Small community win by smart procurement that saves time and puts money back into the local economy

H.Wilson (South Wairarapa District Council), S.Cartwright (Southern Cross Consulting Ltd)

In 2019, after detecting e-coli in the reticulation system, South Wairarapa District Council (SWDC) decided to permanently disinfect the drinking water for the town of Martinborough. However, two of the three bores had high levels of dissolved manganese that resulted in water discoloration which quickly became a major issue for consumers. With only one bore providing acceptable drinking water, a solution to the problem was needed, and quickly.

SWDC turned to Wellington Water Limited (WWL) for help, and in turn they engaged an approved contractor (AC) to produce a concept design and pricing for a manganese reduction plant (MRP). Unfortunately, the cost estimated for the proposed design far exceeded the council’s budget. Even after a value engineering workshop, there was still a vast gap leaving the council with a problem.

Discussions within SWDC identified a local contactor who was suitably qualified and experienced to design and build a manganese reduction plant. They were approached and invited to quote for the work to develop the concept design into a detailed design, and then construct the treatment plant using local sub-contractors.

The local contractor’s price was well within the council’s allocated budget and a NZ3916 design/build contract was able to be awarded. When Wellington Water took over 3 water operations from SWDC on 1st October 2019, they managed the contract through their consultant panel by engaging GHD.

Despite Covid lockdowns, the allocated land being contaminated and delays with international deliveries, the Martinborough Manganese Reduction Plant was completed on time and passed a stringent 30-day trial with flying colours, consistently removing manganese to less than the detectable level.

The fully automated and unmanned treatment plant is operated by Wellington Water on behalf of SWDC. It has been designed so that there is minimal operational involvement, only requiring weekly checks and instrument verifications.

The biggest concerns of the local project stakeholders were potential operational noise and aesthetic appearance. However, these issues were addressed during the detailed design phase with acoustic attenuation and landscaping, with incredible final outcomes.

By using local contractors with low overheads, and some lateral thinking, the SWDC were able to procure a high-quality treatment plant not only within budget, but also gaining some non-tangible benefits such as;

• Employing and managing local skilled labour for a water infrastructure project keeps local taxpayers’ money within the community,

• The knowledge gained during construction is retained locally,

• Construction workers and/or members of their families were involved as community stakeholders and were more willing to assist through difficult phases of the project,

• The community has more pride and ownership of their new asset once completed.

In the next decade, our drinking water systems need a vast amount of improvement work and funding these projects is a major concern for many councils. SWDC has proved that with a wise procurement strategy and careful project management, small local companies can be an alternative/cost-effective option compared to the larger corporations.