Fit to Drink
Project management
Key treatment processes: cells containing submerged membranes
With the innovations involved in the project of this size, delays, errors and budget blow-outs might be expected. However, the project came in $5 million under its projected $38-million cost, on time and with virtually no problems since operations began in July last year.
There are a variety of reasons for this. Mr Oakley says that the project was based on a strategic review of the city's water systems which was sound, and on decisions that have stood the test of time.
"The basics were done right. We had a realistic budget. And we had enough time to do the job right. Funnily enough, if you have enough time and money, then you can save time and money." There were obstacles to overcome, though – in particular, the buy-out of the original consultants by MWH. In 2002, two years after the project began in the hands of City Consultants, a business unit of the Council, the decision was made to sell the unit and the project management contract. Mr McCombie believes the use of outside consultants, in particular Octa Associates, to oversee the design team was critical in keeping the project on track during the upheaval.
All agree that a key factor in the success was the strong project control group. "We had a good balance between the operators, the executives and the consultants," says Mr Avery. And, Mr Oakley adds, "The focus was always on what was right for the project. It was good honest engineering and contracting."
The team was lucky to keep most of its members throughout the project, partly thanks to the stability of Dunedin's workforce.
A potential obstacle in the team's path was changes to the New Zealand drinking-water standards by the Ministry of Health. The new Southern plant was created to meet the drinking-water standards released in 2000, five years after the changes to the standards which lowered Dunedin's previously acceptable grade of water. However, the updated standards were not due out until after the new plant was to become operational, leaving the design team to make educated guesses about what would be needed to meet the more stringent requirements.
Significant areas of change in the 2005 standards affected the required performance for the membranes, the UV disinfection, and the data collection and reporting. The plant more than meets the new standards, and can be readily upgraded to meet any future standard changes.
