Final Total Maximum Daily Loads in the Waters of Silver Bay, Alaska. Part I. Residues and Toxic Substances. Part II. Rationale for Removing the Listing for Dissolved Oxygen

摘要

Under Section 303(d) of the Clean Water Act (CWA), states must identify and list waterbodies that do not meet state Water Quality Standards (WQS). A waterbody must be listed for each parameter for which it fails to meet WQS. The CWA and United States Environmental Protection Agency regulations require the formulation of total maximum daily loads (TMDLs) for all listed waterbodies. A TMDL presents a budget for the parameter of concern. The loading capacity quantifies the maximum amount of a substance the waterbody can receive while still meeting WQS. The wasteload allocation and load allocation assign portions of that loading capacity to the various point sources and nonpoint sources, respectively, that impact the waterbody. This document contains TMDLs for Silver Bay, located near Sitka, Alaska. Since 1993, Silver Bay has been included on Alaska's 303(d) list as water-quality limited for three parameters: residues, toxic and deleterious substances, and dissolved oxygen (DO). In the years since the listing, circumstances have changed. In some instances, the original reasons for listing the Bay as water-quality limited are no longer valid.