Collaboration protocols with specialist companies in several sectors allow the presentation of optimized solutions suited to specific circumstances.

WATERTECH.PT - Company specializing in ultrafiltration and chemical treatment systems; URBASER - Spanish company specializing in projects in the area of urban and industrial waste water treatment PRESECO - Finnish company specializing in composting and anaerobic digestion; ENRICO MAGGIO - Italian auditor specialized in the treatment of textile effluents; INIMA - Spanish company that integrates the OHL group in the area of exploitation of wastewater treatment systems.