Green Plumbing

Answer: D - All of the above responses are standard forms of water quality monitoring. Biological indicators test for the quantities of creatures such as mayflies and bivalve mollusks, which provide insights into the health of a water supply. The pH of a water supply should remain within a specified range near 7.0 to avoid issues of solubility and toxicity, among others. Turbidity monitoring determines whether the amount of minute suspended particles in the water exceeds safe limits.