How do I prepare my public drinking water system in case a bloom occurs in my source water?
Public drinking water systems (PWSs) that receive water from surface water bodies face numerous challenges. Wildfires and accidents that cause a chemical or biological spill can cause rapid changes to the water quality which could overwhelm and damage water treatment plants. PWSs need to have plans in place so they know how to respond to protect the treatment equipment and make sure the contamination cannot enter the distribution system. Cyanobacterial Harmful Algal Blooms (cyanoHABs) pose a similar danger.
Preparing to respond to a cyanoHAB bloom starts with a cyanoHAB management plan. CyanoHAB management plans are similar to emergency response plans, but specific to how a public water system will respond to a cyanoHAB bloom in its source water. The three main parts to a cyanoHABs management plan are monitoring, treatment, and communication. To determine what kind of monitoring a PWS will do, it helps to conduct a surface water evaluation.
Consider a source water’s characteristics:
Is the water high in nutrients like phosphorus and nitrogen?
What kind of seasonal water quality changes are commonly seen? (Blooms frequently include an increase in pH and turbidity).
Is the source water shallow or deep, consistently fast or slow moving?
Risk Communication Toolkit – Interstate Technology & Regulatory Council (meant to help in developing communication plans for environmental concerns such as a HAB event that impacts a public drinking water system)
