The 1994 Surface Waters (River Ecosystem) (Classification) Regulations introduced a
component of the scheme designed to make water quality targets statutory. The NRA has set
water quality targets for all rivers and these are known as river quality objectives (RQO) and they
establish a defined level of protection for aquatic life. They are used for planning the maintenance
and improvement of river quality and to provide a basis for setting consent to discharge effluent
into rivers, and guide decisions on the NRA's other actions to control and prevent pollution.
Achieving the required RQO will help to sustain the use of rivers for recreation, fisheries and
wildlife, and to protect the interest of abstractors. The water quality classification scheme used to
set RQO planning targets is known as the river ecosystem scheme. It provides a nationally
consistent basis for setting RQO. The scheme comprises five classes which reflect the chemical
quality requirements of communities of plants and animals occurring in the rivers. The standards
defining these classes reflect differing degrees of pollution by organic matter and other common
pollutants.