Notebook Ref 6.3

Questions Tier 3 discussion has been addressed separately... How is Tier 1 / Tier 2 protection applied? ALL waterbodies are protected at the Tier 1 level (“existing water uses and the level of water quality necessary to protect existing uses must be maintained and protected Tier 2 applies when “the quality of a water exceeds levels necessary to support propagation of fish, shellfish, and wildlife and recreation in and on the water” Parameter-by-parameter or waterbody as a whole? Parameter approach: defined set of parameters, usually considered to be the established water quality criteria, are used as antidegradation benchmarks Waterbody approach: some type of holistic assessment or other data needed to characterize and predict changes in waterbodies (e.g., geomorphic, biological, chemical, physical)

Waterbody by Waterbody Assigns waterbody (or specific portion) to a particular tier of protection from degradation Based on “overall” water quality Favored by aquatic ecologists Lends itself to use of biological/biomonitoring data

Waterbody by Waterbody Pros Cons Weighted assessments (biological, physical, & chemical) Coincides best with habitat and biological assessments Focuses resources on high quality waters Some waters may not be adequately protected Must decide what data is needed to make assessment Front-loaded work need Delay in implementation and need for procedures to address antidegradation before listing decisions are made More potential for disputes, challenges and litigation

Pollutant by Pollutant Level of antidegradation protection and review is decided for each pollutant separately Case by case basis As new discharges arise No list for Tier 2 protection – all waters with better quality than minimum water quality criteria are protected at the Tier 2 level for each “better-quality” parameter

Pollutant by Pollutant Pros Cons Little or no upfront workload Better understood, more conventional, straightforward when it comes to analysis of degradation Avoids disputes involved in making a decision on overall water quality Can be immediately implemented, as new or increased discharges arise Potentially more reviews Water column data needed, uncertain how biological data can be used Numerous pollutant-water body combinations May not focus implementation efforts on truly high quality waters