Severn Trent Supplied with Wastewater Monitoring Systems

Multi-utility monitoring and telemetry specialist HWM, in partnership with field services expert Enviromontel, has won a contract to supply, install and maintain fixed-point sewer network monitoring equipment for Severn Trent (ST).

In what is thought to be the largest project of its kind, ST is targeting better monitoring of its wastewater networks in order to improve performance and customer service, as well as reduce flooding and pollution incidents.

Following a rigorous evaluation process, ST decided that HWM offered the greatest overall value and was best able to help ST achieve its strategic objectives. HWM is due to provide three separate products over a five-year period, all based on the company’s new Intelligens data logger: 700 Intelligens Flow monitoring systems, capable of recording parameters such as velocity and depth, 3,000 Intelligens WW and SonicSens ultrasonic sensors, used to record the level of flow, and 1,130 Intelligens Flood Alarm systems, which register that the level in the sewer has risen beyond an acceptable height and transmit an alarm.

The intrinsically-safe (ATEX Zone 0) Intelligens is housed in a rugged IP68 enclosure and fitted with a GPRS modem for remote monitoring and reprogramming. The unit’s advanced power management allows for over five years’ data collection and transmission under standard operating conditions. An alarm regime can be configured for each channel and threshold conditions set to trigger faster logging and accelerated data transmission during alarm conditions.

The data logger and associated interfaces are compatible with a variety of sensors including Doppler-effect velocity, hydrostatic depth, ultrasonic level, radar level and digital inputs from rain gauges or float alarms. This allows HMW to offer complete monitoring systems suitable for permanent or temporary flow surveys, level monitoring or flood level alarm. Typical applications for the equipment include foul, combined and storm water sewers, as well as adopted private sewer monitoring, but it can also be used for open channel or outflow monitoring.

The benefits of long-term monitoring in wastewater networks include a reduction in both the frequency and impact of pollution events. Permanent installation of remote monitoring equipment helps to alert network operators to immediate problem sites. It also improves understanding of network performance and delivers data to assist with the development and testing of advanced network models.