Point pollution from rural areas
This is pollution that comes from a single point. It can be the intentional release of sheep dip into a stream rather than disposing over it properly. Or it maybe the accidental release of slurry from a burst slurry pit/tank.
As well as farmers it may come from houses. If a house is not on mains sewage it will have a septic tank. If the tank is not big enough, not properly installed or regularly emptied it may leak causing pollution (which you maybe prosecuted for!)
What can you do?
Buy produce from local farmers and farmers markets as small producers generally are more environmentally friendly than the larger factory farms. Also try and by organic certified food.
Make sure you have a proper septic tank, correctly installed and regularly emptied by certified waste disposal companies.
If you see farmers polluting report it to the environment agency.