Wastewater facilities at Lake Hawea are scheduled to be upgraded, and a resource consent application is to be lodged with the Otago Regional Council next month.
The Queenstown Lakes District Council has commissioned environmental consultants CPG to upgrade the oxidation pond and trench system which processes wastewater for Lake Hawea residents.
The Lake Hawea oxidation pond is south of the township's green-waste disposal centre, off Domain Rd, and previous treatment systems have included discharging wastewater into the Hawea River during periods of heavy rainfall.
The QLDC has revised its initial upgrade proposal, after a review of peak wastewater flows at the existing facility "required a rethink", project manager Ken Gousmett said.
Mr Gousmett and CPG principal consultant Rob Potts, of Christchurch, presented an overview of the proposed upgraded wastewater system to Hawea residents at a meeting this week.
The QLDC wants to implement a treated wastewater spray-dispersal system to land from a trench infiltration system linked to the oxidation pond.
About 2.5ha of land, south of the pond, was bought by the QLDC for the "spray or drip irrigation" dispersal system.
Crops will be grown and used for hay or bales. Lucerne and ryegrass have been identified as potentially suitable crops for the project.
Neighbouring farmers and property landowners across the Hawea River and southwest of the proposed treatment pond had been consulted, Mr Gousmett said.
Technology built into the drip irrigation system would ensure it did not operate during periods of high winds, and it was proposed the system would function only at night, he said.
"Sprinklers will sit about 30cm above the ground, so any spray from the units would be negligible and unlikely to be carried by wind," he said.
Odour at the pond had not been an issue for surrounding landowners and it was predicted the new system would not create any new issues, he said.
The upgrade was estimated to cost about $300,000 during a five-year implementation period.
WASTEWATER PLANS
• Existing oxidation pond and trench system to be upgraded.
• QLDC wants to disperse treated wastewater to land through a spray irrigation system to be built.
• It has bought about 2.5ha of land near an oxidation pond to be irrigated in this way.
• Crops will be grown there and used for hay or bales.
• Estimated cost of five-year implementation: $300,000.
