We can’t let details bog us down
The Government’s new ‘‘Clean up our Waterways’’ scheme, which included, what appears to be a lowered standard of clean water measurement, was bound to create heated public argument. Perhaps it was intended to as a diversion from other issues but we should instead be having a debate based on fact and reason.
Some regions have gone it alone in an effort to reverse the damage to rivers and streams and they include the Waikato Regional Council which has released an ambitious plan to make the Waikato and Waipa rivers safe to swim in but over an 80-year time span. The Healthy River/ Wai Ora project will require nitrogen and phosphorous use on farms to be reduced and stock kept out of all streams. There will also be tight rules for forestry and tougher restrictions for land-use changes. Before it has even been fully explained and considered the project has been slammed by some environmentalists for taking too long and by farmers as too strict and costly.
Unfortunately political posturing and entrenched opinions like this, on how to decide if a waterway is safe to swim in, will not help the debate. The trouble is few people, including many decision makers, have any idea what the different levels of E coli measurements actually mean in terms of risk to human health.
A Ministry of Health’s Provisional Microbiological Water Quality Guidelines for Recreational and Shellfish-Gathering Waters in New Zealand, released in 1992, set an E.coli measure of 235 bacterium per 100ml of water (235cfu/100mL) as safe.
The Government however has set 540cfu/100ml as the new level at which water can be assumed as safe for swimming. The previous official level was half that at 260cfu/100ml.
In layman’s terms that means the new level of bacterium contamination, now considered safe for swimming, is twice that of the old measure but does that mean water with the new level of E.coli is unsafe? Is the Government trying to set a more easily achievable goal or is the new measure a more realistic option?
There is a danger that attempting to restore waterways to some imagined pristine condition of days gone by will suffocate any attempt to make improvements. Very few of our lakes and streams have ever been perfectly pure and clean. Well before the arrival of the first humans a thousand or more years ago coastal lagoons and many inland lakes were heavily contaminated with decomposing waterfowl dung and rotting vegetation. Many of the streams we swam in as children in the undeveloped bushlands of the 1950s would probably not have passed any of the tests applied today.
Nor would the drinking water we took from our roofs where both sparrows and seagulls roosted. Perhaps we developed better natural immunity in those days and perhaps we have gone a bit too far in demanding unachievable water quality levels which never really existed in the past.
Land clearances, farming and industry have no doubt made matters much worse in recent years but, in real terms we have little idea how safe or unsafe our waterways are or have ever been. Regional councils don’t test extensively and when they do they only test for E coli, nitrates and phosphorus. There are many more toxins and contaminants to be wary of which are not measured or tested for. They have always been there but have no doubt increased with the intensification of farming and the application of high levels of various fertilisers. All these tests are designed to establish if water is safe for human activity but perhaps we should test to establish if water is safe for the insects, plants, fish and birds which live there naturally. Many are not and most of our big lakes are now seriously polluted with huge nutrient loads. But do we need to accurately measure that pollution before we take common sense measures to reverse the damage?
While dairy farmers have been berated for contaminating waterways, with some justification, they are not alone and far from the worst offenders. They are, however, one of the few agricultural groups which have put in a real effort to address the issue. For levels of toxins few waterways will match the stormwater outfall from a city
It does not really matter if we have a million or 10 million bacterium in a waterway. As long as there is genuine progress in reducing the known contaminants human activity is putting into our rivers and streams, measuring the minute detail is relatively unimportant.
LETTERS TO THE EDITOR