1. The Department must classify the ecological status of surface water bodies that are not designated as heavily modified or artificial in accordance with the following steps:
(a)estimate representative values of appropriate indicators of the condition of the relevant biological, physiochemical and hydromorphological quality elements from monitoring or modelling results. The appropriate indicators shall include:
(i)indicators of biological and other quality elements expected to be most sensitive to the pressures to which the water body is subject;
(ii)the values for physicochemical quality elements at risk of being so altered as to be failing a physicochemical standard ;
(iii)the concentrations of those specific pollutants likely to be in the water body in quantities that could cause a failure of a specific pollutant;
(iv)the concentrations of those priority substances likely to be in the water body in quantities that could cause failure of chemical status; and
(v)the criteria for hydromorphological elements relevant to high status.
(b)compare the values of the appropriate indicators estimated from monitoring or modelling with the applicable standards and biological boundary values in Schedule 1 of these Regulations.
(c)classify the ecological status of the water body as “high” if the values of all the appropriate indicators of the biological, physicochemical, chemical and hydrological quality elements comply with the highest corresponding standards given in Schedule 1; the assessment of morphological condition carried out in accordance with Part 4 paragraph 1 of this Schedule reflects totally or nearly totally undisturbed conditions; and there is no evidence that a high impact alien species, as identified on the Ecoregion 17 list, has become established and is having an ecological effect on the water body.
(d)where the biological quality elements and the general chemical and physiochemical elements and specific pollutants are high and the chemical status is good but the hydromorphological status is less than high, then the overall status of the surface water body is “good”.
(e)where a surface water body is not classified as “high” ecological status in accordance with paragraph 1(c), the Department must classify the ecological status of the surface water body according to the lowest classed biological or physicochemical quality element. If the lowest classed quality element is a specific pollutant or other physicochemical quality element, the class assigned shall be no lower than “moderate” ecological status.