Revision and Development of Cadmium Criteria Documents

1. Results of Technical Review ofUSEPA 2001 Cadmium Criteria DocumentBasic Standards WorkgroupSeptember 10, 2004 September 2004

2. Review Process • Technical review of 2001 Cadmium Updates • Based primarily on USEPA criteria development guidance • Stephan et al. 1985. Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses. • Literature search • Critically reviewed 2001 EPA database • Updated database • Recalculated criteria with updated databases • Developed “use-specific” criteria • coldwater • warmwater

3. Existing Cadmium Criteria (1995 Updates)

4. 2001 Cadmium Criteria

5. Literature Review • Reviewed literature from 2001 Cadmium Update for: • quality of scientific methodology • relevant toxicological data • Determined 4 papers in document unsuitable • Poor dose response (control higher concentration than LC50) • Pre-exposed organisms • Species not native to North America • Unsubstantiated effects levels • Reviewed cadmium papers since 2001 Criteria Document and earlier papers not included in the document • ~130 relevant papers reviewed • Acute cadmium criteria • 14 data points from 5 sources added* • Chronic cadmium criteria • 12 data points from 6 sources added* • includes data from studies conducted by Chadwick & Associates and unpublished data from CDOW

6. Resultant Acute Database • 2001 EPA acute cadmium database • 55 genera • 4 most sensitive genera • Salmo (brown trout) • Salvelinus (bull and brook trout) • Morone (striped bass) • Oncorhynchus (trout and salmon) • CEC revised acute cadmium database • 56 genera • 4 most sensitive genera = Salvelinus, Salmo, Morone, and Oncorhynchus • i.e., same genera, slightly different order

7. Resultant Chronic Database • CEC revised and 2001 EPA chronic cadmium database • 16 genera (deletions and additions balanced out) • 4 most sensitive genera • Hyalella (amphipod) • Daphnia (cladoceran) • Oncorhynchus (salmon and rainbow trout) • Chironomus (midge)

8. Acute Hardness Slope • 2001 EPA acute hardness slope = 1.0166 • 12 species • Used only adult data for Pimephales promelas (fathead minnow) • despite using only juveniles and fry for toxicity data • CEC revised acute hardness slope = 0.9059 • 13 species (added Oncorhynchus mykiss) • Used juvenile and fry (not adult) data for P. promelas

9. Chronic Hardness Slope • 2001 EPA chronic hardness slope = 0.7409 • 3 species • Used only Chapman et al. manuscript data for D. magna • CEC revised chronic hardness slope = 0.7635 • 3 species (added O. mykiss and deleted D. magna) • Used the revised data for S. trutta • In both cases – slopes based on limited data for only a few species and highly variable

10. Acute-Chronic Ratio (ACR) • No ACR reported in 2001 Cadmium Update • EPA believed available data did not meet requirements • Felt chronic database large enough to calculate criterion directly • Chronic database still limited (only 16 genera) • “Just meets” the 8 family rule • “sample size effect” significant to criterion calculations • CEC calculated ACR = 2.7632 • Adding new species revealed a positive relationship between SMAVs and SMACRs (i.e., use of ACRs now possible) • Calculated as the geometric mean of the 3 lowest SMACRs

11. CEC Revised Cadmium Criteria *using GMAV for Salvelinus; ** calculated with the acute-chronic ratio

12. Use-Specific Criteria • Expanding “site-specific” concept to broader application as “use-specific” • Simplest approach – “cold” and “warm” • Species in acute and chronic databases were identified as coldwater, warmwater or both • Eliminates species from one or the other database that would not be expected given the “use”

13. Warmwater Acute Criteria • 52 genera • More than eight families present • 4 most sensitive • Morone (striped bass) • Hyalella (amphipod) • Ptychocheilus (squawfish) • Simocephalus (cladoceran) • @ hardness = 100 mg/L =13.809g/L or =2.980* g/L *adjusted with lowest GMAV

14. Warmwater Chronic Criteria • 13 genera • More than eight families present, but key family absent • Chronic calculated using ACR and warmwater acute • @ hardness = 100 mg/L = 9.055g/L (calculated w/ ACR) or = 1.954*g/L (calculated w/ lowered FAV and ACR) *adjusted with lowest GMAV

15. Coldwater Acute Criterion • 42 genera • More than eight families present • 4 most sensitive = • Salvelinus (trout) • Salmo (trout) • Oncorhynchus (salmon) • Thymallus (artic grayling) • @ hardness = 100 mg/L = 2.529g/L or = 1.790* g/L *adjusted with lowest GMAV

16. Coldwater Chronic Criterion • 10 genera • Database does not include eight families • Must calculate with ACR • @ hardness = 100 mg/L =1.658g/L (calculated w/ ACR) or =1.174* g/L(calculated w/ lowered FAV and ACR) * adjusted with lowest GMAV

17. Criteria Summary(all values @ hardness = 100mg/L) Acute(g/L ) Chronic(g/L )

18. But, there are data limitations • Revised databases and calculation of criteria equations were derived from best available data • Still, data are often variable and dated • Some data needs include: • Acute data for key fish groups • GMAV of most sensitive species calculated from undefined values (brook trout) and data obtained from undesirable methodology • Chronic data on key species • For example, existing data on Daphnia varies 10 fold • Limited chronic database affect criteria – need more chronic toxicity testing with more species

19. But, there are data limitations • Data needs - continued: • Hardness – slope data • Slopes now based largely on relatively few data from D. magna and P. promelas • Need more testing on more species over wide range of hardness • Paired acute and chronic testing for FACR • Revised FACR calculated from three fish species • Invertebrate data would be useful