6.1 Impact mechanisms and relevant receptors 6.1.1 Potential impact mechanisms
Potential impact mechanisms associated with the planned activities at the HARALD project are summarized based on the project description (section 3) and the technical sections (appendix 1).
Potential impact mechanisms include:
Underwater noise
Physical disturbance of seabed
Suspended sediment
Discharges (physical and chemical)
Solid waste
Emissions
Light
Resource use
Restricted zones
Employment and tax revenue
Oil and gas dependency
The source of the potential impact mechanisms is provided in Table 6-1. The sources of impacts are related to the activities described in the seven technical sections (appendix 1).
Table 6-1 Sources of potential impact mechanisms for the HARALD project. “X” marks relevance, while
“0“ marks no relevance.
Potential impact mechanism
Sesimic Pipelines and structures** Production Drilling Well stimulation Transport Decommissioning
Underwater noise X X X X X X X
Physical disturbance of seabed* X X 0 X 0 0 X
Suspended sediment* X X 0 X 0 0 X
Discharges X X X X X X X
Solid waste X X X X X X X
Emissions X X X X X X X
Light X X X X X X X
Presence/removal of structures 0 X X 0 0 0 X
Resource use 0 X 0 0 0 0 0
Restricted zones X X X X 0 0 X
Employmentand tax revenue X X X X X X X
Oil and gas dependency X X X X X X X
* the potentially disturbed area at the HARALD project is very small (< 1 km2) and related only to seismic survey and placement of drilling rigs.
** no new pipelines or structures are planned, and impacts relate only to maintenance vessels.
6.1.2 Relevant receptors (environmental and social)
The relevant environmental and social receptors described in the baseline for the HARALD project are listed below.
Environmental receptors: Climate and air quality, hydrographic conditions, water quality, sediment type and quality, plankton, benthic communities (flora and fauna), fish, marine mammals, seabirds.
Social receptors: Cultural heritage, protected areas, marine spatial use, fishery, tourism, employment, tax revenue, oil and gas dependency.
The relevant receptors have been assessed based on the project description (section 3) and the potential impact mechanisms (section 6.1). Relevant receptors for the impact assessment are summarised in Table 6-2.
Table 6-2 Relevant receptors for the impact assessment of planned activities for the HARALD project. “X”
marks relevance, while “0“ marks no relevance.
Environmental Receptors Social Receptors Potential
impact mechanism – planned activities
Climate and air quality Hydrographic condition Water quality Sediment type and quality Plankton Benthic communities Fish Marine mammals Seabirds Cultural heritage Protected areas Marine spatial use Fishery Tourism Employment Tax revenue Oil and gas dependency
Underwater
6.1.3 Marine strategy frameworks directive - descriptors
The list of receptors and impact mechanisms described in the ESIS can be directly related to the descriptors set within the Marine Strategy Framework Directive (MSFD; section 2.1.5). The MSFD outlines 11 descriptors used to assess the good environmental status of the marine environment.
The environmental status of the Danish North Sea waters is described in details in /154//154/.
1. Biological diversity is maintained. The quality and occurrence of habitats and the distribution and abundance of species are in line with prevailing physiographic, geographic and climatic conditions.
2. Non-indigenous species introduced by human activities are at levels that do not adversely alter the ecosystems.
3. Populations of commercially exploited fish and shellfish are within safe biological limits, exhibiting a population age and size distribution that is indicative of a healthy stock.
4. All elements of the marine food webs, to the extent that they are known, occur at normal abundance and diversity and levels capable of ensuring the long-term abundance of the species and the retention of their full reproductive capacity.
5. Human-induced eutrophication is minimised, especially adverse effects thereof, such as losses in biodiversity, ecosystem degradation, harmful algal blooms and oxygen deficiency in bottom waters.
6. Sea-floor integrity is at a level that ensures that the structure and functions of the ecosystems are safeguarded and benthic ecosystems, in particular, are not adversely affected.
7. Permanent alteration of hydrographical conditions does not adversely affect marine ecosystems.
8. Concentrations of contaminants are at levels not giving rise to pollution effects.
9. Contaminants in fish and other seafood for human consumption do not exceed levels established by Community legislation or other relevant standards.
10. Properties and quantities of marine litter do not cause harm to the coastal and marine environment.
11. Introduction of energy, including underwater noise, is at levels that do not adversely affect the marine environment.
The receptors identified in the ESIS are related to the MSFD status indicators hydrography (D7), fish, harbour porpoise and benthic communities (D1, D6). The impact mechanisms for planned activities in the ESIS are related to the MSFD pressure indicators seabed (D6), discharges (D6, D8, D9) and underwater noise (D11). Each impact mechanism is further assessed for the relevant receptors in the following sections 6.2 and 0.
6.2 Assessment of potential environmental impacts
Impact assessment for planned activities for each relevant environmental receptor is presented in the following sections.
6.2.1 Climate and air quality
Impacts on climate and air quality relate to atmospheric emissions.
6.2.1.1 Emissions
Emissions have been estimated for the planned activities at the HARALD project, and are presented in Table 6-3 for each of the activities.
Table 6-3 Overview of estimated emissions for planned activities at the HARALD project, provided per activity or per year. The maximum emissions have been used. Estimates have been calculated by Ramboll based on input from Maersk Oil.”-“ refers to an emission which has not been quantified.
Activity
* Note that the calculation for vessels and helicopters are assuming 20% for each of the five ESIS projects.
Emissions are primarily caused by venting, flaring of gas and the use of fossil fuels for production.
Table 6-4 provides an overview of the estimated annual emissions from operation of the HARALD project and the annual Danish emissions 2012, as well as total emissions during drilling and decommissioning.
Table 6-4 Emissions from activities at the HARALD project and national emissions numbers for Denmark /20//21/. ”-“ refers to an emission which has not been quantified.
Total emissions for drilling 2 wells at HARALD
The greenhouse gasses have different warming potential /141/, as some have a longer lifetime in the atmosphere and a higher heat absortion than others. Per definition, CO2 has a global warming potential (GWP) of 1, whereas the GWP is 21 of CH4 and 310 of N2O /141/. By re-calculating the estimated emissions to a GWP, it is seen that CO2 constitutes the largest emission of greenhouse gasses.
Both drilling and decommisioning are emissions related to specific activities, while the annual emissions occur every year until 2042. The annual emissions will therefore over the project life cycle be of the largest quantity.
The annual emissions at the HARALD project (excluding drilling and decommissioning)
contributes up to 0.2 % of the total annual CO2 emission for Denmark until 2042 (percentile will depend on the development of annual Danish emissions). The impact is considered to be of small intensity, a transboundary extent and long-term duration. The overall impact on climate change from emissions at the HARALD project is assessed to be of moderate negative significance.
6.2.1.3 NOx, SOx and nmVOC emissions
NOX and SOx are air pollutants which are spread by the wind and deposited in the surroundings.
The compounds have acidification effects, that can impact the environment in terms of defoliation and reduced vitality of trees, and declining fish stocks in acid-sensitive lakes and rivers. nmVOCs, can have a number of damaging impacts on human health. Some have direct toxic effects (e.g.
carcinogenic), but nmVOCs can also have indirect effects on health by contributing to the formation of ground-level ozone, which causes respiratory and cardiovascular problems.
Annual emissions from the HARALD project production corresponds to 0.3 % of the total annual emission of NOx in Denmark and 0.06 % of total annual emission of SOx in Denmark until 2042 (percentile will depend on the development of annual Danish emissions). The impact is
considered an impact of small intensity, a transboundary extent and long-term duration. The overall impact on air pollution from emissions at HARALD is assessed to be of moderate negative significance.