Hurricanes, Flooding and Wastewater Plants: What Have We Learned?

In recent months, there have been dozens of reports of wastewater treatment plants that have flooded due to heavy hurricane rains and storm surges in Florida, Texas, Puerto Rico and beyond. Both the sheer number of plants affected, and the extent and duration of the flooding have posed significant public health and technical challenges, often stretching communities to their limits. 

To add to these problems, many rural utilities were already struggling to keep their systems operating before the storms struck, so costly, complicated repairs or replacements of damaged infrastructure is simply not an option. For example, Patton Village, Texas had just completed a new wastewater plant — the first of its kind in their community — before Hurricane Harvey struck. Now they can only hope that USDA/FEMA emergency funding will be available to help repair the damage. And even once the systems are up and running again, it is not a given that water systems can count on water rate income to help with their O&M bills - many residents have fled their flood-damaged homes for good.  

The sad truth is that lately, floods have been affecting wastewater plants with unfortunate regularity, and not just in hurricane-prone areas. For example, in Central Illinois, the small town of Hutsonville's wastewater treatment plant has flooded 3 times in the last 2 years, up from once every 5 years, according to its contract operator Shannon Woodward of Connor & Connor, Inc.

Woodward's first piece of advice is not to build on a floodplain, but he also acknowledges that many communities do not have the capital funds for effective protective measures or relocation, and so operators must deal with the hand they are given. His second piece of advice: "Make sure all electrical controls, switch gears and transformers are above the flood stage. That way, when the flood waters subside, you don't have equipment loss and can get back into operation — even if it takes 3 to 6 weeks for the waters to recede." 

Mason City, another small town in Illinois, was able to fund improvements after a flood in 2008 cut off the town’s water supply and nearly overflowed the capacity of its wastewater system. The following year, the city built a stone wall around the water plant, installed flood sensors on the local river, and built effluent pumping stations for the wastewater plant. 

And this article tells the damage and recovery stories of two flooded wastewater plants in Rhode Island. According to the operators of these plants, it is essential to have a flood plan, even if you think your facility is protected. In addition, they maintain it is important to involve wastewater treatment personnel in emergency response exercises or in the incident command structure. On a practical level, the operators encourage SCADA systems to be elevated on the second floor in the operations building if possible. And lastly, they recommend you back up your files and documents electronically. Papers get wet, they say: move them to a dry storage facility. 

Finally, while every community has different characteristics and needs, there are some universal preparedness strategies for wastewater plants. The US EPA recommends practicing mitigation options as the best way to prevent floodwater from invasively appearing. Some of these options include crafting barriers around key assets, having an emergency back-up generator, and keeping key electrical equipment elevated. You can learn more about these options here, or you can watch this helpful video. In addition, many states have their own guidances, such as this one from Minnesota’s Pollution Control Agency.