Halifax Harbour Solutions Project - Sewage Collection System

Dexter has been selected to design, build, and commission the sewage collection systems for the Halifax Harbour Solutions Project.

Project Information:

• Value: $112,000,000 CDN
• Start date: October 10, 2003
• Timeline: 53 months

In response, to the size, duration, and complexity of the project, Dexter has established a management team dedicated to the project.

Key responsibilities of the team include;

• Engineering and design management
• Acquisition of permits and approvals
• Acquisition of real estate easements and licenses
• Subcontractor management
• Quality control and assurance
• Environmental program management
• Health and Safety management
• Procurement
• Construction management

Contract Scope

Project Elements

Other

Dexter believes that there is an evolving trend in infrastructure projects towards larger design-build projects. Public sector departments and agencies continue to look for ways to improve infrastructure quality, to reduce lifecycle costs, and to transfer risk.

Dexter is intent on being able to participate in these projects at the developer level and continues to create the skills, resources, expertise, and management systems necessary to compete successfully in this arena. The Halifax Harbour Solutions Project is an important example of Dexter’s commitment to developing and maintaining its ability to successfully deliver complex infrastructure projects of high quality, on-time, on-budget, safely, and with respect for the environment.

Halifax Harbour Solutions Project – Sewage Treatment Plants

D&D Water Solutions Inc. has been selected to design, build, and commission three (3) Sewage Treatment Plants for the Halifax Harbour Solutions Project.

Project Information

• Value: $133,200,000 CDN
• Start Date: July 7, 2004
• Timeline: 47 Months

Project Team

• D&D Water Solutions Inc.; A special purpose company created to design, build, and commission the three Sewage Treatment Plants. The company is owned by;

   - Degremont Ltee.

• a subsidiary of Suez Lyonnais des Eaux; one of the largest industrial services companies in the world. 2003 revenue - 39.6 billion Euros
• Degremont has built over 2,500 wastewater treatment plants.
• Degremont’s 2003 revenue – 1.0 billion Euros

   - Dexter Construction Company Ltd.

• Largest civil contracting firm in Atlantic Canada
• Design-builder of the sewage collection systems for the Halifax Harbour Solutions Project.

• Major Subcontractors

• Black & McDonald – mechanical and electrical contractors
• Pomerleau – civil and structural contractors
• Harbour Engineering Inc. – design

Sewage Treatment Plant Locations

• Halifax – Upper Water Street and Cornwallis Street
• Dartmouth – Canadian Coast Guard site
• Herring Cove – near Village Road east of Ketch Harbour Road in Herring Cove

Construction Scope

• Site excavation and preparation
• Building construction
• Wastewater treatment process installation

Economic & Industrial Benefit Commitments

• 85% of construction labour from residents of HRM and Nova Scotia
• 40% of materials and supplies from suppliers based in HRM and Nova Scotia
• Work Hours
     - Civil 125,000
     - Process 275,000
     - Total 400,000

Wastewater treatment chosen by HRM:

In general there are three levels of wastewater treatment: primary, secondary, and tertiary.

Primary treatment involves mechanical processes that remove a certain amount of the floating and suspended solid material in the wastewater.

Advanced primary fits between primary and secondary treatment, and removes up to 70 per cent of the suspended solids in the wastewater. HRM has chosen this level of treatment for the Harbour Solutions Project.

Advanced primary treatment improves upon the basic level, through the addition of chemicals known as flocculants to the settling process. These are the same type of flocculants used in the treatment of drinking water. Essentially, the effect of these chemicals is to pull together some of the smaller particles that would otherwise remain suspended in the water column, and cause them to settle to the bottom of the settling tanks, where they and the flocculent will be removed as part of the biosolids sludge.

The final stage of the sewage treatment process is the disinfection of the effluent before it is released into the harbour. Many sewage treatment plants today use a chlorination process to disinfect effluent, but this chemical is not particularly good for the natural environment. The Harbour Solutions Project has determined that a different, more environmentally beneficial process should be used. This process is known as UV disinfection. In this process, no chemicals are added, but rather high-intensity ultra-violet lights are used to kill bacteria in the effluent before it is released into the Harbour.

The addition of this ‘advanced' stage and the use of ultra-violet disinfection to the process significantly improves upon the basic primary process and results in cleaner effluent to be discharged into the harbour.