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Articles in support of small community water and wastewater operators.

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

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.

SRF Could Help Illinois Water Reuse Project

When the Cronus fertilizer plant slated to be built near Tuscola, Illinois is fully operational, much of their water will come from the Urbana-Champaign Sanitation District (UCSD) roughly 20 miles north. UCSD has agreed to pipe over 6 million gallons of effluent to the plant everyday for industrial uses. We sat down with UCSD director Rick Manner last fall to discuss the project and what it will mean for UCSD operations. 

Tell us a little about UCSD.

We treat the sewage from the cities of Urbana and Champaign and the villages of Savoy and Bondville. About 10 percent of our customers are in the unincorporated areas around Champaign and Urbana.

In a typical day in normal weather, we discharge about 22 million gallons of sewage. About two-thirds of that comes out of our plant in northeast Urbana, which flows into the Saline Branch of the Salt Fork River and ultimately into the Vermillion and Ohio rivers. Over in southwest Champaign, about a third of our water comes out of our Southwest Plant. That goes into the Copper Slough, which flows into the Kaskaskia and then the Mississippi River.

In extreme drought conditions, we are down to a total of about 12 million gallons a day, with about three-quarters from our Northeast Plant and one quarter from our Southwest Plant.

That said, our sewers are actually going to be rearranged a little in the near future. Right now, there are a lot of tall buildings being built on campus, and those sewers that they are discharging to are getting the challenge of 20-story buildings where there was previously a mom-and-pop business or a two-story building. It’s actually producing a good deal of burden on those sewers, so we will be rearranging some of our flows within the sewers. We’ll be diverting flows from the Northeast Plant and pushing it over to our Southwest Plant. So, even in times of drought, we will be at about a 60/40 split.

We need to do this to deal with our own sewer issues. But it so happens that it helps in regards to Cronus. The Southwest Plant is closer to them, and that is where they are going to be getting their water from. So, an increase in flow at the Southwest Plant ends up coming at a fortuitous time for them because they are looking to buy some of our effluent from that Southwest Plant.

Why are they interested in buying the effluent?

Cronus Fertilizer is proposing to build just west of Tuscola. Contemporary fertilizer manufactures use natural gas as a primary ingredient, and with that natural gas, there is a lot of energy coming into the process. So, they end up evaporating a lot of water just to keep their equipment cool. If they didn’t do that, the temperature would increase too much and they wouldn’t get the results they want. Overall, they are looking at buying 6.3 million gallons a day of our treated effluent. Of that, about 80 percent will be boiled away and evaporated and the remaining 20 percent will still be discharged and have to meet discharge limits.

They could be using water from other sources, but they approached us about the idea of reusing our effluent, which is water already coming out of the Mahomet Aquifer. This way the water will get a second use—reuse, if you will—down in Tuscola. And Cronus doesn’t have to draw new water out of the aquifer. That is the advantage of reusing effluent.

How would the effluent be transported, and who is responsible for that infrastructure?

Champaign and Tuscola are 20 miles apart, but it happens that our treatment plant and their proposed fertilizer plant are literally north and south relative to each other. So, they are looking at building a 20-mile, 2 ft-diameter pipe that would connect up our treatment plant to their fertilizer plant. They would design, build, and operate that pipeline.

The reason Cronus is in this situation is somewhat interesting. They are proposing to build the fertilizer plant in Tuscola because there are two or three large natural gas pipelines that cross there. But Tuscola doesn’t have a very good water supply. They are not on top of the aquifer anymore. They get their drinking water from a pipeline from the Champaign-Urbana area—from the Bondville wells of Illinois American Water. But the drinking water pipe is not large enough to handle a 6-million-gallon-a-day increase. So, they would be looking at a new pipe either way.  

What changes will UCSD have to make at the plant to move water through the pipeline?

We will need to put in some good size pumps that could pump the water 20 miles south down to Tuscola. That’s the first big infrastructure exclusively for the benefit of Cronus. But we would get reimbursed for that. We get more than reimbursed for that. That’s one of the reasons we are interested in doing this. Not only does it help protect the aquifer, but the payments that Cronus is proposing would help our bottom line.

When we were looking into this scenario, one of the things we became acutely aware of is that there is great sensitivity to not going to zero discharge, even in times of drought. Our rate payers and our board and everybody who commented would like to see some continuing flow to the creeks. To accommodate that, we are building a storage lagoon at our Southwest Plant. The storage lagoon would fill up when there is a lot of rain and moisture in the spring and then would be there holding our final effluent in quantity in case of a drought like we had in 2012.

That lagoon would be another bit of infrastructure that USCD would look into building that would benefit Cronus. Again, though, we would be compensated for that construction project. But in the long run, that is something the sanitation district will benefit from. We know that Champaign and Savoy are growing towards the southwest, so we know the flows are going to be increasing there. When that lagoon is no longer needed to get us through a drought while still meeting Cronus’s demand, we would use it to store influent instead. The lagoon would be turned into what we call an equalization basin, which would allow us to store high volumes of flow so that we don’t have to treat it that same day. We could treat it when our flows are more reasonable. My successor, or my successor’s successor, is going to benefit from that lagoon being built. 

Check back here for part two of our interview to learn about how the State Revolving Loan Fund features in this story and how the district determined the market value of their effluent. 

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