ARC rejects bid to tip waste on harbour island

Puketutu Island in the Manukau Harbour, near Mangere. Photo / Dean Purcell

A plan to dump more than 4 million cu m of treated waste on to an island sacred to Maori has been scuppered by the Auckland Regional Council.

Watercare Services was seeking resource consents from the ARC to deposit, over 35 years, about 4.4 million cu m of biosolids on Puketutu Island in Manukau Harbour.

The 195ha island has been extensively quarried since the 1950s, leaving the southwest portion of the island "a series of water-filled voids", ARC documents say.

But an ARC/Manukau City Council consents panel this week rejected Watercare's bid, saying the dumping of waste would leave the island in a worse state and have "irreversible and adverse effects" on local Maori.

The properties of the biosolid waste to be dumped on the island were also "far from favourable" and disposing of them there was "not an appropriate way to rehabilitate Puketutu Island".

The island was inhabited by Maori for up to 300 years up to the 18th century, and is considered waahi tapu (sacred).

At least 47 archaeological sites have been identified on Puketutu, though it does not have a high heritage rating, coming 240th of 242 listed geological sites in the Auckland region.

Iwi opposed the Watercare proposal.

The company had wanted to dump the solid waste - containing under 10 per cent treated human waste - on the island as fill, slowly rebuilding the original terrain lines obliterated during the quarrying process.

Watercare is a water and waste-treatment operation owned by six Auckland territorial authorities.

It runs the Mangere Wastewater Treatment Plant at the end of a causeway leading out to Puketutu Island.

About 300 tonnes of biosolids are produced each day and are stored in a former oxidation-pond site.

The company sought consents from the ARC for discharges, stormwater diversion, the taking of groundwater and the undertaking of 12 million cu m of earthworks while rebuilding the island.

The hearing panel further ruled that the cosmetic effects on the island would be minimal, and would restrict the landscape to "a very flat, unnatural appearance, with prolonged and obtrusive after care likely to be required".

The hearing panel found no need to "rehabilitate" the island further after Winstone Aggregates' quarry consents expire in 2011. Watercare said it was disappointed with the finding.