In surface waters, phosphorus commonly exists in its phosphate form. A high concentration of phosphate in water is indicative of domestic waste, industrial effluent, and agricultural runoff which can lead to eutrophication. Eutrophication causes an increase in plant and algal growth, which decreases the dissolved oxygen in the water, often leaving the water uninhabitable to organisms. In this application, the quantitative analysis of ortho-phosphate was performed using the LAMBDA 265 UV/Vis spectrophotometer and CHEMetrics ortho-phosphate cell test kit.