Although more than 70% of the earth is covered with water, 97.2% of the water is salt water. Of the 2.8% that is fresh water, most of it is frozen into polar ice; less than 1% of the total water is underground or surface-fresh water. Of all the fresh water, only 1% is drinkable. In other words, only 0.01% of all the water on Earth is drinkable.
According to the World Health Organization, 884 million people lack access to drinkable water. Also, one out of three people worldwide face water stress or the need to compete for a limited amount of water. Climate change will exacerbate these problems, with droughts and floods making the distribution of water resources even more uneven. Efficient water management that conserves water by reducing waste and recycling wastewater more effectively is called for. So is flood mitigation to protect vulnerable cities and infrastructure.
Additionally, agricultural irrigation takes 48% of all fresh water. Of the remaining 52%, energy production takes 22%, with 6% going for industrial use and 24% for activities in residential buildings like flushing toilets, cleaning, and showering. These different sectors share similar problems, such as water leaks and/or inefficient water use. Poor water quality is also a problem.
So what can be done to address these problems? The industrial internet of things (IIoT) may offer some potential solutions.
The water cycle encompasses many points. These points include the buildings and homes where water is used. Other points in the cycle are renewable sources of water such as dams, lakes, and groundwater; water plants; water towers; and wastewater treatment plants. All these points can be made smarter by IIoT probes that monitor water use or quality.
Smarter water-leak detection, smart metering, and smart water distribution
Surprisingly, water damage poses a much bigger risk than fire or theft to homeowners. Water leaks cause water to be wasted. What’s more, the leaks may damage the floors, walls, and ceilings of a house and require expensive repairs. Water leaks are also common in larger buildings across many countries in the EU.
In an IIoT system, moisture sensors can be installed around a building to detect leaks. The sensors will collect data and send it back to the cloud for analytics. As soon as the analytics reveal an anomaly, a command sent to the smart valve will shut off the water automatically, minimizing the leak.
Smart metering can limit water use with remotely programmed automatic “open” or “close” commands, balancing water distribution and preventing uncontrolled use. Smart metering can also keep uncontrolled and unexpected leaks from escalating into floods.
Using smart water management, Robeau has helped airports, restaurants, manufacturing plants, offices, and commercial centers in the EU achieve water savings in the 25% to 40% range.
Cities and municipalities increasingly face flood issues as climate change makes the weather more extreme, causing serious droughts and large floods. Flooding is a real concern in North America and other parts of the world. Unlike in the past, flooding is becoming a year-round event, occurring after huge snowstorms in the winter and following rainstorms and hurricanes in other seasons. Issuing early and accurate flood warnings to save lives and avoid property damage remains a challenge despite advances in satellite imaging and weather forecasting technologies.
In an IIoT monitoring system, a distributed network of GPS-tagged water sensors or ultrasonic depth sensors can be mounted over bridges, rivers, streams, and storm drains. The sensors collect the data on water levels from various locations for analysis. Once the analytics determine an early flood warning is necessary, mobile alerts can be sent to local businesses, first responders, communities, and governments that may be affected. Flood monitoring systems have been deployed to many cities like Virginia Beach and Newport News, Virginia.
Agricultural smart water use
The farming industry consumes more fresh water than any other industry or human activity. The lack of supervision and real-time management has led to wasting a high percentage of irrigation water.
A smart IIoT-controlled irrigation system can collect real-time water usage data from sensors installed around farms. Based on sensor data, the system can switch the water on and off, depending on irrigation needs, to prevent misuse or underutilization. Also, the sensors can help detect and treat leaks in the water pipelines to reduce water waste.
In addition, smart sensors can help farmers track temperature, rainfall, humidity, and wind conditions. And with sensors to help ensure the desired soil moisture levels, crops get watered efficiently. Moreover, the water sensors can monitor other variables in the soil, such as pH levels, as too much soil acidity can prevent plants from absorbing nutrients. Assessing soil salinity is also critical, as some crops are salt-tolerant, while others are not. Lastly, water’s oxidation reduction potential (ORP) indicates its ability to break down contaminants; tracking ORP is useful for monitoring water contaminant levels.
Many pilot projects have shown that farmers can achieve significant water savings with IIoT use. For example, Kerlink, a French IIoT solutions provider, is working with Sensoterra, a Dutch producer of soil-moisture sensors. Robeau is working with farms in Scotland, Ireland, and France to achieve water savings of 25%.
Industrial, agricultural, and domestic wastewater must be treated to remove contaminants or pollutants. Meeting discharge standards for pH, suspended solids, and conductivity is necessary before discharge to urban water networks or natural water sources. Two different methods can be used to measure the contaminants:
- Biological oxygen demand (BOD) measures the amount of oxygen required for bacteria to break down the organic components in the wastewater.
- Chemical oxygen demand (COD) in the wastewater indicates the total amount of inorganic and organic chemicals. A high COD level means a large quantity of oxidizable organic materials in the water, which will reduce dissolved oxygen levels and endanger the higher aquatic life forms.
Thus, a high COD or BOD indicates a higher level of pollution or a lower quality of the treated wastewater.
IIoT sensors that measure variables such as pH, turbidity, conductivity, and oxygen levels in wastewater will help monitor the efficiency of water treatment plants. Stagnant water is also a source of contamination. Using IIoT sensors to monitor stagnant water can help schedule time-controlled purges to reduce the likelihood of contamination.
Design considerations and challenges
Because the IIoT sensors are installed over a large area, connectivity between the sensors and other system components is critical. Sensors used to monitor water are often submerged or exposed to outdoor elements or both, so they must also be ruggedized to withstand extreme temperatures. Ten to 20 years of field operation with no maintenance or battery replacement is expected, meaning power consumption must be ultra-low. Optimization for use in wireless communication bandwidth is a must as well.
Design case 1: Drinking water quality
The Hycleen Automation System from GF Piping Systems is used for maintaining drinking water hygiene in buildings. The system has temperature and flow sensors that continuously collect data on water temperature and flow, respectively. The data is analyzed to direct the system to perform hydraulic balancing, execute controlled thermal disinfection, flush the lines as needed, or alert the user in the case of malfunctions.
Moreover, the consumption-controlled flushing is fine-tuned.
First, measure two effective water consumptions during a specified period. Then compare the data with the target exchange volume. Only the difference is flushed, not the entire volume, thus reducing the flushing volume to a minimum and optimizing energy consumption without increasing the risk of legionella. The Hycleen system can be remotely controlled with any smartphone or similar device via an app.
The Hycleen System can be integrated into the building management system; it has been successfully used in complex buildings, such as hotels, hospitals, schools, apartment blocks, and industrial plants in Europe.
Design case 2: Pollution monitoring
SWARM buoys from Birdz measure the water quality of remote reservoirs. The system’s multi-parameter probes enable the measurement of quality or environmental parameters, such as conductivity, absolute pressure, temperature, active chlorine, turbidity, and organic matters. The real-time data collected is directly transmitted to the end user or remote server via its wireless communication module. Also, the buoy is low-maintenance and energy self-sufficient; it has an energy module comprising a battery and an energy recovery system. The buoys were deployed in the Malmsbury Reservoir in Australia in 2018. The maintenance required was quite low; the system required only one probe replacement and two physical maintenance calls during the first year of deployment.
Looking to the future
There is an initial investment in the implementation of smart water management systems. Using IIoT systems to monitor bodies of water or water quality may take a large number of sensors over areas where monitoring is needed, depending on the applications. Therefore, the cost-effectiveness of the sensors as well as that of the IIoT system is a consideration. The future payback, once the systems have been installed, can be big. The systems will be able to provide smart water monitoring, water leak detection, smart metering, smart water distribution, flood monitoring, agricultural smart water use, and improvement of water quality. And as the sensors are deployed to remote areas, continuously enhancing the sensors to increase reliability and energy efficiency and reduce maintenance is key.
John Koon’s current roles include embedded technology research and publication. He was the Editor-in-Chief of the RTC Magazine and COTS Journal. His current role is a freelance editor/writer working for multiple magazines. Additionally, he has published numerous technical articles, blogs, case studies and eBooks. His area of research include aviation, AI, autonomous driving, robotics, automation, medical innovations, wireless technology including 5G and low-power WAN, Fog Computing (beyond cloud) and edge, IoT, NB-IoT, LoRaWAN, cybersecurity, blockchain, Hyperledger, m2m, MEMS and sensors related, software, connectors, fiber optics and interconnects, aerospace/defense, manufacturing, semiconductor, power and battery, COTS advancements and emerging technologies. Koon has held various management roles including Director, Product Line Manager and Associate VP. Focus mainly on technologies, he worked for HP, Western Digital and distributors of Microsoft. He managed teams up to 11. Other experiences include publication of technology reports and many technical articles in the past 20 years. Speaker at the Del Mar Manufacturing Show and the Sensors Expo. He held a BS in engineering (California State Polytechnic University, Pomona) and an MBA (San Diego State University). He may be reached at email@example.com.