No changes have been made with regard to chemical status of groundwater since the previous management cycle.
Quantitative status
Of the water district's 697 groundwater bodies, 656 have been assessed as having good quantitative status, while data is lacking at present to assess the remaining (41) bodies. The reliability classification of quantitative status is, however, very low, and all assessed bodies in the district have a low (D) degree of reliability, which reflects the deficient monitoring of groundwater levels and the absence of information on water abstraction.
Changes in quantitative status from the previous assessment. No changes have occurred since the previous assessment.
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6.2 Sources of impact and risk assessment
As it often difficult to restore a polluted groundwater it is important to designate and deal with sources of impact before a change is made to chemical and/or quantitative status in them.
By conducting impact analyses, which show where there are problems in the water bodies and which sources of impact are significant, the sources of impact can be dealt with early so that the risk of impact on the groundwater body diminishes. Significant impact means such impact that, alone or together with other impact, may mean that a water body does not meet, or is at risk of not meeting, the environmental quality standards.
As more impact analyses have been done during the period 2009-2015, the number of groundwater bodies at risk of not attaining good chemical status or quantitative status by 2021 is far higher today than in 2009.
Vulnerability studies are also done, which means that it is analysed whether the ground cover retains pollutants or whether there is a risk of pollutants being dispersed down to underlying groundwater.
Procedures and basic assumptions in risk assessment
How the assessment of chemical and quantitative risk for groundwater is to be performed is described in the SGU (Geological Survey of Sweden) regulations on mapping and analysis of groundwater (SGU-FS 2013:1). For more detailed information on methodology in risk assessment, see the complete version of the management plan and regulations SGU-FS 2013:1
Results of risk assessment
Nine groundwater bodies in the Bothnian Bay water district have been assessed as being at risk of not attaining good chemical status by 2021 (Table 1 and Figure 6.3). The risks originate in a feared spreading of environmentally dangerous substances from polluted sites, previous use of pesticides on agricultural land, risk of impact from infrastructure above and densely built-up areas and the mining industry.
One (1) groundwater body has been assessed as being at risk of not attaining good quantitative status by 2021 (Table 1).
Table 1. Risk assessment for groundwater bodies in the Bothnian Bay water district. Chemical risk assessment Number of groundwater bodies
Risk of not attaining good chemical status in 2021 9 No risk of good chemical status not being attained 688 Risk of not attaining good quantitative status in 2021 1 No risk of good quantitative status not being attained in 2021
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Figure 6.3 Groundwater bodies with risk of unsatisfactory chemical status in the Bothnian Bay water district.
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7
Mapping and analysis of surface waters
7.1 Demarcation and classification of surface water bodies
Surface waters are divided into water bodies and types. The basic principle is that water is divided such that category, type and status are as similar as possible. A water body must also be continuous and cannot therefore consist of geographically separated parts. The purpose of this is to be able to group and compare waters with similar natural conditions that depend among other things on climate, natural geographically ecoregion, geology, height above sea level, size and depth.Lantmäteriet's overview map provides the basis for the division of lakes and rivers in Sweden. Lakes that have a minimum surface area of 1 km2 and rives with a river basin larger than or equal to 10 km2 have to be designated as water bodies. Smaller water bodies can also be designated. These may be waters concerned by protection under other EU directives, waters that are of particular ecological value or waters that affect a designated water body in a significant way.
In the area from the coastline out to one nautical mile (1 852 m) outside what is known as the baseline water bodies have been demarcated as coastal waters. Each coastal water body is a demarcated area of coastal water, a sound, a bay or (in some districts) a harbour area. The basic principle in division is that the coastal water bodies have to be similar with respect to natural conditions, impact and status.
In the offshore area between one and twelve nautical miles outside the baseline (territorial waters) 19 water bodies have been demarcated in Sweden. These water bodies are not included in the classification of chemical or ecological status. Indicators in accordance with the Marine Environment Directive are used instead to identify environmental impact. The division of water bodies is reviewed and revised at the start of each water management cycle. The most recent revision of water bodies was performed in 2010-2012. The most important changes made are described below.
A total of 6 885 surface water bodies have been demarcated in the Bothnian Bay water district, of which 4 788 rivers, 1 984 lakes and 113 coastal waters.
7.2 Changes in surface water body classification since the
previous management cycle
The most important changes made during the revision with regard to surface water were that the demarcations for the water bodies established in 2009 were improved and waters constituting protected areas were added, including drinking water sources, waters affected by Natura 2000 sites and waters with EU bathing places. Some water bodies were removed as they did not fulfil the criteria to constitute a water body.
The changes in the Bothnian Bay water district meant a gross decrease of 62 surface water bodies. It is very small watercourses between lakes in particular that have been removed as water bodies, the lakes instead having been linked together to form a water body. It is hoped that the new division will provide the necessary basis for better environmental quality standards and targeted action programmes.
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7.3 Status classification – an assessment of the status of the
water
In order to be able to provide a measure of the quality of the water, all water bodies after classified according to how large the deviation is from the "natural status" of the water. Lakes, rivers and coastal waters are classified on the basis of the present-day status of the water for both ecological and chemical conditions. The way in which status classification is to be carried out is governed by regulations from the Swedish Agency for Marine and Water Management and the Geological Survey of Sweden. This is supplemented by grounds for assessment and manuals. In order to clarify the manuals so that classifications can be done in a more uniform way, the water district authorities in 2012-2013 produced a manual consisting of a number of quick guides to various aspects of mapping work. The quick guides are used as support in the work of the county administrative boards to survey surface and ground waters, and they contain guidelines for status classification, assessment of impact, environmental problems and risk, drafting of proposals for environmental quality standards and designation of HMWBs and establishment of ecological potential.
A digital Questions Box was introduced to enable questions to be asked on procedures for classification work. Questions received through the Questions Box were answered by administrators at the water district authorities with skills in different areas. Around 450 questions were put to the Question Box, the majority coming from the county
administrative boards and being concerned with classification.
The results form all parts of the surveying work can be seen in the VISS database, with the exception of the economic analysis. Here it is also possible to read texts explaining why a water for for example has a particular status or environmental problem.
Assessment of the measurements and their accuracy
The quantity of data underlying status classifications and assessments varies. Measured data is often also complemented by modelling and expert assessments. The quantity of underlying data differs between counties and districts.
What is known as a reliability classification is done to clarify how substantiated a status classification is. The assessment of reliability is a new tool introduced in conjunction with the status classification work in this management cycle. An estimate of the reliability of a status classification can provide an indication of where monitoring needs to be expanded or changed. Reliability classifications have been done for ecological status and chemical status, but also for certain other individual parameters, for both groundwater and surface water. Reliability is shown in VISS by four different classes through the letters A-D, where A represents the highest reliability and D indicates the lowest reliability. A corresponds to Very Good, B - Good, C - Medium and D - Low reliability.
As well as the different classes (A-D) of reliability there is also information on what type of classification or expert assessment has been used (measured values – basis of assessment, measured values – expert assessment, modelling, extrapolation or other expert assessment), what EQR (ecological quality ratio) value/content the classification is based on, how many measurements underlie the assessment and from what years data come. It is important to emphasise that the status classifications underpinning standard-setting and programmes of measures are applicable regardless of reliability. If classification with low degree of
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Working methods and basic assumptions in status classification of surface waters The status classification is based on measured data from national and regional
environmental monitoring, and from receiving water control and municipal environmental monitoring. As well as classification according to the bases of assessment, various models and expert assessments have been used in the work.
The quick guides and the water district authorities' questions box have put the county administrative boards in a better position to make assessments that are as similar as possible. There are, however, still some unclear aspects in the guidelines, and the
assessments for some parameters may vary between different counties and water districts. It is in the assessments of hydromorphology in particular that there are variations. This is due in part to the county administrative boards having widely differing quantities of data and partly to different county administrative boards having applied different considerations. Quality assurance of the classifications is still in progress, to coordinate assessments nationally.
Expert assessments – when the underlying data is not sufficient
The underlying data has been continuously improved, but there is still a lack of complete underlying data for many water bodies, particularly with regard to biological parameters and environmental toxins. What are known as expert assessments have been used to a great extent in status classification for these water bodies. An expert assessment is made on the basis of all available knowledge with data from measurements, impact data, model calculations, previous experience and so on.
There are several variants of expert assessments:
Classification of individual quality factors where there is date, but where an expert judges that application of the bases of assessment results in an incorrect class. Utilisation of data from parameters without bases of assessment for example for
freshwater mussels, crayfish and filamentous algae. Status classification when there is inadequate data.
If an expert assessment results in a water body being assessed as worse than good status, this leads at the same time to the water body having to be monitored operationally. A description is given in VISS of how the expert assessment is carried out for each
individual water body. The reliability classification also provides a suggestion of how well substantiated a classification is.
Classification of ecological status or ecological potential
There are five classes for the assessment of ecological status: high, good, moderate, poor and bad status.