TECH-TIP - Springtime Prompts Review of Treatment Plant Operations

As winter transitions to spring, it is time to pay close attention to water temperatures and their related impacts.  In the spring, days get longer, ambient and water temperatures increase, and production rates begin to climb.  During this time, it is important for operations staff to make a conscious effort to take a proactive, rather than reactive, approach to treatment plant operations. Consequently, water treatment plant operations staff should be aware of some common springtime operational activities:

• Adjusting flocculator speeds - As water temperature increases, water becomes less dense and does not require as much energy to impart the required mixing as in colder, denser water.  A good reference for more information is AWWA M37 – Operational Control of Coagulation and Filtration Processes. 
• Evaluating granular media filter expansion rate – Filter bed expansion is also a function of water density.  Typically, the expansion target during backwash should range from 20-25 percent.  This is measured during backwash to ensure optimum filter performance. 
• Monitoring for organics in reservoirs - Spring is the time to carefully track levels of organic carbon in source water reservoirs, as well as algae type and number.  This information can help to determine what to prepare for in the future.  This preparation may include activities, such as changing withdrawal gates, if possible, or managing pre-oxidant dose if taste and odor algae are present.
• Monitoring for impacts of run-off (river sources) - Springtime in the Rockies can be a very challenging time for water treatment plant operators.  As temperatures heat up and the snowpack melts and makes it way to the river, plant influent turbidities can increase from 1 NTU to > 10,000 NTU in a matter of hours.  If this is common at your facility, consider developing guidelines for how to respond to different levels of raw water turbidity entering the plant.  Consider possible early warning systems or resources that may also be available to help protect the plant.  It can be helpful to collaborate with other utilities treating the same raw water source, in communicating raw water quality.
• Spring is also a good time to review, update, and practice Standard Operating Procedures (SOPs) for anticipated seasonal events, such as:
  • Power outage 
  • Tornado 
  • Run-off response 
  • Coagulation control strategy.
• Reviewing the corrosion control strategy – Be sure operators understand the impact that changing source water conditions (or a seasonal change in source) will have on the corrosivity of the water being delivered to the distribution system.  Spring can be a good time of year to review the plant’s corrosion control strategy and make adjustments accordingly.
• CT/Disinfection – Be sure operators also understand how disinfection is impacted by changing source water quality.  With seasonal changes in pH, temperature, and organic concentrations, Contact Time (CT) and inactivation may be impacted.  Be sure that operations staff understand how to respond to these changing conditions. 

These are just a handful of things to consider as operations transition to the busy spring season. I would also encourage plant staff to hold meetings to discuss “What if” analysis of atypical plant activities or projects.  The value of doing so will be seen in an operations staff that is prepared and has a clear understanding of operational priorities throughout the year.

My challenge to all plants aspiring to be excellent; relentless preparation.  By developing a consistent, uniform, operational response to the myriad of potential plant challenges that can and do happen at water plants every day, a “life ring” will be developed for operators to cling to.  This allows operators to appropriately respond to consequences that could impact operational excellence and the protection of public health that comes from it.