6. Technical Implementation
6.1 Inventory - Pressures
6.1.2 Groundwater
6.1.2.2 Characterization of groundwater bodies
For the initial and further characterization under the WFD a general description of the hy-drogeological, geological, pedological, and stratigraphic characteristics of the groundwater bodies is required.
Additionally, Annex II 2.1 WFD requires the identification of the general character of the overlaying strata of groundwater in each catchment area. This means that surface ments (usually erosion material with low depth on hard rock close to the quaternary sedi-ments) and the so-called covering layers (all rocks within the unsaturated zone over groundwater) are to be characterized.
Groundwater bodies in upper
C b i
Legend
Legend
Groundwater bodies in
quaternary water
6.1.2.2.2 Methodical approach
For the initial characterization of groundwater bodies a geological description of the water – embedding environment (the database comprising the relevant characteristics is complete), petrography (lithography), stratigraphy description, etc. had to be made. A completed data-base with these characteristics using vector geological map with size between 1:100 000 data from the hydrogeological map with size 1:200 000, Geofund Cadastre, EEA and ar-chive geological data is available.
The database contains information on each separate groundwater body information about its filtration coefficient, porosity, amplitude in the groundwater level, average, minimal and maximal depths of the groundwater as from the surface, width etc. These thematic layers are not yet represented as GIS layer due to which they have to be unified in a map of hy-drogeological units or in a combined map (e.g., type of rocks + permeability = type of aqui-fer).
The clarification texts in the reports describe additionally the hydrogeological character of the rock units.
Information on the character of the overlaying strata can be obtained from existing geologi-cal and soil maps and can be presented as a map of the vulnerability of groundwater to pol-lution or of the protection properties of the overlaying strata against groundwater polpol-lution.
The map of the overlaying strata of the groundwater is in the process of being generated with data from the database or by assessment of geological units, the maps on,„Depth to GWB“ (distance to the surface), „Lithology“ and “Field Capacity”. Data is available in the EEA and in the Danube River Basin Directorate - Pleven with the necessary parameters and a description of the minimal, maximal and average depth of the overlaying strata for each groundwater body.
6.1.2.2.3 Basics
Central data storage and GIS processing
• Database for groundwater bodies under Access
• Database under ORACLE in the EEA
• Geological maps (vector GIS map of the scale of 1:100 000)
• Hydrogeological maps (scalar GIS map of the scale of 1:200 000) and
• Soil maps exist as GIS layers.
6.1.2.2.4 Required Reporting and Summary Actions
• The Making of the map „Hydrogeological characterization of groundwater bodies” with single thematic layers
• The Making of detailed maps for the sub-basins
• The Making of the map „Characterization of overlaying strata“
The maps should be explained by texts.
Table 23: Necessary activities at working level – characterization of groundwater bodies
On 19th September 2003 the “Directive of the European Parliament and Council for protec-tion of groundwater from polluprotec-tion” was developed as a daughter Directive of the WFD. It regulates for all Member States unified quality norms for good chemical status – for nitrates (50 mg/l) and for pesticides (0,1 µg/l). The Member States have to determine on their own the threshold values for the substances given below. The specified concentration values should be treated as a proposal for unified threshold values for the European Union with re-gard to eco-toxicological and human-toxicological criteria.
• Ammonium 0,5 mg/l
• Arsenic 10 µg/l
• Cadmium 1 µg/l
• Chloride 250 mg/l
• Lead 10 µg/l
• Mercury 0,2 µg/l
• Sulfate 240 mg/l
• Tri- and tetra-chlorethylen je 10 µg/l
• Vinylchloride 0,5 µg/l
The assessment of the status is made on the basis of the arithmetic mean of the average values from the different sampling points for each groundwater body. A particular groundwa-ter body has a low-grade status when the quality norms and the threshold values are not complied with. Here, sustained trends and lasting increases have to be reversed. A trend reversal is recommended when 75 % of the norm or threshold value is reached.
The WFD prohibits direct discharge of harmful substances. The daughter Directive Ground-water specifies the groups of substances whose discharge into groundGround-water should be avoided or restricted:
No Working step Who?
(Intermediate) product (map, table, text/graphics)
Data location Remarks
1 Database of Groundwater Bodies Basin
Directorates database ACCESS Database 2
Generating of hydrogeological map with different thematic layers for DRBD
Basin
Directorates map GIS-Server
3 Development of short text descriptions
Basin
Directorates texts
4
Making of map "Characterization of overlaying strata" with division of the protection properties of overlaying strata into "favourable-average-unfavourable"
Basin
Directorates map GIS-Server
5
Statistical assessment of the separate degrees of protection property for groundwater body
Basin
Directorates table GIS-Server
• Organo-halogenic compounds and substances that may form similar compounds in water environment
• Organic compounds of phosphorous
• Organic compounds of tin
• Substances and preparations or products from their dissociation with proved carcino-genic or mutacarcino-genic properties, respectively, steroid, thyroid, reproductive or other properties that may lead to disorders in the function of the endocrine system in or through water.
• Persistent hydrocarbons as well as persistent and bio-accumulating toxic organic substances.
• Cyanides
According to the WFD a general prohibition for harmful substances is in force. The dis-charge of the following substances is admissible when the good status is not endangered:
• Metals and metal compounds;
• Arsenic and arsenic compounds;
• Biocides and plant protection preparations;
• Suspending substances;
• Substances contributing to eutrofication;
• Substances having durable impact on the oxygen balance (and which may be meas-ured on the grounds of parameters such as BOD, COD, etc.)
For water bodies endangered by contaminated sites it is necessary to carry out special de-termination of the trends. It has to be ascertained whether the burden is spreading.
6.1.2.2.5 Principles for assessment of the objectives achievement
According to Art. 5 WFD the impact of human activity on groundwater has to be reviewed.
Pressures on the groundwater have to be tested for its qualitative and quantitative status. To be examined separately under Annex II WFD:
• Point sources of pollution;
• Diffuse sources of pollution;
• Quantitative status (abstraction and artificial recharge);
• Other anthropogenic pressures.
Reviews during the inventory have shown that nitrogen input of from diffuse sources and here the nitrate immission pressure on groundwater is the crucial quantity for assessment of the achievement of the objectives.
It is not appropriate to use average values from the measuring of groundwater for the review of the groundwater bodies as the different values do not allow the establishment of a “level”
average value expressing the status. The calculation of the median and the average value leads to completely inapplicable specialized inferences. Assessment criteria based on the statistical distribution of measurement points are more accurate. These show at what per cent value from the measurement points exceeds the borderline value. The statistical distri-bution makes possible an accurate analysis of the load. This allows to give an appropriate forecast on the achievement of the objectives for good status at a later step.