METHODOLOGICAL APPROACH FOR SELECTION OF POTENTIAL REGIONAL LANDFILL SITES ON THE TERRITORY OF BULGARIA

sources as well as on basis of the experience of engineering and consultancy companies accomplished similar projects taking into account the specific conditions in Bulgaria. The implementation of remote sensing surveying methods and geographical information systems significantly shortens the agricultural areas permanent crops investigation period (for instance -1 month for the territory of Sofia region). 2.4.2. Complex cultivation patterns The methodological approach was applied for selection of regional municipal 2.4.3. Land principally occupied by solid waste and hazardous waste landfill sites in many regions on the territory of the agriculture with significant areas of country. The studies are realized at three stages as described below. natural vegetation 2.4.4. Agro-forestries areas

2. PRELIMINARY OFFICE STAGE

3. Forest and 3.1. Forests 3.1.1. Broad leaved forest The stage involves cartographic complex of activities which are based mainly on semi 3.1.2. Coniferous forest the use of available maps of various type - digital, processed in GIS environment and natural areas 3.1.3. Mixed forest hard copies. This represents the ground for identification and preliminary selection of 3.2. Scrub and/or 3.2.1. Natural grassland potentially suitable sites. Important moment here is the existence of many restricting herbaceous 3.2.2. Moors and heathlands factors which are fixed in the respective regulative documents issued by several vegetation 3.2.3. Sclerophylous vegetation ministries. Some of these restrictive factors have forbidding character and others may be associations 3.2.4. Transitional woodland qualified as extremely unfavorable, requiring specialtechnical measures to be applied. scrub Two main methods are applied for the activities from the cartographical complex: 3.3. Open spaces 3.3.1. Beaches, dunes, sand

automated procedures in GIS environment for reduction of selected potential with little 3.3.2. Bare rocks sites in accordance with pre-set categories and criteria based on the regulatory or no vegetation 3.3.3. Sparsely vegetated areas requirements currently in force; 3.3.4. Burnt areas -computer-aided visual interpretation of vector and raster data from the “CORINE Land Cover 2000 -Bulgaria” project (the nomenclature of Corine Land Cover project is 3.3.5. Glacier and permanent snow- presented in Table 1). fields

4. Wetlands 4.1. Inland 4.1.1. Inland marshes Table1Corine Land Cover Nomenclature wetlands 4.1.2. Peat bogs Level 1 Level 2 Level 3 4.2. Coastal 4.2.1. Salt marshes

1. Artificial 1.1. Urban fabric 1.1.1. Continuous urban fabric wetlands 4.2.2. Salines surfaces 1.1.2. Discontinuous urban fabric 4.2.3. Intertidal flats 1.2. Industrial, 1.2.1. Industrial or commercial units 5. Water 5.1. Continental 5.1.1. Stream courses commercial and 1.2.2. Road and rail networks and bodies waters 5.1.2. Water bodies transport units associated land 5.2. Marine waters 5.2.1. Coastal lagoons 1.2.3. Sea ports 5.2.2. Estuaries 1.2.4. Airport 5.2.3. Sea and ocean 1.3. Mines, dumps 1.3.1. Mineral extraction site Note: Classes 223, 241, 244, 335 and 423 are not observed in Bulgaria. The levels and construction 1.3.2. Dump suitable forlandfill sites are marked in bold and are underlined. sites 1.3.3. Construction site 1.4. Artificial non- 1.4.1. Green urban areas During the preliminary office stage two sub-stages are outlined depending on the agricultural 1.4.2. Sport and leisure facilities source of the data based on which the area categorization is done. Investigations in each vegetated areas of the sub-stages are done in several consecutive steps. The selection of regional 2.Agricultural 2.1. Arable land 2.1.1. Non-irrigated arable land municipal solid waste landfill site for Gabrovo region is presented for illustration (Fig. 1 areas 2.1.2. Permanently irrigated land and 2). 2.1.3. Rice fields 2.2. Permanent 2.2.1. Vineyards crops 2.2.2. Fruit trees and berries plantations 2.2.3. Olives groves 2.3. Pastures 2.3.1. Pastures 2.4. Heterogeneous 2.4.1. Annual crops associated with operation, the satellite images from the year 2000 are used for more precise visual assessment and additional outlining of the selected sites with the automated procedures. Step four -elaboration of products for analysis, expert evaluation and selection of suitable sites -layers in GIS with: (1) all potential sites of the selected classes of third level of Corine Land Cover / Land Use before introduction of restricting conditions; (2) all layers from step two; (3) minimum in number sites - intersection of all layers with restrictions; (4) layers with ranked potential sites with the computer-aided in GIS environment visual analysis plus improvements - from step three; (5) elaboration of maps in electronic format in scale 1:100 000 for all investigated regions and in scale 1:25000 for some selected areas. Second sub-stage. Data from other sources for identification of restrictive factors are used. Step one - identification and elimination of karst terrains. During this operation terrains affected by karst processes are identified and localized. The distribution of carbonate rocks (limestone and marble) without terrigeneous admixtures is adopted as leading factor. On the basis of available geological maps in scale 1:100 000 and the Fig. 1. Investigatedterritoryforsuitable regionallandfillsitesin Gabrovo region explanatory notes to them, all areas which fall into the contours with karst and/or karstifying rocks are identified and excluded (Fig. 3). Fig. 2. Reducing of the area after excluding of one-kilometer buffer zones around Fig. 3. Reduced area in Gabrovo region after excluding of the residential areas and residential areas the sections with unfavorable geological settings First sub-stage. The classes from Corine Land Cover Nomenclature and the pre- Step two (depending on the specific case) -identification of territories falling into set restrictions are used for categorization of the areas. The consequence of operations the 13-kilometer buffer zone around airports for civil use, outlined around their control includes: point on the basis of coordinates of the control point. Step one - extraction from the data base at region/municipality level of classes Step three - identification of other territories with protection status, done on the identified during preliminary assessment as suitable for construction of landfills basis of the available maps and information obtained from the respective experts in the (marked in the nomenclature table). municipalities, on which territory the investigated area falls into. The restriction to Step two - creation of new layers in GIS after preliminary automatic selection of locate regional landfill sites on the following protected territories in accordance with the suitable sites using restrictive conditions. regulative requirements is taken into account: Step three - computer-aided (in GIS environment) visual analysis, ranking and selection of suitable sites in the created after the automatic selection layers. During this  National parks and natural reserves, and other protected territories, except in the - land type - if possible unproductive land shall be used, as well as woodless cases when the management plan of specific zones allows activities and operations regions or regions occupied by shrub and invaluable plants, and this way to minimize related to waste treatment; cutting of forests. Opportunities are searched for some of the sites to be on places,  archeological, architectural and other reserves and sites, announced as cultural which in the past have been subject to anthropogenic activities that have caused monuments; unfavorable effects on the quality of the respective terrain;  terrains with unfavorable geotechnical conditions (landslides, land falls and rock - opportunity to use former (cleared) military properties (army sites). falls, etc.), when their elimination and fortification is economically not viable; As a result of the carried out preliminary office cartographic works in GIS  terrains with potential hazard of sinking or collapsing above abandoned mined environment and taking into consideration the specific features of the territory of the workings; respective municipalities, potential sites for field inspections are identified.  Rings I and II of sanitary-protection zones around water sources and facilities

3. FIELD STAGE for drinking-household water supply and around sources of mineral water used for During the field (terrain) inspections the expert team registers the following main medicinal, prophylactic, drinking or hygienic purposes; quality features of the investigated areas/potential sites:  territories with open cast mining of underground resources, included in the

location of the site, distance and direction to the nearest residential area; National balance of reserves and resources

checking of the compliance of the outlined site contour on the map with the real  coastal overflow zones, river beds and protection embankments; status with respect to geo-morphological, geological, infrastructural and other features;  other territories, for which waste treatment activities are prohibited by law.

elevation and relief peculiarities -ridge, gully, slope degree, fragmentation, geo- Using the levels of the Corine Land Cover 2000 data base, which are suitable for morphological features, orientation with respect to erosion basis; situating of landfills, potential sites for carrying out of field inspections are localized

hydrological features - water catchment area, valley or gully with or without (Fig. 4). water flow, or with temporary water flow, distance to the nearest river, existing or potential risk for pollution of the surface water, as well for flooding the landfill by surface water, as well other specific hydrological conditions

vegetation and land use

geotechnical phenomena and processes

hydro-geological peculiarities - type of aquifers, existing water sources on the territory of the site and in its vicinity; characteristics and distance to them

closest water sources, used for drinking water supply

human activities in the area of the site and around it -fields, vineyards, country houses, wood-cutting area, military sites, etc

legal status of the potential sites -protected territories, reserves, distance to such sites, land ownership. Detailed digital photo documentation is collected at all potential sites.

4. FINALOFFICESTAGE Fig. 4. Remaining area in Gabrovo region with potential sites (dark blue) for field During this stage the collected information during field inspections is inspections systematized, summarizedandanalyzed. Detailed description of the sites is elaborated, photo-documentation is systematized and photo-tables are prepared providing visual Taking into consideration of other factors. In addition to the restriction factors, the idea for the specific terrain. The collected information from the field inspections is assessment and the selection of areas for potential regional landfill sites should be discussed and analyzed by a wider team of specialists and the assessment of the conformable with a number of other factors having economic, ecological and social suitability of the potential sites for landfill construction is done together with character, such as: preliminary selection of the proposed sites.

number of the population in the municipalities of the region; The selection is based on a number of criteria (13 in number so far), belonging to

location within the territory of the respective group of municipalities -proximity three categories: general characteristics (area, statute and ownership of land), position to the geometrical center of the territory and favorable position for all municipalities; (distances, location with respect to buffer zones, situation, accessibility and

infrastructural position - proximity to existing road network (mainly national infrastructure), and natural characteristics (relief, exposition, vegetation, geotechnical roads) and favorable location with regard to main residential areas, generating the features, hydro-geological and hydrological conditions). municipal or the hazardous waste; The location of the sites is grounded also with respect to possibilities for future extension, for connecting of the site with water-supply, sewer, power supply systems, as well as connection of the site with existing road network; the relief in the area, climate conditions and wind rose in order to assess the conditions for dispersing of pollutants emissions and odor from the gas-collection installations of the landfill sites and eventual risk of ambient air pollution in the closely located residential areas. During this stage of selection some of the preliminary chosen sites are eliminated and the others are subject to assessment and classification. For better visualizing the information analysis and site selection results are presented in table format. The results give opportunity for selection of at least two potential sites for each region, which are presented to the interested municipalities for discussion and standpoint as well as to the competent authority for approval. In some cases on the top- ranked potential sites preliminary limited exploration works are carried out.

5. FINAL ASSESSMENT OF THE SITES The final assessment for the suitability of the areas for landfill construction is the task of the next exploratory stage. It is achieved by carrying out of detailed exploratory works, which are done at the approved by the competent authorities at least two sites and include geological, geotechnical, hydro-geological and hydrological studies, accompanied by soil and water sampling and laboratorial analyses. Based on the results of the specialized hydro-geological studies, mathematic modeling is done with the purpose of assessment of the permeability of the earth basement. The exploratory works are carried out on the basis of coordinated with the client exploration programs and represent basis for elaboration of technical design projects for construction of regional landfill sites within the contours of the finally selected sites.

* * The presented methodological approach is developed for selection of potential regional landfill sites as the tendency in Bulgaria is to construct predominantly regional landfills. This methodological approach however can be applied in case of necessity and proved economic viability also for selection of municipal landfill sites for household, industrial, construction and/or hazardous waste. The presented here methodological approach is developed in connection with execution of contract “Complex geological, geophysical, geotechnical and hydrogeological investigations on the territory of the Republic of Bulgaria for selection of waste landfill sites” assigned to Consortium Geocomplex Ltd by the Ministry of Environment and Waters after public tender procedure.