Water Quality Standards Rules (Recap)

• Fishable/swimmable are the “default” DUs.
• May not allow/permit impairment/elimination of existing use(s) (Antideg: Rule 1).
• Existing uses must be protected and designated.
• DU = EU ; DU > EU ; DU < EU…Not!!
• May degrade high-quality waters to WQC threshold, but not a “free ride”—must conduct alternatives/socioeconomic analysis and demonstrate benefits (Antideg: Rule 2).
• May downgrade an unmet DU, if certain conditions are met and processes followed.
• May not remove/downgrade an existing use.