We granted a writ of certiorari in this case to determine whether the Court of Appeals correctly held that a permit to allow Gwinnett County to discharge forty million gallons of treated wastewater into Lake Lanier on a daily basis was properly issued.1 The undisputed facts show that the discharge will degrade the water quality in Lake Lanier. Before a permit will issue to allow the degradation of water quality in Lake Lanier, the clear and unambiguous language of Georgia’s anti-degradation rules require the permittee to utilize the “highest and best level of treatment practicable under existing technology.”2 Because the treatment plant at issue, the Hill Plant, is capable of removing more pollutants from the discharged water than the permit requires, the permit violates the anti-degradation rules. Accordingly, we reverse. On August 4, 1999, Gwinnett County applied for a National Pollutant Discharge Elimination System permit to discharge treated wastewater into Lake Lanier. On August 8, 2000, the Environmental Protection Division EPD of the Georgia Department of Natural Resources issued a draft permit for public comment. The EPD issued a final permit allowing the discharge on November 9, 2000. The permit authorized a different discharge location and depth from that which was indicated in the draft permit.
Terrence D. Hughey, a local landowner, together with the Lake Lanier Association and other entities collectively “the challengers”, administratively appealed the EPD’s permit issuance, and Gwinnett County intervened to defend the permit. After a hearing, the Administrative Law Judge found in favor of EPD and Gwinnett County, and affirmed the issuance of the permit. The challengers appealed to the Hall County Superior Court, which reversed the ALJ. Gwinnett County and EPD in turn appealed to the Court of Appeals, which reversed the superior court’s order and re-affirmed the issuance of the permit. This Court then granted the challengers’ petition for a writ of certiorari, and we now reverse the Court of Appeals.
