CONSTRUCTION OF AN IMPERMEABLE LAGOON OF 25.000 m3 CAPACITY FOR THE TEMPORARY STORAGE OF RAW LEACHATES AND CONNECTION TO THE PROCESSING UNIT OF LEACHATES IN THE LOCATION “KLEFTIKA-ERITHRA KAMELI” IN THE AGGLOMERATION OF MAVRORACHI OF THE LOCAL COMMUNITY OF KARTERA, IN THE MUNICIPALITY OF LAGADA IN THE NORTH THESSALONIKI – ELECTROMECHANICAL WORKS