Physicochemical and Biological methods are used for environmental water quality assessment for monitoring natural and semi-natural water body essentially for human health and preserving life of aquatic ecosystem. Macroinvertebrates are main biological parameters widely used to assess ecological health of aquatic ecosystem, but are rarely used in Indonesia to none in Surakarta. Integrating physicochemical and biological parameters for water quality assessment in Pepe River were aimed; 1) to analyze the extent of major contaminant pollutant substances affecting water quality; 2) to examine the composition of biological indicators (bacteria and macroinvertebrates) and usefulness of macroinvertebrates to monitor changes of stream conditions; 3) to determine the correlation for physicochemical and biological parameters. Pepe River fieldwork for sampling, in-situ measurement and further analytical for COD, BOD, PO43-, TSS, pH, TDS, NO3-, CE, Temperature, Turbidity, total coliform and macroinvertebrates were conducted in Sebelas Maret University main laboratory between January and February 2015. For physicochemical assessment Spectrophotometer, conductivity meter, pH meter, Thermometer, Titration, Winkler method, Filtration and evaporation were used. While for fermentation, biochemical test, sorting and identification were used for biological assessment.
Descriptive statistics by PASW (SPSS) 18 and excel 2013 were applied to analyze the data. Evaluation for macroinvertebrates data were conducted using biotic and similarity indices. The correlation for physicochemical and biological parameters ranged from strong significant (r = ± .585 to .699, p < .05) to highly strong significant (r = ± .700 to .995, p < .01). Evaluation for water quality status using Water Pollution Index (WPI) and National Sanitation Foundation Water Quality Index (NSF-WQI) ranged from (6.85 to 7.5) and (40 to 68) respectively, while by STORET method water quality value ranged from (-25 to -48).
In conclusion, water quality status in Pepe River failed to meet the acceptable criteria required by regulation No 82/2001 for water pollution control of Class II. Finally, macroinvertebrates observation results showed are useful biological indicator for monitoring water status change in Pepe River.
Keywords: Biotic Indices; Indonesia National Standard for Water Quality; Macroinvertebrates and Water Quality Indices.