Works Supervision of a Waste Water Treatment Plant in Guadalajara, Spain

The project consisted of the works supervision of the design-build of a new Wastewater Treatment Plant and Motogeneration in the Guadalajara Region
Sector Water Treatment Plants (Water and Environment)
CountrySpain (Europe)


The project consists of the works supervision of the design-build of a new Wastewater Treatment plant in the Guadalajara Region. The new infrastructure will serve a population of 300,000 inhabitants. The total investment for these works and services amounts to 28.111.390 million Euro. The WWTP will reduce the pollution of Henares River.

Technical data:

  • Treatment capacity in equivalent inhabitants: 300.000
  • Treatment capacity in flow (m3/day): 60.000 (Pre-treatment), 45.000 (Primary and biological),60.000 (the sludge line)
  • Water treatment line (3 lines): thick shaft, grinding and sieving, desanding-degreasing, primary sedimentation, biological treatment with elimination of nutrients, secondary sedimentation.
  • Sludge treatment line (2 lines): primary sludge thickening, secondary mechanical sludge thickening, homogenization, digestion and dehydration with centrifuges. Encompasses the treatment of sludge produced as a result of theelimination of pollution present in the incoming water.
  • Gas line: motogeneration (2 x 323 Kw) The energy use of biogas produced during the sludge treatment.

As a result of anaerobic sludge digestion in a biogas digester, biogas with a high content of methane is present in sufficient quantities to be used in a cogeneration plant for electricity production, which will reduce energy consumption installation.

The biogas is used in part by gas compressors, which impel them to 2 bar to the aforementioned heat exchanger to mix with the sludge entering the digester.

The biogas is also driven by three blowers to the cogeneration plant. These blowers are powered by two motor generators of 323 KW, giving the alternator of each 311 kW of electrical power. This is then giving back about 30% of the electricity needed for the operation of the facility. The heat emitted by the engines in the process of the combustion of the biogas is used in a heat exchanger to transfer heat to the water for the digester.

In case the cogeneration plant is not operating, biogas is derived through three gas blowers above the boilers, so that at no time the water temperature for heating the sludge entering the digetsor falls, keeping the digestion process at an optimum.

The gas not used in the agitation of the mud or the warming of it is stored in a gas-operated double diaphragm with a capacity of 2100 m3. Excess gas is burned in a torch.


  • Revision of Designs
  • Review of the specifications, methods of measurements, bill of quantities.
  • Works supervision acting as the Engineer and following Spanish regulation (In line with FIDIC type conditions of contract)
  • Environmental impact assessment
  • Quality and quantity control of managed and implemented works