LEARN - Water Quality
The Political Hatchling's Guide to...
Kiwis are concerned about the quality of our water. In a recent survey, 73% of us said that we were concerned about poor water quality in our waterways (Water New Zealand, 2017). Our Government is responding to our concern too, with plenty of policy around setting high standards of water quality and working toward these. But what are the facts?
Let's start with some science
There are many nasty things that we don’t want to see in our water, but here we will focus on the filthy three: e.coli, nitrate-nitrogen, and phosphorous. E.coli gets into the environment through fecal matter, and can make humans quite sick. When put together, nitrate-nitrogen and phosphorous cause excessive algal growth to occur which can kill wildlife and be harmful to humans.
In monitored NZ rivers, researchers found:
Now this doesn’t sound too bad. For two of our three bandits, more sites were improving than worsening. But before we jump to conclusions, let’s take into account regional differences. These regions are split into urban (cities), pastoral (farming), exotic forest (non-native forests), and native forest. The following statistics are compared to our native forest:
Basically, while our rivers are getting cleaner, you might want to think twice before swimming in urban or pastoral areas!
What about Farming?
Farming is responsible for much of the nitrate-nitrogen, phosphorous, and e.coli in our waterways. This is especially true for high-producing dairy farms, and farms with high stock density. For example, in the Waikato dairy farms account for:
Luckily, the dairy industry recognises its role in polluting our waterways. The Dairying and Clean Streams Accord was an agreement between farmers, the government, and regional authorities, and represents a commitment to improve the environmental impact of dairying. This has found some success, with the most recent report finding that of the monitored sites: the proportion of streams fenced ranged from 66-100%, almost all stream crossings were bridged or culverted, and nutrient plans were in place on 85-90% of farms (Ministry for the Environment, 2009).
When reading the above paragraph, it is important to remember that fences, bridges, and nutrient plans are not always fully effective. For example, Environment Canterbury found places in the monitored sites where fencing and culverting were likely to be ineffective as stock could still find access to waterways (Ministry for the Environment, 2009).
What is the Government doing about all this?
Time to talk about policy. In 2017, National introduced the Clean Water Package. This based the cleanliness of rivers on e.coli concentrations, and of lakes on cyanobacteria. It also defined a river to be swimmable if the risk of getting sick from infection averaged across time was between 1 and 3.5 percent (Ministry for the Environment, 2017).
Now this doesn’t sound too bad, until you dig a bit deeper. Firstly, the new definition doubled the acceptable level of e.coli from less than 260 per 100mL to 540 per 100mL.
Old Standard per 100ml
New standard per 100ml
Secondly, the Northland District Health Board believes that, from a public health perspective, the risk of up to 3.5% is much too high compared to the risk of less than 1% under the previous definition (Northland District Health Board, 2017). Finally, by basing statistics around an average over time (with a minimum of 100 samples over 10 years) means that the average may not be reflective of the actual water pollution, and may confuse contamination from preventable causes with natural variation.
While Labour has not put numbers to their promise of “adopt high standards of freshwater quality standards and set dates to working towards these standards” (New Zealand Labour Party, 2017) , any rise in standards would appear to be a good one.
So now that you know about water quality, you've probably got a lot more questions! Stuff like, how much water do we have left? Who owns our water? Is the loch ness monster real? We have more pages coming soon that will answer all these and more, so stay tuned...