Its saddens us to report that a significant pollution event has taken place affecting the River Irwell in Greater Manchester.
There has been a 15 mile total wipe out of river invertebrates (river bugs) from a point just south of Rawtenstall to the confluence of the River Roch in Radcliffe, and then a 90% reduction in numbers from Radcliffe down to the city centre of Manchester where the Irwell joins the Manchester Ship Canal.
The total length of river affected by this pollution incident could increase significantly beyond 25 miles when test results come in from the Manchester Ship Canal and lower River Mersey.
Our volunteer citizen science kick sample team (who take part in the national Riverfly Partnership monitoring initiative where river health is monitored by regularly counting numbers and species of river invertebrates ) have discovered the location where a pollutant which we believe to be a form of agricultural insecticide has entered the water course. See map below, click on icons for video evidence.
Whilst it appears to us that the entry point to the river is via a Waste Water Treatment Works – we do not think that the water company is at fault for this catastrophic incident, rather that an irresponsible individual/business in the sewer network area around the treatment works has illegally disposed of toxic chemicals down the drains.
This toxin has made its way through the sewer network, through the sewage treatment beds (settlement beds are designed to treat human biological waste and not chemicals) and then into the river via the water treatment works outflow.
We are 100%sure that this is the pathway the pollutant has taken, as kick samples 100 yards upstream of the treatment works outflow show a healthy invertebrate population (see video below)
And at a point 100 yards downstream of the water treatment works outflow there is a 100% absence of river invertebrates. See video below.
The Environment Agency have been working extremely hard taking water samples and conducting chemical tests to determine the exact toxic substance which has caused this incident and will no doubt share this information as soon as lab test results come in.
However we are reasonably confident that this pollution disaster has been caused by a pesticide substance as there was a recent pollution incident on the River Kennet which had great similarities to this event. In the case of the River Kennet it was a pesticide called Chlorpyrifos – due to the similarity in the damage on The Irwell we are confident that the same or similar chemical has been dumped into our river system.
So we now have a good idea as to what has happened we have serious concerns about the long term effects….. what are fish going to eat now that their main food source has disappeared?
A fish stuck in the middle of this pollution event is going to have to swim at least 8 miles in order to find food. How is other wildlife that has managed to re-colonise our post industrial river going to survive now that their staple diet has been removed ??
The Grey Wagtails, the Dippers, the Swallows and Sand Martins?
What about the colonies of bats which have returned to wheel above our rivers at dusk feeding on the invertebrates that have hatched out as river flies?
The effects of this pollution incident are already horrific and the wildlife of The Irwell is going to really suffer as a vital part of the food chain has been obliterated by pesticide.
For all nature lovers – this event is just so saddening.
A river which for so many years was nothing but an open conduit for industrial and human waste – suddenly burst back into life in the 1990s due to the hard work of The Environment Agency, local Water Companies and the hard work of unpaid volunteers – now plunged back towards the dark ages by the actions of an uncaring polluter.
The big challenge now for the Environment Agency (once laboratory tests have identified the pollutant) is to trace the pathway of the toxin upstream through the drainage network of Rossendale to hopefully identify and then prosecute the polluter – not an easy task, but with expertise and determination – not impossible.
Now what for The Irwell and its wildlife ?
A long slow recovery – as the resilience of nature will always be stronger than humans best efforts to destruct and destroy
If you see anything which might be or cause pollution on our waterways – please don’t hesitate to call the Environment Agencies pollution hotline – 0800 807060
If you would like to take part in our program of monitoring river health – please contact us and we will get back to you.