Proposal by Lithuania for deletion of the Hot Spot No. 41 Šiauliai WWTP

Transcription

1 Proposal by Lithuania for deletion of the Hot Spot No. 41 Šiauliai WWTP 1. Name of the Hot Spot Šiauliai wastewater treatment plant. 2. No. of the Hot Spot Location Šiauliai, Lithuania 4. Reason for being the Hot Spot Šiauliai region was acknowledged as one of the largest contaminators of the Lielupe river basin when the Baltic Sea region countries signed the Convention on the protection of the Marine Environment of the Baltic Sea Area and the Government of Lithuania ratified it. The Hot Spot No. 41 has been defined in JCP as a treatment of municipal and industrial wastewater from Šiauliai city and surroundings. 5. Reason to delete the Hot Spot. The Šiauliai secondary Wastewater Treatment Plant (WWTP) was constructed in This was one of the first secondary WWTP built in Lithuania. Hence, it is not surprising that by 1990 the Šiauliai WWTP was no longer functioning adequately. As charts (See Attachment 2, Figure 3) clarify, the Šiauliai WWTP needed to be renovated. Thus, it was decided that a new WWTP should be build. In 1996, JSC Šiaulių vandenys started to implement the Environment Project of Šiauliai. The objective of the project was to reduce pollution, promote environmentally sustainable management and development, and cooperation in the sphere of environmental protection, improve reliability and quality of services through modernization of the company ' s activities. During five years many projects were carried out. These include construction of modern water quality improvement plant, low efficiency deep well pumps were replaced by modern long life time pumps; 3,4 km of the oldest sewerage network in the center of the city were renovated; rising main to the new wastewater treatment plant was constructed, and the main wastewater pumping station was built. Having implemented this project, the Šiauliai region is no longer be pollution source of the Baltic Sea: the wastewater treatment comply with the environmental requirements for wastewater handling of the Republic of Lithuania and HELCOM. JSC Šiaulių Vandenys is a modern customer - orientated company providing water supply and sewage collection services. It is the first water supply company in Baltic States, which has implemented quality management and environmental protection management systems, complying with international standards ISO 9001:2000 and ISO 14001:1996 and received confirming

2 certificates. The main activities of JSC Šiaulių Vandenys are water extraction, improvement and supply, as well as wastewater collection and treatment. The company also provides other specific services: design and construction works of water supply and sewerage systems, diagnosis and cleaning of pipe systems, leakage detection, installation, repair and testing of metering devices, etc. The company operates water supply stations, wastewater treatment plant, km of water, 176,4 km of wastewater and 120 km of storm water networks. Significant attention is paid to institutional strengthening and improvement of management of the company: new system of management and planing of company was created; specialists of the company were taught new and effective work methods; computerized management and technical novelties were implemented, namely, technological processes management system, accountancy and financial management software complying to international accountancy methods and standards, billing software and GIS. Currently the centralised water supply system and wastewater collection systems are being used by about 85% ( ) of Šiauliai city residents, the remaining part - residents of Pabaliai, Medelynas and Kalniukas residential areas - have neither centralised water supply nor wastewater collection systems. These systems will be installed when the the investment project of Venta - Lielupe Basin is implemented and % of city residents will have the possibility to use this system because when the wastewater treatment plant was designed and constructed these future wastewater volumes were considered. The area of the city of Šiauliai is 81,13 km 2. According to preliminary calculations the area of the territory in which JSC Šiaulių Vandenys provides wastewater management services is 69 km 2. Industries discharging wastewater to Šiauliai WWTP operated by JSC Šiaulių Vandenys are as follows: metal processing enterprises, which have galvanic units, tannery processing, food processing, auto transport services, electricity and heat supply, petrol stations, gas supply, construction materials production, service provision, weaving - knitting, enterprises engaged in other activities. In 2005, volume of wastewater that came from industries to Šiauliai WWTP was m 3 ( 6,55 %). Šiauliai biological wastewater treatment plant with N and P removal process was completed in The technology scheme includes: Mechanical treatment: screens, grit chambers, primary sedimentation tanks; Biological treatment: active sludge reactors with N and P removal process based on modified technology of Cape Town University, secondary sedimentation tanks. See Attachment 1. The capacity of Šiauliai WWTP is m3/day for P.E., with the design wastewater treatment indicators: BOD 7-15 mgo 2 /l, suspended solids - 20 mg/l, total nitrogen - 18 mg/l, total phosphorus - 1,5 mg/l. Incoming load to Šiauliai WWTP, the amounts of wastewater and pollutants discharged are included in Attachment 2 Figure1.

3 6. Compliance with relevant HELCOM's recommendations and EU requirements. Parameters of treated wastewater at the outlet and concentrations of heavy metals in sewage sludge are in compliance with HELCOM's recommendations and EU requirements. See Attachment Investment costs. The total investments in the Šiauliai Environmental Project amounted to the 22, 85 million USD. This project was funded by the loan of the World Bank (5, 82 million USD or 30% ), Grants of the governments of Sweden (31, 5 million SEK or 20%), Finland (1,8 million USD or 8%), Norway (1,5 million USD or 7% ) the budget of the government of Lithuania (7,6 million USD or 33%) and Šiauliai city municipality (0,45 million USD or 2%). World Bank loan Lithuanian Government Budget Siauliai municipality Budget Swedish Government Grant Finnish Government Grant Norwegian Government Grant

4 Attachment 1

5 Attachment 2 Figure 1. Incoming load to Šiauliai WWTP in P.E Figure 2. Amounts of waste water discharged, in 1000s cubic metres per annum

6 Figure 3. Amounts of BOD 7, nitrogen and phosphorus discharged, in tons per annum BOD 7 Total N Total P The figure 3 shows, that the amounts of discharged BOD 7, nitrogen and phosphorus have decreased significantly. Attachment 3 Compliance with relevant HELCOM's recommendations and EU requirements for parameters of wastewater at the outlet Parameters of wastewater at the outlet Reached by the plant Required by Year Concentration mg/l Reduction % HELCOM EU BOD ,5 69,3 15 mg/l and 25 mg/l ,7 87,5 90% reduction or ,2 97, % reduction ,3 97, , ,4 97, ,7 98,73

7 2005 4,5 98,63 Parameters of wastewater at the outlet N ,7 57, ,5 42,11 15 mg/l or 70-80%reduction 10 mg/l or 70-80%reduction , ,5 58, , ,8 87, ,1 85,2 P ,9 51, ,5 52, ,2 79, ,2 70, ,2 76, ,0 72, ,24 87, , ,5 mg/l 1mg/l or 80% reduction Figure 1. Concentration of BOD7, nitrogen, phosphorus discharged, in mg/l BOD 7 Total N Total P Changes of concentrations of BOD 7, nitrogen and phosphorus were significant during the last

8 15 years (Figure 1). The concentrations of these substances were not exceeding the limit values set in Lithuanian national regulations, HELCOM Recommendations and EU Directive 91/271 EEC concerning urban wastewater treatment. Average concentration of heavy metals in sewage sludge (mg/kg d.w.) Heavy metal Concentration of heavy metals in sludge Limit values of heavy metals concentration in sludge according to national legislation Limit values of heavy metals concentration in sludge for use in agriculture according to Directive 86/278/EEC Lead Cadmium 20 0,79 1, Chromium Copper Nickel Zinc Mercury - - 2, Sludge volume, t (SS) ,6 2533,7 - - This table shows that last year's concentrations of heavy metals in sewage sludge is in compliance with requirements of EU Directive 91/271 EEC. Mixed sludge, sludge from primary clarifyers (in average 100 m 3 /day) and excess sludge (in average 980 m 3 /day) after thickening by centrifuges is transported to sludge storage areas. The volumes of sludge, transported to sludge storage areas are as follows: 2004: 9210 m 3 /year, 84,6% humidity sludge (in average 34m 3 /day) or 1412,6t/year. 2005: 16875m 3 /year, 84,2% humidity sludge (in average 46m 3 /day) or 2533,7 t/year.