Operation, preservation, and maintenance of the Abrera group sanitation system

Operation, preservation, and maintenance of the Abrera group sanitation system

La Agència Catalana de l’Aigua (Catalan Water Agency - ACA) has awarded the contract for operation, preservation, and maintenance of the water purification systems of Abrera, Castellbell i El Vilar, Monistrol de montserrat, Viladecavalls este, Viladecavalls oest and Vacarisses.

Agència Catalana de l’Aigua (ACA)
2017-2020 prorrogable 2 años más
Type of work:
Operation and maintenance
The works to be performed include the operation and maintenance of the purification facilities of the Abrera Group in the Llobregat River basin, in order to ensure the proper functioning of those facilities and the quality of the water treated there.
The total flow treated is about 50,000 m<sup>3</sup>/day for a population equivalent to 160,000 people, in six sanitation systems covering a network whose total length exceeds 70 km of collector lines.

Technical data

Abera WWTP System
The system will serve the municipalities of Abrera (Abrera, Les Carpes, Santa Maria de Villalba, Ca La Cília); Olesa de Montserrat; Esparreguera; Collbató and El Bruc with 30 km of collection lines and 6 pumping stations designed to treat 34,000 m3/day using an active sludge biological process that removes nitrogen and phosphorus.  The process consists of 2 pretreatment lines, sand removal and screening, 2 primary decanters, 4 biological reactors with a capacity of 4,100m3, and 2 secondary decanters. The sludge line includes a 16m flotation thickener, 1 anaerobic digester and dehydration with 2 45m3/h centrifugal decanters. The biogas generated in the digestion process is used to generate electrical power to be used by the system itself.

Castellbell i El Vilar WWTP
Designed to treat 5,500 m3/day with a 12 km collector network and 7 pumping stations, an active sludge biological process and a low-load carrousel-type system for nutrient removal, with a 4,600m3 line and a 25m secondary decanter. The sludge line includes a 210m3 dynamic thickener, and dehydration is accomplished with 2 centrifugal decanters.

Vacarisses WWTP
Designed to treat 2,320 m3/day. The process consists of pretreatment with fines screening, desander, degreaser, a conventional prolonged-aeration active sludge process with final separation of effluent and biomass using 2 MBR-type ultrafiltration membrane racks of 32.6m2.

Monistrol de Montserrat WWTP
Treats 3,300m3/day. The system consists of 6 km of collection lines and 2 pumping stations. It has a 1,500m3 homogenization tank, with agitation, aeration, and a prolonged-aeration biological reactor, as well as a secondary decanter measuring 19m in diameter. The sludge line consists of a gravity thickener.