1. Levels of Dissolved Solids Associated With Aquatic Life Effects in Virginia’s Central Appalachian Coalfield Streams Tony Timpano Stephen Schoenholtz, David Soucek, Carl Zipper VirginiMarch 29a Tech, 2011 1

2. Background Question: what is TDS relationship to aquatic life? Challenge: TDS often with other stressors Approach: Evaluate TDS effects with other stressors minimized 2 Wayne Davis USEPA EcoAnalysts, Inc. E phemeroptera (Mayflies) P lecoptera (Stoneflies) T richoptera (Caddisflies)

3. Site Selection Systematic: GIS prescreen, ground-truth High-Quality Habitat Avoid Non-TDS Stressors: 3 Iron SeepSedimentation

4. Data Collection Field – RBP Benthic Macroinvertebrates – RBP Habitat – Temp, pH, DO, Cond. – Water grab samples – Fall 2008, Spring 2009, Fall 2009, Spring 2010 Lab – Family & Genus “bugs”, VASCI – TDS – Alkalinity (for HCO 3 - ) – SO 4 2-, Ca 2+, Mg 2+, Na +, K +, Cl – – Al, Cu, Fe, Mn, Se, Zn 4 R. J. Krenz

5. Site Selection & TDS Composition 5

6. 6

7. Results – Site Selection Non-TDS stressors not evident – Habitat comparable to reference – pH 6.6 – 8.5 – No obvious NPS Pollution 7 155 160 165 170 175 180 185 190 Mean RBP Habitat Score RefTest

8. Reference Site (22  S/cm)Test Site (265  S/cm) Test Site (1,670  S/cm)Test Site (594  S/cm) 8

9. TDS Mean Ion Proportions 9 Reference Sites Mean TDS: 21 mg/L Test Sites Mean TDS: 406 mg/L

10. Test Site Mean Ion Concentrations 10

11. Test Site TDS Seasonal Variability 11 0 200 400 600 800 1000 1200 1400 TDS (mg/L) Fall 2008Spring 2009Fall 2009Spring 2010 566 n = 8 371 n = 16 485 n = 19 371 n = 21 Means:

12. VASCI – TDS Associations 12 Analyses that follow should not be interpreted to indicate actual, potential, or suggested water quality criteria for TDS or component ions.

13. Analysis Methods VASCI = multimetric index of benthic macroinvertebrate community integrity (0-100 pts) Evaluate VASCI-TDS Relationship – Least Squares Linear Regression – Quantile Linear Regression Observed Effect Concentration (OEC) = TDS concentration where VASCI = 60 13

14. Correlations: Test Sites 14 VASCI TDSSCCa 2+ SO 4 2- Mg 2+ K+K+ HCO 3 - Na + mg/L  S/cm mg/L TDS -0.64 SC -0.630.99 Ca 2+ -0.610.910.90 SO 4 2- -0.580.920.910.94 Mg 2+ -0.550.870.850.950.94 K+K+ -0.540.900.890.820.830.81 HCO 3 - -0.420.640.670.450.380.350.63 Na + -0.350.340.370.310.67 Cl - 0.300.58 Highly Correlated MeasuresMeasures Evaluated all correlations significant (p < 0.05)

15. VASCI Seasonality 15 Reference Sites 60 65 70 75 80 85 FallSpring VASCI Score n=6n=9 Test Sites 40 45 50 55 60 65 70 75 80 FallSpring VASCI Score n=27n= 39 Spring VASCI scores > Fall VASCI scores at test and reference sites

16. VASCI vs. TDS (LS Regression) 16 Model SC (  S/cm) TDS (mg/L)SO 4 2- (mg/L) Spring768528336 All - Year634422219 Fall523337143 OECs: VASCI = 60

17. VASCI vs. TDS (Quantile Regression) 17 Quantile SC (  S/cm) TDS (mg/L)SO 4 2- (mg/L) 90not sig. 75903637392 50625421219 25429263133 1028114248 OECs: VASCI = 60 Q90: 90 th quantile = 90% of data below line Q50: 50 th quantile = 50% of data below line Q10: 10 th quantile = 10% of data below line Q-value = probability of VASCI < 60

18. Observed Effect Concentrations (OECs) OEC = concentration where VASCI = 60 18 Method Probability of VASCI < 60 at OEC (%) Model/ Quantile (%) SC  S/cm TDS mg/L SO 4 2- mg/L OLS RegressionFall523337143 50All-Year634422219 Spring768528336 Quantile Regression10 28114248 25 429263133 50 625421219 75 903637392 Measured Values0All-Year33219070 100All-Year1,3661,108849

19. Probability of VASCI < 60 19

20. Considerations OEC ≠ Toxicity TDS Composition: SO 4 2- and HCO 3 - dominant, Ca 2+ dominant cation VASCI Seasonality: Spring > Fall Variability of VASCI – TDS Association Variability of TDS (Temporal) 20

21. Field Sensitivity Distributions 21 Analyses that follow should not be interpreted to indicate actual, potential, or suggested water quality criteria for TDS or component ions.

22. Field Sensitivity Distributions Salt tolerance of individual benthic macroinvertebrate genera Maximum Field Concentration (MFC) – MFC = highest conc. where genus observed Cumulative Distribution Function (CDF) of MFCs X% Observed Effect Concentration (OEC X ) – OEC X = conc. affecting X% of genera 22

23. Macroinvertebrate Genera 97 genera Excluded genera (37) – < 4 observations/genus (5% of 81 samples) – Genera not at reference sites 60 genera used Spring, Fall, All-Year models 23

24. TDS FSDs 24

25. X% Observed Effect Concentrations Water Quality Parameter Proportion of Taxa Affected Model FallSpringAll-Year Specific Conductance (  S/cm) 5%450465462 10%476511490 20%653647652 TDS (mg/L) 5%273291281 10%288311298 20%421422411 SO 4 2- (mg/L) 5%120160108 10%163221156 20%210250221 25

26. Orders 26 Mayflies most sensitive (E) Stoneflies least sensitive (P)

27. Considerations OEC X ≠ Toxicity Small Sample Size = Few Taxa Method sensitive to rare taxa Truly rare taxa?  too few samples to know Temporal variability of TDS 27

28. Further Research Needs TDS Temporal Variability 28 Data: DMME & VT ?

29. Questions? Study Sponsors: Virginia Dept. of Environmental Quality Virginia Dept. of Mines, Minerals, and Energy Powell River Project 29