Turbidity is the term used to measure the amount of particulate matter present in water. Water with high turbidity decreases the photosynthetic rate of aquatic plants and increases water temperature. Both can be harmful to a host of aquatic organisms. Soil erosion, runoff, industrial wastes, and excessive organic material cause turbidity. It is measured in Nephelometric Turbidity Units, generally ranging from 0 to 100, 0 being the clearest. Site 5 had the highest turbidity measurement at 59 NTU. The area is enclosed by townhouses and subject to excessive runoff and soil erosion, both of which could explain this exceptionally high reading.