A Rainwater Harvesting and Treatment System for Domestic Use and Human Consumption in Native Communities in Amazonas (NW Peru): Technical and Economic Validation
Table 8
Installation costs of concrete-based rainwater harvesting systems versus a cheaper wood-based alternative in native areas.
Aspects
Quantity
Unit
Unitary price
Tank support
Reinforced concrete support (S/) estimated in total prices
Local alternative (wooden board) estimated in total prices
Cost of land
1
Global
84.00
84.00
Cost of transport
1
Global
1,200.00
600.00
Cost of installation local labour
1 operator from outside the locality
10
day
110
1,100.00
0.00
1 officer from outside the locality
10
day
80
800.00
0.00
1 community labourer
10
day
40
400.00
0.00
1 carpenter from outside the community
13
day
110
0.00
1,430.00
2 community labourers
13
day
80
0.00
1,040.00
Cost of hardware materials (for concrete base vs. common wood alternative in native areas)
1/8-inch thick galvanised metal platen supports
38
Unit
6.8
258.40
258.40
Self-drilling fastening bolts for gutters, hexagonal head
76
Unit
0.6
45.60
45.60
PVC catchment funnel
4
Unit
25
100.00
100.00
PVC pipe, 4 inches
4
Unit
20
80.00
80.00
4 inch × 90 degree PVC elbows
16
Unit
6
96.00
96.00
Codos de PVC 4 × 2 pulgadas, con ventilación
4
Unit
6
24.00
24.00
2-inch PVC plug
4
Unit
2
8.00
8.00
Reduction from 4- to 3-inch PVC
4
Unit
6
24.00
24.00
2 inch × 90 degree PVC elbows
8
Unit
4
32.00
32.00
PVC pipe, 2 inches
8
Unit
13
104.00
104.00
PVC tee, 2 inches
4
Unit
5
20.00
20.00
PVC ventilation cap, 2 inches
4
Unit
5
20.00
20.00
3/4-inch PVC ball valve
4
Unit
15
60.00
60.00
PVC union with 3/4 inch thread
4
Unit
3
12.00
12.00
PVC reduction, 3/4 to 1/2 inch
4
Unit
1.5
6.00
6.00
PVC adapters, 3/4 inch
16
Unit
1.5
24.00
24.00
PVC pipe, 1/2 inch
4
Unit
10
40.00
40.00
3/4-inch PVC pipe
2
Unit
12
24.00
24.00
Mixed PVC joint (thread and spigot), 1/2 inch
4
Unit
2.5
10.00
10.00
1/2-inch PVC spigot union
8
Unit
1.5
12.00
12.00
1/2 inch × 90 degree PVC elbows
10
Unit
2
20.00
20.00
1/2-inch PVC tap
4
Unit
15
60.00
60.00
PVC glue × 1/8 gallon
1
Unit
20
20.00
20.00
Polyethylene tanks with ultraviolet protection, 1,100 L capacity
4
Unit
475
1,900.00
1,900.00
Black annealed wire, 16 gauge
20
kg
5
100.00
0.00
Black annealed wire, 8 gauge
20
kg
5
100.00
0.00
Portland cement type I
32
Bags
26
832.00
0.00
3-inch wood nails
15
kg
8
120.00
0.00
3/8-inch corrugated steel
10
Rod
16
160.00
0.00
1/2-inch corrugated steel
42
Rod
27.5
1,155.00
0.00
1/4-inch corrugated steel
11
Rod
7
77.00
0.00
Cost of materials in the area
River concrete
4.5
m3
120
540.00
0.00
Ordinary timber for shuttering
183
p2
4
732.00
0.00
Wood for tank supports
461.5
p2
4
0.00
1,846.00
Total cost (4 systems)
10,400.00
8,000.00
Total cost (1 system)
2,600.00
2,000.00
Category of labour force, existing in civil construction (worker, journeyman, and labourer); p2 = square feet; and Bl = bag of cement weighs 42.5 kilograms.
