The Main Event: Pumped vs. Billed Water
It seems simple: A utility pumps a certain amount of water, and its customers pay a certain corresponding amount for their use of that water. But a lot can happen to the water on the way: Leaks on the service line, theft and tampering, and main breaks or leaks can turn it into nonrevenue water.
Utilities have a new tool in the fight to conserve a precious resource and reclaim revenue. Using time-synchronized midnight meter reading, a utility can determine the total consumption for any given group of meters within a district or “area.”
These district metered areas (DMAs) also make it easy to mass balance an entire system’s water pumped versus water billed, where the total consumption is compared to a master or “bulk” meters servicing the area. Districts with a large discrepancy between the total consumption and the respective master meters indicate potential distribution system leaks within that particular area. DMA analysis helps to identify water losses both on the service line as well as pinpoint problems along the utility’s distribution system—down to the neighborhood level.
The key to DMA monitoring is system-wide, time-synchronized meter reading. As part of a two-way, advanced metering infrastructure (AMI) system, this ability to take a precise snapshot in time of the entire meter population goes a long way to recapturing nonrevenue water. It is a unique tool, and it is already yielding dividends for utilities using Neptune’s ARB FixedBase System based on R450 technology. For the first time, it is possible to compare meter to meter and calculate total consumption on a daily basis.
No Place for a Leak to Hide
It is only by synchronizing meter reads that a true comparison can be made. Without this
synchronization, all of a utility’s meters would deliver their reads and data at various times throughout a 24-hour cycle. One read would come in at 4:30 a.m., another at 8:10 a.m., another at 2:45 p.m. and so on. It is like trying to hit a moving target to get an idea of what is happening across the whole meter population at any given time.
By comparing “apples to apples,” so to speak, and reading every meter at midnight, a utility can see the total picture, including each consumer’s usage. The only way to compare the consumption of two meters or groups of meters is for their consumption to be on the same synchronized time basis. In the case of ARB FixedBase, that means midnight.
These synchronized meter readings are possible thanks to the fully two-way communication that allows meter interface units (MIUs) with transceivers not only to initiate signals back to the collector and then back to the host software, but to receive them as well. This includes daily time synchronization (to prevent time drift within the MIU) and remote programming.
When consumers inquire about a high water bill, they may not understand how much a single leak may add to what they owe. That is where historical consumption graphs—hourly, daily or monthly—come in handy. The ARB FixedBase System provides 24 one-hour consumption intervals on a daily basis to determine exactly when end-users are using water. Customer complaints about high water bills now can be resolved more expediently with the ARB FixedBase System’s capability to e-mail customers’ usage graphs that profile their water consumption, identifying leak situations as well as when actual water consumption occurred.
Together with time-synchronized meter reads, 24 one-hour consumption intervals allow utilities to easily and effectively monitor usage restriction programs (such as odd- or even-day usage) to further reinforce the importance of water conservation. And for more time-sensitive issues, utilities using the R450 radio frequency MIU connected to Neptune’s E-Coder can monitor 15-minute interval flags for leak, tamper and reverse flow detection. For example, this detailed usage data means the resident who tries to disable or tamper with a meter to disguise excessive water consumption will be identified more easily and quickly so that corrective action can be taken.
It is not just residential consumers whose use can be tracked. Hourly consumption and correct meter sizing for institutional, commercial and industrial users also can be monitored using time-synchronized midnight meter reads and 24 one-hour consumption intervals. If need be, a utility can make an informed decision to resize a meter for a specific application. Knowing when hourly consumption reaches its highest levels also gives utilities the ability to enforce water use restrictions on high-revenue users to manage supply.
In addition, accurate hourly consumption data supports time-of-use billing schedules, allowing utilities to better manage their resources and maximize revenue.
Critical Information in Alarming Situations
Using the ARB FixedBase System’s secure two-way communication (FCC-licensed 450 band) from the host software to the R450 RF MIU, a utility can remotely configure the MIU for priority alarms when specific conditions occur at the meter source and along water distribution lines. In this mode, when predefined flow parameters are met, an MIU will override its scheduled transmission time and immediately communicate the alarm condition across the two-way network. The utility can configure its system so that a critical alarm situation such as a 24-hour continuous leak or a major reverse flow event will send out an e-mail or text message to critical utility staff automatically, who then can quickly address the situation by dispatching maintenance personnel.
Like the consumer side of a system, so too the distribution side must be monitored carefully. Working together, Neptune’s two-way ARB FixedBase System and AMR Permalog acoustic noise leak monitoring devices can detect leaks in the distribution system. With early notification of distribution main leaks, utilities can take a proactive approach to these conditions and repair these leaks, even preventing distribution main breaks with their potential loss of millions of gallons of water.
Leaks on residential supply lines, stopped or inaccurate meters, unauthorized consumption and leaks on distribution mains—there are a number of common sources of nonrevenue water. All of these conditions can be monitored daily using the ARB FixedBase System, with priority alarms ready to help address critical situations.
When it comes to being more proactive for water conservation, enhanced customer service and improved overall operational efficiencies, it all comes down to timing—something synchronized midnight meter readings improves exponentially. If it is not in sync, revenue is going down the drain.