The industrial enterprises (mainly in the light industry, the food, wine and tobacco industry, the timber processing industry and the textile industry), located in the industrial zone in the south-west part of the town are sources that pollute the atmosphere in the town of Sandanski, other pollutants are the fuel equipment in the catering establishments and in the residential buildings; the motor vehicles. The pollution is mainly a result from the dust and the sulphur oxide, but they influence slightly the air content in the residential neighbourhoods, because the winds are mostly from the north and north-west and blow the gases outside the town area.

Major sources of refuse waters of the industry are the enterprises in the region as the basic pollutant is "Medika" PLC, which is 20% of the total water quantity. The bigger industrial enterprises have own implemented stations for purifying of the waters which favour their protection.

The purifying station for refuse waters is located south-west of the town of Sandanski at about 2,5 km (air way) from the regulation of the town. The closest villages are the village of Struma, which is 1 km (air way) to the north-west and the village of Lebnitsa - 1,5 km to the south-west. The sewerage system is almost 100% constructed, but the sewer along Sandanska Bistritsa river is not constructed yet as well as the connection of some or several enterprises from the industrial zone with the main sewer. The sewer is constructed at about 200 m from the Purifying station for refuse waters and temporarily mouthed in Sandanski Bistritsa river.

The construction of Purifying Station for Refuse Waters is of significance for the protection of the environment and the restriction of the pollution of Struma river and Sandanska Bistritsa river. The purified waters may be used for watering during the summer season and the precipitates - for fertilizing.

Prior ecological problems

• Construction of a city purifying station for the drinking waters (there is a developed working project and it is partially constructed).
• Construction of a city purifying station for refuse waters (there is a developed working project).
• Exploitation of scraps.
• Purifying of previous pollution and re-cultivation of already exploited terrains.
• Construction of a sewer along the left bank of Sandanska Bistritsa river (partially constructed).
• Making projects and construction of shoots along Sandanska Bistritsa river (in the area of the city park).
• Making projects and construction of sewerage net in the village of Dzhigurovo.
• Construction of a sewerage net in the village of Lebnitsa, the village of Struma and the village of Valkovo (there are developed projects).
• Reconstruction of water-conduit for watering in the park in the town of Sandanski.
• Restoration and preservation of the biological variety.