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WaterOperator.org Blog

Articles in support of small community water and wastewater operators.

Cellular Metering for Small Systems

Cellular Metering for Small Systems


Guest post by Brenda Koenig, Illinois State Water Survey.

Cellular-enabled water meters – also called smart meters – can make all the benefits of smart grid technology attainable for even for small systems on a budget. In this post, we’ll review the pros and cons of cellular vs. traditional metering systems.

Cellular meters offer service benefits

Due to their independence from physical infrastructure, a cellular system is better equipped to continue working through emergencies, such as floods, that might damage a large physical network. Cellular networks also make it easier to service dispersed or geographically diverse areas.

One of their greatest benefits is the speed of data. Cellular meters allow utility managers and customers to monitor their activity in real-time on the web. This improves leak detection and provides more opportunities for water conservation.

Weighing the costs

Cellular meters have potential to save utilities money on some fronts. Their use of cloud-based advanced metering analytic (AMA) software eliminates the need for expensive software installations at the plant. They also eliminate the need for a physical network of antennas, repeaters, wiring installations, and data collection units. Without the need for physical site visits to read traditional meters, utilities may also save staff time.

However, start-up costs for cellular metering can be significant, even without the expense of physical infrastructure. Buying and installing cellular meters can cost two to three times more than traditional meters. Staff and infrastructure costs will depend on what system you currently have in place. Cellular monitoring is compatible with most DEP and AWWA approved, AMR-compatible meters, but incompatible meters would need to be replaced. Staff may need to be retrained to install, maintain, and operate the new systems, as well as manage data, train customers, and set rates.

A growing trend

By 2020, it is estimated that 600,000 cellular water meters will be distributed annually, with companies such as Badger Meter, Arad Group, Neptune Technology Group, and Master Meter introducing cellular metering technologies.

So how does a small system decide if and when they too should adopt these new, game-changing cellular-based tools that are becoming more widely available and affordable? Much depends on each unique system’s needs and priorities, as well as the funding and political context in which they operate. Systems that are leak-prone or that need to step up their water conservation efforts may benefit from the daily feedback offered by cellular meters. Pilot programs or a comprehensive cost-benefit analysis can help utilities decide whether the tradeoffs in staff time, technology, and infrastructure expenses make sense. Finally, one of the best things to do is to talk to other systems about their experiences. Utilities with similar budgets, sizes, and goals can provide a lot of advice and references.

Resources:

Novato water district rolls out ‘smart’ meter pilot project news article, Marin Independent Journal 3/21/17

Big Data Flows: Water, Outsourcing, and the Flood of Data news article, EarthZine 6/30/15

Moving Towards Sustainable and Resilient Smart Water Grids journal article, Challenges 3/21/14

City looking to tap new water meters news article, Kingsville Record 3/1/15

RCAP - Water Metering Technologies presentation, RCAP Prezi 4/29/15

Advanced Metering Infrastructure, memo, City of Novi 4/24/15 

Lessons from the California drought: Planning rates and water conservation can protect utilities from lean times ahead.

By the time California entered its fifth year of historic drought last summer, water utilities across the state were dire straits. Statewide conservation orders had succeeded in many areas at reaching their much-needed target reductions, yet water agencies were struggling to meet their operating costs while facing millions in lost revenue.

Planning ahead can be critical to operating through decreases in demand or water use restrictions like those seen in California, especially with drought predictions ahead for states like Virginia and New Jersey. In the Twin Cities of Minnesota, the Metropolitan Council has assembled a suite of programs and practices water suppliers can implement to do just that.

This Water Conservation Toolbox for suppliers deals with the practical need to align rates with revenue, reduce water losses, and develop a water conservation program for your community.

Setting water rate structures that encourage conservation

The Toolbox includes two programs to help utilities set rates that work for water conservation. Learn through videos by the Water Research Foundation, or run calculations for different scenarios through University of North Carolina’s Water Utility Revenue Risk Assessment Tool. The tool allows utilities to calculate how much of revenue is at risk of loss if their customers lower their consumption, providing estimates based on the utility's own rate structure, customer demand profile, and weather conditions.

If you find a rate increase is needed for your utility, see our blog posts on how to lay the groundwork for approval and gaining community buy-in.

Stopping water and energy loss

Programs to audit leaks, recycle and reuse water and reduce energy can all save utilities money during water conservation. The Toolbox provides resources to learn about the close tie between water and energy efficiency at your utility, and how to identify losses. If you see a need for change, the Toolbox can connect you to help like the Water Loss Control Resource Community.

Building a water conservation program

Finally, the Toolbox features a suite of water conservation programs to borrow ideas from. Browse a library of options from rebate and voucher programs to school education from the Alliance for Water Efficiency. And when a change in infrastructure is needed to stop water loss, the U.S. EPA provides a list of resources for financing new water infrastructure in your community.

Getting a head start to avoid disaster

In the height of the California drought in 2016, Water Board chair Feilcia Marcus told the Sacramento Bee that, with the state facing longer, more frequent droughts, local districts need to devise rate structures that take into account prolonged conservation.

“It’s certainly a challenge for some of them, but not one that can’t be overcome,” Marcus said. “The right answer can’t be that we can’t save water in the worst drought in modern history because we haven’t gotten around to changing our rate structures, or because somebody might yell at us.” 

Common Distribution System Deficiencies

This article was first published in the Winter 2012 issue of Spigot News, the Ohio EPA's drinking water program newsletter. Many thanks for allowing us to republish it! You may also be interested in the articles Common Source Water Deficiencies and Common Treatment Deficiencies

This article is a continuation of the series on common deficiencies, covering source, treatment and distribution deficiencies. This article covers different aspects of the distribution system, including cross-connection, backflow, depressurization events, water age and infrastructure deterioration. 

Cross-connection
A “cross-connection” occurs in areas of the plumbing system where non-potable water comes in contact with potable water. There are two types of cross-connections: direct and indirect cross-connections. 

Direct cross-connections – the potable system is permanently connected to a non-potable system (for example a submerged inlet pipe for a chemical feed system). 

Indirect cross-connections – there is a potential for a connection of the potable system to a non-potable system (for example, a garden hose connected to an outside hose bid without a vacuum breaker or a bidet with a douche sprayer or jet that fills the bowl below the rim). 

Establish cross-connection control ordinances for municipalities with diligent inspections of new and existing plumbing to prevent possible cross-connection issues. These issues may be identified during a sanitary survey or when real estate is bought and/or sold within the municipality. 

Backflow and Backsiphonage
A “backflow event” is when non-potable water is forced by pressure into the potable water supply due to a direct cross-connection. All distribution systems must maintain a minimum pressure of 20 psig and a 35 psig working pressure during all water demands including fires. Distribution systems that fall below these minimum pressures may experience a backflow event if an overpowering pressure differential is experienced by a competing cross-connection within the system. 

A “backsiphonage event” is when water flows backward in the water distribution system from a vessel or other contamination source because the distribution system has lost, created or reduced pressure. 

Backflow devices (backflow preventers, double check valves, testable reduced pressure zone device, etc.) are required on certain businesses that pose the most threat to a potable water system, but municipalities can require all businesses and homes within their jurisdictions to install and inspect backflow devices every 12 months. Another preventative measure may be to conduct a hydraulic assessment of the distribution system to identify those areas at most risk of a backflow event. Once identified, these areas can be targeted for improvement.  

Depressurization Events
System-wide depressurization events are rare but can occur when mains break or electrical power is lost. When an event occurs, it is strongly recommended to issue a boil alert to those affected. Public water systems can issue a boil alert without consulting Ohio EPA, but boil alerts that affect a major portion of the distribution system must be reported within 24 hours. The municipality may lift voluntary boil alerts after the system is pressurized and the designated operator clears the system for providing drinking water. (Editor's Note: Please see your state agency for reporting requirements that affect you.)

The best way to avoid a depressurization is to keep the water and power flowing. When all power is lost through the electrical grid an alternate source of energy that will run the treatment plant and the distribution system critical components, such as a generator, is an excellent choice. 

Water main breaks are resolved by isolating the break quickly while maintaining water pressure to the rest of the system. This approach works well when all valves are accurately identified and working properly. A valve exercising program identifies the valves and keeps them working correctly in case they are needed. 

Water Age
The issues related to water age are directly attributable to water quantity and quality needs. These vital needs are always in conflict because quantity objectives dictate excessive storage issues while quality strives to minimize storage time while maintaining appropriate disinfectant residuals. Public water systems must strike a balance to minimize water age, effectively limit the formation of disinfection by products (DBPs) such as HAA5s and TTHMs, and keep disinfectant residuals within regulatory limits. 

A Distribution System Optimization Plan (DSOP) offers a mix of options for public water systems to meet quantity and quality standards by optimizing treatment and storage capabilities. OAC Rule 8745-81-78 (Note: This is for regulated entities in Ohio.) details the DSOP requirements and options. For more on sanitary surveys for small water systems, read Preparing for a Sanitary Survey for Small Public Water Systems.