Measuring water consumption simplified with automatic meter reading systems

Charging by metered use is common throughout the western world, with the notable exception of the United Kingdom. Even in the UK, however, the benefits of measuring the consumption of water are increasingly being acknowledged.

Water utilities around the world are moving towards deregulation and privatisation, as are electricity utilities. In both cases the value of metering as a management tool in a commercially motivated industry is universally accepted. Metering systems can be used to monitor trends, extremes and general demand criteria. This information, together with the assessment of local or regional factors, can be used to assist in the optimisation of current plans and for the enhancement of future network management. When demand is reduced and wastage and losses are easily identified and controlled, the result is a reduction in source, storage, process and pumping costs. A further benefit is that sensitivity to cost encourages the availability of water-efficient consumer products. This in turn leads to savings in existing plant costs, and even the deferment or cancellation of new works. The need for increased storage in some areas can be contained, and reduced waste leading to lower pumping and processing costs could also apply. If demand is to be stimulated or moderated by price, tariff or penalty, consumers must have the freedom to choose, or at least have some control over, the circumstances in which a commodity is purchased. The `fair society' philosophy implies payment for consumption, and a choice of supplier. In order to be the supplier of choice, water utilities need to contain costs and offer improved customer service. Evidence from the USA and Europe indicates that a saving in customer support resources can be realised when an automatic meter reading system is installed. Water companies face the same problems as their electric counterparts when it comes to reading meters. Employing meter readers to visit sites and manually record meter readings is time-consuming (especially if access is a problem) and prone to human error in logging data, both at the meter site and when entering the information later into the billing computer. The move from manual reading to hand-held electronic reading, and ultimately to radio- or telephone-based systems, already a common feature in the electricity industry, is being made by more and more water utilities too. Although a substantial capital outlay is required in terms of meters, reading systems and installation, the technology is being developed at such a rate that cost effective approaches have improved viability, particularly in the areas of integrated systems and automation.

Automated on-site reading systems

Mid Kent Water, a utility situated in one of the driest parts of south-east England, launched a pilot study in 1993 to measure the effects of metering on water demand. A total of 3 500 meters was to be installed, and all these meters had to be read in under a week. An automated reading system was therefore essential, and the Sensus TouchRead system was chosen. The meters were installed in boundary meter boxes with pit lid reading modules mounted in each hinged iron lid. These lids had been specially designed with a cast-in hole to accept the pit lid reading module. Once metering was underway, a reduction in demand was clearly noticeable. A further benefit of measuring consumption was that the total water supplied into a zone could be compared with consumption taken out of a zone, thereby providing the water balance. Mid Kent Water has been able to build up an increasingly detailed picture of the consumption within the pilot area, and is in the process of extending the automated on-site reading system to all domestic households. In future the utility plans to upgrade its present system to a radio-based version, and the TouchRead system allows for this upgrading.

Radio-based remote reading systems

The hand-held computers used in automated on-site reading systems speed up the meter reading process considerably, while billing errors are minimised. However, a visit by a meter reader is still necessary before the data can be gathered. The introduction of radio-based remote reading systems removes the need for a personal visit to each meter. Billing errors are still minimised, however, because of the automatic meter reading (AMR) process. When a radio-based remote reading system is installed, each meter is fitted with a small radio transponder or transceiver unit, while the meter reader or drive-by vehicle carries an interrogate/receive device. The device sends a `wake-up' signal to the meter, and the transponder sends back the meter reading, which is automatically captured and stored in a hand-held unit, if the meter reader is on foot, or in a portable PC if a vehicle is used. The interrogator and PC can also contain pre-loaded route information, which compares readings and data to ensure all meters are read and to alert the operator to any problems, such as a large increase in consumption, which could indicate the presence of a leak in the network. Some radio-based metering systems can pick up the data from the meter at distances of 200 feet or more. Certain systems allow data to be collected if the drive-by vehicle is travelling at speeds of up to 45 miles per hour (72km), so it is not always necessary to slow down or stop to take a reading. In addition, with some systems line of sight is not always necessary for transmission success. The speed at which large amounts of meters can be read is one of the major features of radio-based systems.

The benefits of telephone-based systems

Telephone-based meter reading is not always a viable option consumers may not have a telephone at all, or if the meter is at a holiday home, the telephone may be switched off when the building is unoccupied. However, in those cases where telephone-based meter reading is appropriate for example, at hazardous meter installations where the possibility of employee injury is increased the system has many ad-vantages. Unlike the hand-held electronic or radio-based options, telephone-based meter reading is battery free, which means greater dependability and fewer maintenance problems. There is instant access for making final reads or for tracking water use, and water utilities can improve their cash flow, thanks to a fast reading-to-billing cycle. No assistance is required at the customer end, and installation is easy.

It seems evident that the use of AMR systems to measure water consumption will continue to increase in domestic and industrial sites as improvements in technology drive the initial cost of these systems down, and as privatisation makes it imperative for utilities to control ongoing costs and offer improved service.