Minimizing water supply interruptions by introducing measures to protect water meters from freezing and bursting
Due to the widespread impacts of global warming, Korea has been suffering from water supply interruptions during winter time. As a countermeasure, Seoul Metropolitan City has implemented policies to protect water meters from freezing and bursting in order to minimize water supply interruptions and inconvenience to citizens. Furthermore, our efforts have been focused on improving citizens‘ standard of living by promoting technological innovation and implementing various other preventive measures.
Overview of the Policy
<< Upgrading and deploying water meters designed to withstand cold weather
<< Upgrading and deploying insulated meter covers for apartment (multi-family) establishments
<< Installing heat-insulating materials for meter boxes at single-family houses
<< Introducing protection measures against water meter freezing at small construction sites
<< Waging a water meter frost prevention campaign
Water plays a vital role in day-to-day human life. If a water meter bursts in winter, it becomes difficult to use the heating boiler, toilet, and cooking facilities. In addition, melting frozen water pipes can be very costly, imposing sizable financial burdens on citizens.
To minimize the potential inconvenience of citizens, we have been pushing through with various water meter insulation and protection policies.
Until the mid-2000s, citizens themselves protected water pipes during winter by placing insulating materials around water meters and pipes. Note, however, that such measure was found to be ineffective against the unexpectedly cold temperatures due to global warming effects as witnessed after El Niño.
Process of Policy Implementation
After the multi-layered analysis of the water meter bursting issue, we realized that the priority should be the development of water meters that are more resilient to freezing and bursting. Even if we built strong meters, however, we realized that other parts of the water supply facilities could burst if water freezes and its volume expands, leading to even bigger problems.
To tackle such problems, we established the “Technical Standard for Manufacturing Frost- Resistant Water Meters in Seoul,” a technical standard used to test and certify water meters that meet the technical requirements to be considered frost-proof.
After the introduction of the Standard, many manufacturing companies started to develop water meters that are more resistant to freezing weather. In 2006, the first certified water meters were developed and introduced to communities that were more susceptible to winter frost, thereby greatly reducing the number of water pipes damaged by frost.
Moreover, we have applied various other measures, such as introducing the standard for water meter boxes and improving the insulation of water meter covers to reduce the incidence of water meter bursts effectively.
Freezing and bursting of water meters depend largely on the pipes and the environment where the meters are located, such as housing types (apartment, town house, shopping area, or construction site). To prepare a suitable protection measure for each type of environment, we have been conducting complete enumeration surveys of the water supply systems since the beginning of 2000. The surveys allowed us to count the number of water supply systems by housing type and pipe.
Upgrading frost-resistant water meters
Regular water meters are susceptible to damage from cold weather because the water volume expands when it freezes inside. Note, however, that the frost-resistant water meter can better withstand subzero temperatures because it includes a special component that can absorb the expanded volume. The airbags found inside these water meters can absorb 8-13% increases in water volumes, effectively minimizing the troubles and costs incurred by water meter freezes.
In an experiment performed by the Ministry of Security and Public Administration in December 2012, under minus 15 degrees, a regular water meter froze and burst in five hours, but the frost-resistant water meter did not. In fact, the Korean government is carrying out various support mechanisms -- including financial support -- to deploy frost-resistant water meters more widely across the nation.
Upgrading and deploying insulated meter covers for apartment buildings
For water meter boxes located outside buildings like corridor-type apartments, we have been distributing insulated meter covers together with posters like the images below. Corridor-type apartments experience the highest incidence of water meter bursts, which sometimes escalate into bigger problems. Therefore, Seoul has long been committed to resolving the bursting issue in these types of buildings. In particular, since 2013, we have been pushing to improve the insulation of meters by developing the double-lid meter cover instead of the single-lid one since the upgraded version shows improved insulation by creating an air layer between the two lids.
Installing heat-insulating materials inside meter boxes for single-family houses
During the first half of 2013, we conducted a complete enumeration survey of all meter boxes in order to repair those that have been deformed or those with damaged heat-insulating materials.
The survey found that 110,000 units of meters were in need of repair works, and we are currently replacing them with PE insulation materials in order to minimize the risk of freezing.
Water meter insulation for small construction sites
According to research conducted over the past years, water pipe freezing and bursting are most likely to occur on pipes located outside, during holidays, and at night when water stops running, all of which are basic conditions of small construction sites.
Therefore, we plan to require small construction sites to install frost-resistant water meters when they apply for temporary water supply, and we will issue permits only when all the measures are in place. Moreover, we will enhance the level of inspection for construction sites that are more susceptible to water pipe freezes and run a campaign for protecting water meters from frost.
Promotion of campaign for winterizing water meters
We are cooperating with local district governments and media to run a campaign to educate citizens on how to winterize water meters. For example, we have utilized various communication channels such as the Korea Meteorological Administration and media to inform citizens on how to winterize the meters. We also distributed communication materials and posters with precautionary warnings to communities that are especially vulnerable to water meter freezes, made announcements to apartment residents, requested cooperation from local authorities, campaigned through various media channels, and used large electronic billboards and websites to communicate campaign messages.
Know-how & Insights
Seoul has faced many obstacles in implementing new measures to tackle water meter freezing and bursting; below are some lessons learned from our experiences.
Selecting a standard water meter for the city
Selecting the most suitable water meters for Seoul from so many meters produced by a myriad of manufacturers was not an easy task, made even more difficult when all the manufacturers present evidence of meters being scientifically proven and quality-tested.
Moreover, we only had a very limited time to make such a difficult decision since the bursting problem was recurring every winter. In addition, we felt that selecting the best-quality water meter for our citizens was our duty.
After numerous discussions and consultations with manufacturers, meter installers, and staff members, we were able to set up successfully the “Standard Test for Frost-Resistant Water Meters,” which manufacturers had to pass in order to supply their meters to the public.
Once the Standard was in place, we made the information widely available to all manufacturers so that they are clear on what our objectives and methods are. In other words, we encouraged them to follow the standard as closely as they can to be selected as our partners. We equipped the Waterworks Research Institute and Waterworks Material Management Center with the tools needed to conduct the test for manufacturers.
Upgrading and deploying insulated water meter covers for multi-family houses
In many apartment buildings, water meter boxes are placed in the corridor outside the house. As water meter boxes outdoors become exposed to cold air in winter, many meters freeze or burst. Some citizens voluntarily used insulated water meter covers to protect the water meters from frost. Still, such method proved ineffective in protecting water meters when temperature dropped to below minus 10 degrees. We recognized the urgent need to seek ways to improve the insulating capabilities of the water meter lids.
At first, we used insulating materials called "Atiron" or aircap to cover the water meter lids. Note, however, that this measure proved to be ineffective because the materials got easily detached due to their heavy weight. After many trial and errors, we decided to adopt the double-lid meter cover, which shows improved insulation by creating an air layer between two lids. So far, it has been found to be the most effective insulation method. Though we are quite satisfied, we will continue to push ourselves even further so that we can deliver the best services to our citizens.
Installing heat-insulating materials for meter boxes at single-family houses
Water meter manhole covers can be easily damaged from the weight of pedestrians or heavy cars parked over the covers. Previously, there were disputes as to who should be responsible for the cost of replacing the water meter boxes — the city government or the users themselves. In the end, Seoul decided to pay for the cost to reduce the inconvenience to its citizens. Currently, a new investment plan has been set up to fund the cost of replacing the damaged water meter manhole covers.
Policy Outcome & Evaluation
The change in temperature is the most critical cause of water meter damage from frost. The table below shows that, at similar temperature, the number of water meter damage cases dropped to 1/9 in 2013 or after the policy was implemented; thus proving the effectiveness of our policy. (Compare the data of 2009 and 2011, 2010 and 2012, and 2008 and 2013.)
This is an encouraging result since fewer meter bursts mean not only less financial burden on the citizens but also less stress and higher quality of life for our citizens.
Applicability of the Policy
The Korean government and many other local governments in Korea are exerting various efforts to deal with water meter freezing and bursting, and some have approached the Seoul Metropolitan Government for advice on this issue.
We believe that maximizing the benefits of such policy requires public support and engagement, which in turn necessitates rapid and accurate communication among the government and citizens.
For one, we can take advantage of the strong infrastructure of the Korea Meteorological Administration (KMA), which delivers more accurate weather information than ever before. For example, when we get weather forecast from KMA that the temperature tomorrow is going to be below minus 10 degrees, we can send a warning message to our citizen’s smartphones the night before. The message will prompt the citizens to leave their faucets at home open to let the water run very slowly through the night, which will prevent bursting.
Besides KMA, we can also work with the media and newspaper to give the same information to citizens to raise their awareness of the need to take precautionary measures and to be more engaged in the city‘s initiative.
How effective have the frost-resistant water meters and the insulated water meter cover been?
• Effectiveness of frost-resistant water meters
Compared to regular water meters, frost-resistant water meters are 7-9% less likely to freeze and burst from the cold temperature.
• Effectiveness of insulated water meter covers
According to an experiment conducted by the Waterworks Research Institute, installing water meter covers raises the temperature to up to 1.5 degrees. In addition, when water meter boxes were filled with enough insulating materials and protected by the insulated covers, such caused the temperature to rise by up to 7 degrees.
What are the differences between frost-resistant water meters and regular water meters?
• Characteristics of frost-resistant water meters
Frost-proof water meters can withstand frosts without getting damaged because they contain airbags that absorb 8-13% increases in water volumes. Such water meters can be used again when they thaw, thereby greatly reducing the costs and inconvenience related to water meter damage.
In an experiment performed by the Ministry of Security and Public Administration in December 2012, under minus 15 degrees, a regular water meter froze and burst in five hours, whereas the frost-resistant water meter did not. This shows the outstanding performance of frost-proof water meters compared to regular meters.
What are the criteria, standard, and method for the water meter frost resistance test?
① Internal pressure test - it has to be able to withstand pressure of 20kg/cnf for more than 1 minute
② Primary test for frost resistance
③ Secondary test for frost resistance
※ Conduct a flow test after repeating the process above for 7 out of 14 times.
④ Final flow test: The measurement error has to be within the user‘s tolerance (±4%).
⑤ Dismantling inspection: There should be neither deformation nor damage of the internal parts.