The Hillsborough County Environmental Protection Commission is stepping up its monitoring of water quality at Cypress Creek.
Recent cases of construction runoff from a giant mall project polluting the creek, a state-designated Outstanding Florida Water, have alarmed Hillsborough's environmental watchdogs.
The creek feeds Hillsborough's drinking water supply.
Developer Richard E. Jacobs Group is building Cypress Creek Town Center, a 1-million-square-foot mall at Interstate 75 and State Road 56. State, county and federal officials have charged the builder with allowing construction discharge to illegally muddy the nearby creek at least twice in the past five months.
Hillsborough environmental officials will now collect turbidity data - which measures murkiness - every other week when there is no rain, and daily when it rains, said Bob Owens, a supervisor with the EPC. The EPC used to check turbidity only when citizens complained or on random visits, Owens said.
The commission will also increase the number of its monitoring sites from one to three, including two in Pasco it never had before.
It used to take readings only where the creek crosses the county line from Pasco to Hillsborough.
Now, the EPC will add a monitoring site where the creek runs next to the mall and another just north of State Road 54, upstream from the mall.
The idea is to get a better picture of how the turbidity - measured in something called "nephelometric turbidity units," or NTUs - fluctuates before, at and after the mall site.
"Any increase in turbidity over the normal NTU levels is considered a violation of Hillsborough water quality rules," Owens said. "With the status of the Outstanding Florida Water, any increase is worrying."
Generally, EPC officials have taken readings that measured between 3 to 5 NTUs. Zero is the least turbid. A reading taken Jan. 25, after the discharges from the mall site, measured 6 NTUs.
That's still not quite enough data for the EPC to build a strong case, which is why Owens is now adding monitoring stations and the frequency of his checks.
"What's abnormal is a man-made increase in the turbidity value," he said.
Mall officials didn't respond to a call for comment on the EPC's new measures.
The question is: What can the EPC do with the data, since its jurisdiction ends at the Hillsborough County line?
"That's a good question," said Rick Tschantz, the commission's attorney. "We'll work with the state and federal agencies as the lead agencies. But if we see something's not happening, we'll go on our own authority. It's hard legally, but I'm not saying it's impossible."
It wouldn't be the first time the EPC took action beyond county lines, Tschantz said.
In December 1997, it joined state and federal officials in enforcement action after 55-million gallons of acidic water spilled into the Alafia River from the Mulberry Phosphate fertilizer plant in Polk County and caused a massive fish kill.
Chuin-Wei Yap can be reached at email@example.com or (813) 909-4613.