Local Govt | National News Video | Parliament Headlines | Politics Headlines | Search


Water storage lake to be drained

Water storage lake to be drained

Greater Wellington Regional Council has this week begun draining one of its water storage lakes, in an effort to remove an organic compound, recently found at higher than normal levels in the lakes.

The naturally occurring compound, known as Geosmin, can cause water to taste and smell ‘earthy’. Geosmin poses no health risk and the water remains safe to drink.

Lake water with normal levels of Geosmin is routinely treated at the Te Marua Water Treatment Plant using powdered activated carbon (PAC). However due to the exceptionally high levels in Lake 2 in recent weeks, not all of this taste and odour causing compound can be removed from its water. The level of Geosmin in Lake 1 is presently normal, which means that the PAC treatment is able to effectively remove the Geosmin.

Because storage lake water is only used as a back-up water source when river water is unavailable (for example, after heavy rainfall when river water is too dirty to treat) and water from Lake 1 is able to be used, regional council officers have made the decision to drain Lake 2 and refill it with fresh water.

Greater Wellington Regional Council Water Supply General Manager Chris Laidlow says that while all water being supplied to the public remains completely safe to drink, it made sense to drain the lake.

“When we’re using water from the storage lakes – which isn’t often – organic compounds such as Geosmin are removed using PAC. While that process sometimes doesn’t remove all of the compounds from our water, it is completely safe and complies with the NZ Drinking-water Standards.

“We decided this week that it is better to drain Lake 2 rather than continue to try and treat the high levels of Geosmin. Now is a reasonable time to empty the lake as there is a very low risk of a water shortage at this time of year and we have plenty of time to refill the lake before next summer.

“We don’t yet know the cause of the high levels of Geosmin but we’re looking into this and also methods for dealing with high levels of Geosmin in the future.”

Lake 2 is the southern of the two lakes and holds 2,067 million litres of water. It will be empty by 20 May and is expected to take 6-8 weeks to refill.


© Scoop Media

Parliament Headlines | Politics Headlines | Regional Headlines


Environment And Conservation: Changes To Our Oceans Pose Serious Concerns

New Zealand’s oceans, coasts, and marine wildlife are under growing pressure, according to the first national report from the Ministry for the Environment and Statistics New Zealand about the marine environment. More>>


Police Authority: Use Of Taser Was Disproportionate And Unjustified

The Independent Police Conduct Authority has found that an officer’s second use of a Taser on a mentally unwell Hokitika man was disproportionate and unjustified. More>>


Gordon Campbell: On Holidays, Hekia Parata And Badlands

Hekia Parata, adieu. Reportedly, she’s been ‘passionate’ about education. She has “bravely’ led the charge on the government’s education reforms. In the past week , many of the postscripts to Hekia Parata’s career as Education Minister have sounded like a schoolteacher desperately trying to find some reason why a D student can be marked up to C minus. More>>


Minister of Finance: Plan Shows $100 Billion Infrastructure Projects

Finance Minister Bill English has today launched the Government’s Ten Year Capital Intentions Plan (CIP) which shows a pipeline of $100.9 billion worth of infrastructure projects over the next decade. More>>


Werewolf: Safe Landings Gordon Campbell on the safety challenge to the Wellington runway extension.

The safety-related legal challenge revolves around the size of the 90 metre long Runway End Safety Area (RESA) being proposed for the runway extension. More>>


Environment Commissioner: We Need To Work Together On Climate Change And Farming

“The debate around agricultural emissions and the ETS has been polarised for too long,” said the Commissioner. “But the ETS is not the only way forward – there are other things that can be done.” More>>


NZ Super Fund: Seeking To Put A Market Price On Climate Change

Oct. 19 (BusinessDesk) - The New Zealand Superannuation Fund says it will devise a set of rules to assess investment winners and losers under climate change, a strategy that could rule out fossil fuels or producers such as current portfolio member Exxon ... More>>


Rejuvenation: Parata Will Not Contest 2017 Election

Education Minister and National List MP Hekia Parata has today announced that she will not be contesting the next election. She advised the Prime Minister of her decision earlier this year. More>>

Get More From Scoop



Search Scoop  
Powered by Vodafone
NZ independent news