PAMSIMAS - Treatment System ImprovementElement 1: Development of Treatment Technology

(DRAFT)

PEAT WATER TREATMENT PROCESS

Current Experience in Peat Treatment Process

1. Peat water (air gambut) is usually found in the swampy area where peat exists, as indicated by the brownish/blackish color of the water. Peat water is commonly found in the swampy areas in Kalimantan and Eastern coastal areas of Sumatera. Peat water is characterized by high intensity of (true) color (as high as 1,000 PtCo scale), low pH (3.0-5.0), high organic content (up to 1,500 mg/L KMnO4), low cationic content, low turbidity and low suspended solids. The following table indicates characteristics of peat water in several areas in Kalimantan and Sumatera.

No Parameter Unit Peat Water MOH Std for Water Quality*

South Kalimantan

West Kalimantan

Central Kalimantan

South Sumatera

Riau

1 Color PtCo 753 527 725 1,315 1,152 152. Turbidity mg/L SiO2 32 0 0.5 5 9 53. Electric Conductivity µ mho/cm - 30 50 78 75 -4. pH - 4.1 3.9 3.6 5 4 6.5-8.55. Organic mg/L KMnO4 278 194 172 290 243 106. Alkalinity 0G 2.05 0.48 - 5.5 1.4 5007. Calcium mg/L - - - 4.5 - -8. Magnesium mg/L 8.83 2.1 - 20.9 6.2 -9. Iron mg/L - - - - - 0.310. Manganese mg/L - - - - - 0.411. Chloride mg/L 11.11 5.48 - 162 18 25012. SO4 mg/L - - 5.1 11.2 - 25013. HCO3 mg/L - 51.4 - - - -14. Aggressive CO2 mg/L - - 31 - 80.6 -Ref: Irianto, 1998 as quoted by Susilawati, 2010: Model Pengolahan Air Gambut Untuk Menghasilkan Air Bersih Dengan Metode Elektrokoagulasi*Ministry of Health Decree No. 492/2010

2. Peat water treatment on household scale can be found in the market. It usually comes in the form of cylindrical tube filled with filter media. Clay is usually added as coagulant aid. The experimental plant was made, among others, by LIPI in Central Kalimantan and Bengkalis. The process includes coagulation and filtration with silica sand and anthracite as filter media. The color is removed by means of biological process due to the formation of biofilm in the media’s surface. Activated carbon is added to remove odor and improve taste. The plant created by LIPI has a filtering capacity of 60 L/minutes, enough to serve 100 households. The plant and process obtained the patent in 2012, but mass production is yet to be planned (Kompas, August 2012).

1

3. Housing and Building Research of the Ministry of Public Works (Puslitbang Permukiman PU) and some universities (USU, ITS, ITB) have carried out a number of researches on peat treatment with degrees of complexity and results. Coagulation and filtration are the common treatment process, combined with biological process as a result of biofilm formed in the media.

Justification for the construction a peat treatment plant

4. Peat water treatment is not considered as ‘low cost’ technology. It requires higher level of technical knowledge for the designer and contractor, more so for the local people. It also needs regular maintenance and cleaning. There were too many ‘hearsay’ about the treatment methods, but none have proven to be a real solution to the problem of peat water. Before taking any decision to construct a peat water treatment, it would be advisable to check first if the people really in need of clean water, and if there is sufficient capacity and willingness to maintain the facility when it is completed. The following chart provides useful guide before a decision is made to construct peat treatment plant.

Urgent need for clean water

Socio-economic condition

Capacity to implement

Willingness to maintain

Move to other

locations

Funding support from

LG/private/CSR

Existing raw water: high color, low pH, high

organic content, low turbidity

Y

N N

N

N

Y

Y

Y

Construct peat water treatment!

Training for community/ contractor

YN

Treated water: acceptable quality

(MOH Std)

Important to note that lack of experience and knowledge could be overcome by providing training prior and during construction, but lack of willingness to maintain is crucial for the plant sustainability, and therefore considered as prerequisite.

5. Recent experience on peat treatment is found in Desa Jejangkit, Kabupaten Barito Kuala, South Kalimantan, where a plant was constructed in 2010. The plant uses combination of filtration process (roughing, rapid and slow sand filters) with different filter media and biological process. The plant capacity is 45 – 60 L/minute and serves about 450 people (90 families) through series of public

2

hydrants. With the same technology, a number of plants were constructed in other places in South Kalimantan and in Sumatera. The plants’ performance is so far found to be satisfactory. The table below indicates significant reduction of color and improvement of other parameters (shown in bold).

Parameters Tested Unit South

Kalimantan*Riau**

South Kalimantan*

Riau**

Physical characteristicsTemperature 0C 25 25.5 25.7 25.5EC 38Turbidity NTU 0.48 68 0.76 0.44Total Dissolved Solids mg/L 19 305 347Color PtCo Scale 635.38 1250 19.3 5

Chemical characteristicsAmmonia-N mg/L 3.71 - -Arsenic mg/L 0 - 0 -Iron mg/L 1.42 0.6 0 0.03Fluoride mg/L 0 - -Chloride mg/L 9.4 122.76 33.63 97.02Manganese mg/L 0.1 0 0 0Nitrate mg/L 16.5 - 25.56 -Nitrite mg/L 0 0 0.16 0.07pH 5.4 7.44 7.7 7.83Zinc mg/L 0.25 - 0.11 -Sulphate mg/L 21.65 0.9 9.43 2Copper mg/L 0 - 0 -Cyanide mg/L 0 - 0 -Organic content (KMnO4) mg/L 190.79 5.1 1.79

Remarks:*Kec. Gambut, KM16, Banjarmasin, South Kalimantan, tested 8 November 2006, Laboratory of the Ministry of Health, Jakarta**Desa Sialang Panjang, Tembilahan, Riau, tested 15 August 2009, Laboratory of the Ministry of Health, Jakarta

Raw Water After Treatment

Based on the above experience, the proposed peat water treatment plant is further elaborated below.

Proposed Treatment Process

6. From technological point of view, the proposed peat water treatment is relatively simple, and could easily be constructed by local laborer using local materials, but it requires proper operation and regular maintenance. The treatment process is simply consisting of combination of rough, rapid and slow filtering processes. The basic treatment unit includes horizontal roughing filter (HRF), where raw water is passed through a 6-meter long and 0.6 m wide channel filled with gravel. The filtered water enters into an intake well before it is pumped through a pressured rapid sand filter (RSF) to collection tank. From collection tank, the filtered water is passed through series of PE tanks/barrels filled with different filter media. The water in the subsequent tank is flowing up and down. To allow

3

for gravity flow, the tanks are to be placed in the elevated floor made of wood, concrete or steel structures (in Kalimantan where wood is easily available, wooden floor is advisable). Treated water is delivered to public hydrants or via pipe network to houses. The collection and treatment tanks are made in two rows in parallel to allow for cleaning on one row while the other row is still operating. Below is the schematic diagram of the treatment process.

7. The overall performance of the treatment process depends on the performance of each treatment unit. The plant is designed to cope with fluctuation of raw water quality. HRF acts as preliminary treatment to remove grits and sediments in the water. The gravel, made of limestone reduces color to some degrees. Depending on the turbidity of raw water, HRF is easily clogged and will need regular cleaning to remove accumulated grits and sediments. From HRF the water is pumped into RSF with quartz sand and zeolite as the filter media. The RSF also functions to remove fine materials left from HRF. From RSF, the water flows into each of collection tanks placed in parallel.

8. From the collection tank the water enters to series of treatment tanks. The first treatment tank is filled with limestone gravel as the media, where biological process is taking place in the media. A biological layer called ‘schmutzdecke’ is formed in the surface of the media. The process in the tank will reduce color and improve pH. The second tank is filled with bentonite and zeolite, which act as purification and detoxification agents. The last (third) tank is filled with activated carbon to eliminate pathogenic bacteria.

CONSTRUCTING THE PLANT

Foundation and Supporting Structures

4

river

horizontalroughing filter (HRF) made of

limestone gravel

intake well

sump pump

pressured rapid sand filter (RSF)

Series of treatment tanks, made of PE with diameter 1.07 m, 1,100 liters each, filled with different media

river intake

e

to public hydrants

collecting tank

clear well reservoir

to public hydrants

to house connections

9. The plant construction is relatively simple and can be constructed by the skilled local labors. The main construction steps consists of (i) preparation works, (ii) (ii) intake works, (iii) structural works for support, (iv) installation of RSF, tanks/barrels including accessories and filter media, and (v) installation or clear water tank/reservoir, public hydrants and piping works.

10. Preparation works. Preparation works consist of site clearing and measurement. The treatment plant will need about 50 sqm of land for intake works, treatment unit and clear well. The site for locating the intake and the treatment unit should be chosen as such that it is closest to the areas to be served. Avoid choosing the intake point at the river curve or bend to avoid scouring. Avoid undulating areas to avoid deep trenches.

11. Intake works. Intake works include construction of roughing filter and intake well. First, a trench of 1m wide and 6 m long is made between the river and the well, which is located about 8 to 12 m from the river. The depth of the trench from the river to the well is about 3 m or made the same with the depth of the river. The housing for roughing filter (HRF) is made of ulin or similar wood. The housing shape is a rectangular box with 6.0 m long, 0.6 m wide and 0.6 m deep. The housing is then placed in the trench, connecting the river and the well. The well is made by digging the hole on the ground, located at the end of the filter. A concrete culvert with 0.8 m in diameter is installed into the well. The well depth is about 4 meters from the surface. Once completed, the well is connected with the HRF. During intake construction, the filter should not be connected to the river, to avoid river water inundates the filter and the well. The connection is only made after the HRF and the well are completed.

12. When all of the components of intake construction are completed, fill the filter (HRF) with the media (limestone gravel), and cover the filter with wooden cover. Cover a whole HRF unit with excavated soils. Finally, connect the filter with river, to allow the river water flows into the HRF and fill in the well.

13. Structural works for support. The structural works are needed to support the treatment unit and public hydrants. For the area where soil is dry, it consists of foundation and upper structures. The foundation is made by digging an area for the unit with the depth of 0.50 m. At the base, place galam or dolken or similar woods horizontally, two pieces for every post of ulin wood. Every post is reinforced with pair of ulin wood, placed diagonally, and connects tightly (see sketch below). Above these posts a wooden plank is placed as the floor for the facilities. Alternatively, in the areas where woods are not easily available, steel and concrete structures are also possible. The steel should be galvanized to protect from rusting. With the absence of woods, steel construction may save 20 to 30% of construction cost.

5

original land surface

wooden floor

excavated level

0.50 mgalam or dolken wood

ulin wood

14. In the area were soil is wet or land inundated, at the base of every ulin wood post, four pieces of galam wood with diameter 10-12 cm, 2-3 m long are inserted into soft soil. The distance between galam wood is 25 and 40 cm. The excess woods are cut to make it level. In very two galam woods a piece of ulin wood is placed to form the base for the post (see sketch below).

Plan (as seen from above)

Side view

Installation Works

15. Installation of treatment unit, accessories and filter media. Collection tank and treatment units (tanks) are carefully placed above the wooden floor. Collection tank consists of two PE tanks of 1,100 liter placed in a row. Treatment unit consists of six PE tanks placed in a row of three. Each of the tank is connected with connecting pipe, equipped with valves and filled with media. See construction drawings for detail pipe and accessories installation. Filter media is placed in each tank

6

galam wood 12 cm in diameter

wooden post 10/10 made of ulin

25 cm

40 cm

wooden post 10/10 made of ulin

galam wood 12 cm in diameter

shoe 5/10 made of ulin

girder, 5/10 made of ulin

in accordance with the treatment process (see the process in point 6 above). The type and size of the media in the respective tank are in accordance with the Technical Specifications.

16. Installation of clear water tank, public hydrants and piping works. Clear water tank/reservoir is placed above the wooden structure as described in points 12 and13 above. See construction drawings for details. Intake and distribution pumps are installed in accordance with the Technical Specifications.

PLANT OPERATION AND MAINTENANCE

Notation:1. Roughing filter (HRF); 2. Intake well; 3. Intake pump; 4. Rapid sand filter (RSF); 5. Collection tank; 6. Treatment tanks 1, 2 and 3; 7. Clear water reservoir; 8. Distribution pump; 9. Public hydrant

Preparatory Works Prior to Operating the Plant

17. Roughing filter and intake well. Check the entrance point of the HRF that connects to the river and remove accumulated sediment and rubbish to allow for the river water to flow freely to the filter. Clean up the intake well from accumulated sediment by taking out sediment at the bottom of the well with sucking pump. Once the water level in the intake well has reached certain level, operate the pump to fill in collecting tank.

18. Rapid sand filter, Collection and Treatment Tanks. Before raw water is pumped from intake well, make sure that multiport valve at the RSF is in the filtering position. Make sure that the pump

7

PEAT WATER TREATMENT PLANT

Longitudinal cross section

and pipes have been properly installed so that raw water could be pumped into the collecting tank. Check if the drain valve at the collection tank has been closed, and ball valve located between collection tank and treatment tanks is opened. Check drain valve at the treatment tanks has been opened, and ball valve from treatment tank to reservoir is in close position.

Operating the Plant

19. When the above steps have been completed, the following steps need to be carried out subsequently:

a. Turn the pump on.

b. Wait until raw water enters into the collection tank and when the tank is half full, the water will start flow to the treatment tank 1 then tank 2 and finally tank 3.

c. During the filling, make sure that all the floating materials at each tank is removed.

d. After the collection tank is almost full, watch the water level when it reaches the position of floating ball and ensure that the pump stops automatically after reaching the floating ball. Adjust the position of the floating ball to make sure that the collection tank is really full.

e. When the treatment tanks have all be submerged with water, open test valve from the outlet of the treatment tank and leave it open for a while. Close the test valve when the water coming out from the tank is already clean. Then open the valve connecting outlet of treatment tank and reservoir.

f. Treated water at the reservoir is then pumped to public hydrant through distribution pipe. Before treated water fills in the hydrant, make sure that the piping is cleaned up by flushing it with treated water.

Maintaining the Plant

No Component Maintenance Works Maintenance Period

1. Roughing filter 1. Clean up the side of the river around the roughing filter from accumulated sediment and rubbish.

2. Clean up roughing filter by pumping the water into the roughing filter towards the river.

Every three months

Every year

2. Intake well Clean up the intake from sediment, garbage and other unwanted materials Every three months

3. Pump Conduct regular service, change damaged parts and cables

Every year

4. RSF Conduct RSF backwashing Every week5. Collection tank Clean the filter media at both collection tank by

removing the upper layer about 7 cm deep, lift up filter mat. Clean the media and place it back into each

Every six month

8

collection tank.6. Treatment tank Clean the media at the treatment tanks Every one to two

years7. Distribution pipes Check the pipe for leaks, tighten pipe connection,

carry out regular flushing Every year

8. Public hydrants Cleaning and flushing the hydrants Every six months

Trouble Shooting (Problems and Suggested Solutions)

No. Problems Possible Causes Suggested Solutions

1. Water in the intake is not enough to be pumped to collection tank

Raw water from river is not flowing freely to the intake, due to clogging of the filter by sediment or rubbish

Clean up sediment or rubbish in front of the roughing filter.

2. - Pump does not operate- Flow of water from the

pump small

- Damage on cable, fuse, or cross circuit

- Serious damage on the pump- Suction pipe at the well

clogged by rubbish

- Carry out pump service- Replace damaged parts- Clean up suction pipe from rubbish

3. Flow from collection tank declines or totally stop

- Sediment or fine particles settle above the media in the collection tank

- Clog in the pipe or at the ball valve

- When collection tank is empty, detach pipe/ball valve to remove dirt, and attach again after all dirt are removed.

- Lift upper layer of the media with about 7 cm thick including filter mat, take them out from the tank and wash till clean, put them back again after cleaning

4. Flow from treatment tank declines

- The media in the treatment tank is condensed

- Fine particles settle in the media at the treatment tank

- Take out the upper layer of the media for about 10 cm thick, wash them until clean and put them back again after clearing

5. Flow to public hydrant declines

- Leaks occur at the distribution pipe

- Pipe connection disconnects

- Check for any leak and disconnection of distribution pipe, do pipe repair and replace the pipe if needed

6. Water is not flowing into the public hydrant

- Damage at the floating ball- Pipe from distribution hydrant

is disconnected

- Check floating ball at the public hydrant, do the repair and replace floating ball if needed

- Repair the disconnected pipe7. Water flow declines or

not flowing at all to the house

- Leaks occur at the pipe or pipe connection

- Check piping from distribution pipe to the wter meter, do the repair and replace the pipe if needed

- Fix the disconnected pipe

Cost Estimates

20. The table below shows rough cost estimates for the construction of a typical peat treatment plant, which is around Rp 153.6 million per unit. The cost estimates is based on the unit cost for year 2013. This cost estimates is prepared as a guide only, the actual construction cost will come from the results of the bidding.

9

No Work Item Total Costs, Rp1 Preparation works (site clearing, measurement, documentation,

reporting 2,500,000

2 Intake works (excavation, culvert, well cover) 2,075,000

4 Rapid sand filter (filter, accessories and filter media) 6,079,209 5 Construction of clear water reservoir (2 @ 3,000 ltr PE tanks,

earthwork, foundation, sand filling, accessories) 7,629,600

7 Pipes and accessories 4,770,000 8 Construction of public hydrants (hydrant, 2,000 ltr PE tank,

supporting structure, pipes and accessories) 33,164,100

9 Pumps and accessories  6,200,000 10 Others (transportation to the site, if needed) 16,200,000

Total 139,671,344 VAT, 10% 13,967,134 Grand total 153,638,478 Rounded 153,638,000

43,913,033 6 Collection and treatment tanks (2 @1,100 ltr PE tanks, 6@ 1,200 ltr PE tanks, media, pipes and accessories, supporting structure) 

3 Trenching work for roughing filter (cofferdam, foundation, filter housing, filter media, piping, earthwork)

17,140,402

Treatment Plant Packaging

21. The peat water treatment could be easily packaged to serve larger consumers, adding more tanks and/or enlarging tanks’ volume. The present design allows for the following plant packaging: 30 L/minute, 45-60 L/minute and 60-90 L/minute. The construction costs for different plant capacities are Rp 80 million, 160 million and 240 million respectively.

Assessment of Investment and Operation Costs

22. With the production capacity of 45 L/minute (0.75 L/second) and construction cost of around Rp 154 million, the construction cost is about Rp 205 million per L/second. This is on the high side, but still considered viable considering that peat water treatment requires more advanced technology as compared to conventional water treatment to reduce turbidity. Higher production capacity will lower the construction cost thus will also lower production capacity cost. The experience shows that the operation and maintenance cost are around Rp 6 to 8 million annually.

23. The plant with production capacity of 45 L/minute could serve up to 450 people or 90 families. With the construction cost of Rp 154 million, per capita cost is about Rp340,000 (US34.0) per capita which is considered reasonable (the norm used for rural water supply system is US$40 per capita). Again, the more people to be served, the lower the cost per capita would be.

10