General. Numerical toxic substance criteria for ambient surface waters are established to protect human health or aquatic life. Four types of numerical toxic substance criteria shall be adopted. The purpose of these criteria is to protect: Human health through ingestion of public water supplies; The wholesomeness of fish for human consumption; Fresh, estuarine, and salt water aquatic life from acute toxicity impacts; and Fresh, estuarine, and salt water aquatic life from chronic toxicity impacts. Fresh Water, Estuarine, and Salt Water Boundaries. For any toxic substance for which no estuarine criteria appear in Regulation .03-2G, Table 1, the salt water criteria apply in estuarine waters. Fresh water and estuarine or salt water boundaries begin at specific points for the purpose of applying the numerical toxic substance criteria for aquatic life protection. These points are: The stream segment and all tributaries which confluence with the stream segment upstream from the boundaries specified in §B(3) of this regulation are assumed to be fresh water. Except for Sub-Basin 02-13-01—Coastal Area, the stream segment and all tributaries which confluence with the stream segment downstream from the boundaries specified in §B(3) of this regulation are assumed to be estuarine water. In Sub-Basin 02-13-01—Coastal Area, the stream segment and all tributaries which confluence with the stream segment downstream from the boundaries specified in §B(3) of this regulation are assumed to be salt water. Tributary headwaters. Since the headwaters of some tributaries to stream segments designated as estuarine or salt water may be fresh, the Department may: Require the discharger to provide site specific salinity measurements or accept site specific salinity measurements provided voluntarily by the applicant; and Review the information provided in §B(2)(d)(i) of this regulation, and determine that the area is more appropriately designated as fresh water. For the purpose of applying numerical toxic substance criteria, the following are designated as the boundaries between fresh waters and estuarine or salt waters: Lower Susquehanna River Area (Sub-Basin 02-12-02)—All waters are fresh waters. Coastal Area (Sub-Basin 02-13-01) boundaries are: Bishopville Prong—State boat ramp at Daye Road; Birch Branch—Route 113; Middle Branch—Route 113; Church Branch—Route 113; Turville Creek—Route 589; Ayer Creek—Route 376; Newport Creek—Hayes Landing Road; and Poplartown Creek—Beaverdam Creek Road. Pocomoke River Area (Sub-Basin 02-13-02) boundaries are: Pocomoke River—A line connecting the mouth of Bullbegger Creek and the east entrance of Fair Hill Channel; and Manokin River—Sharps Point. Nanticoke River Area (Sub-Basin 02-13-03) boundaries are: Nanticoke River—A line connecting Newfoundland Point and Hat Crown Point (includes Marshyhope Creek); Wicomico River—A line connecting Pine Beach and Holland Point; Blackwater River—Mouth at Snake Island; and Transquaking River—Mouth at Fishing Bay. Choptank River Area (Sub-Basin 02-13-04) boundary is a line connecting Bow Knee Point and Wrights Wharf. Chester River Area (Sub-Basin 02-13-05) boundaries are: Chester River—A line connecting Piney Grove and Primrose Point; Grays Inn Creek—A line crossing the creek at Cherry Tree Point; Herringtown Creek—All waters are fresh; West Fork Langford Creek—A line crossing creek at Fox Point; East Fork Langford Creek—A line connecting Piney Point and Longmarsh Point; Philip Creek—All waters are fresh; Reed Creek—Tilghmans Neck Road; Corsica Creek—A line crossing the creek at Jacobs Nose; Emory Creek—All waters are estuarine water; and All tributaries to the Chester River upstream from Deep Point. Elk River Area (Sub-Basin 02-13-06)—All waters are fresh water. Bush River Area (Sub-Basin 02-13-07)—All waters are fresh water. Gunpowder River Area (Sub-Basin 02-13-08)—All waters are fresh water. Patapsco River Area (Sub-Basin 02-13-09) boundaries are: Patapsco River—A line connecting Lazaretto Point and the southern terminus of the Baltimore Harbor Tunnel; and Back River—a line connecting Rocky Point and Cuckhold Point. West Chesapeake Bay Area (Sub-Basin 02-13-09) boundaries are: Severn River—Bridge on State Highway 3; All tributaries to the Severn River upstream from MD Route 648; Magothy River—A line connecting Henderson Point and Pea Patch Point; All tributaries to the Magothy River are fresh water; and South River—A line drawn due north from Beards Point. Patuxent River Area (Sub-Basin 02-13-11) boundary is a line connecting Chalk Point and God's Grace Point. Lower Potomac River Area (Sub-Basin 02-14-01) boundaries are: Potomac River—A line connecting Upper Cedar Point and Chotank Creek; and All Maryland tributaries of the Potomac River upstream from St. Catherine Island are fresh water. Washington Metropolitan Area (Sub-Basin 02-14-02)—All waters are fresh water. Middle Potomac River Area (Sub-Basin 02-14-03)—All waters are fresh water. Upper Potomac River Area (Sub-Basin 02-14-05)—All waters are fresh water. North Branch Potomac River Area (Sub-Basin 02-14-10)—All waters are fresh water. Youghiogheny River Area (Sub-Basin 05-02-02)—All waters are fresh water. Conewago Creek Area (Sub-Basin 02-05-03)—All waters are fresh water. Chesapeake Bay Proper (Sub-Basin 02-13-99) boundary is a line connecting Booby Point (39.284206 north latitude, -76.381400 west longitude) with Handy's Point (39.291944 north latitude, -76.181388 west longitude).