y conclusions about plant uptake of chromium from sewage sludge amended soils, and thus cannot justify an otherwise unsupported cap premised on uptake-potential.


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In sum, the EPA's relevant evidence (1) provided no data for chromium uptake at soil concentrations greater than 3000 kg/ha, and (2) showed no uptake danger at a soil concentration of 3000 kg/ha or at any other concentration.  Indeed, it indicated a declining probability of plant uptake with increased soil concentration.  Based on this data, the EPA chose as the ceiling chromium soil concentration 3000 kg/ha because that was the highest concentration for which it had data.  While the EPA "may 'err' on the side of overprotection," it "may not engage in sheer guesswork."  American Petroleum Institute, 665 F.2d at 1186-87.

VI. ADDITIONAL CLAIMS

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The AMSA challenges the EPA's classification of dedicated beneficial use sites as "surface disposal" rather than "land application," arguing that this classification is arbitrary and "promotes a negative public perception of dedicated sites as 'dumping grounds.' "   AMSA Brief at 36.  Dedicated beneficial use sites are sites "generally owned, operated, and controlled by, or are controlled under long-term leases to, the municipal sludge operator."  58 Fed.Reg. 9259-60.  Although dedicated sites may be used "to produce crops, such as corn, which are sold as animal feed or for alternative fuel production," 58 Fed.Reg. 9260, the EPA did not classify dedicated sites as a type of land application.  The EPA explains this decision on the grounds that dedicated sites involve the application of sludge "at greater than agronomic rates" and public access is generally strictly controlled, thus making it appropriate for other aspects of the regulatory regime to differ.  58 Fed.Reg. 9259.  The EPA acknowledges that its "distinction is one of degree, since both land application sites and dedicated sites involve the placement of sewage sludge on the ground."   EPA Brief at 40.  Indeed, land reclamation sites, which also inv