The orange sections show where new Nitrate Vulnerable Zones (NVZ) have been declared, meaning new rules have to be observed in the distribution of manure, slurry and fertiliser.

Even in the blue areas, where NVZs already existed, the rules will become tougher, and more expensive to comply with. In both pink and blue zones, there are small excepted areas – which show up white when the maps are blown up to give detail.

That can be done through a website organised by the Department for Environment Food & Rural Affairs, at http://
tinyurl.com/3gquou

The new NVZ map takes in the catchment for the River Derwent – including most of the North York Moors – and some previously undesignated land draining into the Humber.

It means there is not much non-NVZ land left in the region. But that applies to most of England.

Scotland and Wales get off lightly because their farming is less intensive – and also because the human population's contribution to river pollution is smaller.

A few former NVZs have been de-designated, to the relief of the farmers within them – including a big chunk of the Vale of York.

Farmers who think the NVZ designation rules have been wrongly applied have until January 31 next year to lodge appeals. Defra will not pay for slurry storage but hopes to help farmers by encouraging and subsidising the development of anaerobic digestion plants, which can produce gas and electricity from organic matter including manure and straw. Environment Minister Phil Woolas said: "I am already in discussion with farming groups and other interested sectors about how we address the barriers to increased take-up."

Existing NVZs will have to adhere to some of the new rules from January 09 and new NVZs from January 2010.

But farmers have up to three years to achieve full compliance with slurry storage requirements.

They are still waiting to hear whether that means they have three years to comply with the new "closed periods" for muck-spreading.