Screening the range of options for controlling wet weather flows Phase 3. Evaluating costs and benefits of preferred control options. Once the plan is completed it will be submitted to the Clean Environment Commission for their consideration. What are the Effects of CSOs on River Quality Aquatic Life To determine the effect of overflows on fish habitat, the City has been measuring the quantity of oxygen and ammonia in the water. Oxygen is needed to breakdown the organic matter in the water, reducing the amount available for fish.
Ammonia is a byproduct of the breakdown of human waste and can be poisonous to fish.
Findings indicate that CSOs do not significantly affect the oxygen or ammonia levels in the river. When a CSO occurs, bacteria from human and animal waste are discharged into the rivers. These bacteria can cause flu-like illnesses and skin or eye infections in some of the people who swim or waterski in the rivers. The risk to public health can be estimated by measuring the number of coliform bacteria in the water. Aesthetics You may have noticed material like cigarette butts, drinking straws and food packaging floating in our rivers.