Advisory remains in place for water schemes affected by aluminium

An advisory remains in place for some rural water schemes in the Clutha District, after water sampling from an accredited lab found aluminium levels exceeding the new drinking water standard of 1mg/L.

Since sampling results first identified the issue on 1 February and an advisory notice was issued on 6 March, there has been intensive sampling, from water treatment plants, households and the pipe network.

Changes have been made to water treatment filters, procedures and systems. Upgrades to filtration systems at the Moa Flat and Puerua treatment plants are planned. These plants have Boil Water Notices in place due to filtration issues, rather than due to aluminium.

Sampling is ongoing and we are continuing to take direction from the water services regulator, Taumata Arowai.

The health advice is that the risk of consuming water from the affected supplies is negligible; no health effects would be expected at these levels of aluminium exposure, even if water was consumed over a period of weeks to months. This includes effects for people with kidney disease, infants, and children.

Work is underway at water treatment plants for the affected schemes.

Kaitangata

A Boil Water Notice is currently in place for this water scheme. This is due to the filtration issue rather than due to aluminium.

There was a single aluminium exceedance at the Kaitangata Water Treatment Plant (taken on 17 February) which supplies Kaitangata and the Wangaloa Rural Water Scheme.

Since 7 March there has been intensive sampling, from the water treatment plant, households and the pipe network. There have been no further exceedances. Sampling is ongoing and we are continuing to take direction from the water services regulator, Taumata Arowai.

Moa Flat

A Boil Water Notice is currently in place for this water scheme. This is due to the filtration issue rather than due to aluminium.

There have been six aluminium exceedances for the Moa Flat water scheme. This scheme supplies the Moa Flat area including the township of Heriot.

Since 7 March there has been intensive sampling, from the water treatment plant, households and the pipe network. There have been no exceedances since 19 February.

Changes have been made to water treatment filters, procedures and systems. The filtration system is not working properly and an upgrade is needed. This will happen as soon as parts arrive.

Sampling is ongoing and we are continuing to take direction from the water services regulator, Taumata Arowai.

North Bruce

There have been 16 aluminium exceedances for the North Bruce water scheme (some on the same date in different parts of the scheme). This scheme supplies the North Bruce area including the township of Waihola.

Since 7 March there has been intensive sampling, from the water treatment plant, households and the pipe network.

Changes have been made to water treatment filters, procedures and systems, and filtration has been increased. Since implementing these changes, the treatment plant has not had any exceedances. There have still been exceedances in samples taken in the pipe network and we are reviewing possible reasons for this.

Sampling is ongoing and we are continuing to take direction from the water services regulator, Taumata Arowai.

Puerua

A Boil Water Notice is currently in place for this water scheme. This is due to the filtration issue rather than due to aluminium.

There have been 21 aluminium exceedances for the Puerua treatment plant and associated water schemes (some on the same date in different parts of the scheme). This scheme supplies the Richardson South area and the township of Kaka Point.

Since 7 March there has been intensive sampling, from the water treatment plant, households and the pipe network.

Changes have been made to water treatment procedures and systems. The filtration system is not working properly and an upgrade is needed. Planning for this is underway.

Sampling is ongoing and we are continuing to take direction from the water services regulator, Taumata Arowai.

Waitahuna water treatment plant

A Boil Water Notice is currently in place for this water scheme. This is due to the filtration issue rather than due to aluminium. E-coli has been detected in samples from the 24 March from this water treatment plant. It is not safe to drink this water without boiling first.

This scheme supplies the Balmoral 1 & 2 and Tuapeka East Rural Water Schemes.

Since 7 March there has been intensive sampling, from the water treatment plant, households and the pipe network.

Changes have been made to how water is processed through the plant.

This water treatment plant will be decommissioned in the future and water will instead come from the new Greenfield Bore Supply. Work on this is underway and the new scheme is expected to be operational in approximately 18 months.

Sampling is ongoing and we are continuing to take direction from the water services regulator, Taumata Arowai.

More information, including questions and answers, and water sampling results can be found on the council’s website - www.cluthadc.govt.nz/water-advisory.