Encoding Leaks, Decoding Conservation

In the face of revenue pressures, increasing operational costs and manpower shortages, utilities can?t afford to ignore water loss. Nor can they afford to literally underestimate the problem. As utilities review better methods to conserve water and control costs, leak detection has become a critical component of any modern utility management system. This article will explore how utilities utilizing Neptune Technology Group?s R900 and R450 Systems can build successful leak detection programs, whether collecting meter data through mobile automatic meter reading (AMR) or through fixed network advanced metering infrastructure (AMI).

The Foundation for Leak Detection

With either a Neptune AMR or AMI system, the keystone and starting point is the value-added encoder: the E-Coder solid state absolute encoder. An E-Coder-based system provides an advanced level of leak detection and detailed consumption data that accurately identifies water leaks on the customer side of the meter.

Providing advanced eight-digit, high resolution data, the E-Coder provides resolution down to one- tenth of a gallon (1/100th cubic foot, 1 liter). This allows the utility to identify leaks that might otherwise be overlooked by lower resolution encoder registers that cannot deliver granular enough data to the AMR/AMI system to enable post processing leak detection.

The E-Coder divides each 24-hour day into 96 15-minute intervals and monitors flow during each of those intervals. The E-Coder continually checks for consumption in each 15-minute interval while its ?smart? meter distinguishes between intermittent and continuous leak conditions. It also keeps track of the number of days the leak condition has existed. The E-Coder sets flags in the register to mark these leak conditions, updating the flags every 15 minutes. This level of advanced data, or E-Coder PLUS data, is a valuable tool in water conservation and customer service. It also allows the utility to get the value of critical 15-minute usage monitoring without the need to backhaul and manage terabytes of data to do it.?

A small leak may seem insignificant. But if not caught early, it can add up to a significant volume of water. Leak detection for most competitive systems is dependent on meter reading resolutions of one to 10 gallons from conventional 6-digit encoders. At best, these systems have to rely on algorithms programmed into the MIU or software analysis at the host to ?infer? that a leak state existed ? never really knowing whether there was a true leak. Essentially, a 6-digit encoder may not increment in an hourly interval with flows that are indicative of leaks, so neither the algorithm in the MIU nor post precessing in the host can accurately determine whether a leak has in fact occurred.?

Consumption graphs based on Neptune?s E-Coder further illustrate the value of the E-Coder?s eight-digit resolution. Figure 1 shows a typical residential utility service connection using a traditional six-digit encoder with a visual registration of 10 gallons.? Figure 2 demonstrates the same residential utility service connection with E-Coder?s eight-digit reading which provides one-tenth of a gallon resolution. This residence developed a four-gallon-per-hour leak at 12 a.m. (see the circled area on Figure 2). The E-Coder?s eight-digit resolution not only identifies the leak but also displays the consumption when the leak starts. Additionally, the E-Coder sets flags for each 15-minute interval during a 24-hour period when this leak is present. With a 6-digit encoder, the leak could be masked as this consumption would not register for three hours until the low resolution encoder incremented. In all likelihood, it would appear as normal consumption.

For utilities using the R900-based raidio frequency system, Neptune?s solid-state E-Coder, R900i provides data logging capability for a rolling 96 days of hourly meter readings, plus leak and reverse flow flags. The? hourly readings and leak flag data generated by the E-Coder R900i can be transferred to N-SIGHT R900 software, where utilities can view reports that identify not only when leaks start but also the duration of the leak event.

R900 Data Logging as a Customer Service Tool

Historically, when responding to customer calls regarding high water bills, a utility?s only option was to issue a service order and dispatch a technician to the residence where the complaint occurred. The technician would then go through the process of ensuring that all of the external faucets were turned off, verify with the customer that no water was running in the home, and then check the leak indicator on the water meter. Sometimes the technician could verify the leak on the spot, but other times he or she would leave the homeowner frustrated and unhappy about their water bill.

The E-Coder R900i records consumption as it happens, every hour, allowing utilities to analyze usage patterns as proof of when and how much usage occurred. This historical consumption data can then generate consumption graphs within N-SIGHT R900 software. These graphs are available for either daily or hourly consumption. Leaks can be identified either when usage does not reach zero over a 24-hour period or when an E-Coder leak flag is triggered. In addition, reverse flow events are also illustrated.

R450 Data Logging

Neptune?s R450 System, with its intelligent N-SIGHT R450 host software, provides time-synchronized reads at midnight and 24-hour customer usage profile data for every customer under the network. Customer service representatives can, with the click of the mouse, pull up hourly, weekly and monthly usage information in an easy-to-use ?dashboard? format that assists in resolving high water bill complaints. Up to two years of consumption history is retained in N-SIGHT R450, so consumption data can be compared from one year to the next for the same period of time. Also, if the utility wants to have its customers get more involved in their own usage monitoring, they can look to Neptune?s N-SIGHT IQ, an intelligent data management and analytics system. N-SIGHT IQ provides utilities with the capability to deliver all metering data directly to their customers. The customer portal allows customers to view their own data and take control of their usage. Some of the utility configurable features of the IQ customer portal are:

? Detailed online access to a customer?s own usage
? Inclusion of weather data synchronized against interval usage
? Comparison of usage against utility defined groups
? Leak alert monitoring and notification
? Backflow monitoring and notification
? Setting, monitoring, and notification for a daily water budget

Consumption data is displayed in graphical and tabular formats, making analysis quick and easy. Utilities that seek to proactively notify their customers of potential leaks can have their billing or customer information system provider transfer the E-Coder leak information directly to their customers? bills, allowing customers to fix water leaks before the condition reaches the point where they issue a high water bill complaint.

Detecting Leaks on Distribution Mains

For utilities using either an R900 System or an R450 System, Neptune has combined its ARB technology with field-proven acoustic leak monitoring devices. When mounted on a distribution main, the acoustic logger ?listens? for leaks and transmits that data through the MIU and upward to the host software for early notification of distribution main leaks. Through this type of supply line monitoring, utilities can take a proactive approach to these conditions and repair leaks prior to distribution main breaks and potential loss of millions of gallons of water.

Water Audits and District Metered Area Monitoring

The Neptune R450 System provides time-synchronized meter readings at midnight from every water meter in a utility?s system, allowing utilities to compare production water versus revenue water and conduct District Metered Area (DMA) analyses.

Using the system?s time-synchronized meter readings, the utility will have the total consumption for any given collection of meters within a district or ?area.? This total consumption is compared to the master or ?bulk? meter(s) servicing the area. Systems having a large discrepancy between the total consumption in the area and the respective master meter(s) are indicative of potential distribution system leaks within a particular area. This is only possible with exact time-synchronized reads for accurate comparison.

Water leaks in any form ? leaks at the meter on the customer side or leaks along the distribution system – can be extremely costly for a utility. Using Neptune?s E-Coder technology, data logging, acoustic leak noise logging, and, in the case of the R450 System, synchronized system-wide meter reading, utilities can help prevent the loss of millions of gallons of water while recapturing revenue.

Dave Hanes is the Director of Strategic Marketing for Neptune Technology Group, based in Tallassee, Ala.?

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