The Challenge

The Malcolm Park Wastewater Treatment Facility is a primary treatment plant that is adjacent to the City of Nassua, located on the northeast end of New Providence, Bahamas.  The original facility was built in the 1930’s and through time has had much of its infrastructure out-of-service.  Some initial design problems with the sludge removal system curtailed the effectiveness of the treatment process and limited operation and maintenance activities also impacted the condition of critical facility components. Consequently, the facility was in need of improvements and upgrades.  The challenge for this project was to implement the most critical improvements based on a limited budget and to align the improvements seamlessly to preliminary concepts developed for a possible new facility at or near the current location.

The Interdisciplinary Approach

After completing a comprehensive inspection, the most critical facility needs were identified as the following:

• Reduce odor emissions,
• Improve safety of the facility
• Provide for replacement or rehabilitation of process equipment
• Improve effluent quality to promote injection well reliability
• Improve pumping efficiencies and overall facility operations

Due to time and budget constraints, the components were addressed following a synchronized path of completion according to its importance to the Bahamas Water and Sewerage Corporation (WSC).  Task 1 involved providing a safe and odor free environment for WSC employees who work at the facility, as well as tourists and citizens who traverse near the facility on a daily basis.  Task 2 included providing an assessment of the integrity of the facility system components including the sludge holding tanks and piping and valve infrastructure.  Task 3 provided an evaluation and offered conceptual design alternatives to improving the existing screening capabilities in the system headworks.  Finally, Task 4 included a semi-comprehensive flow monitoring program to evaluate the characteristics of the flows entering the system such as effects of inflow and infiltration and average and peak flows.

The Sustainable Result

The result from completing the fours task described in the above achieved a first step toward addressing the most critical facility needs that could also be utilized for a future new treatment facility.  Under task 1, aluminum covers were provided for all open chambers that were on-site.  Included with the covers were customized design specifications for each chamber which was submitted to a local contractor to complete the work.  Task 2 included several valve replacements to allow access to a secondary disposal to be used while the active well is being maintained or repaired.  Task 3 provided detailed specifications for an automated wastewater course screening and dewatering devise to be installed in the existing headworks chamber.  Task 5 provided WSC with recommendations for immediate pumping system upgrades needed for the current treatment facility and proposed upgrades for future use in the design of a future facility.