“More Protection, Less Process”

www.dep.state.fl.us

Additional Modeling and Monitoring Information for Hillsborough County 

As discussed in the department’s October letter, the conditions that caused previous 

violations of the National Ambient Air Quality Standard (NAAQS) for lead in 

Hillsborough County no longer exist. The secondary lead smelter responsible for high 

ambient concentrations in the past (the former Gulf Coast Recycling facility) has 

essentially been demolished and is being rebuilt from the ground up by new owners. 

The new facility, EnviroFocus Technologies, when complete later this year, will be the 

best controlled lead recycling facility in the U.S., with multiple controls on its process 

operations, including operating within a total enclosure under negative pressure. All of 

the EnviroFocus control measures are embodied in the federally enforceable air 

construction permit enclosed with the October letter. The air modeling results 

referenced in that permit show that the maximum impact of the EnviroFocus facility is 

predicted to be approximately 50% of the standard and would occur at the fence line of 

the facility. We have reasonable assurance that the new EnviroFocus facility will not 

cause or contribute to a violation of the revised lead standard. 

Figure 1 (attached) is an aerial view/map showing the location of the EnviroFocus 

facility (dark blue) relative to nearby ambient monitoring sites and airports. Figure 2 is 

a closer view of the facility locale. To verify that the new facility will not cause or 

contribute to any violation of the lead NAAQS, the Hillsborough County 

Environmental Protection Commission will continue to operate the two current lead 

monitoring sites located 0.2 kilometers south and 0.4 kilometers north of the center of 

the facility (labeled “CSX” and “Patent,” respectively, on the maps). In addition, the 

county recently began operating two new monitoring sites located 0.3 kilometers 

northwest and 0.9 kilometers north of the facility (labeled “EFS” and “Kenly,”

respectively). The data from all of these monitors will be collected in accordance with 

state and federal quality assurance requirements and submitted to DEP and EPA. The 

primary reason for continuing the current designation of unclassifiable is to provide 

time for this network of four monitors to collect data representative of the changed 

conditions in the area. 

Figures 1 and 2 also show some modeling results based on the EnviroFocus permit 

application. The model output, which includes all point sources in the immediate area 

and an assumed negligible background concentration, was post-processed to show the 

maximum one-month average concentration for each receptor site in the area for the 

“worst” modeled year (2004), a conservative approximation of the three-month average 

upon which the lead standard is based. The outer border of the light pink area in the 

figures represents a modeled concentration of 0.015 micrograms per cubic meter 

(ug/m3), or 10% of the NAAQS level. The outer border of the light blue area in Figure 2 

represents a modeled concentration of 0.0075 ug/m3, or 5% of the NAAQS level. This 

figure shows that at a distance of 1.5 kilometers (red circle) from the center of the 

current unclassifiable area, the predicted concentrations drop to approximately 5% of 
the NAAQS level. As further illustration of the extremely localized nature of these 

impacts, a lead monitor (“Tessy”) was operated from 1998 to 2002 at a location 

approximately two kilometers north of the old Gulf Coast Recycling facility and did not 

record any concentrations that would have exceeded the revised lead standard (see 

table below). 

Criteria

Site Parameter Interval

L0571074 PB 001d

Report Created:04/28/2010 15:35

Lead (12128 [25 °C]; 14129 [LC]) Units: μg/m3

Site:L0571074 - Co H2O Dept Maint. Facility County:Hillsborough AQS Monitor ID:12-057-1074-12128-1

Year 1

st Max 2nd Max

Quarterly Averages (#Valid Observations)

Annual Max 3 

Month Rolling 

Average

38 Month Max 3 

Month Rolling 

Average

# 

Avgs

> 

1 0.15 st Quarter 2

nd Quarter 3rd Quarter 4th Quarter

1998 .50 (05/17) .40 (02/22) 0.07*[10] 0.07 [14] 0.04 [14] 0.00 [16] 0.09(07/1998) 0.09(07/1998) 

¶

0

1999 .40 (05/30) .20 (01/18) 0.02 [15] 0.07 [13] 0.02 [15] 0.00 [15] 0.10(07/1999) 0.10(07/1999) 

¶

0

2000 .20 (04/24) .10 (01/01) 0.03 [16] 0.01 [15] 0.02 [15] 0.00 [15] 0.04(02/2000) 0.10(07/1999) 

¶

0

2001 .30 (01/19) .20 (01/07) 0.06 [15] 0.02 [16] 0.02 [15] 0.00 [12] 0.05(01/2001) 0.10(07/1999) 0

* There was insufficient data to produce a valid average.

¶ Data substitution was done when computing 3-month rolling averages, since there was insufficient data to produce a valid average.

Finally, we understand that EPA may have concerns about the possible impact of the 

EnviroFocus facility on lead concentrations at two nearby general aviation airfields. 

The locations of these airfields relative to the new EnviroFocus facility are shown on 

Figure 1. The same modeling that predicts ambient lead concentrations to drop to 

about 5% of the lead NAAQS at a distance of about 1.5 kilometers from center of the 

unclassifiable area also predicts that the impact of the facility at both the Peter O. 

Knight and Vandenberg (Tampa Executive) airports would drop to well less than 1% of 

the lead NAAQS. There is simply no interaction of lead impacts from the EnviroFocus 

facility with these airports that would warrant a designation of nonattainment.
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Telephone: 

202-566-1744 

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202-566- 9744 

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