Canal de Isabel II earmarks €12.2 M for treatment of 70,000 tonnes of sludge at Loeches plant

The contract for this project will cover the next three years, with the option to extend it for a further 12 months. The plant treats 55,000 tonnes of sludge at its thermal drying facilities, while 15,000 is composted for use in agriculture and gardening. The project seeks to achieve the goal of improving environmental quality and energy efficiency, which forms part of the company’s Strategic Plan.

Canal de Isabel II is to invest a total of €12.2 million in outsourcing the operation and maintenance of its Loeches composting, thermal drying and CHP plant. The contract has a duration of three years, with a one-year extension option.

An annual average of 70,000 tonnes of sludge from the company’s WWTPs are treated at this plant. 55,000 tonnes are treated in the thermal drying facility and the remaining 15,000 tonnes are composted along with pruning waste to obtain 13,000 tonnes of dry granule and 5,000 tonnes of compost. These products are used in agriculture, gardening and landscape remediation.

Through the thermal drying process, which uses the heat produced in the cogeneration system, the volume of the sludge is reduced, and input dry matter content is increased from 21% to 90%. The result is a hygienised end product in the form of dry sludge granules, which can be used in agriculture as a fertiliser or as fuel in certain industrial processes. 

In addition to producing the thermal energy for the drying process, the CHP modules have the capacity to generate up to 158,400 MWh/annum for self-consumption, while excess energy is sold to the grid.


The sludge treatment process carried out at the Loeches plant seeks to achieve the goal of improving environmental quality and energy efficiency, an objective which forms part of Canal de Isabel II Strategic Plan. This also incorporates the Clean Generation or Zero Kilowatts Plan, which aims to obtain 100% of the energy required for self-consumption through renewable sources.

Canal de Isabel II was founded almost 170 years ago to supply water to the city of Madrid. Today, the company’s employs more than 2,800 people, who work on a daily basis to provide a high-quality service to over six million people throughout the region. Canal de Isabel II is an innovative publicly-owned enterprise and a leader in the sector. The company is internationally recognised for the quality of its integrated urban water cycle management.

Canal de Isabel II operates 13 reservoirs; 78 groundwater catchments; 17,601 km of water supply and distribution network; 131 drinking water and 133 wastewater pumping stations; 15,083 km of sewage networks; 65 stormwater tanks; 157 wastewater treatment plants; and 615 km of reclaimed water network.