St. Petersburg injects into aquifer
By BRYAN GILMER
© St. Petersburg Times, published April 21, 2001
The idea of pumping water that may contain bacteria into the earth has caused controversy in Florida since the Legislature voted to allow it, but St. Petersburg and Pinellas County have been doing it for years.
However, there are key differences.
The new legislation, which seems certain to become law, lets governments inject excess lake and river water (which may contain bacterial contamination) into the underground aquifer without treating it. Later, governments could pump that water back to the surface, treat it and use it for drinking or moistening the Everglades.
Pinellas and St. Petersburg have used the aquifer not to store drinking water but as a place to get rid of treated sewer water.
Rarely water with bacteria or even sewage is injected, but that is only during an emergency when a piece of equipment at one of the plants fails, city Utilities Director Bill Johnson said.
"You can inject for two reasons: either surplus or reject water," he said. "Reject water is very minimal. But it does happen."
He estimated that 99 percent of injected water is fully treated first.
Pinellas County has experienced what some environmentalists fear from the new statewide bill to allow aquifer storage and recovery: evidence that injected water can mix with the underground drinkable water supply.
The county will soon stop injecting the highly treated wastewater from its Cross Bayou plant after finding evidence in 1998 that the deep-injected waste was seeping up toward people's drinking wells, which draw from a shallow aquifer.
The county is spending more than $100-million to make treated wastewater pure enough to dump into Joe's Creek if reclaimed water customers don't need it for irrigation.
St. Petersburg, on the other hand, continues to inject wastewater because there are no drinking wells in the city to worry about, Johnson said.
Injecting wastewater into the ground is better than dumping it into Tampa Bay or the Gulf of Mexico, he said, and plant upgrades like Pinellas County's would cost the city too much.
The U.S. Environmental Protection Agency has questioned the city's practices over the years; the city operates under a consent agreement, not a normal permit.
Johnson said he is working to obtain a long-term permit to continue injecting. He hopes President Bush's administration will look favorably upon the request.
But previous EPA administrations did not like that the injected water is migrating upward in St. Petersburg, because the shallow aquifer is considered a potential drinking water source. Johnson says that is ridiculous because the water is too salty. He wants the agency to declare that the side-effect is harmless -- water near the surface merely becomes a little less salty after mixing with the injected water.
Johnson says the aquifer could be a good place to store surplus wastewater for the city's reclaimed water system, which provides non-drinkable water for lawn irrigation.
Other bay area counties are planning to go a step further. Pasco may look into putting surface water into the aquifer for recovery later and treatment to drinking water standards. The city of Tampa wants to do the same with excess water from the Hillsborough River.
In northern Pinellas, the county wants to inject excess water from Lake Tarpon and draw the water back to the surface to supplement reclaimed water, said county hydrogeology manager Dave Slonena. It drilled its first exploratory well for the project days ago, and he said the legislation makes that project easier.
"It helps you from the treatment end before you inject it -- you don't have to," he said. And the county should be able to get its permits for the project faster.
Slonena said those worried about environmental damage from any bacteria that gets injected should realize that there are safeguards.
"The fears that you are going to contaminate all the overlying aquifers is a little overstated," he said. "You have to test at every phase of the process."
If the monitoring wells show that underground water away from the well is being harmed, the injection must stop, or the water must then be treated before being injected, he said.
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