Monday, November 24, 2008

Puketutu Landfill Proposal against Public Interest

I sent this letter to NZ Herald last week, knowing that Watercare had publicly notified its consent application to discharge sewage biosolids into Puketutu, on the Monday after the General Election. Sure - this complies with the letter of the law - but the public now have just a few days before Christmas to lodge an appeal....

"...The public interest is poorly served when expediency and cost minimisation drive major public infrastructure decisions.

In newspaper notices published the Monday after an exciting election, Watercare notified its intention to dump sewage sludge from the Mangere Wastewater Treatment Plant onto Puketutu Island in Manukau Harbour. Submissions will close a few days before Christmas.

Modern cities around the world keep trade waste chemicals out of sewage pipes, and apply treated sewage back to land where the nutrients can be reused. Landfilling of biosolids is mostly not permitted.

There’s a whiff of wishful thinking in Watercare’s claim that its proposed Puketutu Sewage Landfill is a land rehabilitation project that will eventually become a park promised to Auckland Regional Council. Auckland’s City Councils own Watercare and presumably supported this proposal at a confidential meeting.

But it’s actually a cheap dump that will belch methane for decades, just as Watercare’s sewage landfills do today on the edge of the Manukau.

We would not allow a private operator to do this. Auckland's public services can do better...."


Again, this letter was not published.

2 comments:

Anonymous said...

Why do you think that it is going to 'belch methane for decades'??

Joel Cayford said...

Good question. Methane is mainly emitted during the treatment plant anerobic digestion process. But organic material remains which continues to decompose underground in the landfill, producing methane. Stabilised biosolids - with lime added - emit ammonia. So gases additional to methane are also produced - depending on temperature and water presence. These gases rise to the surface and escape through cracks and gaps in the clay cap used to seal landfills. I understand that pockets of material in landfills continue to decompose for decades after closure.

Monday, November 24, 2008

Puketutu Landfill Proposal against Public Interest

I sent this letter to NZ Herald last week, knowing that Watercare had publicly notified its consent application to discharge sewage biosolids into Puketutu, on the Monday after the General Election. Sure - this complies with the letter of the law - but the public now have just a few days before Christmas to lodge an appeal....

"...The public interest is poorly served when expediency and cost minimisation drive major public infrastructure decisions.

In newspaper notices published the Monday after an exciting election, Watercare notified its intention to dump sewage sludge from the Mangere Wastewater Treatment Plant onto Puketutu Island in Manukau Harbour. Submissions will close a few days before Christmas.

Modern cities around the world keep trade waste chemicals out of sewage pipes, and apply treated sewage back to land where the nutrients can be reused. Landfilling of biosolids is mostly not permitted.

There’s a whiff of wishful thinking in Watercare’s claim that its proposed Puketutu Sewage Landfill is a land rehabilitation project that will eventually become a park promised to Auckland Regional Council. Auckland’s City Councils own Watercare and presumably supported this proposal at a confidential meeting.

But it’s actually a cheap dump that will belch methane for decades, just as Watercare’s sewage landfills do today on the edge of the Manukau.

We would not allow a private operator to do this. Auckland's public services can do better...."


Again, this letter was not published.

2 comments:

Anonymous said...

Why do you think that it is going to 'belch methane for decades'??

Joel Cayford said...

Good question. Methane is mainly emitted during the treatment plant anerobic digestion process. But organic material remains which continues to decompose underground in the landfill, producing methane. Stabilised biosolids - with lime added - emit ammonia. So gases additional to methane are also produced - depending on temperature and water presence. These gases rise to the surface and escape through cracks and gaps in the clay cap used to seal landfills. I understand that pockets of material in landfills continue to decompose for decades after closure.