How to use every drop of water in a desert area where more than half population of a country lives?
This is case in Peru, where its complex and heterogeneous geography makes it difficult to provide drinking water to all its inhabitants. Divided by Andes, coastal and desert strip of Pacific is home to 56% of population (more than 15.8 million people) and only 53 seasonal rivers run through it.
In addition to great demographic pressure on water resource, this region presents greatest water needs for both agriculture and industry.
As a result, water stress - when demand exceeds amount available over a given time - has become main threat brought by climate change, which is exacerbated by increasingly frequent natural disasters, such as recent El Niño phenomenon that affected large areas of Peruvian coast.Treat and reuse residual or used water
One response to this phenomenon is, according to experts, fullest use of wastewater.
In Peru, only 70% of residential wastewater in urban areas receives some type of treatment before discharge into waterways, usually at sea. In addition to this considerable waste, treatment of wastewater in urban areas of country is 44%, excluding city of Lima, with about ten million inhabitants.
That is why achieving reuse of wastewater is one of main environmental, technological, financial, institutional and social challenges of Peru and region.
Leaking (treated or untreated) wastewater to sea means losing a valuable resource that could be used to irrigate and forestate desert, develop agricultural ventures, increase green areas in cities, or enable new industries that create jobs and promote economic growth .Solutions
The agency for Promotion of Private Investment in Peru recently announced that 15 wastewater treatment plant projects will be awarded in next two years. This is in line with National Sanitation Plan 2017-2021 that seeks expansion and construction of treatment plants for an investment value of US $ 1.1 billion over next two years.
Two examples worthy of mention are projects in two emblematic places in Peru: Lake Titicaca, largest in South America, and Villa El Salvador, one of most populated districts of Lima, with almost 400,000 inhabitants.
The "Lake Titicaca Basin Wastewater Treatment System" is a private initiative co-financed (Public-Private Partnership) in concession modality, for a period of 30 years. This proposal includes a comprehensive solution for infrastructure related to treatment plants and final disposal of sewage from altiplanic lake.
Meanwhile, Huascar zonal park, in desert of Villa El Salvador south of Peruvian capital, is supplied with water from wastewater treatment plant of Lima's water and sanitation company that irrigates green areas and has a recreational use.
These are just two of many ideas to promote use of existing resources in wastewater.
Or possibilities are generation of electricity or gas from anaerobic treatment, use of nutrients in mud and reuse of water treated for afforestation. The participation of private sector is relevant, especially to provide technological and financial solutions, as well as for management of plants or in reuse of wastewater treated in industrial processes.
To meet se challenges, Government of Peru and World Bank are discussing with stakeholders a number of proposals, including:
- · Select treatment processes based on easy-to-operate technologies that ensure a low investment, operation and maintenance cost;
- · Make permitted limits more gradual, to facilitate implementation of recommended technologies;
- · Ensure that operating companies have budgets and financing for operation and maintenance, as well as knowledge and skills for successful management; Y,
- · Reuse and take advantage of water, biosolids and biogas energy.
A key partner in this initiative is Government of Spain, through Directorate General of Water, which is making very important contributions based on its experience in integrated management of water resources, wastewater treatment and reuse. Spain is an international leader in se issues.
With all this underway, famous saying can be adapted to "waste water and treated, do not let it run".
Sandra Arzubiaga is a communications officer for World Bank