RHMS-Environmental Division- Water Quality Control, 11000 Beograd, Kneza Višeslava 66*
The results of extra monitoring on rivers Sava and Ibar were presented. Both of them belong to the Danube River Basin. In the river Sava water the increased levels of herbicide atrazine were observed, from the boundary location Jamena to the river mouth into Danube. In the river Ibar the increased levels of phenol at locations Raška and Kraljevo were registered. In both cases the extra monitoring was conducted in order to detect the pollution wave and consequence accidental alarm and emergency warning of qualified services.
Key words: Surface water, pollutant, monitoring, atrazine, phenol, and Danube river basin.
At recent appearance of atrazine in river Sava water at the end of the year 2002 and the beginning of year 2003 extra monitoring was organized by Republic Hydrometeorological Service of Serbia (RHMS) along the river, from boundary location Jamena (197 km), via Šabac (103 km), TE Obrenovac, and Ostružnica (15 km) to location Makiš (10 km), i.e. Belgrade Water works .
Atrazine is the common name for 2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine . It was introduced in 1958 as a selective herbicide and in many western countries its usage is prohibited. It is of low toxicity. According to Regulations on harmful substances in waters  atrazine was not specified in the List of harmful substances but for the herbicides 2,4-D , 2,4,5-T and simazine the maximum allowable concentration (MAC) amounts 0.1 mg/l for I/II Class and 3.5 mg/l for III/IV Class of water streams. In the drinking water the MAC value of 0.1 μg/l was specified , whereas WHO  recommended the amount of 2.0 μg/l and EPA 3.0 μg/l.
Within January and February 2003 the increased levels of phenols in river Ibar were observed at locations Raška (93.3 km) and Kraljevo (7 km) . Ibar is a tributary of river Zapadna Morava and both of them are falling into Danube River Basin. Extra monitoring was conducted, with a sampling frequency of 6 hours, and at appearance of higher concentrations at every 3 hours.
Phenols are hydroxy derivatives of benzene  and can be present in municipal and industrial wastewaters, as well as drinking water abstractions. Specified MAC for phenol in surface waters  amounts 0.001 mg/l for I/II Class and 0.300 mg/l for III/IV Class of water streams. In drinking water the allowable concentration amounts 0.001 mg/l . Atrazine analyses were carried out by gas-chromatographic technique  with instruments PY-304 GC-ECD and PE-8500/GC/NPD, and the phenol analyses by 4-aminoantipyrine method  on spectrophotometer LKB Ultraspec II.
RESULTS AND DISCUSSION
Increased atrazine levels in Sava river water at the boundary location Jamena in December 2002 were observed. Consequently, 23.12. the value of 1.174 μg/l in the sample from 4 m depth and the middle of the river was found, whereas 04.01.2003. value of 1.390 μg/l in the sample from the same site was registered. Later, also, levels higher than MAC were observed: 06.01. concentration of 0.850 μg/l, 27.01. amount of 0.300 μg/l, etc. On this site the samples from the left and right bank and the middle of the river were taken, from 0.5 and 4 m depth.
At the downstream sites the propagation of pollution wave was observed, so that in Šabac the maximum value of atrazine concentration was found 24.12. (0.960 μg/l at hydrological station) and 25.12.2002 (1.124 μg/l downstream from town).
This wave was observed 25.12. at the site Makiš, when the maximum atrazine concentration at the water abstraction amounted 1.100 μg/l and 26.12.2002. – 0.985 μg/l. Later, the highest levels were 0.450 μg/l (05.01.2003), 0.400 μg/l (07.01.), etc.
According to results of ICPDR-Joint Danube Survey, the atrazine levels in River Sava water (at mouth into Danube) of 0.78 μg/l were found .
Concerning the phenol appearance in river Ibar, the maximum concentration at Raška site of 54.0 μg/l was registered 18.01.2003. and later the amounts of 11.5 μg/l (21.01.), 10.1 μg/l (26.01), etc. At sampling site Kraljevo the highest level of 7.0 μg/l was observed 14.01. and then few values above MAC: 2.4 μg/l (20.01), 3.0 μg/l (22.01), etc.
Adequate measures were undertaken on the monitoring results basis. In the first case, i.e. for the atrazine occurence in the river Sava water, the enhanced control at water abstraction Makiš was established and the appropriate drinking water purification in Belgrade water works. In the case of the phenol appearance in river Ibar it was suggested that the pollution originated from Kosovo, coming with the flooding wave from river Sitnica. Thus, the drinking water supply of town Kraljevo was endangered, due to the doubt of water abstraction pollution.
 S.Mijović et al.: Appearance of atrazine in river Sava – Monitoring and results Conference on water use and protection “Voda 2003”, Zlatibor, 3-6.06.2003,Proceedings, p .219.
 Pesticide Manual, H.Martin& C.R.Worthing Ed., British Crop Protection Council, 1977, p.23.
 Regulations on harmful substances in waters , Sl. glasnik SRS br.31/82.
 Regulations of the sanitary quality of the drinking water, Sl. list SRJ br.42/98.
 Guidelines for Drinking Water Quality, Volume 1: Recommendations, World Health Organisation, Sec. Ed., 1993.
 S.Mijović et al.: Appearance of phenol in river Ibar – Monitoring and results, Conference on water use and protection “Voda 2003”, Zlatibor, 3-6.06.2003, Proceedings, p. 223.
 Standard Methods for the Examination of Water and Wastewater, 16 Ed., APHA, Washington D.C., 1985
 Standard ISO 6468, 1996 (EPA Method 608).
 ISO 6439:1990 : Water Quality – Determination of phenol index – 4-Aminoantipyrine spectrometric methods after distillation.
 Summary of the Final Report- Joint Danube Survey, May 2002, ICPDR-International Commission for the Protection of the Danube River, Vienna, Austria