Water: Water Quality Standards Academy
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Education & TrainingTraining ProgramsWater Quality Standards AcademyDeriving the CMC: Factoring in Water Characteristics
Education & TrainingTraining ProgramsWater Quality Standards AcademyDeriving the CMC: Factoring in Water CharacteristicsDeriving the CMC: Factoring in Water Characteristics
Course Navigation
- Listing Impaired Waters and Developing TMDLs
- Monitoring & Assessment
- NPDES Permit Program
- Human Health Ambient Water Quality Criteria
- Aquatic Life Criteria
- EPA's Role
- Two Concentration-Related Criteria
- Steps in Deriving the Criteria
- Prioritizing Chemicals
- Collecting Effects Data
- Assessing Acute Effects Data
- Calculate the GMAVs
- Rank the GMAVs
- Calculate the FAV
- From FAV to CMC
- Factoring in Water Characteristics
- CCC Approach Based on Available Data
- Assessing Chronic Effects Data
- CCC Calculation of the FCV
- FCV to CCC
- Criteria Review Process
- Site-Specific Criteria
- Summary
- Quiz
Basic Course: Supplemental Topics
For these materials, the relationship of toxicity to hardness is calculated. Then, the CMC is adjusted accordingly. The same approach is applied for characteristics associated with other materials as appropriate.
EPA has been working cooperatively with various organizations to develop a model called the biotic ligand model, or BLM. The BLM predicts acute toxicity based on site-specific water quality parameters like pH, hardness, and dissolved organic carbon (DOC). This model accounts for the major variables that effect toxicity rather than only accounting for hardness.
