Water treatment plants do not control the water quality of their source water. Rain events, temperature shifts and unique groundwater features create a lot of variability.
“For water quality, the cards they’re dealt is what they get,” he said. “It’s not like making oil and gas at an oil refinery, where they can control the raw materials. You have raw materials that you don’t have any control over.”
Temperature, turbidity, pH, alkalinity, hardness, and dissolved organic materials affect water quality. These variables come in different combinations and change over time. Treatment plants have to make treatment decisions on the back end and determine if they met multiple water quality targets that are chemistry driven.
The water sources are also changing due to climate.
“We get more intense rainstorms, so you get more turbidity (murkiness) coming in. You have different alkalinity now and the ability to manage these complexities is stressing the various plants’ technical capacities,” he said.
There are, however, chemicals and treatment processes operators can control, with multiple outputs and multiple objectives. Within limits, that is. For example, the objectives in the regulatory environment alone are increasing.