Nature’s call carries a $300k price tag
Visitors to New Zealand’s Great Walks invariably leave one thing behind, writes Jonathan Carson.
While the Department of Conservation (DOC) asks visitors to ‘‘carry out what you carry in’’, it thankfully makes an exception for toilet waste.
But with more than 117,000 people venturing out on Great Walks in the past financial year, that’s a whole lot of waste.
DOC estimates that visitors deposit close to 300,000 litres of excrement in the 192 Great Walk toilets each year.
The cost of nature’s call in our national parks in the past financial year was close to $300,000, DOC figures show.
With the number of Great Walk visitors increasing 12 per cent in the past year, the cost of dealing with the waste is also on the rise.
‘‘Managing human waste is a major consideration in providing public facilities, especially in remote locations,’’ said Gavin Walker, DOC’s acting director of recreation, tourism and heritage.
‘‘Determining what is the most suitable and cost-effective system is specific to each location taking into account factors such as the environment, numbers using the facilities and other considerations.’’
Seasoned trampers will be familiar with DOC’s standard long drops – their earthy odour and lack of anything to wipe with. But what happens when that hole in the ground is full?
On some of the Great Walks – the Milford, Kepler and Heaphy – the toilets have septic tank systems in which liquid is separated out through filters and spread over dispersal fields.
The remaining solids are contained in tanks and removed either by helicopter, pump tracks or, in the case of the Abel Tasman Coast Track, by barge.
On Great Walks where waste dispersal is unavailable or inappropriate, toilet deposits are stored in containment tanks.
In the modern age of Great Walk tramping, the world-renowned Routeburn Track is the first to be equipped with flushing toilets.
Each of the four huts has three to five flushing toilets, which use septic tank systems to filter and disperse the waste.
‘‘Where possible, the preference is to have on-site septic sewage treatment and disposal systems that use biological activity to naturally treat the sewage,’’ Walker said.
‘‘The initial costs of installing on-site septic sewage treatment systems are higher but it reduces ongoing operating costs.’’
The cost of dealing with toilet waste is only a small proportion (3 per cent) of the $9,181,276 that DOC spent on managing Great Walks in the past financial year.
Currently, visitors to Great Walks pay between $22 and $54 a night to stay in huts and less than $20 for a campsite. But they don’t have to pay an entry fee. Managing human waste is a major consideration in providing public facilities.