Water for Village in Sanan (1)

1. Existing Condition

Posting the earthquake disaster almost all community’s well in Sanan Sub-Village became dry. Before the earthquake, some of the community’s wells still could be used for daily need especially in dry season. Nowadays, posting the earthquake disaster and in dry area above Sanan Sub-Village got lack of water because of the depth of the well which is very deep and the lack of groundwater surface so then community have problems in getting the water to fulfill their daily need.

Half of the community who live on higher area compote their need of clean water for family and cattle by taking water from dug well that prepared for the community for about 1 km from the community house down the village and community have to queue to get the water.

Due to water as the main factor in human live while community are hardly in getting the need of clean water, so then community have a strong willingness to have a communal water supply system that can be dependable and sustainable to be conducted together.

2. Data and data preparation

a. Assessment

Sanan Sub-Village located in Bawuran Village, Pleret Sub-District, Bantul District, Yogyakarta which constituted as higher area and hill. The land condition mostly consists of clay and soft rock. The main road which is linking between sub-village and village is elastic street among the community house is still usual footpath. Dry and rainy seasons are not very influence dominantly for the community. In relation with the water source fluctuation, season changeover is not giving significant influence about the raise and the low the ground water surface. The use of land is mostly only for houses.

Tabel 1

Number of Community in Each Household

Area	Number of Household (2007)	Number of person (2007)	Number of person (2012)
RT 03 RT 04 RT 05 RT 06 RT 07 and Segoroyoso	25 KK 42 KK 31 KK 38 KK 71 KK	125 210 155 190 355	129 216 159 195 364

The community growth based on Balai Pustaka Statistik (BPS) Bantul community are raising 0,5% in each year. The community density is still lower with the ration which is larger between community population which is small and area which is wider. Community livelihoods are mostly in cattle sector and small medium enterprise. Cattle sector is mostly become the main sector where cow as the main source. On the other hand, there only few small industries which is running in sector furniture.

2. Survey and Survey Result Analysis.

v Topography Survey

Topography in Sanan Sub-Village dominated with slant between 8 – 9 %. The highest location is on 60 m viewing from Zero point where the location is planning to be building the well, while fisiography surface land condition is abrupt. From Topography survey coordinates and elevation data is collected and applied in Water Net program to get availability of water network. This Water Net program running is in progress.

v Geography Survey

Generally, condition of geography in Sanan Sub-Village are consists of clay with white soft rock. The groundwater is on 15 – 20 m depth. The groundwater quality is rather clean, not smelly, yet only in rainy season the well become turbid because the land already contaminated.

v Mapping of Dug Well and Drill Well.

Mapping of dug well and drill well that already exist and plotting of the water source location. Deep well location is determined according to properties available and water table depth. Water location is surveyed by geo-electric method for some location available. Deep well will be bored about 100m depth. Dug well is dug about 15 m depth.

v Geophysics Survey

The work consists of geophysics survey, sounding Schlumberger geo electricity methods. The measurement minimal is 8 points with the length of electrodes is 200 – 250 m by using Mc Ohm meter utility mode 2115 digital and booster.

Survey result analysis of geo electricity is to get the depth of groundwater surface (skin deep, medium deep, and deep), groundwater temperature, groundwater conductivity in denomination Ohm-meter and other information/data which is needed to support the data so that it could be mapped in form of a groundwater depth map.

v Drilling (Pilot Hole, Wire Line Log, Reaming)

1. Drilling of Pilot Hole

The beginning drilling will be using diameter 6” with 100 m depth, it is done to find types of litology before doing the next step.

Utility:

a. Drilling Rig THS 5

b. Clay Pump NAS 5

c. Drill Rod 84 mm with 100 m long

d. Collar

e. Mata Bor Tricone dia 6”, Corel barel dia 6”

f. Chainblock, Pipe keys, Chain key and others equipment.

Material:

a. Bentonite

b. Gasoline (solar dan olie)

Analysis:

a. Take a sample from some rocks and analyzing the sample (description of the rocks) from each meter cutting.

b. Observe and noting each meter of drilling penetration.

c. Observe the thickness of clay drill.

2. Wire Line Log

After the pilot hole work done, there will be a drill hole geophysics testing which is usually called electrical logging. There will be 3 (three) method in electrical logging: Log Resistively, Spontaneous Potential, and Gamma Ray.

Equipment: Geologer OYO 2000

3. Reaming

From electrical logging data and litology description it will be made a deep well construction design plan (shop drawing) which is there will be drill hole enlargement diameter 12” until 81 m depth.

Equipment:

a. Drilling Rig THS 5

b. Clay Pump NAS 5

c. Drill Rod 84 mm with length 100 m

d. Collar

e. Eye drill Tricone dia 12”, Corel barel dia 12”

f. Chainblock, Pipe keys, Chain keys, and others equipment.

Material:

a. Bentonite

b. Gasoline (solar dan olie)

v Deep Well Construction.

Well construction’s planned with 100 m depth; consist of GIP pipes with diameter 6” with length 42 m, GIP pipes with diameter 4” with length 15 m.

For gravel pack it is using gravel with size between 5 – 7 mm until the depth is below the water aquifer which is used by the community.

Equipment:

a. Drilling Rig

b. Las Machine

c. Saw, Hammer, Pipe keys, and others equipment.

Material which will be put:

a. GIP Pipe diameter 6” with length 42 meter

b. GIP Pipes diameter 4” with length 24 meter

c. Screen stainless steel pipes diameter 4” with length 15 meter

d. Gravel with size 5 – 7 mm

v Cleaning Deep Well

After the construction work is done, the next step is cleaning deep well. This work will be done by doing water jetting until the well truly clean from sludge.

Methods:

a. Water Jetting will be done by put ting clean water into the well by using high pressure pump through conductor pipes

b. High Velocity Jetting/Air Jetting will be done by putting high pressure air into the well by using a compressor through conductor pipe.

c. Time in doing the work is 1 x 12 hours.

Equipment:

a. Compressor with capacity is 12 atm

b. High pressure air pump

c. Pipa tiup dia 1,5” with length 80 meter

d. High pressure lapse

e. Others equipment

Material:

a. Solar, oil, stenvet

b. Sodium Tri Poly Phosphate (STPP)

v Pumping Test

This work is aimed to know the capacity types of the well and the well efficiency.

Pumping test will be done in two ways:

- Step draw down test within 2 x 4 hour

- Long period test within 1 x 24 jam

Equipment:

a. Submersible Pump

b. Conductor Pipe

c. Genset/Electricity and Electricity Panel

d. V-Notch

e. Tap

f. Sounding, meteran, Clock

g. Pipe Keys, tanggem

h. Stationary

i. Others equipment

Analyzing:

a. Observe and noting lowing of water surface

b. Observe and noting relapsing the surface water.

c. Counting the optimum debit capacity and maximum well based on the data