Guest Column | August 1, 2018

Jumpstart Smart Infrastructure By Adding Sensors To AMI

By David Rubin

Smart water networks today do more than read meters. They also collect data from sensors on distribution networks to help reduce non-revenue water losses, monitor and control pressures in water mains, and prevent unwanted sewage discharge. These new smart infrastructure solutions help water utilities expand the definition of smart water — going beyond applications aimed at improving billing accuracy and efficiency.

Just like smart metering made billing more efficient, smart infrastructure solutions, which incorporate the characteristics of the Internet of Things (IoT), help utilities meet regulatory requirements, prevent pipe bursts, reduce energy costs, and identify hard-to-detect sources of water loss that result in lost revenues.

Underground leaks, for example, are a primary concern for utilities worldwide and a leading cause of non-revenue water losses. The Asian Development Bank reports that Asia loses around 29 billion cubic meters of treated water each year to leaks, at a cost of approximately $9 billion. The European Environment Agency also estimates drinking water losses from the distribution system average of around 30 percent in most countries, with leaks in urban reaching 70 to 80 percent in some cities. In the UK, even consumers are voicing concerns, with about 70 percent believing that their utility is not doing enough to reduce leaks, as reported in The Guardian.

Pinpointing Underground Leaks

These unapparent leaks can go unnoticed for years, washing away dirt and gravel under roads and buildings until a sinkhole appears and causes major infrastructure damage. However, utilities can extend the benefits of their advanced metering infrastructures by adding sensors that that use acoustic sensing to identify and locate leaks in water pipes.

These acoustic logging solutions help utilities:

  • Avoid high-cost catastrophic pipe failure
  • Extend infrastructure and treatment plant lifecycle costs
  • Conserve water and power
  • Meet consumer and regulatory service expectations

A variety of acoustic logging solutions are available on the market today, but unless the data collected from the loggers is also analyzed properly, utilities will have too many false positives that identify leaks where there are none, or worse, false negatives that miss leaks altogether. The right software solution combined with the acoustic logging will eliminate the noise and electrical interference that renders some leak-detection solutions ineffective.

What’s more, an acoustic logging solution should take into account pipe materials such as metal, concrete and PVC to provide for more accuracy in identifying leak locations, as pipe materials have different acoustic characteristics. In addition, solutions should install in standard valve stacks to give the fastest and most direct access to pipes.

Other factors to consider when considering acoustic leak detection are:

  • Application software that remotely correlate data and provides visual identification of high probability leak locations
  • Diagnostics software that ensure the system is operating at peak performance and notifies operators when problems arise
  • Time synchronization of analyses and sound recordings to provide system-wide correlation remotely without use of handheld devices

The Aclara leak detection solution is a smart infrastructure solution that provides automatic, accurate, and effective acoustic data logging and correlation.  It leverages both the proven capabilities of the Aclara RF network advanced metering infrastructure (AMI) solution and acoustic loggers from Gutermann, a global technology leader and innovator in intelligent water loss technologies and leak detection technology based in Baar, Switzerland.

Aclara leak detection technology operates on private, not public, radio frequencies over the Aclara RF fixed-network AMI. It can be implemented as a standalone fixed-network solution for leak detection or as a valuable add-on to Aclara RF meter-reading network.

The Aclara leak detection system is an example of a sensor that can be used effectively on an AMI network. The solution can identify the location of underground leaks to within a few feet.

Guarding Against Sanitary Sewer Overflows

Preventing sanitary sewer overflows (SSOs), which can unintendedly discharge raw sewage into the environment, is a national enforcement priority for Environmental Protection Agency (EPA) in the U.S. An estimated 40,000 SSOs each year are caused by events such as severe weather, vandalism, and improper system operation and maintenance.

The regulatory agency is vigorously moving to eliminate SSOs from municipal collection systems and to ensure that wastewater is conveyed to treatment plants in accordance with the requirements of the Clean Water Act. To eliminate SSOs, EPA uses a mix of compliance and enforcement tools, including traditional administrative and judicial penalties. These penalties can run to the millions of dollars.

And although the U.S. EPA has led the world in recognizing the problem presented by SSOs, other countries such as the European Union (EU) are also evaluating the problem. A report on the impact of SSOs in 28 EU member states, issued by Milieu Law & Policy Consulting, outlined the state of current legislation and regulatory policies and recommended implementing similar strategies as those used in the U.S. for managing SSOs.

As a result of this government focus, water and wastewater utilities are looking at a variety of technologies to prevent SSOs. One is the use of sensors to determine when water and sewage levels are rising in sewers or when manhole tampering has occurred.

These sensors, when operating on a fixed network, reliably provide near real-time monitoring of manholes and other key sewer locations. Whether used for early warning of overflows, informing maintenance schedules, compliance reporting, or deeper analytics (such as capacity modeling and performance reporting) sewer monitoring is a crucial solution for managing SSOs.

Aclara has designed an SSO solution that installs in manholes and will integrate into an Aclara AMI environment. It is available in two configurations — as a level alarm to provide warnings of impending overflow or level monitoring for tracking system efficiency and cleaning/maintenance effectiveness.

The Aclara SSO solution also offers:

  • Manhole level trends over time that indicate signs of decreased flow capacity — triggering a need for a clean out
  • A water consumption data over a sewer level versus time report to separate normal wastewater generation from inflow and infiltration (I&I) stormwater
  • Four user-configurable alert level thresholds to maximize operational flexibility
  • An event mode where intelligence in the endpoint adapts to changing conditions (can read/transmit more often when an alarm is tripped, for example)

Monitoring Pressure To Prevent Leaks

Another way to identify leaks and keep a water system operating optimally is through pressure monitoring. Pressure sensors located in the water distribution network can identify anomalies that could indicate leaks or the potential for leaks. Having pressure sensors monitored automatically on a fixed-network increases their effectiveness and efficiency in making pressure adjustments.

Pressure monitoring is especially useful in district metering areas to:

  • Perform flow and pressure calculations to show leaks
  • Compute water balance and determine minimum night flow
  • Identify where pressure can be lowered to reduce leaks
  • Control DMA gate valves

Automatic pressure monitoring on an AMI network also can help utilities reduce the damage caused by leaks and lower the chances of burst pipes by allowing operators to quickly reduce pressure when necessary. It also is useful in helping operators monitor pressure to maintain minimum service pressures as well as determine where problems exist when they receive low-pressure complaints. Pressure monitoring is also helpful in collecting the data necessary to calibrate hydraulic models.

Aclara integrates with a variety of pressure sensors with standard fittings to provide the data needed to understand how pressure is affecting the distribution system. The solution operates at multiple pressure levels and offers configurable alarms.

By harnessing AMI technologies to build out smart infrastructure solutions, water utilities can have an impact on their bottom lines and reclaim lost water revenue. Aclara powers the data-driven information and advanced applications utilities need to leverage AMI investment to improve services and manage water distribution networks.

David Rubin is the Director of Product Management - Product Marketing/Water for Aclara.