36 conference paper amg corregido (2)

8/11/2019 36 Conference Paper Amg Corregido (2)

http://slidepdf.com/reader/full/36-conference-paper-amg-corregido-2 1/6

MERCADO&ROMERO

1

36th WEDC International Conference, Nakuru, Kenya, 2013

DELIVERING WATER, SANITATION AND HYGIENE SERVICESIN AN UNCERTAIN ENVIRONMENT

Microbiological contamination risk and water quantity inCochabamba city periurban water community systems.

A. Mercado, &A.Romero, [Bolivia]

REFEREED PAPER

Periurban neighbourhoods in Cochabamba, are not covered with municipal water supply system. People

have built their community water supply systems. A diagnostic on 36 of this type of systems looking attheir infrastructure, water quality, and volume water supply provided is the topic of this paper.

Diagnostic of infrastructure was made based on reported inspection on main structures of the system.41% of systems presented high pollution risk, 15% medium risk, 32% low risk, and 6% very low risk.Water quality analysis at sources presented Iron above regulations in 33% of sources, andmicrobiological contamination in 46%. At consumption points microbiological contamination reached50%, this type of contamination increased from 28 to 43% when the source is groundwater.Water supply per inhabitant per day in 10 of 36 systems showed that 90% is below the volume providedby municipal water company, and below national water supply design standards.

Introduction

Only 47% of Cochabamba city population is covered by water supply from the municipal company

(SEMAPA, 2010), most of the non-covered population is placed in periurban areas. In the area where thereis no coverage by central system, there are independent water supply systems, which basically have twoschemes: they have their own source (mostly underground), and others only have the infrastructure butdepend on water trucks which frequently deliver water to their tanks, which deliver the water to the network.

Most of these water supply systems are maintained by the users, organized in committees which takecharge of distribution of water and fees collection, as well as some basic operation activities. In generalcommittee members do not have adequate training on technical issues related to the water distributionsystem.

ASICASUR is a social organization that groups community water systems in order to improve theirmanagement capacity among other objectives.

According to WHO (Rojas, 2006), water quality for human consumption can be controlled by monitoringwater sources, storage system, distribution management and household water handling; these tasks should bedone by water distribution system operators.

Previous studies (Lee and Schwab, 2005) reported that poorly maintained distribution systems can act asvehicle of distribution of pathogens; similarly a study conducted in 16 periurban water distribution systems

in Cochabamba, Bolivia reported that microbiological contamination increased from sources to user points, probably due to the lack of maintenance of the water distribution system (Mercado Guzman, 2012)(Romero, 1992) (Romero A. C., 2008)The main objective of the present study is to evaluate infrastructureand water quality of community water distribution systems related to ASICASUR in order to providesuggestions to improve the water quality. It is expected that simple actions arise, which could be made bythe users of the water distribution systems.

It is also foreseen to study how much water people of community water systems receive, and compare itwith national design standards and values provide by the municipal water distribution company.



MERCADO&ROMERO

2

Methodology

Table 1. Example of protocol used for infrastructure diagnostic

A. SOURCE : GROUNDWATER Answer

1. Is there a pipe of the well sealed? Yes No

2. Is the pipe of the well in good conditions (without cracks)? Yes No

3. Is the pipe of the well at least 50 cm above ground? Yes No

4. Is the well adequately protected? Yes No

5. Is the area surrounding the well free of puddles, garbage and grass? Yes No

6. Is there perimeter fencing? Yes No

7. Does perimeter fencing avoids the entry of animals? Yes No

8. Is there a protection Trench? Yes No

9. Is the protection trench cleaned? Yes No

10. Is the area 30 m around free of latrines? Yes No

Pollution risk . Number of “ No ” answers: 8 to 10 (Very high) 5 to 7 (High) 3 to 4 (Low) Less than 3, (Very

B. DRIVE LINE

1. Is the well flow rate regulation valve protected? Yes No

2. Are accessories and drive line free of leaks? Yes No

c. STORAGE TANKS

3. Is storage tank free of crack son walls and roof? Yes No4. Is the inspection cover well sealed? Yes No

5. Is the inspection cover without cracks and damage? Yes No

6. Is the inspection cover locked? Yes No

7. Is the interior of the tank free of sediments and algae? Yes No

8. Is vent pipe free of clogging, and with a mesh for avoiding the entry of birds and other elements? Yes No

9. Is over flow pipe free of clogging, and with a mesh for avoiding the entry of birds and other elements? Yes No

10. Is cleaning pipe in good conditions and free of clogging? Yes No11. Are valve chamber and cleaning pipe chamber clean and locked? Yes No

12. Are valves of cleaning pipe and distribution pipe free of leaks? Yes No

13. Is surrounding area clean, free of puddles and garbage? Yes No

14. Is there perimeter fencing? Yes No

15. Is perimeter fencing in good condition and avoiding the entry of domestic animals? Yes No

16. Is there a protection trench? Yes No

17. Is the protection trench free of garbage? Yes No

D. DISTRIBUTION NETWORK

18. Is network buried in all its length? Yes No

19. Is network free of visible leaks in pipes? Yes No

20.Are distribution valves in good conditions? Yes No

21. Are stand posts with support bases, in good conditions and with no puddles surrounding? Yes No

E. HOME CONNECTIONS AND TAPS (Check only 20% of home connection in every inspection)

22. Are cutting valves in good conditions? Yes No

23. Are water meters working in good conditions? Yes No

24. Are home connections and taps in good conditions, with no leaks and puddles around? Yes No

25. Is the tape free of hoses connecting to open containers or puddles? Yes No

F. OTHER

26. Is the water supply continuous? Yes No

27. Is there enough pressure in the last points of the network? Yes No

Formatted: Font: (Default) Arial, 8 pt, ItaliFont color: Auto

Formatted: Font: (Default) Arial, 8 pt, ItaliFont color: Auto, English (U.S.)

Formatted: Font: (Default) Arial, 8 pt, ItaliFont color: Auto, English (U.S.)

Formatted: Font: (Default) Arial, Italic, Foncolor: Auto

Formatted: Font: Italic, Font color: Auto,English (U.S.)

Formatted: Font color: Auto, English (U.S.)



MERCADO&ROMERO

3

28. Is there a chlorination system in the water supply system? Yes No

Pollution risk . Number of “ No ” answers: 18 to 28 (Very high) 10 to 17 (High) 5 to 9 (Low) Less than 4, (Very low)

Water quality diagnostic was made with samples both in sources and consumption points. At sources a physicochemical and bacteriological analysis was made, while only bacteriological at consumption points. Itwas presumed that deterioration in bacteriological quality from source to consumption could be caused by alack of maintenance of the infrastructure.

Diagnostic of infrastructure consisted in reported survey of a visit to the components of the waterdistribution system; the visit was made in company of the operator of the system. Main parts consideredwere: source, storage tanks, water distribution network, and home connections. An example of the protocolused is presented in Table 1.

Degree of pollution risk is based on the number of “No” answers of the protocol , this pollution risk can belabeled as very high, high,medium lowandverylow.

Several systems were visited between 2009 and 2011. In 2009 water distribution systems were visitedonce, in 2010 and 2011 systems were visited two times. In 2012 some water distribution systems werevisited in order to know how much water each person received; these calculations were based on flow rate of

the source, and information on consumption of average family in the water system.ResultsA summary of microbiological pollution risk of studied water distribution systems is presented in Table 2

Table 2. Microbiological pollution Risk of studied water distribution systems and their sources.

Nº Systems 2009 Risk. Nº Systems 2010 Risk Nº Systems 2011 Risk

1 Asociación Mulamayu-Groundwater Low 17

Virgen del Rosario -Groundwater High 29

Central Itocta – Watertruck High

2Comité de Agua PDA -Groundwater Low 18

Señor de Burgos -Groundwater High 30

San Andres – watertruck Low

3 Asociación Agua Cruz -Groundwater High 19

El Palmar -Groundwater Medium 31

APAAS -Groundwater High

4 Asociación de Agua SanMiguel Km 4 - Groundwater. Low 20

San Jose de laBanda Alambrado -Groundwater High 32 Bolivar - Groundwater Low

5Comité de Agua EucaliptosNorte - Groundwater Low 21

RocasBlancas – water truck High 33

Calicanto – Watertruck High

6Señor de Exaltación -Groundwater Low 22

22 de abril – Watertruck High 34

Villa IsrraelCisternas-Water truck Low

7

Asociación de agua potable yriego Morro Itocta -Groundwater Low 23

San Severino -Groundwater High 35

Villa IsrraelVertiente – Water truck High

8 Asociación 14 de Septiembre- Groundwater Low 24

Buena vista -Groundwater 36

Villa Venezuela -Groundwater Low

9

Comité de servicios de aguapotable 1ro de mayo.. -Groundwater

VeryLow 25

Mejillones-Groundwater High

10Comité de agua Nuevo

Amanecer - Groundwater Medio 2626 de noviembre -Groundwater Medium

11 Asociación de agua Fortalezael Paraíso - Groundwater

VeryLow 27

Tamborada A -Groundwater High

12 Asociación de agua potableNiño Divino - Groundwater Medium 28

San Miguel AltaTensiónGroundwater High High Risk 41%

13 Asociación de agua potableSan Haniel - Groundwater Medium Medium Risk 15%

14Comité de agua Chaquimayu- Spring High Low Risk 32%

15

Prestación de serviciosbásicos Sivingani -Groundwater Medium VeryLow Risk 6%

16Comité de agua Aguas deManantial - Groundwater Low

Formatted Table

Formatted: Font: 10 pt

Formatted: WEDC - Body text - P2



MERCADO&ROMERO

4

According to table 3, 56% of the water systems present a medium and high microbial pollution risk. Thismeans that infrastructure deficiencies may promote microbial contamination to water provided to users.These deficiencies could be avoided with simple and not expensive measures of operation and maintenance.

Table 3. Percentage of samples above Bolivian water quality regulations. Sampling points/Nª

samples Turbidity Conductivity Iron ManganeseThermo tolerantColiforms

TotalColiforms

Total Sources/48 19 17 33 27 46 44

Groundwater/ 32 19 25 41 41 28 22

Springs / 5 40 0 40 0 80 80

Watertrucks/ 11 9 0 18 0 91 91

Consumption/46 9 9 26 37 50 35

Groundwater/ 37 11 11 32 46 43 27

Springs / 1 0 0 0 0 100 100

Watertrucks/ 8 0 0 0 0 75 63

Figure 1. WEDC –Turbidity on watersystems

Figure 2. WEDC – Conductivity on watersystems

Figure 3. WEDC –Iron on water systems Figure 4. WEDC –Microbiologicalcontamination on water systems.

Table 3 indicates that iron and manganese are above regulation in 33% and 27 % of analysed samplescoming from sources and 46% of samples present microbiological contamination by thermo tolerantcoliforms. Iron and Manganese are naturally present mostly in groundwater sources, while microbiologicalcontamination comes mostly from springs and water trucks. At consumption points it is visible thatmicrobiological contamination increases in systems with ground water sources, while it keeps highconcentration in systems coming from surface and water truck sources.

Conductivity is above regulation in 17% of sources, which correspond to groundwater. Most of thesystems depending on groundwater which in some areas present high concentration of salts, giving a not



MERCADO&ROMERO

5

pleasant taste to the water. In these cases people uses water mostly for other uses than drinking, usuallydrinking water is provided by water trucks.

Figures 1, 2, 3 and 4 present results of water quality for turbidity, conductivity, Iron and Microbiologicalcontamination, for groundwater and other sources, besides consumption points. Bolivian regulations for the parameter is presented in red line.

Increasing of microbiological contamination from source to consumption point, is related with activities ofoperation and maintenance, since most of the water system boards have no knowledge about water quality,therefore they pay little or no attention to these activities. See Figure 4.

Another factor influencing water quality at consumption points is that there is no treatment processes inany of the visited systems.

There was no visible correlation between bacteriological contamination at consumption point with themicrobiological pollution risk obtained for each community water system. Neither there was relationship between the other water quality parameters presented and the microbial pollution risk of water systems.

According to Bolivian regulations design water supply per inhabitant in communities up to 500inhabitants in highland areas is between 30 and 50 l/h/d, for cities between 20000 and 100000 inhabitants inthe valley zone (such as Cochabamba city) the value is between 150 and 200 l/h/d. Table 4 presents valuesas low as 20 l/h/d in some community water systems, mainly due to lack of water in sources, therefore people living in many community water systems receive as much water as very small rural communities.

Table 4. Estimation of volume per inhabitant per day in community water systems comparedwith the municipal system.

Water system name Type of sourceMean volume of water used in themonth per connection (m 3)

Volume perinhabitant per day(l)

Central Itocta Water truck 4 27

San Andres Water truck 3 20

San Miguel km 4 Groundwater 4 27

PDAGroundwater and watertrucks 5 33

Villa Isrrael Water trucks 3 20

Sivingani El rincon Groundwater 5 33

Niño Divino Groundwater 12 80

San Haniel Groundwater 5 33

Señor de Exaltación Groundwater 20 133

14 de Septiembre Groundwater 14 93

SEMAPA** 130** Municipal water company which provides water to the city of Cochabamba

CONCLUSIONS

Diagnostic of 36 water community systems in Cochabamba city, showed that 41% of them presented highrisk, 15% medium pollution risk, 32% low risk, and 6% very low risk. Water quality in the same systems atsources presented Iron above regulations in 33% of sources, and microbiological contamination in 46%. Atconsumption points microbiological contamination reached 50%, this type of contamination increased from

28 to 43% when the source is groundwater; since most of the systems do not have adequate maintenance it is possible to be the cause of the increase of contamination from source to consumption.Water supply per inhabitant per day in 10 water community systems showed that 90% is below the

volume provided by municipal water company, and below national water supply design standards, with 40% between 20 and 30 l/h/d, and 80% between 20 and 80 l/h/d, meaning that people living in areas covered bythese water systems receive less water than people living in area covered by municipal water system.

Deficiencies found from Microbiological pollution Risk for each community water systems could berepaired with simple activities that could be performed by water boards.

Developing a training program for these water boards could reduce pollution risks in water communitysystems.



MERCADO&ROMERO

6

AcknowledgementsThe authors would like to extend thanks tothe project “ Yaku al Sur - Fortalecimiento de la Gestión Comunitaria del Agua en Cochabamba (Bolivia) – AID CeVI/9137“, “ Yaku al Sur - strengthening of watermanagement at community level in Cochabamba (Bolivia) – AID CeVI / 9137”, who financially supportedactivities partially presented in this paper.

ReferencesCEDIB. (2006).“ Datos de la zona Sur Cochabamba ” – Data from South zone of Cochabamba.

Cochabamba: CEDIB.Centro de Aguas y Saneamiento Ambiental. (2009). "Calidad de agua en sistemas de abastecimiento en

poblaciones rurales dispersas" - Water quality in scattered communities water supply systems. Cochabamba.

Mercado Guzman, A. R. (2012)."Diagnostico de la calidad del agua e infreaestructura en 16 sistemas deagua comunitarios de la zona sur de cochabamba" - Diagnostic of water quality and infrastructure in16 community water systems of south zone of cochabamba city.XII Congreso Nacional de IngenieriaSanitaria y Ambiental. Cochabamba.

MINISTERIO DE SERVICIOS Y OBRAS PÚBLICAS . (2004). " Norma Boliviana NB 512. Agua Potable, requisitos" - Bolivian standard NB 512. Drinking water, requirements. La Paz: IBNORCA.

Ministerio de Vivienda y Servicios Básicos. (1999). " Programa de control y seguimiento de la calidaddel agua en servicios de agua para comunidades menores a 5000 habitantes" - Water quality program

for water supply systems in communities with less than 5000 inhabitants. La Paz.Rojas, R. (Marzo de 2006)."PLANES DE SEGURIDAD DEL AGUA (PSA). Hojas de divulgación

técnica" - Water security programs . Organizacion Panamericana de la Salud . OPS.Romero, A.M., Iñiguez, M.T., Gonzales, G., Arnez, M (1992). “Saneamiento Basico en zona s perifericas

de la ciudad de Cochabamba” – Sanitation in periurban areas of Cochabamba city . Centro de Estudios

de Población. Serie Documentos Nº 16, Cochabamba – Bolivia, 1992.Romero, A. M., Coronado, O., Muñoz G., Claros L.“ Reuso de aguas residuales y su impacto en suelos y

aguas freáticos ” – Reuse of wastewater and its impac on soil and water table. Congreso internacionalGestión sostenible del agua: reutilización, tratamiento y gestión de la calidad. ISBN 978-958-44-3709-9

Pag.: 335-340. 2008. ColombiaSEMAPA. (2010). http://www.semapa.com.bo. Verified on november 8th 2012,http://www.semapa.com.bo/institucional2.asp

Contact details

Álvaro Rodolfo MercadoCentro de Aguas y Saneamiento Ambiental, Facultadde Ciencias y Tecnologia. UMSS. Calle Sucre Frente alParque La Torre. Cochabamba. BoliviaTel: 591-4-4250660Fax:591-4-4229480Email: [email protected]

www: http://casa.fcyt.umss.edu.bo

Ana María RomeroCentro de Aguas y Saneamiento Ambiental,Facultad de Ciencias y Tecnologia. UMSS. CalleSucre Frente al Parque La Torre. Cochabamba.BoliviaTel: 591-4-4250660Fax:591-4-4229480

Email: [email protected]: http://casa.fcyt.umss.edu.bo

36 conference paper amg corregido (2)

Documents