QoWater - A crowd-sourcing approach for assessing the water quality

Nikolaos Rapousis, Michalis Katsarakis and Maria Papadopouli

UNIVERSITY OF CRETE Department of Computer Science

Department of Computer Science, University of Crete Institute of Computer Science, Foundation for Research & Technology – Hellas (FORTH)

http://www.ics.forth.gr/mobile mgp@ics.forth.gr

This research has been funded by a GSRT Research Excellence grant (2012-2015) , a Google Faculty Award (2013-2014), and EU Hydrobionets

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Resources WHH-WASH Sector Report, FAO, WHO, UN

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Roadmap • Introduction & Motivation

• Related work

• QoWater system

• Proof-of-concept & pilot testbed

• Preliminary field study & evaluation results

• Conclusions and future work

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Contamination events • Pressure loss or change may result in backflow incidents during which

contaminated soil water enters the water distribution network (WDN) through pipe breaks or leaking joints

• Corrosion of iron, copper, and lead parts of the WDN (e.g., due to free chlorine for disinfection)

• Bioterrorism

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Motivation • Efficient monitoring & management of the infrastructure, including the last-mile

access network

• Incorporation of customer feedback

• Increased customer awareness about the water quality & querying mechanisms

• Fast & efficient warning/alerting in the case of contamination

• More accurate models for assessing the quality of the water

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Roadmap

• Introduction & Motivation

• Related work

• QoWater

• Proof-of-concept

• Evaluation

• Conclusions and future work

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Related activities in water contamination 1. Mobile apps for querying specific sensors & providing feedback e.g., [Jonoski’13, Delhi Jar board, 311]

2. Sensor placement for supporting warming systems e.g., [Murray’10, Perelman’13]

3. Detection algorithms for drinking water contamination e.g., [Murray’10, Mix’12]

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Roadmap

• Introduction

• Related work

• QoWater system

• Proof-of-concept

• Evaluation

• Conclusions future work

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Health Organization sensors

Citizens/Customers with QoWater client

Water Distribution Network

QoWater client

QoWater server

Regulators, administrators, scientists

sensors sensors

QoWater system: client-to-server architecture

QoWater clients on mobile devices • Collect customer/scientist sentiments & store them locally • Upload data to the QoWater server • Query the QoWater server to acquire quality related info for various regions

QoWater server • Collects client and sensor data in spatio-temporal geo-DB • Responds to queries sent by users, providers & regulators

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Sensor measurements pH, temperature, conductivity oxidation-reduction potential & Ion Chlorine

Main screen

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Query based on clients score or sensor measurements

Results for query area, based on clients option eg, customer score

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Color: red/brown, green/blue, white, black Taste: bitter, salty, sweet Odor: sewer, chlorine, gasoline, chemical Appearance: floating particles, sand, milky, rusty, stain, animal, plant Pressure: no water, low, high

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Taste: bitter, salty, sweet Odor: sewer, chlorine, gasoline, chemical Appearance: floating particles, sand, milky, rusty, stain, animal, plant Pressure: no water, low, high

Chemical: turbidity, Br, Cl, Na, K, Mg2, biochemical oxygen demand, acidity, disssolved oxygen, etc Biological: ephemeroptera, plecoptera, excherichia coli, coliform bacteria, etc

QoWater Architecture QoWater server

Secure sensor readings upload

Certificate Manager

Memcached service

Certificate Authority

Data receiver

Query handler

Access control geoDB

Event detector

Data validator

Analyzer

HTTP service

PHP application

Upload data

QoWater sensor node Broadcast sensor readings

Monitor

Temperature

Conductivity

ORP

PH

Chlorine ions

Back-end interface

WiFi interface

QoWater client

Android device

Posi

tion

Ener

gy

Que

ries

Save

dat

a

Data Recorder

Cust

omer

Fo

rm

Scie

ntist

Fo

rm

Que

ryin

g

GUI

Sensor reading

GPS

Camera

Battery

Feedback

CSV

Measurement location

Back-end interface

Save sensor readings

SQLite

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QoWater server

Secure sensor readings upload

Certificate Manager

Memcached service

Certificate Authority

Data receiver

Query handler

Access control geoDB

Event detector

Data validator

Analyzer

HTTP service

PHP application

Upload data

QoWater sensor node Broadcast sensor readings

Monitor

Temperature

Conductivity

ORP

PH

Chlorine ions

Back-end interface

WiFi interface

QoWater client

Android device

Que

ries

Save

dat

a

Data Recorder

Cust

omer

Fo

rm

Scie

ntist

Fo

rm

Que

ryin

g

GUI

Sensor reading

GPS

Camera

Battery

Feedback

CSV

Measurement location

Back-end interface

Save sensor readings

SQLite

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Rely on the end-to-end security that protects the integrity & confidentiality by leveraging standard technologies (eg public-private key pairs, TLS)

Use Hadoop Distributed FS & Hbase for higher aggregate I/O throughput

Preliminary field study Three sources of drinking water: tap, purified, bottled

Objective measurements by sensor node • Duration of sampling: 36 minutes • One data point every 10 seconds • Collection of 215 data points (omit the first 50 data points)

Subjective measurements (QoE score) by 44 subjects • Three cups containing tap, purified & bottled water with no indication of the source of the water • Each subject inspects, smells, tastes the water from each cup and provides its score immediately

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QoWater Testbed Sensor • Equipped with a micro-controller that operates at 14MHz frequency • 8 KB RAM memory • 2 GB SD card • IEEE802.11b/g WiFi Server • VM with 2 cores at 2.4 GHz • 4 GB RAM • 27 GB storage • Ubuntu 14.04 OS

Client • Android 2.1

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The correlation of QoE with conductivity, ORP, & pH is negative, while with ion Chlorine is positive

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Divalent metal ions (i.e., Ca++, Mg++, and Fe++) influence the conductivity & hardness Conductivity and hardness impacts negatively the perceived water quality

Official Chemical Analysis

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Divalent metal ions (i.e., Ca++, Mg++, and Fe++) influence the conductivity & hardness Conductivity and hardness impacts negatively the perceived water quality

Official Chemical Analysis

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Official Chemical Analysis

Main outcome

• The QoWater, a crowd-sourcing/sensing system, provides collector & querying mechanism

• The QoWater can inform customers & regulators for contamination events

• Preliminary field study indicates that users can distinguish different sources of water

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Future work

• Implementation of the data validation & access control modules • Deployment of a larger-scale testbed & perform empirical studies

• Better understanding of the user sensitivity regarding the water quality

• Detection of contamination events

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