WATER RECLAMATION AND REUSE IN SABADELL

The challenge

The city of Sabadell has been an important center for producing textiles, a highly water-consuming industry, which is why the city has a historical sensitivity regarding the availability of water resources.

Aigües Sabadell (joint venture, owned by Sabadell City Council and Agbar) has been promoting the use of alternative resources in the city since 2002, incorporating in 2011 the regeneration of water from the Riu Sec WWTP.
This plant is equipped with an advanced purification system with Membrane Bio-Reactor (MBR) that provides high quality treated water. Thanks to the Municipal Ordinance approved in 2010 by Sabadell City Council, the new Sant Pau de Riu Sec industrial and commercial estate, opened in 2012, already had a double distribution network (drinking + reclaimed water) to comply with this regulation. Since then, the water from the treatment plant has been used for toilet flushing and irrigation of green areas, both public and private. There is also a hydrant for truck tankers 24/365.

Veolia’s solution

Aigües Sabadell and Sabadell City Council have been working on this project in a progressive and planned manner. The first actions to use resources from disused wells and mines were carried out in 2000-2003. In 2004 the Master Plan for the Use of External Water in the Distribution Network was approved, which defined the necessary infrastructures and the economic study and investment planning for the use of alternative resources. In 2007, the municipal water service regulations were updated, incorporating the supply of non-potable water. In 2010 the City Council approved the Municipal Ordinance regulating the use and saving of water in Sabadell, facts that gave an impetus to the growth in the use of alternative resources to drinking water. In 2011, the regeneration had the financial support of the water tariff in Sabadell (price similar to potable water, single block, exemption from the general fee).

Currently, the expansion of the reclaimed water network to other neighbourhoods in the city is under planning; as well as to other cities and towns nearby Sabadell.

The benefits

In Catalonia around 620 Hm³ wastewater are treated every year. Out of that, less than 10% is reused. Boosting reclaimed water as a resource will allow reducing water abstraction from Llobregat and Ter rivers, which will make Catalonia more resilient against droughts.
Reclaimed water is an alternative resource that, if not used, would flow to the sea. Through beneficial reuse, this water saves drinking water. The water produced by the advanced MBR treatment in the Sabadell Riu Sec WWTP is of high quality and requires only disinfection to be beneficially reused.
A very important benefit of using reclaimed water is that it is not affected by water restrictions that apply to drinking water in a drought event, so in many cases it is the only option to ensure certain uses such as streets cleaning, green areas watering or cleaning urban architecture elements and sewers.

The water reuse project in Sabadell is characterized by:

• Utilization of reclaimed water from the Riu Sec WWTP. Water resource for various uses that do not require potable water: irrigation of green areas, street cleaning, industrial uses, toilet flushing...
• There are currently 63 supply points, 104 contracts (58% private, 42% from Sabadell City Council) and more than 33 km of reclaimed underground water distribution network.
• Two newly built areas of Sabadell have already implemented the double distribution network available to all users; the Polígon de Sant Pau de Riu-sec (public, commercial and industrial uses) and the Can Gambús sector (public and residential uses).
• The Riu Sec WWTP was the first concession for sanitary discharge use in Catalonia.
• The reclaimed water dispenser for tanker trucks at the Riu Sec WWTP is operational 24h/365 days. Pioneering experience to promote the use of regenerated water that already has 42 contracts. In the current times of drought, this resource allows activities such as cleaning sewers, cleaning streets and urban architecture elements or gardening certain green areas to continue.
• The growth of the distribution network within Sabadell and the nearby towns make it possible to foresee a growth projection in the distributed volume of the order of 500,000 m³ per year in the next 5 years.

Altogether, this project puts Veolia as a key actor for adaptation to climate change in Sabadell city.