by Robert Burchard
Good to the last drop: A memorable coffee company slogan, but not really what a water utility manager responsible for continuous service delivery wants to hear. Water and wastewater utilities across the United States vary greatly in size, charter and focus, but they all face similar challenges to operate more efficiently in the face of increasing demand and the need to replace aging infrastructure.
The deployment and use of wireless broadband communications in support of advanced automation applications holds significant potential to help water utilities improve the efficiency of their operations across a range of business applications and business processes, including metering, infrastructure operations/control, field force communications, and leak/usage compliance monitoring. This article outlines potential broadband wireless communications approaches for water utility consideration in voice, data, mobile, and fixed applications. It also provides a summary of business process improvement opportunities and a review of a sample of technical considerations for use in both rural and municipal water system environments.
National Water Efficiency Imperative
Demand growth for water has strained many states' natural abilities to meet their needs, particularly in drought-hit regions such as the Southeast where surface groundwater comprises the major source of supply. With an estimated 65% of water consumed in the United States dedicated to agricultural irrigation, the challenge of efficiently managing and monitoring water consumption in rural and agricultural regions across the U.S. heartland is particularly vital to support the sustainable growth of the agricultural sector. Recent decreases in tax collections nationwide have placed significant pressure on municipal and state budgets, and the debt markets that water utilities rely upon to fund infrastructure and improvements have tightened considerably.
The Water Infrastructure Network estimates that over the next two decades alone, the United States will need to invest approximately $25 billion more per year than the current $60 billion spent annually to build, operate and maintain water and wastewater systems. The EPA estimates that $388 billion will be needed between 2000 and 2019 to address the United States' clean water infrastructure problems. In light of these demands and market conditions, collectively, the pressure to operate significantly more efficiently has grown into a national water utility industry imperative.
Smart Grid & Smart Water: Sharing Smarts?
In the May 2008 WaterWorld cover story, industry veteran consultant Ralph Abbott outlined the movement underway in the electric utility industry to deploy advanced metering infrastructure (AMI) systems, underpinning a ‘smart grid' movement that could help spur the growth of similar ‘smart water' systems for water utilities. Abbott cited the opportunity for electric and water utilities (when they aren't already combined, as is the case for many combined service municipal utilities) to collaborate on these initiatives.
Abbott wrote, "Municipal water utilities with an electric counterpart should communicate soon and often…most [electric utility] AMI system investments rest on a complex business case and using the same infrastructure for both electric and water obviously enhances the case…and both utilities reap the benefits."
While the field and network communication requirements of an electric and water utility vary in complexity, Abbott's point bears careful consideration. The communication systems that support real-time electric system control, monitoring and two-way meter communication across broadband and wireless fixed networks have many of the inherent characteristics of security, reliability and throughput needed for the deployment of potential ‘smart water' systems. Equipped with wireless metering, pumping station SCADA command and control, field crew communication and automated vehicle location, water utilities can achieve significant operational savings and proportional increases in operational efficiencies equivalent to or greater than the 20-25% that the Water Infrastructure Network reports are available.
The Need For Rural Water Utility Field Communications
The field communications requirements of water utilities vary somewhat expectedly according to their relative size and the physical characteristics (rural vs. urban) of their service territories. According to the National Rural Water Association, these differences in physical service territory can drive significant variance in the cost of service for customers depending on customer clusters and agricultural usage concentration in rural areas. The EPA reports that water systems that serve 100 people or fewer have an average of 33 customers per mile of water pipe, while systems that serve more than 10,000 people have an average of 71 customers per mile of pipe. For these reasons, the availability of reliable, secure and affordable broadband communications holds significant promise for improved operational efficiency across rural water service territories. In these areas, the cost of field crew travel for repairs, meter reading and service calls coupled with the relatively limited availability of commercial communications coverage options has resulted in limited connectivity and associated automation to date. For example, rural water utility systems have lower adoption rates than their urban counterparts where wireless drive-by AMR systems and telemetered pumping station controls with fiber or private radio network communications are becoming more prevalent.
Key Factors for Consideration
Regardless of size or location, there are six general criteria that many water utilities consider when evaluating the relative merits of various field communications options. In no specific order these include: price, investment return (based on multiple applications and coverage provided), utility control, financial flexibility, risk mitigation, and network option value. While the Quality of Service (QoS), security and other technical requirements for field communications vary across mobile, data, voice and fixed telemetry (metering/SCADA) applications, the three main options a water utility has for all of these various individual communication applications are:
- Buy radio equipment, integrate, and build private networks (900 MHz, 802.11g/WiFi).
- Source service from a commercial/telephony carrier (Sprint/Nextel, AT&T).
- Work with a dedicated provider of hosted broadband communications systems focused on utility applications.
Depending on its individual weighting of importance for the six requirement areas listed above, water utilities now enjoy an increasing range of field communications options — some with broadband service — at generally more affordable prices. This has significantly improved the business case for automation, including mobile work management, advanced/automated metering, remote/SCADA control and monitoring, leak detection and compliance field monitoring. High speed wireless broadband connectivity can even support advanced applications to enhance health, safety and critical infrastructure protection monitoring with remote, real-time video surveillance.
While there is no silver bullet solution or one-size-fits-all approach, the benefits of a licensed 700 MHz spectrum broadband communications system should be carefully considered.
Snapshot of One Potential Deployment
Figure 2 shows a system that can provide many connections such as SCADA and mobile workforce management on a single sector. The system can also support multiple applications on a single modem. Many electric utilities use a single modem to provide backhaul for a Wi-Fi access point, video surveillance, VoIP and SCADA. These same applications are available to water utilities. Up to 8,000 of these wireless modems can be supported with a single base station.
Arcadian Networks, a private wireless communications carrier, builds wireless broadband networks that are based on licensed, secure 700 MHz spectrum. A typical system configuration starts with a 700 MHz base station, which provides the foundation for its carrier-class solution. The base station supports data speeds around 1 Mbps per sector (depending on encryption overhead, etc.) and consists of a backplane with hot-swappable Access Modules and dual-redundant power supplies. An Access Module consists of a digital card, which handles all of the time-dependent MAC layer signaling and QoS assignments, and an analog card, which modulates and converts the signals from baseband to RF.
The solution depicted here allows a water utility to fulfill its pressing needs for ubiquitous, high-speed communications for SCADA integration and automation with a single, simple solution. Rather than patching together a quilt of disparate solutions from many vendors or telecom service providers, a water utility can deploy one solution that meets its data communication needs, including simultaneous backhaul for SCADA and aggregated advanced wireless metering. The same system can also provide portable data coverage and secure Internet access to workers in the field, as well as ISP services to rural customers in concert with the above. –wum
Conclusion
Water utilities face relentless pressure to increase operating efficiencies. The advancement of new field communications options from a variety of sources and at lower costs has improved the business case for the deployment of wireless field automation solutions. Rural water utilities in particular can benefit from new communications solutions that meet their unique needs for coverage over large geographic territories and multiple applications at an affordable price.
About the Author:
Robert Burchard is Director of Technology at Arcadian Networks. With 22 years of experience in the wireless industry, Burchard has served as a system operator and as a field engineer for specialized hardware design and manufacturing companies. He has designed and deployed microwave communications systems in sixteen countries and UHV systems in both the U.S. and South America.
