Kauai Department of Water

Known as the Garden Island for its picturesque beauty, Kauai is a 550 square mile island whose geographic centerpiece, the mile-high Mount Waialeale, receives more rain than any other place on earth. The potable water system for the island, operated by the County of Kauai, Department of Water (KDOW), KDOW Logo includes a series of wells, intake shafts (a sump that naturally fills with water and is equipped with a pump), tunnels (free flowing ground water sources), and booster stations. The system consists of 85 remote sites, organized into 19 hydraulic “zones,” scattered throughout coastal regions, sugar cane fields, steep canyons and mountainous rainforest.

Before this project, KDOW maintenance crews spent much of their time driving from site to site, many of which are difficult to access, checking on the status of equipment and performing emergency maintenance. Level control for this far-flung system depended on start-stop control signals from tank level switches carried over leased copper telephone wires to pumps at remote locations. The most important tanks were equipped with level switches connected via leased lines to alarm panels at local fire stations. When one of these tanks overflowed or went dry, the firemen would receive an indication and call the County Dispatcher, who in turn would report the problem to the appropriate KDOW personnel. If the message was successfully relayed (which was not always the case), KDOW personnel would be dispatched to the remote site to fix the problem. However, for sites without these alarm systems, problems were identified during the periodic site visits or via customer complaints. Control of the system was problematic and resulted in tanks occasionally running dry or overflowing.

In 1999, the Kauai Department of Water acted on this long-standing need to improve the reliability and safety of water distribution on the island of Kauai by selecting Timberline Engineering to study their needs and then design a Supervisory Control and Data Acquisition (SCADA) system to meet those needs.

When this project started, the owner had very limited expectations. They recognized that they needed technology to improve the control of their system, but they had so little experience with technology, they were concerned that they could be creating a whole new set of problems. In the Project Kickoff Workshop, Timberline asked KDOW, “How will you measure the success for this project?” KDOW’s General Manager said that beyond the obvious goal of a system that performed the intended functions, on schedule and within budget, the system would only be a success if their operation staff fully accepted and used the system.

Timberline is happy to report that after six years of study, appropriation of funding, design, bidding, integration, construction, and acceptance testing, KDOW has embraced technology and has come to rely on the SCADA system. The system performs its intended functions of control, monitoring, and reporting better than they hoped and the operations staff that uses the system every day have embraced it and found that it makes them more effective with less effort. In the words of the General Manager, “We are very pleased…the overall process has exceeded our expectations!”

Timberline Engineering is involved in another project on Kauai and has kept in touch with the Department of Water. After six years of use, the system is still as good as new and fulfilling the Department's needs.

Study Phase

Kauai’s remoteness and ruggedness presented unique challenges that Timberline responded to through innovative use of technology. As with most projects, understanding the client’s requirements and constraints is paramount to project success. For this project, the client’s needs were very complex, and significant interchange between KDOW and Timberline was necessary.
Can You Hear Me Now?
As such, Timberline immediately recognized that the time zone difference between Albuquerque and Kauai, and KDOW’s lack of email and internet access would create an impediment to effective communication. (These days, we expect everyone to have email and internet everywhere all the time; however, in 1999 KDOW had neither email nor internet access!) To help alleviate this problem, Timberline encouraged KDOW to adopt e-mail and web access for their employees, a program they had been contemplating but had not yet implemented. Once KDOW had that access, Timberline set up a database-driven website to communicate project requirements, facilitate system design, and provide a repository for project documents. Then as the design progressed, KDOW was able to participate fully, despite the distance and time zone difference.

In addition to these logistical challenges and the normal issues involved in the design of a SCADA system, this particular project included four unusual and complex problems, the solution of which required innovative applications of technology: hurricane survivability, corrosion and pest control, communications across rugged terrain, and the challenge of communicating alarms to a mobile workforce with varying needs and capabilities.

Design Phase

This project included four unusual and complex problems, the solution of which required innovative applications of technology: hurricane survivability, corrosion and pest control, communications across rugged terrain, and the challenge of communicating alarms to a mobile workforce with varying needs and capabilities.

Hurricane Survivability

When this project started in 1999, there was still abundant evidence of the damage caused by the Category 5 Hurricane Iniki that devastated Kauai in 1992. Consequently, it was imperative that SCADA system design consider the impact of tropical storm and hurricane damage. This requirement dictated that control of the system be decentralized. Then if some of the system was destroyed, the remainder would continue to operate. The requirement was met by installing submaster programmable logic controllers (PLCs) in each hydraulic zone, or group of neighboring hydraulic zones, that operate independently of the other submasters and the SCADA host computers. A wide area network was designed to allow high speed access between the submaster PLCs and the SCADA host computers via frame relay (high speed leased telephone data circuits) under normal operation and lower speed connectivity over either dial-up or cellular telephone in the event of frame relay failure. These concepts allow the SCADA system to maintain control of functioning aspects of the water distribution system even after complete failure or loss of communication to the SCADA servers.

With regard to the physical installations, it was determined that SCADA remote terminal units (RTUs) and associated antenna masts at individual sites should be able to withstand 115 MPH winds and that the monopoles supporting four submaster antennas withstand 150 MPH winds. Timberline engaged Boyle Engineering of Albuquerque, New Mexico to perform a structural analysis/review of Timberline’s standard design to ensure the design met this graded approach. (Boyle Engineering was the only subconsultant engaged by Timberline for this project.)

Finally, in consideration of the loss of power that invariably accompanies storms, all sites have been provided with battery backup systems (duration of operation depends on the importance of the site), and a sophisticated power management scheme that shuts-down non-critical RTU loads based on the duration of the outage. Key sites have also been equipped with solar powered battery charging systems to allow (weather permitting) for indefinite loss of utility power.

Corrosion and Pest Control

Corrosion and damage by pests is more subtle than a hurricane, but no less serious. Because of Kauai’s humid, rainy climate, equipment installed in unconditioned environments will rust very quickly. Even cabinets made of Type-316 stainless steel will show significant rust less than two years after being installed on the island. Submaster Cabinet with Separate Battery CabinetSince this project involved installing electronics in cabinets outdoors and in unconditioned buildings throughout the island, it was important that Timberline determine the best possible design to limit corrosion.

Timberline’s research into corrosion led to the finding that applying heat to stainless steel, through actions such as drilling, welding, and punching, caused the material to lose much of its corrosion resistance. To mitigate this problem, Timberline specified high-quality Type-316 stainless steel cabinets with a polyester powder coat finish. The specifications also called for all drilling, welding, and punching to be conducted in the factory before the cabinets were coated. No field modifications were allowed. In addition to equipment cabinets, a combination of epoxy painted steel, stainless steel, and non-metallic material were used as appropriate for the specific component and particular application. As a result of these carefully considered measures, cabinets and material installed in the early phases of the multi-phase installation process show little effect from the environment after nearly ten years.

Because of the temperature and humidity in Kauai, it was necessary to use ventilated cabinets. However, equipment is plagued by damage due to those “cute but pesky” geckos that are so prevalent in Kauai. Geckos find equipment cabinets to be an irresistible habitat, and they are capable of entering through very small openings. Almost every electrical cabinet that Timberline entered during field investigation contained geckos and their “droppings,” both of which cause problems to the components in the cabinets. The solution to the gecko problem was to specify cabinets with tight fitting, gasketed doors with multi-point rolling latches and ventilation louvers with filters and stainless steel insect cloth. The result is cabinets that have proven to be generally free of gecko infestation.

Communications Across Rugged Terrain

Kauai’s rugged terrain required a sophisticated application of radio and wired telemetry. Generally, SCADA systems communicate between master and remotes over multiple address system (MAS) radio. Photosim of Monopole at Princeville Tank In a typical system, the master station will communicate to all the remote sites over one or two MAS master radios situated to provide coverage over the entire system. In the case of Kauai, Timberline performed detailed radio path analysis followed by on-site radio testing to allocate the 19 hydraulic zones to nine submasters, each equipped with spread-spectrum MAS masters. In addition, four spread-spectrum end-link repeaters were needed to extend coverage to 11 outlying RTUs, and three of the sites required leased telephone service; two because their remoteness made radio communication impractical and one because of its proximity to an explosives storage, where radio transmissions were prohibited.

In addition to rigid-galvanized-steel (RGS) conduit antenna masts at most project sites, the radio system also required the installation of four monopoles ranging in height from 40 to 100 feet. For use in the permitting process and discussions with the public about project impact, Timberline prepared photosimulations for each of the monopole sites and some representative RGS antenna mast sites.

Communicating Alarms to a Mobile Workforce

The nature of KDOW’s workforce required sophisticated, flexible interfaces to the SCADA system. KDOW did not want a system requiring personnel to monitor SCADA screens on a 24/7 basis, as their existing operation staff works a standard Monday-Friday day-time schedule and are often located far from the main offices where the SCADA master station is located. Therefore, it was important that the SCADA system be able to deliver alarm information on a 24/7 basis to the operation staff, regardless of their location, in a clear, efficient manner. Furthermore, the maintenance staff has varying levels of technological sophistication, so a solution was needed that would work for everyone.

Timberline’s solution to this issue is a SCADA system that can analyze an alarm and contact the appropriate person (based on area of responsibility, time of day, and day of week), by the method that is most convenient for that person. Choices include voice synthesized telephone calls, e-mailed text messages, and pager messages. In addition, when a maintenance person receives an alarm message, he can call the SCADA system from a land-based or cellular telephone and interrogate it for more detail or log on to the SCADA system from his office, home, or mobile computer to look at the system in detail before responding to the alarm. This approach used sophisticated technology to make operation of the system readily accessible and remarkably transparent (given the complexity of the system) to KDOW’s mobile workforce.

Construction Phase

The Construction Phase of a SCADA project includes software development, RTU layout and fabrication, equipment procurement, physical construction, testing, and commissioning. Erecting the Monopole in LihueFor Kauai, the construction phase began in January 2003 and ended with final system acceptance in November 2005. The project had a construction budget of $4,500,000. The successfully contractor/integrator was award the project at $4,499,471. During construction, the owner added $285,618 in additional scope, including adding sites that were not in the original project, resulting in a final cost of $4,785,089. The project had multiple delivery dates throughout the various phases, and all work was completed on time or early. The project was substantially complete and KDOW was given full use of the SCADA system on July 5, 2005, the date the Availability Test Phase of the project began. The system passed the Availability Test on October 4, 2005, and after final punch list completion, the project was accepted in November 2005.

Because Kauai is distant from Timberline's home and from the System Integrator's facility, Timberline required that the contractor build "one of each" RTU type and hold for inspection before installing additional cabinets. That gave Timberline a chance to make a hold point inspection trip to the island. During that trip, one of 20 during the course of the project, Timberline noted variations between the project requirements, as shown on the project specifications and drawings and explained to the contractor what needed to be corrected for the project to be acceptable. Timberline has found that hold point inspections like these greatly reduce project risk by eliminating the chance that dozens of sites will be installed "wrong" and have to be reworked.

In the end, the SCADA system was completed on schedule and under budget and the resulting project was a huge success.

Overview SCADA ScreenSubmaster SCADA Screen


SCADA Benefits the Community

The island of Kauai, like every other community, requires a safe, dependable supply of potable water. Because many of Kauai’s facilities are very remote and located in harsh physical environments, equipment failures are not uncommon. Before the SCADA system was installed, these failures sometimes went unnoticed until the water supply was disrupted. Tanks overflowed, tanks ran dry, and occasionally chlorine residuals dropped to the point of having to issue boil water notices.

The SCADA system addresses these needs in two ways. First, equipment failures do not go unnoticed. When equipment fails, operations staff receive an alarm within minutes and have the information needed to decide if action is needed immediately or if the repair can be made at a later time. Second, SCADA supervisory control includes multiple sources of water for many of the tanks. If a pump is called to provide water to a tank, and the pump fails to start, the SCADA system reports the failure and then calls another water source to meet the demand. Consequently, the situation of a tank running dry or overflowing has been virtually eliminated.

In addition to ensuring the safety and reliability of the water supply, the SCADA system also has the potential to reduce the cost and frequency of equipment failures. Because KDOW staff doesn’t have to be dispatched to remote sites to check their operational condition on a routine basis, more time is available for preventive maintenance and system improvements. The availability of information also means that when there is a problem, the staff that responds will be equipped with information that will save time finding and fixing the problem. Finally, via the SCADA system’s SQL database, key information about water system performance is now readily, although securely, available to KDOW management, engineering and planning staff — a critical tool for analyzing their current and future operational needs.