Determination of water quality and pollution level of Pazarsuyu stream (Bulancak, Giresun)

Pazarsuyu Stream, flow into sea from Bulancak- Giresun in East Black Sea region, is an important river of the region with its 80 km length, 872 km2 watershed, 674 hm3 annual flow volume, and average flow rate of 21,4 m3/sec. Studies on its water and sediment quality are important for preserving the ecosystem in the region as being the drinking and usage water source for especially Bulancak and Piraziz District. Aiming to determine the water and sediment quality of Pazarsuyu Stream, facing the pressure of HES construction, stone and gravel mines, the present study was carried out between June 2014 and May 2015. The average values of the water samples which are collected from four stations monthly to determine water quality are as follows: Temperature; 10,93°C, pH;7,98, oxygen saturation; 95,66, dissolved oxygen;10,30 mg/L, electrical conductivity; 65,53 µScm-1, specific elektrical conductivity; 87,02 µScm-1, salinity;0,03 ppt, oxidation reduction potential;-61,02 mV, total dissolved solids; 54,80 mg/L , total alkalinity; 30,17 mg/L CaCO3, total hardness; 40,52 mg/L CaCO3, total phosphate; 0,11 mg/L, soluble reactive phosphorus; 0,02 mg/L, total ammonia nitrogen; 0,31 mg/L, total suspended solids; 31,67 mg/L, biological oxygen demand;1,24 mg/L, chlorophyll-a; 3,74 µg/L, Si; 4,49 mg/L, Cl2; 42,35 µg/L, NO2--N; 0,04 mg/L, NO3--N; 1,17 mg/L, SO3-2; 2,29 mg/L, SO4-2; 8,30 mg/L, surfactant (anionic);0,12 mg/L, phenol; 0,21 mg/L, chemical oxygen demand;7,07 mg/L, NH4-N; 0,28 mg/L, NH3-N; 0,03 mg/L, total coliform; 2,63 log10 cfu/ml, fekal coliform;1,86 log10 cfu/ml and E. coli; 1,63 log10 cfu/ml. Heavy metal levels measured as ppm from sediment samples seasonally by ICP-MS. The average annual levels were found as follow; Cr:10,64, Mn:155, Fe:8312, Co:5,73, Cu:17,79, Zn:32,74, Cd:0,16, Pb:19,69. Additionally, sediment pH and organic matter contents amount were 6, 64 and 5,02 %, respectively. SPSS statistical program was used to evaluate obtained data. Obtained data were evaluated statistically by One Way ANOVA Tukey, Pearson Corelation, cluster and factor analyses and comparison has been made with national and international reference limit values. According to these comparison Turkish Surface Water Quality Regulation Pazarsuyu Stream is determined to be in class II. for its TP, anionic surfactant, amonnium nitrogen, nitrite nitrogen, total coliform and fecal coliform, in class III. for its free chlorine, and phenol, in class I. for the rest of the parameters. Additionally, sediment's heavy metal levels are not determined to be at dangerous level for aquatic life. Key words: Giresun, Pazarsuyu Stream, Water Quality, Sediment Quality, Heavy Metal Levels, Microbial Pollution