I read an article in The Ecologist that says 'water companies, not farmers, are to blame for river pollution'.
Photo: Ruscombe Farm with two ponds at the top of the Ruscombe brook
Here is the jist of the article: "Phosphorus from human and household waste, rather than fertiliser run-off from farming, is the main source of river pollution, according to recently published findings. A ten-year study of nine rivers including the river Thames used another chemical, boron, found in washing powders, to help identify household waste as the main source of phosphorus....Excess levels of phosphorus in water contributes to the process known as eutrophication, whereby certain species, for example algae, thrive and rapidly begin to dominant the river at the expense of other species, including fish. When the algae die, their decomposition removes vital oxygen from river waters."
The article goes onto say that farming has been seen as being the main problem - ie about 50 per cent of phosphorus while human and household waste are responsible for some 24 per cent. However this new report indicates farming are responsible for just 20 per cent of phosphorus pollution, with household waste contributing 73 per cent. The Environment Agency, commenting after the publication of the findings, said it agreed with the analysis and believed sewage effluent accounted for 60-70 per cent of the total phosphorus entering rivers.
This blog has had much discussion about sewage - not least because of all the serious incidents occurring in the Ruscombe Brook (see pictures left and point 3 here for background on that). The article acknowledges we still need to target farming - especially high-risk areas of intensive livestock production - or perhaps better still I would argue we should call for much tighter controls and an end to such practices as battery hens. Anyway the report calls for more action on identifying effluent sources from households, including septic tanks and local drains.
It is worth noting that the report acknowledges that simply removing phosphorus might not provide the solution to good river ecology. Analysis of targeted phosphorus removal on the River Kennet, off the Thames, found eutrophication to still be a major problem. This means we need to also address the wider picture - such as flow, habitat, and water resources - the report suggests this 'requires new science that looks at the complex relationships between hydrology, biology, chemistry and habitat, as well as our interactions and needs.'
Is sewage the problem?
Well as Stroud District Council's representative on the Customer Liaison Panel of Wessex Water I have had some dialogue on this issue with Wessex and indeed other colleagues interested in water. I should note that Wessex has won various awards for it's sustainability policies - I don't know where other water companies like Severn Trent sit on this?
Anyhow this report's findings, although billed as 'news' is apparently old news. In fact where Wessex Water do not have phosphate removal at sewage treatment works it is likely that treated effluent is the major source. Wessex have phosphate removal at all works which discharge into sensitive areas - where they have this treatment, agriculture is then the major source, for example the Stour or the Somerset levels.
It seems clear that control at source is a key management tool that can be used to tackle the problem. I am aware for example that Wessex have worked hard to get soap manufacturers to remove phosphate from their products and continue to work with farmers to manage their application of mineral phosphate (every little helps). But what to do with the human population?
The usual concentration of phosphate in effluent is about 10 milligrams. Water companies can usually reduce the phosphate concentration in the effluent by about 80% by applying a specific treatment, but there is a downside. To do this on most works requires companies to add Iron Sulphate. This traps the phosphate but does mean that the water companies have to import this chemical from Spain or Scandinavia where it is a by product of the metal industry. This means that the process has a very unpleasant carbon footprint, so we solve one problem by introducing another.
Pee in the compost?
It would seem that unless we can get the human population to pee in their gardens, or at least into a bucket that can be poured onto the compost heap, phosphate will always be a problem, because human urine is the most abundant source of phosphate. Is this a campaign anyone wants to take on?? Certainly many organic gardeners already practice this but I am sure many people will be reluctant to consider and others will have small gardens (like myself) that could lead to questions from the neighbours?
I did cover a video about using pee here after one of the Open Homes noted the use of urine - see also here about the book 'Liquid Gold', cows urine in drinks and peeing in the shower.
So anyone for a campaign to encourage more folk to pee in their compost?
I understand there is research going on looking at how urine can be kept separate from solids - but there is a long way to go with this work. Reed beds are one solution and Wessex have a research project looking at different types of reed bed starting shortly. Severn Trent have also used reed beds - indeed have more than all the other water companies put together, but are still seemingly resistant to using them for solutions locally.
I have talked lots about reed beds in this blog - see for example basic description here - see also here about the ponds that deal with sewage at Hawkwood.
"The Carbon fields"
Graham Harvey, author of the excellent "The Killing of the Countryside" is also the Agricultural editor for the Archers and recently put reedbeds into the Archers plotline ... they even went off gravel beds (because of humus/carbon clogging) and switched to ponds because of this. A comment from a local water expert was "shame he didn't understand rb's need to be planted only in humus...though these microbes also appear (when applied weekly) to make sewage pond systems far more reliable ... maybe better than soil/humus rb's"
Harvey's new book, "The Carbon Fields" I have just started reading - it is very profound....here is what is said about the book: "A simple and elegant solution to some of the world's most pressing problems – rising food prices, increased carbon emissions and the health crisis. The answer is here for us now if we're bold enough to take it. No breakthroughs are required, no "fad" diets. There's no need to throw away the car keys or give up real butter and juicy steaks. So why haven't we been told about this great natural gift? Award-winning author Graham Harvey investigates the murky world of food and farming and reveals how global corporations have hijacked Britain's most basic source of life and health."
This blog has covered stuff re soil before - see here and here - See Harvey's book here or get it at Stroud Bookshop like me.