Wireless Sensor Network application for water quality monitoring in India

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2012 National Conference on Computing and Communication Systems (NCCCS)

Wireless Sensor Network application for water quality monitoring in India Dr. Seema Verma

Prachi

Department of Electronics Banasthali University Tonk, India [email protected]

Department of CSE & IT ITM University Gurgaon, India [email protected]

Abstract— Polluted water became a very serious issue for civilization from last few decades. Scarce access to potable water due to acceleration in urbanization, industrialization along-with crowded population, untreated sewage disposal and industrial effluents leads to various life threatening diseases especially in case of infants and women. To control level of contamination water surveillance becomes important. Manual water quality surveillance methods in India dramatically exacerbate water quality deterioration. Considering monitoring essence, we need a continuous, real-time, in-situ monitoring system for water quality management. Wireless Sensor Network (WSN) fascinated us for pro-active water quality management due to their real-time, continuous and dynamic nature, to act as early warning system so that WSN can trigger appropriate alarm in hazardous situations. Despite years of research and their extreme capabilities, application of WSN in environmental monitoring remains limited. In this paper, our aim is to discuss requirement and suitability of WSN for water quality surveillance. Keywords-Water; WSN; Water Quality Monitoring; India

I.

INTRODUCTION

Water is one of the most essential commodities for human well-being and substantial for socio-economic development of a country. Water is not only life-sustaining drink for humans and all other organisms but also vital for industrialization and agriculture. Total amount of water remains constant throughout the planet and adequate to meet all demands of civilization but potable water reserves are rapidly depleting all across the world. Growing population, discharge of toxic chemicals, untreated sewage, climate change and other human activities definitely impact water resources in densely populated regions if not handled effectively. In addition, water is not evenly spread throughout the planet so non-uniform, unsustainable and inequitable allocation results in problem of scarcity and availability. Over the major part of world, people use contaminated water tainted with diseases vectors and unacceptable level of various toxins for usage in drinking and cooking because of scarce access to potable water. In this paper, we choose India as a test case because as on one side, India is emerging as one of the most powerful nation and growing economies of developing world in terms of GDP growth but on other hand, India face many challenges on their way to economic wellbeing due to rapid increase in population growth. After

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independence, India has sustainably achieved many of the Millennium Development Goals (MDGs) like reduction in extreme hunger and poverty by increasing self-sufficiency in food grains. However, it has been unequivocally demonstrated that India is still far behind than many of the developing countries to suffice some basic requirements like water especially in rural areas where majority of population (72%) lives. Water has direct influence to safeguard human health since life conditions are deteriorating from contaminated water supply. Contaminated water is major cause of infirmity and leads to desolation and thousands deaths every day in several developing countries like India especially in children under age five years. Hence, one of their major health concerns is to reduce water-borne diseases. Diarrhea is one of the major causes of infant mortality in India. 70% of diarrhea cases are because of insufficient access to clean water and sanitation. In such cases, water quality is a direct culprit. Traditionally, India was well endowed with large fresh water reserves. However, increased urbanization and change in consumption patterns due to increased usage of water intensive products lead to overall increase in per capita water consumption. In 2005, 1.1 billion people lack access to drinking water resource. International community has recognized the need to control and monitor quality and quantity of water resource. As a result, drinking water availability is declared as one of the United Nations MDG to achieve and decade 2005-2015 as “Water for Life”. To achieve MDG for target date of 2015, UNICEF/WHO is working from last two decades to track progress on water and sanitation, they try to improve availability and reliability of water and develop monitoring procedure to improve it. According to UNICEF/WHO progress report of Drinking Water and Sanitation for 2012, over 680 million lack improved potable water resources and 2.5 billion lack improved sanitation all over the world [1]. If trend continues, this number will remain unacceptably high in 2015. Remainder of this paper is organized as follows: In section 2 we present the drinking challenges faced by various developing countries. Thereafter, in section 3 we review certain existing technologies used to handle the problem of water quality surveillance in India. Section 4 presents an introduction to WSN in respect to water quality monitoring. Section 5 discusses advantage proposed by WSN in respect to existing technologies. Related work in this context is

discussed in section 6. Finally, section 7 draws the conclusion. II.

FEW CHALLENGES

In several developing countries like India, rapid growth in terms of population, urbanization, industrialization amplifies consumption of water. Moreover, increase in usage of water-intensive products further enhances per capita overall usage of water. With rising consumption, deteriorating water quality and inadequate governance, India is likely to face a water shortage by 2050. UNICEF/WHO progress report for 2012 discusses few challenges that are yet to achieved: A. Huge disparities exist Most of the developed countries have achieved 90 percent or more improved water supply sources, while developing countries still lack behind with 86 percent improved sources and only 63 percent population with improved water sources within least developed countries. Moreover, coverage disparity may also found within a country between urban and rural areas. Rural areas suffer from acute water shortage. B. Lack of comprehensive information regarding water quality for global monitoring Monitoring methods acts as a pre-requisite when we need to know the extent of water quality degradation to improve water quality. Most of the countries lack systematic approach of measuring water quality through physical, chemical and biological parameters at national level. Monitoring procedures implemented by most of the countries are prohibitively expensive, complicated and non-periodic. Lack of information may involve a type of compliance and decision support risks. C. Lack of improved water sources In 2010, 680 million people lack improved water sources all over the world. More than one-tenth of global population relies on unimproved water sources in 2010. According to WHO/UNICEF statistics, in 2010, India is next to China with 97 million population lack to improved water sources. Investment in India for drinking water and sanitation is likely to exceed 90,000 crore from 2007-2012. Despite of Centre and States combined efforts of 1,35,000 crore till 2010-11, goal of clean and adequate amount of water to every rural person in the country still needs to achieved. III.

REVIEW OF CURRENT MONITORING METHODS IN INDIA

India has recently recognized the need to effectively handle fresh water resource to avoid water scarcity in future. Like most of the developing countries, water quality monitoring (WQM) in India is done through manual procedures. In India, Central Pollution Control Broad (CPCB) is chief regulatory agency and act as apex body of WQM [2]. A network of monitoring stations is established on rivers across the country for manual monitoring. WQM started in

1976 with 18 stations on Yamuna River in India. Idea is further extended to develop network of monitoring stations on rivers across the country and in 2007, more than 1032 stations and today 1700 stations spread across various important water bodies like rivers, lakes, wells, ponds, canals etc. Manual methods monitor surface water on monthly basis and ground water on half-yearly basis. Water specimens are collected and send to laboratories for subsequent analysis of physico-chemical and bacteriological parameters against standard value of these parameters at laboratories under National Water Quality Monitoring Program to determine gap, if any. However, with country of such a vast geographic expanse these methods are very insignificant and associated with various deficiencies A. Infrastructure Studies reveal that concentration of pollutant increased in urban areas. Stations should be laid down by taking into consideration varying magnitude of pollution. Identify major polluted area or pollution prone centre depending upon background details of that area and locate station accordingly. B. Delay tolerance These types of methods also consider subsequent delays but delay in analyzing specimens may adversely affect results. Water sample may get vary with time so if not analyzed in timely fashion results may get affected. C. Variation in various analysis methods Detection limits of instruments vary from laboratory to laboratory. Some laboratories may only contain measuring equipment for biological constituents and some for chemical constituents of water that may not suffice a specific application requirement. D. Manpower for data management and statistical tool Need skilled and trained staff for operation and maintenance. However, human may not reach at all places of deterioration e.g. in pipes. Some situations are beyond human reach. E. Temporal Contamination In case of temporal contamination, we are not proficient to capture reason for illness even if we take specimen after some time because contamination was temporary. So, it became difficult for us to find out exact reason of illness from water-borne disease. F. Non-real time monitoring Real-time monitoring applications like water safety, disaster prevention are delay bounded because these types of applications are critical for human survival but as aforementioned, manual methods consider subsequent delays. G. Alerts or early warning system Considering water quality surveillance significance, immediate alert is mandatory to cope up with degradation in

water quality and to take appropriate steps. However, lack of immediate alerts or absence of early warning system in manual monitoring procedures is hazardous or life threatening in some cases. H. Precision Unreliable, incomplete and time consuming data collection and lack of sophistication in these analytical procedures don’t enable us to achieve high accuracy but incur huge cost and low efficiency. Also, we need to intensify monitoring to gain spatial or temporal variation in water quality and to ensure complete and inclusive inspection. Results of a single sample are only valid for that particular location and time at which sample was taken. Furthermore, sampling should be done at various levels and at different locations to cover whole area because different areas may have different value for various parameters for water quality depending on contamination in that area. I. Resources Skilled manpower besides energy and cost intensive laboratory analysis results in huge cost that ultimately leads to inadequacy of resources. J. Installation, handling and maintenance Installation of stations after detection of pollution-prone areas, their operation and maintenance involve lots of human intervention and resources. It also consumes loads of time. K. Non-continuous, In-situ monitoring Even if safe water is delivered to customer, water can deteriorate on its way to customer. Deterioration can occur through different ways: • Emission of air-borne pollutants causes long-range contamination, not only in vicinity of industrial regions but also in remote areas. • Similarly, combination of gases produced by burning of fossil fuel with moisture in air results in acid rain and lead to contamination of surface water. • Part of reservoir or pipe can get stagnant due to growth of algae Apart from aforementioned causes, natural disasters always remain an important factor to add-on impurities. India and China still homes to 28 percent of unserved global population. But, we cannot guarantee access of safe and clean water to rest of the population due to poor monitoring methods available in India. Importance to maintain clean and safe water signifies the need to pioneer some advanced technological Water Quality Monitoring procedures for real time surveillance of water. However, monitoring strategy should also take into consideration requirements, objective of monitoring, cost involved and budget allocated. IV.

WATER QUALITY MONITORING WITH WSN

Recent improvements in MEMS technologies motivated development of small and inexpensive sensors. Sensors

collaborate to form WSN that allow congregating and processing all kind of data at a minimal cost with high precision. WSNs are easily deployed in ample of monitoring applications diversified in several areas like monitoring enemy territory in battlefield, terrorist tracking, patient surveillance with homecare, revealing presence of noxious gases, gauging crucial parameters in nuclear reactors, rescue operations in disasters (e.g. volcanoes, earthquake), advanced industrial process control, monitoring of aquatic biological communities and monitoring of waste-stream effluents. Therefore, WSNs are crucial tool for revolution in environment monitoring. They empower us for continuous monitoring of surface and underground water. Water quality Monitoring WSNs, also referred as aqueous sensor network (ASN) able to autonomously, continuously, in-situ and in real-time monitor streams, lakes, ocean bays, liquid streams in processing plants, and other bodies of water [3]. Depending upon the required application, we can incorporate different types of physical, biological or chemical sensors, allowing long-term, wide area, in situ multi-parameter monitoring. Each node of the sensor network is capable of measuring environmental parameters of interest. Beyond helping to ensure drinking water quality, the aqueous sensor network is a tremendous tool for biologists seeking to monitor the temperature, flow characteristics, and chemical environment of aquatic communities. They can be deployed in long-term aquatic monitoring (pollution detection etc) or short-term aquatic exploration (natural resource discovery). Through regular water quality monitoring, identify gaps with standards. Based on gaps appropriate action is taken for treatment. To determine drinking suitability, we continuously monitor water quality determination indices like pH continuously. An appropriate alarm is triggered when indices go out of restricted range, so that appropriate steps can be taken. However, we should take into consideration number of important factors before deploying sensor nodes in a typical environment: A. Selection of sampling locations Selection of sampling location should be done according to type of monitoring application. If monitoring is carried out for judging drinking water then monitoring site should be closer to intake points. B. Optimum number of locations Few sensors may give poor coverage and large number of sensors incurs enormous cost and discrepancy because underwater sensors incorporate high cost due to water proof casing, acoustic transmission etc. So set a limited number of sensors at various levels and locations so that optimum coverage of area can be achieved. C. Frequency of sampling Frequency of sampling depends on its intended use and location we are monitoring. Water used for drinking requires more frequent sampling than used for irrigation or industrialization. Besides, more polluted areas like city

located near industry required more rigorous and intensive sampling than for less polluted areas. V.

ADVANTAGES PROPOSED BY WSN IN RESPECT TO EXISTING TECHNOLOGIES

WSN is able to deal with all the deficiencies of manual method and present us with several benefits in comparison to previous methods. Here, we will discuss how WSN is able to handle these deficiencies one by one: A. Infrastructure WSN can be easily deployed in variety of water bodies irrespective of pre-defined infrastructure e.g. lakes, reservoir, ponds, wells etc. WSN permit real time monitoring of events, even if physical environment changes rapidly over time. WSN support rapid and flexible deployment of nodes for various monitoring applications, they can be either thrown from an aircraft or placed one by one by human or robots. Their ability to self-organize makes them easy to deploy, maintain and resilient in case of individual failures. B. Delay tolerance As we already discussed, water quality monitoring is a real time application and critical for human survival. So, WSN should be able to tackle the problem of quality degradation instantaneously. C. Variation in various analysis methods In manual methods, detection and precision limits of instruments vary from one laboratory to another. In case of WSN, we can precisely select various types of available sensors depending on requirement of application whether to check biological or chemical or both constituents of water. D. Manpower for data management and statistical tool WSN consist of huge number of intelligent sensors that can easily operate without human assistance for example in pipes etc to measure any chemical and bacterial change for detecting water quality deterioration. E. Temporal Contamination Water condition may get varies with time and contamination may be temporary but WSNs has the potential to localize the problem and generate immediate response in case of contamination. So, it became easy to prevent illness from water-borne disease. F. Real time monitoring As we already discussed that monitoring applications like water quality surveillance is a real-time application and disaster prevention is delay bounded. WSN perfectly suited to monitor and control real time aspect of quality deterioration. G. Alerts or early warning system WSN measurements are done and notified at real time to identify sudden degradation in water quality, in order to act

as early warning system so that appropriate alarm can be triggered immediately. H. Precision Only precise knowledge results in proper assessment of the situation and respective countermeasures can be taken by issuing timely alerts. Sensors work in a coordinated manner to cover all area at various levels to measure spatial or temporal variation in quality of water to provide complete, precise and intensified monitoring. I.

Resources Advancement in wireless and MEMS technologies results in generation of unmanned low cost sensors that can be easily deployed without human assistance. Furthermore, self-organizing feature of WSN greatly help to reduce cost involved in installation and maintenance of measuring procedures.

J.

Installation, handling and maintenance WSN have self-organizing capabilities and they can be easily deployed using aircraft without human intervention. Furthermore, if a sensor runs short of battery they can easily reconfigure themselves.

K. Non-continuous, In-situ monitoring WSN are able to handle continuous and dynamic surveillance of underwater environment that is not otherwise possible in time critical manner. WSN is a pioneering effort to maintain and control public drinking water resources and best to meet the increase demand for pro-active water quality management because WSN provide maximum return on their technological investment. VI.

SIMILAR WORK

Major concern with potable water safety is management, surveillance and control mechanisms to ascertain level of contamination involved. A number of researches have been done in various countries for the implementation for WSN for water quality monitoring. M. Zennaro proposed a prototype implementation of Water Quality Wireless Sensor Network referred as WQWSN in [4] based on SunSPOT technology. Main purpose of this project is to measure water quality at Malawi but it also tries to mitigate the problem of inter-networking and energy consumption. It uses threelayer architecture with gateway, wireless sensor node and water sensor board where gateway is responsible to collect data from sensor motes and make this information available via wireless sensor network. Remote WSN for water quality monitoring with the help of WSN and CDMA (Code Division Multiple Access) is implemented in [5] by Ji Wang et al. CDMA wireless data is responsible for implementation of remote detection and realtime monitoring of natural water. Optimization of node distribution is done with the intention of reducing energy consumption and ensuring effective information acquisition. Data transmission uses master-secondary station mode. Low-power Zigbee radios are used by small sensor nodes

whereas super-nodes use CDMA for transmitting data far away. The deployed WSN nodes transmit acquired water quality parameters including dissolved oxygen, pH, Conductivity. The SmartCoast Project presented in [6] by B. Flyrm et al. was co-funded by the Marine Institute and the Environmental Protection Agency (EPA). This project aimed to develop novel monitoring technologies that can continuously collect water quality parameters in lakes, rivers and reservoirs. Objective of this project is to provide environmental monitoring in Ireland. The system can be used to investigate various water quality parameters such as temperature, phosphate, dissolved oxygen, conductivity, pH, turbidity and water level for real time surveillance by remote users via internet. Water Quality Monitoring System using high power Zigbee Based Wireless Sensor Network together with the IEEE 802.15.4 compatible transceiver was introduced in [7] by Z. Rasin to offer low power consumption with high reliability. High power WSN is perfectly suitable for large area monitoring in industries for various activities such as manufacturing, constructing, mining etc. Base station of WSN consists of a Zigbee module programmed as a coordinator to receive data sent by sensor nodes (end devices and routers) wirelessly. Coordinator is normally mains powered because it need to continuously receive data from the end devices. Nadjib Aitsaadi et al. address the problem of optimal deployment of sensors in Underwater Wireless Sensor Networks [8]. They propose a simple algorithm that gives the position of underwater sensors that could be used to monitor the water quality in a small closed area (e.g. a lake). The mesh should have small triangles sizes where high sensibility is required and large sizes where low sensibility is required. The algorithm aims to minimize the number of sensors while ensuring a sensing sensibility value of each unit of the area.

and addresses the prospect of drinking water scarcity. Current WQM procedures in India are manual, expensive and time consuming. Here, in this paper we propose a new approach of WSN for water quality surveillance that is realtime, remote, automatic, effective and efficient with high precision. We also discuss how WSN is proficient to handle problem faced by manual monitoring methods available in country. REFERENCES [1] [2]

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CONCLUSION Significance of clean and safe water makes water quality surveillance a matter of essence. Our goal is to confront an emerging technology that performs continuous and dynamic monitoring of water by delivering high QoS whilst minimum cost dealing with new uncertainties linked to climate change

[8]

“Progress on Drinking Water and Sanitation 2012,” www.unicef.org/media/files/JMPreport2012.pdf, March 2012. “Guidelines for Water Quality Monitoring,” http://www.cpcb.nic.in/upload/NewItems/NewItem_116_Gui delinesof%20waterqualitymonitoring_31.07.08.pdf, July 2008. X. Yang, K. G. Ong, W. R. Dreschel, K. Zeng, C. S. Mungle, C. A. Grimes, “Design of a wireless sensor network for longterm, in-situ monitoring of an aqueous environment,” in Sensors, vol 2, pp. 455-472, 2002. M. Zennaro, G. Dogan, Z. Cao, M. Bahader, H. Ntareme and A. Bagula, “On the design of a Water Quality Wireless Sensor Network (WQWSN): an Application to Water Quality Monitoring in Malawi,” in Mieso, Denko, Eds. Proceedings IEEE NGWMN, Vienna, Austria, 2009. Ji Wang, Xiao-li Ren, Yu-li Shen, Shuang-yin Liu, “A Remote Wireless Sensor Networks for Water Quality Monitoring,” in International Conference on Innovative Computing and Communication and 2010 Asia-Pacific Conference on Information Technology and Ocean Engineering, pp. 7-12, Jan. 2010 B. Flyrm, R. Matrinez, J. Cleary, C. Slater, F. Regan, D. Diamond and H. Murphy, “SmartCoast: A Wireless Sensor nd IEEE Network for Water Quality Monitoring,” 32 Conference on Local Computer Networks, pp. 815-816, 2007 Z. Rasin, M. R. Abdullah, “Water Quality Monitoring System Using Zigbee Based Wireless Sensor Network”, International Journal of Engineering & Technology IJET, vol. 9, no. 10, pp. 24-28 N. Aitsaadi, N. Achir, K. Boussetta and G. Pujolle, “Underwater Sensor Network Deployment for Water Quality Monitoring”, in ACM WUWNet’06 in conjunction with ACM MobiCom’06. Los Angeles, California,USA,September 2006.