Inauguration of phase one of the Taboada WWTP
On 21 February the President of the Republic of Peru, Ollanta Humala, officially opened phase one of the Taboada Wastewater Treatment Plant. This plant will treat the wastewater from the cities of Lima and Callao, servicing an equivalent population of more than 4,300,000 which represents 56% of the population of Lima and Callao and 75% of the wastewater generated by the two cities.
The plant was put into operation following completion of the outfall, which is almost 4 kilometres long (500 m on land and 3,500 m underwater) and is made of high-density polyethylene pipes 3.0 metres in diameter. In phase one it is treating 7.0 m3/s, increasing to a nominal rate of 14 m3/s in phase two with peaks of 20.3 m3/s. Phase two is expected to go into operation in July, and will make it the largest wastewater treatment plant in South America.
Before the plant was put into service only 16 percent of the wastewater generated by the capital was treated using a small number of plants and oxidation ponds. The start-up of the new WWTP will solve the sanitary problem caused by dumping untreated wastewater into the sea and the Rimac River and represents the beginning of the decontamination of the sea off the coast of Peru.
The Taboada WWTP is equipped with what are considered to be the world’s largest screening filters, 22 filters 3,000 mm in diameter, in addition to roughing grates with a screening size of 6 mm, desanding-desilting and 1 mm fine screening. This WWTP uses no chemicals or disinfectants with a negative impact on sea flora and fauna. It also guarantees the removal of 90% of the organic concentration of the discharge flow.
The plant is equipped with an integrated system that removes all sedimentable solids, discharging only colloidal and water-soluble substances easily assimilated by the marine environment. Initially, the pre-treated water will be sent through the underwater outfall. The calculations for defining the discharge zone of the outfall were based on the study of the sea currents in the final kilometre of the underwater section, which is equipped with 250 diffusers to allow the sea to assimilate the flow in less than three hours, as required by the environmental standards established by the National Water Authority of Peru.
In August 2009, SEDAPAL (Lima Drinking Water and Sewer Service), through the state-run enterprise Proinversión, awarded ACS Servicios Comunicaciones y Energy the concession contract (BOT) to design, build, operate, and maintain the plant for 25 years. In turn, ACS subcontracted all the work for the preparation of the project, construction, commissioning, and operation to its subsidiary TEDAGUA, a member of the Cobra Group.