Diversity of macro invertebrates and surface water quality in rice field adjacent to waste disposal site at Chachoengsao province
The study on the diversity of the fresh water macro invertebrates and surface water quality in rice field that located adjacent to the waste disposal site in Bang Nam Priao district, Chachoengsao province found that 5 Orders and 15 Families of Arthropoda Phylum of which the Order Ephemeroptera had the highest number (43.05%). This number of fresh water macro invertebrate families tends to increase as the distance away from the waste disposal site. The diversity index values of were 1.66, 1.09, 1.49, 1.49, 1.88, 2.06 and 1.96 respectively. In study relationship between the distance from the waste disposal site and the diversity of macro invertebrates, it was found that there was no statistical relationship at the 95% confidence level (P - value = 0.057). The Average Score per Taxa was in the range of 4.33-4.80. This finding revealed the quality of surface water was medium to rather dirty. Considering the physical and chemical qualities of water as compared to water quality standard for National Environmental Committee Announcement No. 8 (1994), the type 3 water source is used for agriculture. It was found that dissolved oxygen was lower than that of the standard water quality, whereas the Biochemical oxygen demand and ammonia-nitrogen values of were found to exceed the standard water quality, which was likely due to the contamination of organic substances.