Gainesville Regional Utilities (GRU) handled increased wastewater on Tuesday with heavy rains seeping into pipes and manholes as Florida’s water table heads closer to its seasonal tipping point.  

GRU’s two wastewater facilities treated an average daily flow rate of 18.3 million gallons on Tuesday—a 2.1-million-gallon increase from Monday. Combined, the wastewater treatment plants max out at 22.4 million gallons per day. 

Rachel Lockhart, director of GRU’s water and wastewater treatment operations, said the system’s response has been really good so far in the season. But she noted that rainfall and groundwater levels accumulate faster than they dissipate. During Tuesday’s rains, GRU monitors reported groundwater rose by half a foot in some locations. 

All of Gainesville received two to three inches of rain in the last 48 hours, with some parts reaching four to five inches.  

Lockhart said that rainwater will continue filtering through the wastewater system over the next few days and the groundwater table will take weeks to lower. 

“Assuming we don’t get a ton of rain over the next few days, it should kind of start to drop back down,” she said.  

Lockhart described the water table as a cup. At the start of summer, Gainesville didn’t get a lot of rain, and the cup was dry. As July’s rainfall overtakes June’s totals, the cup has started to fill, and a higher water table makes it easier for water to leak into the wastewater system. 

Eventually, Lockhart said the water table will reach a tipping point, overflow the cup and quickly enter GRU’s wastewater system.   

“When we hit that tipping point, that’s when that storm response kicks in, and we’ll start to utilize generators and pumps and the flow transfer, where we can move flow from one side of town to the other,” Lockhart said. 

Lockhart said continual system maintenance helps the utility handle large rain events. 

Jennifer McElroy, supervising engineer and utility designer for GRU, said new maintenance methods have multiplied the utility’s effectiveness at finding problem spots within the system. 

By sending acoustic signals through wastewater lines, McElroy said teams can determine if the line is completely or partially blocked and then request it to be cleared. She said GRU conducted inspections of 155 miles of pipes in the past year with the acoustic device. In past years, GRU only covered 10 miles of pipes with a manual camera inspection. 

McElroy said GRU has also inspected 4,000 manhole covers and lined three linear miles of pipe to prevent water intrusion. She said the goal for the upcoming fiscal year is to line 10 miles of pipes.  

McElroy said GRU has a more proactive approach to maintenance than many utilities.  

“It’s very common for utilities to have a reactive approach just because it’s hard to find the right tools to be proactive, especially when you have a system as large as ours,” McElroy said. “But we’re seeing real dividends that are being paid with these programs.” 

Lockhart said getting debris and non-biodegradable materials out of the system before a significant rainfall or storm aids GRU’s response.  

In the past, she said the increased flows would push these materials into a lift station, which raises wastewater into elevated pipes to allow gravity to carry the wastewater. The lift station would get enmeshed and clogged by the materials, causing a backup and requiring GRU to send a crew.  

Gainesville geology changes from clay soils in the east to sandier, well-draining soils in the west. This soil variety and the unique nature of each storm changes how the water accumulates across the city.  

Lockhart said GRU waits each year to see how the water table rises and when the tipping point comes—likely in September, she estimated. But for now, the system is keeping up with demand and handling July’s rainfall heading through hurricane season. 

“We anticipate that [tipping point] coming each year,” Lockhart said. “It likely will come, but it’s just a matter of when and what storms decide to run us over this year. Maybe, fingers crossed, it won’t be any, and we’ll be good.”