Nichola GreavesQueenstown Lakes District Council Private Bag 50072 Queenstown 9348
Rachel OzanneOtago Regional Council PO Box 1954 Dunedin 9054
Dear Nichola and Rachel
Re Monitoring of Lake Hawea
The Lake Hawea Community Association and the Guardians of Lake Hawea are seeking information from both Queenstown Lakes District Council (QLDC) and Otago Regional Council (ORC) about the monitoring of E.coli and any other monitoring of ecosystems and water quality in Lake Hawea. We are seeking information from both ORC and QLDC to address community concerns about water quality and also because we are unclear as to the boundaries between responsibilities of the two councils as it relates to lake, river and groundwater monitoring. Some of our earlier questions about the E.coli monitoring were answered by the brief report “Lake Hawea Water January 2014 E.coli event” from QLDC and we thank you Nichola for sending that, however there is quite a lot of local interest in issues of water quality and we have some additional questions.
Questions for QLDC:
- How frequently are samples taken to test for E.coli?
- How many and where and are the lake samples taken – upstream of the water supply intake?
- Why are so few samples taken in the town reticulation system (as indicated in your January report)?
- Where & by whom are the samples tested?
- What is the Most Probable Number of E.coli/100ml, (and how many such positive samples are required) to trigger a boil water notice, and/or the use of chlorination? What triggers the chlorination being stopped?
- At what level of E.coli in the incoming water does the UV system fail to provide adequate protection?
- How long will chlorination be continued following the January event? We understand it is still being applied.
- Is the community notified when the chlorination is stopped and how is this notification done?
- How long does it take for chlorine to clear the town water reticulation system once application is stopped?
- Does QLDC monitor for hyper chlorination?
- Who has responsibility for tracking the likely source of contamination by E.coli?
- Can the HCA please have a copy of the past E.coli, pH and turbidity data collected for Lake Hawea.
- At what level of lake water turbidity does the UV treatment become compromised?
Questions for ORC:
1. What biological or physical attributes are being monitored in Lake Hawea and in any of the lake catchments, by the ORC and/or subcontractors?
2. How are these being measured?
3. How frequently are these measurements being undertaken?
4. What sites around the lake are used for the measurements?
5. Can you list any other monitoring of the Hawea River and the Hawea Basin aquifer?
Questions for both ORC & QLDC:
How do QLDC and ORC cooperate on aspects of their statutory roles with respect to monitoring Lake Hawea and catchments, the Hawea River and Hawea Basin Aquifer?
- Are there any areas of overlap in QLDC-ORC responsibilities with respect to these water bodies?
- Are there any gaps you are aware of between the two organisations responsibilities with respect to these water bodies?
We look forward to hearing back from you both.
Yours sincerelyAlison Brown Secretary, Guardians of Lake Hawea Don Robertson Vice Chair Hawea Community Association
Cc: The residents of Lake Hawea and Hawea FlatChief Executive Officer (QLDC) Chief Executive Officer (ORC)