Public-private partnership aimed at stemming Puerto Rico utility’s vast water loss
Companies vie to install $400 million smart-meter system
SAN JUAN — The Puerto Rico Aqueduct & Sewer Authority (Prasa) is studying public-private partnership (P3) proposals for a $400 million smart meter system aimed at diminishing the utility’s prodigious loss of water due to leakage and theft.
The public utility issued an invitation for bids on the project in April and three companies responded, Prasa Executive President Elí Díaz Atienza told Caribbean Business. He said “some” of the P3 proposals involve consortiums with local companies.
“We are evaluating these proposals and we should have this up and running during the first or second quarter of 2020,” he said, declining to give more details due to bidding confidentiality issues. The company awarded with the P3 contract would run with the costs of installation and would profit from the “new income” received as a result of the water saved, he said.
The proposed metering system would involve the use of advanced metering infrastructure (AMI) and automatic meter reading devices (AMR), Díaz said.
The plan calls for the replacement of all mechanical water meters in Puerto Rico with digital meters with a useful life of up to 20 years, he said, noting that mechanical meters become obsolete after five years. Prasa has 1.24 million customers, of which 95% are residential.
The AMI would rely on antenna communication to relay real-time information on water use patterns between Prasa and its customers, while the AMRs would utilize the same antenna communication for drive-by readings of the meters whose information will be stored digitally, Díaz explained.
Prasa loses almost three-fifths, or 59%, of the water it distributes to customers due to leakages and illegal hookups, according to the utility’s last revised fiscal plan report issued in June, which notes that such losses amount to about 299 million gallons a day. Of the 507 million gallons of water produced and distributed daily by the utility, 250 million gallons, or 49%, are lost to pipe ruptures and leakages, and 42 million gallons daily, or 8%, are lost to unauthorized water consumption, inaccurate consumption estimates, and water tank overflows, according to the report.
The proposed P3 aims to bring that figure down to single digits with technology, Díaz said, noting the success of the smart metering system installed in Madrid, Spain. This infrastructure will involve the implementation of so-called district metering, with digital meters and water pressure-measuring sensors placed at key points in the system, he said.
“We have no problems with visible pipe ruptures, which are quickly reported. The problem we have is with leakage involving pipes that are underground. This technology will detect these hidden pipe ruptures to quickly fix the problem,” Díaz said, noting that software would be used to analyze water pressure patters to detect these leakages as well as the unauthorized use of water.
The proposed meters would not only monitor water use but also store information on water-use patterns at a home or business. The advanced metering infrastructure would provide Prasa customers as well as the utility with remotely transmitted, real-time information on water use.
“For example, the day you fill the pool, you will know how much water you used doing that. You will be able to follow your daily consumption of water in your account,” the Prasa chief said, noting that customers could have access to an application with which they could track consumption at certain times of the day.
“This technology could be more difficult to implement in some rural areas, but meter readers would be continued to be used there. The problem we have with the loss of water, commercial as well as residential, is that we don’t know where this water is being lost,” Díaz said. “If 100 gallons are sent through a pipe, but only 80 gallons are being charged, then I know that 20 gallons are either lost through leakage or someone is stealing the water. This information is critical to know leakages due to pipe ruptures that are either visible or are not visible because the pipes are underground.”
The utility currently employs 200 meter-reading workers, he said, adding that the utility would need fewer employees with the new system, the number of which will be determined based on the proposal approved.
“Some employees are going to be absorbed by the private company and others will be reassigned to other functions,” he said.