May 14, 2021

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Water management in Puerto Rico unsustainable




More than a supply problem, the rationing that already affects 16,000 clients of the Aqueduct and Sewer Authority (AAA) –which could be expanded this week– evidences unsustainable management of the resource water and an absence of diverse and integrated strategies to ensure the continuity of the service in times of drought.

That is the opinion of several experts in planning, engineering and environmental management consulted by El Nuevo Día, who lamented the absolute dependence on It rains so that Puerto Ricans receive water in their homes.

Precisely, the AAA was kept vigilant yesterday at the Carraízo reservoir which has been at the level of operational adjustments for almost two weeks. A tropical wave that passed over the local area did not produce the expected rain, and Carraízo dropped 7 centimeters from Friday to stand at 37.46 meters. If the downward trend continues, the public corporation could announce a rationing plan for 180,000 subscribers in the San Juan metropolitan area.

Customers already experiencing scheduled outages in Río Grande, Canóvanas, Loíza and San Lorenzo, receive water from plants that feed on rivers whose flows have dropped due to drought.

“It is a shame that, being surrounded by water and having spent months of heavy rain, we are talking about rationing. We cannot depend on rain to have water; That is unacceptable from an engineering point of view. It is a strategic planning problem, "said the president of the College of Engineers and Surveyors, Juan Alicea.

According to the Servicio Nacional de Meteorología (SNM), January of this year It was the fourth wettest since records began in 1989. That month, the Luis Muñoz Marín International Airport Weather Station recorded 9.08 inches of rain, which was 5.32 inches above normal or expected to date.

Likewise, last February ended as the rainiest in the country's climatological history, with 8.23 ​​inches of precipitation registered at the airport. Until then, according to the SNM, the record for the wettest February was 1950, with a record of 7.90 inches.

“How is it possible that, just four months after those records, we are talking about rationing? Puerto Rico has to evolve so that, even if there is a drought, which is something that we cannot control, we do not have rationing. The measures are and are known, but a month or two before rationing there is not much that can be done, except conserve water, ”said the former director of the Caribbean Environmental Protection Division of Federal Environmental Protection Agency (EPA) Carl Soderberg.

The latest report by the United States Drought Monitor, released Thursday, details that 77.48% of the country exhibits abnormally conditions dry. Of that total, 59.84% is in moderate drought and 26.11% in severe drought.

On Thursday, the SNM reported that the east-interior of the island accumulates a rainfall deficit of between 8 and 12 inches. Other sectors, in towns like Trujillo Alto, Canóvanas and Loíza, have a deficit of between 12 and 16 inches. The term rain deficit refers to the precipitation that it does not receive in a given time. In the case of Puerto Rico, that period is 60 days.

Examples to follow

Alicea, Soderberg and the planner Félix Aponte, who until June 19 occupied a chair in the AAA Governing Board as representative of the public interest, pointed out that Puerto Rico must look at and emulate what various countries have done, throughout the planet, to effectively manage the water resource.

Near here, In the Lesser Antilles, it is common for homes and businesses to have rain tanks to collect rain and use that water in various tasks, such as cleaning, irrigation and industrial processes. On islands like St. Thomas and St. Croix, for example, the collection of rainwater in cisterns is required by law and is complemented by desalination of seawater.

The downside of desalination is its high operational cost, particularly in energy consumption, said Aponte. He stressed, however, that, in cities such as Sydney, Australia, there are projects to desalinate seawater using solar energy.

"In Sydney, anticipating the consequences of global warming, six or eight years ago, They started this project of using solar energy to remove salts at certain water flows to incorporate them into the system, and have been successful. It is an option that Puerto Rico should look at, "said the planner.

Alicea highlighted, meanwhile, that the cogenerator EcoEl Eléctrica, in Peñuelas, has a desalination plant, the production of which is used for cooling and other internal processes. "It is not the most modern plant, but it has given them quite good results," he said.

Another initiative that, in several countries, has been successful, but that in Puerto Rico is in its infancy, is the reuse of treated water . Israel, for example, recollects 80% of its waters and combines it with desalination so that its inhabitants do not lack service in the middle of the desert.

Likewise, Singapore, which imported all its water from Malaysia, cut off the dependency when deciding to reuse 100%. This even means that they make it drinkable to make it suitable for human consumption.

“In Singapore, they decided to be self-sufficient and reused 100% of the treated water. They have plants that they call water factories, in which they treat used water and discharge it to reservoirs so that they supply the water treatment plants, "explained Soderberg, who is executive director of the Puerto Rico Chapter of the Inter-American Association of Sanitary Engineering and Environmental.

He added that, in San Diego, California, they reuse treated waters to supply aquifers (groundwater systems). Statewide, which produces 40% of fruits and vegetables in the United States, treated water is also collected for agricultural irrigation.

The AAA treats approximately 200 million gallons of water daily at 51 plants, according to data provided by the public corporation. With EPA authorization, that water is directly discharged into the sea and other surface bodies, such as rivers and streams. Here, the only facility that collects treated water is the AES Puerto Rico cogenerator, in Guayama, which consumes 5 million gallons a day, from a nearby filter plant, for cooling processes.

Unacceptable loss

The interviewees stated that the main problem is that AAA loses 58% of the water it produces, which is equivalent to 292 million gallons per day.

According to AAA, 250 million gallons correspond to physical losses (leaks, tank overflows, broken pipes, etc.) and the remaining 42 million gallons correspond to commercial losses (theft, errors in the meters or in handling of data, old meters, and water that is authorized, but not billed, such as hydrants).

In terms of how customers are affected with so much loss, the AAA specified that 3,495 subscribers have what known as “poor service” that is, they experience outages at least three times a week.

The global standard for loss in a water distribution system, Alicea and Soderberg said, ranges from 15% to 17%. [19659003] "If we were to reduce the losses to 17%, we would have available the equivalent of 2.5 times what Carraízo produces daily and there would be no need to think about additional reservoirs," Soderberg illustrated.

Aponte added that, in systems such as that of Madrid, Spain, the loss is only 3%, because the city allocates between $ 200 million and $ 300 million annually for the replacement and maintenance of transmission and distribution infrastructure (pipelines). He urged, therefore, to prioritize local investment in that direction.

“The problem of losses in the system must be solved. It is an inefficient operation 365 days a year, which has a cost for the Authority for the incomes that do not arrive, but also for the clients, who pay this inefficiency on the bill, "said Aponte.

The president-elect of the Puerto Rico Water & Environment Association, Héctor Julián Camareno, indicated that, once the AAA solves its problem of water loss, options such as dredging of reservoirs would have better results.

The AAA itself recognized, in February 2019, that the reservoirs lost –on average– 10% of their storage capacity due to the sedimentation caused by Hurricane Maria. In some lakes, the loss would have been greater due to the enormous amounts of sediment that carried the rain runoff in the days after the cyclone.

“Dredging is a critical element in this situation. If we had greater capacity in the lakes, we would not be facing rationing. But it is an expensive option, and the Authority has financial problems, so what we see now is the result of that combination, "Camareno said, recalling that the AAA expects the Federal Emergency Management Agency (FEMA) to allocate part from post-Maria recovery funds to dredging.

Camareno and Soderberg added that, to control sedimentation in reservoirs, it is also necessary to reforest the hydrographic basins. According to the International Tropical Forestry Institute of the federal Forest Service, Hurricane Maria destroyed 144 million trees as it passed through the island. Trees naturally retain sediment.

Another possibility is a constant dredging project, that is, leaving machines in reservoirs continuously removing sediment.

Finally, the interviewees warned that no project will be sufficient if it is not accompanied by the social responsibility to consume water in moderation, since it is a finite resource.



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