37 Building construction services, namely, providing services for building water treatment plants; construction, repair and maintenance of water treatment plants, apparatus, devices and static or mobile installations for distributing, treating, purifying and filtering water and wastewater, namely, repair or maintenance of water treating and purifying apparatus, repair or maintenance of water pollution control equipment; services for putting into service, repairing and maintaining apparatus, devices and static or mobile installations for the purification of urban and industrial wastewater, namely, repair or maintenance of wastewater purification machines and apparatus, environmental remediation services in the nature of waste disposal services; services for putting into service, repairing and maintaining apparatus, devices and static or mobile installations for rendering water drinkable, namely, repair or maintenance of water purifying apparatus, repair or maintenance of water pollution control equipment; services for putting into service, repairing and maintaining apparatus, devices and static or mobile installations for the treatment, disinfection and filtration of sludges, namely, repair or maintenance of sludge treatment and disinfection machines and apparatus; services for putting into service, repairing and maintaining apparatus, devices and static or mobile installations for the treatment of waste in the context of domestic, municipal or industrial applications, namely, repair or maintenance of water treating and purifying apparatus, all of these services are provided in the field of water treatment for purifying and rendering water drinkable and meet quality standards with regard to environmental protection relating to ecology, sustainable development and environmental quality