GES is achieved if the indicator (Cs-137) concentration values do not exceed the threshold values from Helcom core indicator reports.

Within coastal and territorial waters GES is determined via contaminants selected in accordance with Directive 2000/60/EC: contaminants for which environmental quality standards are laid down in Annex II of the Directive 2013/39/EU; River Basin Specific Pollutants according to Annex VIII to Directive 2000/60/EC and regionally agreed HELCOM hazardous substances core indicators. Beyond territorial waters GES is determined via regionally agreed Helcom hazardous substances core indicators. GES is achieved if the indicator (contaminants) concentration values do not exceed the threshold values from Directive 2013/39/EU, national legislation of agreed River Basin Specific Pollutants and threshold values from Helcom core indicator reports.

GES under criterion D8C2 is determined by assessing reproductive disorders, specifically malformed embryos in amphipods. A good environmental status is considered achieved when more than 50% of the monitoring stations meet the GES threshold (GES >50%).

GES under criterion D8C3 is determined via the number on significant acute pollution events. GES is achieved if no significant pollution event occurs in the assessment period. The significant acute pollution event is determined as follows: extent of the spill exceeds 2,25 km2; removal time of the spill exceeds 48 hours (from first alert of the spill until removal of the spill); volume of the spill exceeds 5 tonnes or 5 m3.

GES under criterion D8C3 is determined via the number on significant acute pollution events. GES is achieved if no significant pollution event occurs in the assessment period. The significant acute pollution event is determined as follows: extent of the spill exceeds 4,5 km2; removal time of the spill exceeds 48 hours (from first alert of the spill until removal of the spill); volume of the spill exceeds 10 tonnes or 10 m3.

GES is achieved if the indicator (oil spills) values do not exceed the threshold values from Helcom core indicator reports.

GES under criterion D8C2 is determined via white tailed eagle (Haliaeetus albicilla) productivity. GES is achieved if all three parameters are above the threshold values. Threshold values for the parameters are: Productivity: 0,97 nestlings (period average); Brood size: 1,64 nestlings (period average); Breeding Success: 0,59 (59%).

Adverse effect of significant acute pollution can be assessed only if a significant acute pollution event occurs. For the criterion D8C4 no specific indicators or GES threshold values have been determined. In case of significant acute pollution event the scale of assessment is as used for assessment of the species groups or benthic broad habitat types under descriptors 1 and 6. According to descriptors 1 and 6 an estimate of the abundance of each species that is adversely affected and an estimate of the extent of each broad habitat type that is adversely affected has to be given.