WATER & WASTEWATER Existing Facility Rehabilitation > Our Expertise > Water Treatment > Existing Facility Rehabilitation The expected life for concrete structures is 50-100 years. For most mechanical equipment, it is approximately 25 years. Given the speed of technology, it can often be less. Rehabilitating and retrofitting wastewater treatment plants is one of the trickiest types of construction and the one with the biggest risks. Kokosing acts as your partner working side-by-side with your team to restart the clock on one of your biggest assets.