River water samples were collected in 250 mL plastic bottles from the canals and Ginfel River. Two samples from each study site were brought to the laboratory,
centrifuged to remove the suspended particles, filtered through 0.45 mm micro pore filter sand preserved with 1.0 mL of 70 percent HNO3.
The filtered samples were stored in a refrigerator to minimize volatilization and biodegradation between sampling and analysis.