Water Monitoring Key to Competition
By Seanica Reineke
"In Nebraska, water is money." Water issues are a growing source of conflict and competition in many areas of the world, including the Midwest. But technology, such as water monitoring technology, may help alleviate some of the problems associated with water conflict, according to David Admiraal, associate professor of civil engineering at the University of Nebraska-Lincoln.
"Water itself is, of course, one of the most important things for human life and for life in general," Admiraal said. Requirements for accurate water quality and quantity measurements have gone up throughout the past four decades, he added, because both quality and quantity have decreased.
Also, he said accuracy is more important now because of the emphasis placed on the environment and on health.
Health is a main reason why people should care about water monitoring, he added, because everyone uses water and is affected by the quantity and quality of water available. People are concerned about
developing cures for cancer and other diseases, but Admiraal believes it is better to never have a disease than to have a cure for it.
"Having access to clean, healthy water prevents the spread of diseases that were at one time a far greater risk than cancer," Admiraal said.
"Whether it is water that we directly drink, water that we play in or water that our kids stomp through that flows in the gutters of our streets, I think most of us would agree that if possible, we prefer it to be free of unhealthy bacteria, viruses and chemicals."
People have realized that discharging polluted water into streams and rivers is not acceptable from a health standpoint, Admiraal said, because any non-natural chemical or substance has the potential to negatively impact the quality of life. He said water regulation in the United States has "vastly improved the health of the population by preventing the spread of potentially deadly diseases like cholera and other diseases that spread through human waste."
This also includes monitoring stormwater runoff, which requires programs to prevent contamination of water by oils, pesticides and fertilizers along with structural changes to water networks to help remove contaminants that impact the quality of life and the environment. Admiraal works with stormwater in his water quality projects with the city of Lincoln, sampling the water to monitor the levels of a variety of pollutants with the goal of developing better strategies for water quality improvement in streams.
Water is needed for various reasons: to fuel agriculture, for household uses, to produce economically feasible electricity and also for recreational purposes, Admiraal said. He added that water has helped develop Nebraska's strong agricultural economy. However, with increasing pressures on water usage, water monitoring is becoming a necessity.
"The science that studies contaminants and related issues is rapidly changing, but it will always be important for us to be able to quantify the extent of the problem," Admiraal said, "and this quantification will require that we know not only how much of any given substance is in the water, but
also the quantity of water that is being affected." He added that knowing the amount of water available makes it easier to decide how much water users, such as irrigators, ethanol plants and recreational users, receive. Not knowing makes it easy to misallocate that amount of water, which is already a limited resource, going to each user.
Water Monitoring- Measuring Quality, Quantity
Water monitoring measures the quality of water, including the water temperature, the chemicals- and the amount of chemicals- in the water. Monitoring also measures water quantity, which is the depth and flow rate- or gallons per minute- of the water. There are various ways to monitor water with different technologies.
Emerging technologies and techniques measure various features of water quality and quantity, but the accuracy of many of the economical devices is limited. Currently, some aspects of water quality can be measured instantaneously with electronic sensors, but few low-cost devices are available. Water monitoring relies heavily on laboratory analysis of samples to determine specific quantities of chemicals and constituents in the flow that cannot be measured accurately with electronic devices, he said. Based on his work, Admiraal believes cost-effective sensors that can directly and accurately measure specific chemicals in streams are "a long way down the road."
He said the most common way to measure water quantity is with a weir- a concrete structure, like a dam, that is installed to back up flow in a canal or river to form a reservoir, divert water into a side channel or purely for the purpose of measuring flow. Weirs cost anywhere between $1,000 and $100,000, depending on size, and can be placed in different types of channels- from small ditches to large canals.
There also are some newer technologies being used, though Admiraal said it is still sometimes difficult to get trustworthy measurements with them. One new technique is measuring surface velocities of rivers with radar, microwave and imaging techniques. Another technique is with hydroacoustic devices, which can measure velocities throughout the water column, which is the water flowing in a river between the surface and the bed. Admiraal said these technologies hold promise for: improving measurement accuracy; making measurements in a short time; reducing the need for a skilled operator for long periods of time; and measuring flow rates in places too dangerous for an operator to go.
Future Improvements and Developments Necessary
Currently, typical water quantity measurements are 10 percent accurate, which Admiraal said leaves plenty of room for improvement. He said new technologies, such as those with remote sensing capabilities without structures and without on-site operators, are needed. He said those technologies currently are being developed. Typical water quality measurements are even less accurate and more difficult to obtain than water quantity measurements. "We need devices that can not only identify the quantity of a contaminant, but what contaminants are present, and that's a pretty complex thing to do."
Admiraal said scientists and engineers need to produce devices or improve existing devices that measure flow from a distance over a wide area, allowing for better estimates of the total water budget across Nebraska and the United States. He said these devices would ensure more accurate allocations as a result of more accurate measurements. "Competition for water will grow independent of water measurement," said Admiraal. "Knowing the amount of water won't affect how people try to get their hands on it, but it does allow us to determine if it is being distributed correctly. Accurate measurements make sure what was promised and delivered are the same."
Already, Admiraal said, "big strides have been made" in thermal measurements by using thermal cameras to measure water surface temperatures from a distance. He described how a number of researchers have used thermal imaging to measure temperatures near power plants because they use
water as a coolant. "I would expect to see not just thermal imaging, but other technologies pop up in the future that are going to help us come up with better flow measurements, better water quality measurements," Admiraal said. "It's an emerging technology, and just like any emerging technology, you find new uses for it and it becomes less expensive as they find new ways of using it or developing that technology."
However, he said there are tradeoffs between accuracy, cost and where each method can be used effectively.
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