As our population increases, the demand for clean, fresh water will also rise, making existing supplies a very precious resource. The Illinois Sustainability Technology Center (ISTC) launched a One Billion Gallon Water Challenge in 2014 to promote water conservation measures by businesses, industries, communities and the general public in Illinois.
The ISTC, a part of the University of Illinois, performs research, spreads awareness and facilitates implementation regarding practices, technology and systems that improve sustainability. It focuses its efforts in the areas of pollution prevention; water and energy conservation; and materials recycling and beneficial reuse.
To help achieve its 1 billion gallon goal, ISTC funded projects and conducted field-based research with industries, municipalities and universities that would result in measurable and meaningful water savings. It has funded projects with Carus Corp., American Water, Loyola University, City of Urbana, Illinois Water Survey and the Illinois Green Economy Network.
American Water and Echologics
ISTC partnered with American Water and Echologics, an affiliate of Mueller Water Products Inc. to validate the efficacy of an advanced leak detection technology based on acoustic monitoring within the metropolitan Chicago area. This project uses advanced continuous acoustic monitoring technology that alerts the utility to water leaks literally when they begin rather than when they surface. At the same time, the metering of the system supply serves to both quantify leakage and determine the extent of non-revenue water losses.
The project had four main goals:
(1) To promote water conservation in an area of the state where the availability of water could become a future bottleneck to economic expansion due to restrictions placed on withdrawals of water from Lake Michigan;
(2) To act as a test pilot and case study for the large number of surrounding municipal utilities that stand to benefit from the field research;
(3) To emphasize operational efficiency within private and public utilities; and
(4) To showcase an example of a successful public-private partnership that delivers major societal benefits.
Economic analysis included water production cost-savings, but also added secondary benefits to include reduction of worker overtime due to leak repair and damage caused by leaks. The system under study has non-revenue water of more than 45 million gals per year; it is anticipated that 15 million gals may be saved in the nine-month study period after installation of the monitoring technology.
How Acoustic Monitoring Works
Acoustic monitoring detects leaks by monitoring the sound signatures of water flow. The location of the leaks is determined by using multiple sensors and sophisticated signal analysis. The sensors themselves are relatively small and can fit in within fire hydrants.
The sensors are capable of identifying extremely faint acoustical noises emitted by leaks before they become detectable by conventional methods. This early detection capability enables utilities to prioritize repair based on actual need and the most effective allocation of repair crews.
Once a desired monitoring zone is identified, fire hydrants are fitted with the intelligent nodes. The nodes communicate with a central data collection hub and multiple data collection hubs are used for larger monitoring zones which can be expanded in phases. Flexible information backhaul options enable the use of the platform for utilities of all sizes.
As nodes collect data at predetermined times, proprietary filters are applied and the data is compared to baseline acoustical signatures at each hydrant location. When an acoustical anomaly is identified, the node sends a data file to the multi-channel Echologics Analysis Module (EAM). The EAM automatically requests additional correlation data from surrounding nodes, and automatically performs multiple correlation combinations to accurately target the location of the leak or acoustic anomaly. When a leak is confirmed, a notification is sent to the utility.
Installation of nodes into a fire hydrant offers several benefits that improve system performance and extends equipment life. The above-ground location of the node antenna enables a stronger and more stable radio signal. Placing the node in a hydrant cap also offers a better protected installation environment compared to valve box installations that can suffer from salt, silt, and dirt accumulation.
Des Plaines’Waycinden Water District
Des Plaines, Ill., within the Metropolitan Chicago area, was one of the six areas chosen for an ISTC-funded project. Water in Des Plaines’ Waycinden district is purchased from an adjacent water utility that provides water from Lake Michigan. Stopping water loss is critical because this water is significantly more expensive than the cost of water production from a groundwater source for American Water.
City of Des Plaines’ Waycinden District:
• Customer served: 750
• Annual water use: 255 million gals
• Percent of Non-revenue water: 20
• Anticipated annual savings: 20 million gals
In September 2014, the acoustic monitoring successfully identified a leak that was draining into a storm sewer. Water from this leak was unlikely to surface. It could have taken more than six months for the break to grow large enough to be detected. With monitoring, the leak was identified and repaired within 12 days with minimal damage to surface features.
It is estimated that this leak would have lost approximately 3.25 million gals of water over 90 days. Echologics’ software identified the location of the leak within 20 ft of the actual location, allowing digging of a very small trench. Early intervention helped avoid costly demolition and reconstruction of surrounding pavement that could have been necessary if the break had been allowed to grow.
The study will continue to collect data through the summer. It will collect details on the number of leaks detected, avoided water loss and avoided costs. While still early, the results to date suggest that taking advantage of advances in sensor technologies and signal analysis can provide substantial benefits to avoiding both water and economic loss.
This article was provided by Mueller Water Products Inc.