
10 cm
10 cm
bedding
70 cm
trench depth
Valve
Boxes
• Design options
– Obtain pre-cast valve boxes with lockable lids locally
– Build from bricks and mortar with metal lids
• Specifications
–
–
–
–
4” Pipe centered about 55 cm below ground level
Box should extend 10 cm above ground level
Internal dimensions roughly 45cmx45cm
Place support under valve
Photos of current valve boxes installed in Las Delicias
Valve Box Design
Drawing of valve boxes to be constructed at Las Delicias
Thrust Anchors for
Elbows &Tees
From Russ Turner, Tetratech
Summary of May 2012 Implementation
Keys to Success:
• Success assured by working closely with:
– Local community providing excavating equipment, funds, land
and labor.
– Local Rotary Club and Structural Engineer Daniel Rivera
providing funds, logistics and expertise.
– NGO – Project FIAT helping with funds, logistics and volunteers
as well as arranging for a cement mixer. FIAT has vast
experience doing these types of projects in El Salvador.
– The Honorary Consul of El Salvador in Philadelphia is working
with one of our members (Paolo) to help coordinate the project
with the local Mayors office. She has also informed us that she
will arrange to allow us to ship components (such as pumps) to
the country tax and duty free.
– NGO - FIMRC providing local health related services to the
community and EWB by helping us define objectives and
measure results.
Summary of Finances for
Implementation
• Local community provides excavation equipment, land, material
transportation and field labor (assume avg. 4 people, 8 hrs/day for
duration of project)
• Chapter currently has about $28,500 available for this project including.
– $15,000 Rotary Grant (must be used by September – specifically earmarked for tank)
– $8,000 from Project FIAT
– $5,500 in chapter funds
• Costs are estimated at about $27,000 including:
– Tank estimate - $12,500
– Piping estimate - $10,500
– Transportation estimate $4,000
– We plan to raise additional funds to cover gap costs between now
and May. We will delay piping if funds prohibit completion until the
Fall.
Logistics and Implementation Plan
• Engineer – Daniel Rivera of Local Rotary in San Salvador will
coordinate with local government, obtain building permit, help
organize material delivery and oversee installation through periodic
visits.
• Project FIAT volunteers will coordinate with local community,
organize material deliveries, hire an albañil, provide secure space
for materials, provide cement mixer, supply working volunteers and
provide lodging and transportation for EWB volunteers.
• Local community will provide land, excavating equipment and labor
as well as help in transporting materials to site.
• EWB volunteers will provide supervision, project management and
labor. EWB volunteers will cover entire 5 week installation.
Schedule for Implementation
Contingency Plans (worst case
scenarios) for Implementation
• Project can proceed even if EWB members are
not present every day.
• Control runoff and use tarps if heavy rains
become problematic.
Material Procurement
• Project Fiat has executed many similar projects. They know exactly
where the type of materials used on this project can be obtained
locally. Project FIAT will provide a locked building close to the tank
site where materials can be securely stored.
• All material will be sourced locally. All materials are common
everyday building materials.
• Daniel Rivera has reviewed the material list and did not have any
issues with our selections. (He did recommend using grade 40
rebar instead of 60 and we followed his recommendation)
• The area near the village includes heavy industry and business
enterprise and the community is only 15 miles from a major city.
We foresee no major issues sourcing materials.
Plans for Phase II Implementation
(Fall 2012)
• Install new pump (or VFD)
• Install Power Factor Correction Capacitors
• Install Timer Circuit to allow Night time
Operation
• Install additional distribution pipes.
Metrics
• Increase water supply by ~40% without
increasing operating cost
• Increase in % of homes receiving sufficient
water (at least 2x per week)
Concluding Remarks
• Project is sustainable through community involvement and
use of:
– Locally available materials
– Standard construction techniques typical to the area.
– Adding to existing water system infrastructure using
identical technologies. O&M will be the same as they are
doing now.
– The community already has people in place to operate and
maintain the water system.
• Community will benefit through better distribution and more
abundant supply with no increase in operating cost.

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