Real Time Sewer Monitoring for the 21st Century The Evolution of the UK s First Real-Time Fixed Network for Blocked Sewer & Drain Detection, CSO Spill Duration Measurement and Pollution Mitigation Brian M Back BEng(Hons) CEng FIET MIoD
Background - The Global Water Challenge Countries across the World are now embracing the need to improve receiving water quality. For example in Europe this has resulted in the publication of the revised Bathing Water Directive. The links between water quality, public health and economic fortunes are clear and we must all now do our best to reduce pollution. This is the story of an innovative development that started in 2010 and by 2013 become an international success with over 1000 installations and according to customers has enabled significant reductions in pollution levels / incidents has been delivered..
Traditional Sewer & Drain Monitoring Worldwide circa 99% Complaint Driven When it is too Late! Backed up Toilets Sewer Flooding Polluted Beaches Polluted Shellfisheries Reported by the angry public, bathers, the media, enforcement..
The Political and Social Pressure are Mounting In Europe there is a now dashboard showing the quality of bathing waters http://www.eea.europa.eu/themes/water/interactive/bathing/state-of-bathing-waters-1
2010 Industry Survey Key Findings were: Monitoring predominantly data logging without real time data or devices that used the cellular GSM/SMS/GRPS networks shortcomings: o o o o o o o Variability of signal by the day / hour /overnight impacting on battery life and reliability (poor signal sites with battery life < 6 months) Lack of any coverage in remote areas Apparent year on year reduction in coverage (lost /orphaned assets) Lack of SLA from cellular companies Inability to be able to use the data locally has to go round the loop first Lack of assurances over 2G and 3G migration plans Spiraling cost of data hosting / server management Level & Flow Transducers (Ultrasonics & Radars) shortcomings: o o o o Difficulty of setup programming trip points / span, etc. leading to numerous operator errors and inability to service in bad weather. Poor testability! Complex installation process often requiring confined space entry High Battery consumption / slow wakeup time False alarms from steps and inability to work in deep or shallow chambers Cost o Growing uncertainties over the impact of TOTEX
What the Industry Tried to Achieve Blockages: Advanced warning of full or partial blockages detected through high level detection at manholes Combined Sewer Overflow (CSO) Activation: The flow duration at the overflow Surcharges into Properties: Advanced warning of events that may lead to surcharges through high level detection Equipment Failure: The monitoring of critical equipment that could lead to spills, surcharges or discharges. Such as the failure of pumps, small works, the blinding of screens, through high level detection and pump monitoring etc Correlation with Rainfall: The real-time correlation of rainfall intensity, soil moisture deficiency combined with high level detection within the sewers, plus rainfall correlation with the flow duration through a CSO overflow to prevents false alarms and helps to identify dry CSO spills
Industry Wishes Proactive Response to Blockages: Real-time correlation of risks associated with blockage real-time data and correlation with a historic database of history of event, rainfall and consequences. Helps to priorities responses when there are multiple events and/or resource constraints. Storm Response: Use real-time data to control pumps, to hold off flow or to boost flow Activate pumps to empty wet wells prior to forecasts of storms Divert storm flow to holding / storm tanks Use real-time data concerning flow duration to warn shellfisheries of CSO spills Use real-time data of flow duration to warn bathers / surfers when CSOs activate Surcharge Reduction: Use real-time data and high level detection deliver advanced warning of events, threats to property owners and businesses at risk
Industry Wishes Proactive Containment Dry Spills of Sewage: Fit and control containment valves/weirs using real-time data (rainfall intensity) to close of CSOs when a dry spill event detected Fit flushing weirs to storm drains suffering from misconnections to dilute pollution and using high level detection to identify pollution spills Expandability to include: Pump failure detection Surface flood alarms Security of assets Commercial drive for low TOTEX Future proof no worries over obsolescence No software maintenance cost Elimination of hosting cost Long Life Simple permitting anybody to service
Summary of Industry Priorities TOTEX Real-Time Data Effective High Level Detection Sensors Flow Duration Integration of Rainfall Intensity Risk Databases Pump Control Containment Valves/ Weirs Flushing Weirs Flood Alarms
The Solution of High Level Detection 2010 The Bulk Dielectric Transducer Level Detector Simple to set level curl the cable to set required depth Cable lengths up 10m Rapid fit - easy to install and setup from surface no confined space entry Power consumption < 1/50,000 of an ultrasonic device Responds and transmits in < 10ms Includes wireless uplink transmits every 2.5 sec permits patrolling ATEX certified Visual Set Point
The Solution of Flow Detection 2012 The Flow Detection Transducer Multi-axis accelerometer based technology cannot get jammed by ragging Simple to set level curl the cable to set required depth Cable lengths up 10m Rapid fit - easy to install and setup from surface no confined space entry Power consumption < 1/50,000 of an ultrasonic device Responds and transmits in < 10ms Includes wireless uplink transmits every 2.5 seconds permits patrolling ATEX certified Visual Set Point
Solution to Real-Time Data Real-time data National Ofcom licenced channel 2011 Band II frequency for good penetration of trees and urban environments Protected by Ofcom criminal offence to jam or tamper with signals No specified protocol - permitting the development of a lean and battery efficient protocol Fixed cost irrespective of the number of messages sent or the number of units deployed Deliver data to local assets
Network Architecture The Gateway Receiver Relay contacts outputs Signal monitor alarms Battery backup The Booster Repeater Extends range up to 5km Battery life up to 5-years Self test every 5-minutes
The Gateway Receiver - Universal Data Interface To Telemetry Outstation To PLC / Pump Control Compatible with a 1 year or 40 year old outstation, easy to test and utilises spare capacity
The Test Tools Instant boot up, receives messages from transducers and back-link data Instant roadside or vehicle reading of level or flow aids with the location of manholes
The Case Studies Case Study 1
Anglian Water Initial Trial Autumn 2011 After an Initial proof of concept demo North Lincoln was chosen for the trial as this had on-going pollution issues where rapid response was required and ultimate plans were to fit a containment valve.
Anglian Water Phase 1 - Rollout 2012 Feb 2012 the first rollout of 350 devices with 80 Gateway Receivers over a 6-week period during the wettest spring on record.
Anglian Water Phase 1b Containment Valve Trial Spring 2012 the first automated containment valve/ weir fitted to a storm drain to monitor for sewage intrusion from an up stream CSO. Valve kept normally closed and rate of change behind weir monitored using dual BDTs. If level increases excessively in dry weather then alarm raised. Otherwise valve opened periodically to flush and dilute contamination
Anglian Water Phase 2 Rollout 2013 A further 450 units with approximately 120 Gateway Receivers were installed mainly FDTs and mainly over a coastal region stretching from Southend to Hull. Phase 3 Rollout 2014 A further 25 FDT systems for coastal protection. Systems for real-time pump control / pollution mitigation planned
What Worked Installation Phase Demonstrated system easy to install and setup without the need for highly skilled staff, laptops or programming (enabled installation in the rain with nothing more than a battery powered drill and cable ties) Easy to visually verify the accuracy of installation Major improvement in health and safety by eliminating the need for confined space entry Numerous locations that were difficult to measure using traditional methods, due to steps, overhangs or lack of signal were successfully equipped Fully Integrated with the Anglian Water telemetry was simple with no worries over compatibility or security risks. Reduced traffic management costs through extended battery life and speed of installation Visually easy to audit and locate units once installed using handheld tool
What Worked Long Term Reported in 2013 to have assisted in the reduction of pollution incidents in pollution hotspots by up to 60% - helped to keep Blue flags flying Running cost for data delivery for all AW sites just 3900 per year in spite of 80-million messages. This figure will remain constant even as the deployment grows! The FDT demonstrated exceptional accuracy in the time domain resolving within +/- 2.5 min, no reports of false alarms Live data now used locally to control pumps and containment valve No occurrence of premature battery failures have been reported Modular construction permitted swapping of BDTs and FDTs in the field (we offer cloning of electronic serial numbers) Testability minimal training required for system maintenance. Handheld receiver able to resolve issues without lifting manholes or stopping traffic
Challenges Along the Way Rising Mains pumping at high level into chambers spraying both BDTs and FDTs causing false alarms. These locations not suitable for even ultrasonics. Hence the wireless float switch! Reluctance to installing standard boosters in parks lead to the development of the bird house booster / repeater that can be covertly mounted on trees. Call for a multi-level BDT for 3 stage warnings due 2014
The Case Studies Case Study 2
Guernsey Water a Different Challenge Challenge Develop PC based SCADA as the Islands existing SCADA was obsolete and offline Monitor 18 coastal CSO locations using FDTs to monitor the overflows. Deliver the signals back to Guernsey Water HQ with an antenna mounted on the existing congested radio mast. 78Km square coverage just one repeater location! Signals have in many areas had to cope with steep cliffs Lack of public structures for repeater stations
Guernsey Water a Different Challenge Challenge (cont) Antenna height limited to just 20m up the tower Receiver had to reject noise and inter-modulation products from the high power transmitters on the tower. Received data had to be relayed over > 200m using spare LAN cables Largest challenge getting the unilateral agreement from France and Ofcom that our licence could be extended.
Single Repeater Station at Victoria Tower Repeated Signal RS485 Data Cable Direct Signal
What Worked Windows Sentinel Software able to display and track activity across the Island. Customer able to configure GIS and drag and drop icons. Logging and e-mail alarms used by client. Able to re-deploy equipment at leisure The FDTs withstood the 2014 storms that brought 10m tides and damage to the coastal infrastructure of the island The adaptability of the system has now lead to a new contract for dual system to interface with the new islands SCADA and also to monitor the running of pumps around the island.
Summary Over 1000 installations across the UK and Channel Islands Delivering c 85,000,000 messages per annum, plus a growing number of commercial and industrial clients
The Outcome Eastern Region Innovation Winner 2013 Innovation Award 2012 Innovation Award Green Technology Innovation Award 2013 3rd National Awards 2014