Nitrogen and Phosphorus Nutrient Neutrality

The much discussed issue of nutrient neutrality affects 74 local authority areas in various parts of the country. Excessive levels of phosphates and nitrates contribute to the growth of algal blooms, which causes reduced oxygen levels with adverse impacts on aquatic life.

There are ways of achieving nutrient neutrality however practically and cost are the issues. For on-site solutions the natural options of fallow land and wetlands are generally impractical due to lack of space and the cost of treatment plants renders this out of reach for any but the largest schemes.

Off-site options are often therefore considered. Natural England requires mitigation to be provided within the same local catchment area as the development and to be maintained for a minimum of 80-125 years. 

There are many excellent articles dealing with the issue in depth, here are three useful ones by Environment Analyst , Michelmores and JDP.