Agricultural Runoff and Water Quality

spraying09:35 Thursday 20th March 2014
BBC Radio Cambridgeshire

[A]NDIE HARPER: Could the wetter and warmer winters we’re having be having a negative impact on our rivers? I suppose this is the first wetter warmer winter we’ve had for some time. But that’s the subject of a new study, after environmental scientists suggested nutrient runoff from agricultural land could be lowering the quality of water in the rivers. Dr Bob Evans is from Anglia Ruskin University’s Global Sustainability Institute, and is involved in the study. Good morning to you.
BOB EVANS: Good morning.
ANDIE HARPER: Now I say the wetter warmer winters that we have now. Well that was the case for quite a few years, then we had that burst of cold ones. But if there’s ever been a wet warm winter, this has been it.
BOB EVANS: Well yes. But it was a very wet winter last year, which was also very difficult for the farmers. So these things go up and down. It’s really quite difficult to work out whether the trend is towards a particularly wet sequence, or a drier sequence. These things, they happen. They’re very difficult to predict.
ANDIE HARPER: Now there was always a concern about our water courses, wasn’t there, in the halcyon days of farmers putting sprays on fields willy-nilly? But most of us are under the impression that they’re so controlled these days that that doesn’t happen.

BOB EVANS: Well again probably it does rain. So farmers can follow all the regulations, all the instructions, and they’re generally very good, and they try very hard. But if the topsoils get really quite wet, then you spray, if it rains quite quickly after you’ve done the spraying it’s likely to run-off down the tractor wheelings, because that’s where the soils really compact, and where the rain can’t really sink into the soil, so it just runs off down the tractor wheelings and gets into the nearest stream.
ANDIE HARPER: So given that that does happen, and it is the case, what effect do these things then have on our water courses, on our rivers?
BOB EVANS: Well the water companies have to give you a quality of water through your tap that doesn’t have pesticides or too much nitrates for instance, or in the study that I’m concerned with, that’s phosphates. That’s phosphate that just, I don’t think it harms you, but it’s not very good for the ecology of the streams and stuff like that. But for the water companies, some herbicides and pesticides are very difficult to remove. So it means in fact they’ve to stop taking water out of the river in winter, and go to another source of supply. Well in the East of England very often they can do that, because they’ve got bore holes into the chalk. But it’s actually quite difficult to be switching around from one supply to another.
ANDIE HARPER: And is the concern about it getting into our water supply, or is the concern mainly about the life in the river?
BOB EVANS: It is a concern of you getting it into your water supply, because if it comes through, there’s one pesticide that they’ve got on the land to kill slugs. And that’s very very difficult for water companies to take out of the water. So if it came through in your tap, in your kitchen, and somebody said to I think it’s the Drinking Water Inspectorate, will you analyse this please, and has it got any pesticides in it, and they said, yes it has, the water company is in really really serious trouble.
ANDIE HARPER: Is the concern more in arable areas like this, as opposed to, let’s say, areas which have more pasture? I know that cattle rearing and the like isn’t as common as it used to be. You’d drive to the Cotswolds, and there’d be fields everywhere, Now they’ve been ploughed up. But generally speaking is there more concern in arable areas such as East Anglia?
BOB EVANS: There is. A bit of background for the study. Originally the guys who have a lot to do with it were all working down the South West, where it’s dominantly cattle. And there is more phosphate knocking about the system, because you put manure on the land and stuff like that. So that’s why that study was started. But the kind of processes that get phosphate off the land and into the rivers is the kind of process that will move pesticides for instance off the land and into rivers. In other words, where the soils are wet and it rains.
ANDIE HARPER: So what’s the answer then Bob? Less rain. (THEY LAUGH)
BOB EVANS: Actually it’s really really difficult. Somebody like me would say well I think farming might have to change, or the regulations will have to change. But it’s rather difficult for the moment, because farmers have done what they were asked to do, which is produce food as cheaply as possible, and they’ve gone down that route. And you’d be a very brave farmer not to have done it. But what it means is the kind of agriculture we’ve got now, there is a greater chance of herbicides and other pesticides going into the rivers than there was before. Though some pesticides have already been banned.
ANDIE HARPER: It’s been really good to talk to you. Thanks for joining us.
BOB EVANS: That’s fine. Thank you very much indeed. Bye.
ANDIE HARPER: That’s Dr Bob Evans from Anglia Ruskin University’s Global Sustainability Institute.