If it goes in the ground, it stays in the ground.
Just because that rubbish is out of sight, it has not miraculously disappeared. And just how long is it going to stay hidden, given erosion and extreme weather events?
New Zealand has a plethora of waste sites and legacy landfills holding contaminated materials lurking around the countryside. Many of these were built close to the coast or the edge of rivers, and some were even used to build out into the water to effectively reclaim land for sports fields.
Others are literally at the bottom of the garden, or at least down the back paddock on the farm, some filled with rusting equipment, various pesticides, herbicides and other agricultural chemicals, leaking batteries, asbestos, and cans of old paint.
As authorities in Otago are discovering, more of these old rubbish dumps are being uncovered all the time, as pressure comes on to use land for new development around the fringes of urban centres.
The Otago Regional Council says there may be more than 170 former landfill sites around the region.
Only four of these are currently listed as contaminated sites on the council’s register, but it is possible another 75 of these could also contain toxic waste, as they have yet to be investigated.
The onus is on landowners to investigate whether contamination may have happened at those sites and to supply information to the council.
Climate change is inexorably making these old sites more hazardous, particularly those near the coast and alongside rivers.
Take Kettle Park in Dunedin, for example. The landfill below the park near Middle Beach is being investigated to see what it actually contains and how it can either be removed or protected from ongoing and possibly accelerating erosion.
Contaminated materials have already been exposed nearby in the sand dunes at Middle Beach, including traces of arsenic, asbestos and other industrial chemicals dumped before the landfill was capped in the 1940s.
At the back of everyone’s minds will be images of what can happen when the elements conspire to remove a badly sited legacy landfill.
In March 2019, pristine South Westland beaches ended up strewn with old rubbish after torrential rain fell in the catchment of the Fox River.
The roiling river cut into its banks and tore open the old Fox Glacier Township Landfill, removing rubbish such as old car tyres, engine batteries and plastic. The detritus then washed into the Cook/Weheka River and ended up covering the river bed and more than 50km of beach.
The cleanup took many months and was only possible due to the huge efforts of hundreds of volunteers.
Like with many things, climate change is only going to make the situation worse. More extreme rainfall and runoff, or river flooding, will erode the thin and often tenuous cap on top of these sites, exposing their poisonous contents to all and sundry.
As many legacy landfills were located within a kilometre of the sea, these are targets for storm surges and will eventually be affected by sea-level rise. A Local Government New Zealand report on vulnerable infrastructure calculates there are at least 110 known closed dumps around New Zealand which will end up exposed to the sea if there is just a 0.5-metre rise in average sea levels.
There is an increasingly pressing need for strong leadership in this area, particularly from LGNZ and regional councils, and from the Ministry for the Environment and the Government.
Country-wide landfill remediation funds should be prioritised. There are many things we need to resolve and tidy up to make life better for future generations. Let the buck stop here, with this generation, when it comes to dealing with the rubbish of our predecessors.