SAHM: Treating 60% of a megacity’s wastewater for safe crop irrigation.

Before the vision of the Atotonilco plant, only 8% of Mexico City’s wastewater was being treated. In recent years, this situation was causing serious sanitary and environmental problems. For over a century, wastewater and runoff from the megacity has been used to irrigate the valleys to the north, providing water for thousands of hectares of crops. The National Water Commission (CONAGUA) wanted Atotonilco to lead its long-term sustainable water management programme. The plant would turn 60% of the wastewater from more than 10 million people into safer, cleaner water for crop irrigation in the Tula Valley. Some towns would have clean water for the first time.

Construction of the plant, the largest of its kind to date, presented an enormous logistical challenge for SAHM. This consortium of companies was formed to construct and operate the plant for 22 years. Planners had to coordinate high volumes of materials arriving from around the world. Another key concern was controlling the manufacture and shipment of heavy equipment from Europe and other global manufacturing sites.

Quality inspection for the world's largest wastewater plant

Answers to the consortium’s key challenges lay in a manual. We produced a set of inspection procedures for the plant, providing a tailor-made schedule of global certification. The solution was informed by extensive practical experience. This includes providing specialised inspection services to the wastewater treatment industry in Spain for over 30 years.

The consortium benefited from our understanding of:

• the full set of requirements and criteria for all types of water management installations, from capture of wastewater to the desalination of seawater

• the scopes of inspection required against the latest standards and regulations 

• in-depth surveying expertise in this area.

Our independent inspection services covered the plant’s critical, heavy equipment through to key electromechanical equipment. This included inspection and witnessing of tests during fabrication and packaging, as well as monitoring delivery deadlines. Here, SAHM also benefited from our network. Led from Madrid, project support was also provided by our other offices in Belgium, China, Finland, France, Germany, Mexico, the USA and UK.

“It was very important that the coordination achieved between the LRQA and SAHM consortium teams met time and quality standards required in Atotonilco. LRQA’s team exceeded these expectations, and through their coordination helped keep the project on track.”

Elena Cabeza del Pozo

Supplies Manager, PTAR Atotonilco

LRQA has a long partnership with Acciona Agua, one of the Atotonilco’s investors. We are Acciona Agua’s preferred third-party and vendor site inspection supplier for their projects in Spain and abroad, including plants in Australia, Chile and the UK.

100 inspections in nine different countries to a bespoke schedule of global certification, significantly minimising supply-chain cost.