Phosphate Plant Spill Threatens Tampa Bay GIBSONTON (WUSF) - No one quite knows the number of fish that were killed in the aftermath of a spill of more than 41 million gallons of acidic wastewater into Archie Creek, near Gibsonton.

Cargill Crop Nutrition is facing fines by environmental regulators after the breach from a phosphate gypsum stack during Tropical Storm Frances on Sunday.

Company officials say the breach was capped on Monday and bulldozers have been brought in to make permanent repairs. Christine Smith is a Cargill spokeswoman.

SMITH: I can see it right now. They're out there working to fortify what they've already done temporarily.

As water burst from the breach, it poured down to an overflow ditch that encircles the gypsum stack. But that ditch can only hold 30 million gallons of water.

Officials worried about keeping that ditch intact opened a valve to release at least some of the flow into the creek.

Smith says crews are pumping the water up to an inactive gypsum area on the west side of U.S. Highway 41. Smith says this will give the company at least another 60 million gallons of water storage.

State environmental regulators say they won't know the affects of the spill until later this week, at the earliest. Russell Schewiss is with the Florida Department of Environmental Protection.

SCHWEISS: There's a lot of factors, considering it happened during a hurricane. You've got runoff coming into Hillsborough Bay. There has been testing done by NOAA and by Hillsborough County EPC to test the pH levels in the water coming out of Archie Creek, and they've been measuring lower-than-normal pH levels more than half a mile out of Archie Creek.

He says they have no estimates on the number of fish that may have been killed by the high acidity and low oxygen levels in the bay.

Schweiss says Cargill will likely face fines and an assessment of why the breach occurred. He says the only option Cargill had to get rid of excess water from earlier rains was to discharge it into Archie Creek. In July and August, the area received 18 inches above what is considered normal rainfall.

SCHWEISS: We do anticipate enforcement against Cargill. Prior to enforcement, we have to do a complete assessment of the situation, how they followed their contingency plans, and the entire process which led up to the dike breach and the discharge into Archie Creek.

The company has found new supplies of caustic soda to neutralize the high acidity in the water, after they ran out at the height of the storm. Smith says the company did everything it could to prevent the breach, which happened after heavy rains in August already saturated the region.

SMITH: We prepare just like we prepare in our homes, and unfortunately, we all have homes that were ruined, no matter how much we try to prepare, and we have very strict hurricane preparation plans, and we certainly will take a look at that, because we very much regret this situation in our neighborhood and our community.

Another concern is the effects of the rain on the Piney Point phosphate plant, several miles to the south near Port Manatee. Hundreds of thousands of gallons of acidic water were pumped from the closed plant into the Gulf of Mexico.

Schweiss says there's no danger of Piney Point overflowing from the rain.

SCHWEISS: Piney Point can handle, at last check, over 78 inches of rain under normal conditions. And you can increase that by another 20 inches by going to emergency conditions. So we've done an enormous recovery of Piney Point, and taken what was a pretty big environmental hazard and turned into into a minimal environmental hazard.

He says state game and fish inspectors should have a preliminary report ready on the damage from the Cargill spill by the end of the week. © Copyright 2012, WUSF