1. Spatiotemporal Analysis of Surface Water Tetrachloroethene in New Jersey Presentation of the project of Yasuyuki Akita Temporal GIS Fall 2004

2. About Tetrachloroethene

3. Tetrachloroethene: C 2 Cl 4 Tetrachloroethene: C 2 Cl 4 Volatile organic compound Volatile organic compound Nonflammable colorless liquid at room temperature Nonflammable colorless liquid at room temperature Ether-like odor Ether-like odor Synonym: Tetrachloroethylene, Perchloroethylene, and PCE Synonym: Tetrachloroethylene, Perchloroethylene, and PCE

4. Use and Production Mainly Used for dry cleaning, chemical intermediates, and industrial solvent Mainly Used for dry cleaning, chemical intermediates, and industrial solvent PCE used in dry cleaning industry has been declining during 90s PCE used in dry cleaning industry has been declining during 90s Recent Demand: 763 million lb (1980) Recent Demand: 763 million lb (1980) 318 million lb (1999) 318 million lb (1999)

5. Exposure pathway Primary route Primary route –Inhalation –Ingestion of contaminated food and water Widely distributed in environment Widely distributed in environment –38% of surface water sampling sites in the U.S. –771 of the 1430 National Priorities List sites –154 of 174 surface water samples in N.J. (1977~1979)

6. Health Effect of Tetrachloroethene Acute Effect (inhalation exposure) Acute Effect (inhalation exposure) –Dizziness, headache, sleepiness, confusion, nausea, difficulty in speaking and walking, unconsciousness, and death Chronic Effect (oral/inhalation exposure) Chronic Effect (oral/inhalation exposure) –Detrimental effect to kidney and liver

7. Carcinogenicity Reasonably anticipated to be a human carcinogen (US DHHS) Reasonably anticipated to be a human carcinogen (US DHHS) Group 2A (Probably carcinogenic to humans) (IARC) Group 2A (Probably carcinogenic to humans) (IARC) Animal studies: tumors in liver and kidney Animal studies: tumors in liver and kidney

8. Quality Standard for Tetrachloroethene Maximum Contaminant Level (MCL) in drinking water - 0.005 mg/L Maximum Contaminant Level (MCL) in drinking water - 0.005 mg/L Surface Water Quality Standard in New Jersey - Surface Water Quality Standard in New Jersey - 0.388 μg/L N.J. adopted more stringent standard

9. Monitoring Data

10. Monitoring Dataset for New Jersey Data Source Data Source –NJDEP/USGS Water Quality Network Website –EPA STORET database Data used in this study Data used in this study –369 measured values –171 monitoring stations –From 1999 to 2003

11. Monitoring Data – Histogram Raw Data Log-Transformed Data

12. Monitoring Data – Statistical Moments Raw (μg/L) Log- transformed (log-μg/L) # of records 369369 Mean0.156965-2.597410 Standard Deviation 0.3042711.043757 Coef. of skewness 5.2128341.119187 Coef. of kurtosis 39.5059124.080646

13. Distribution of Data Points

15. Distribution of Data Values

16. What we want to know is … Challenge of our research Challenge of our research –Assess all river reaches –Taking into account the space/time variability Framework for the space/time estimation Bayesian Maximum Entropy (BME) analysis of TGIS

17. Covariance for Residual S/TRF

19. BME Estimation – Temporal Fluctuation

20. BME Estimation – Spatial Distribution

22. (Apr. 15, 2002)

23. BME Estimation – Contaminated Area Area above the quality standard: 0.388μg/L BME mean estimate BME mean estimate Upper bound of the BME 68% confidence interval Upper bound of the BME 68% confidence interval Upper bound of the BME 95% confidence interval Upper bound of the BME 95% confidence interval (Apr. 15, 2002)

24. BME Estimation – Along River Stream Equidistance points along river stream Equidistance points along river stream –More accurate estimation for surface water

25. BME Estimation – Along River Stream Mean 68% CI 95% CI Feb. 5, 2000 0.79%1.48%15.03% Mar. 11, 2001 0.98%6.86%66.96% Apr. 15, 2002 1.50%9.04%69.63% May 20, 2003 0.59%3.24%46.08% Fraction of river miles that does not attain the quality standardFraction of river miles that does not attain the quality standard

26. Fraction of River Miles

27. Identifying Contaminated WMAs The state of New Jersey is divided into 20 Watershed Management Area (WMA) The state of New Jersey is divided into 20 Watershed Management Area (WMA) Assess which part of the state is contaminated Assess which part of the state is contaminated Contribution of each WMA to the fraction of river miles assessed as Contribution of each WMA to the fraction of river miles assessed as –Highly Likely in Non-Attainment –More Likely Than Not in Non-Attainment

28. Contribution of WMAs Highly Likely in Non-Attainment Highly Likely in Non-Attainment

29. Contribution of WMAs More Likely Than Not in Non-Attainment More Likely Than Not in Non-Attainment

30. Fraction of River Miles in WMAs

31. Conclusion

32. Conclusion About Monitoring Data About Monitoring Data –Some high concentration values are observed in New Jersey between 1999 to 2003. –Monitoring data shows high Space/Time variability in terms of location of the monitoring point and monitoring value Application of BME method of TGIS Application of BME method of TGIS –It enables us to take into account high space/time variability and to estimate the concentration all river reaches

33. Conclusion New Criterion New Criterion –New criterion takes into account the uncertainty information of posterior PDF –It is used to complementary criterion for the conventional one –Fraction of the river miles assessed as “Highly Likely in Non-Attainment” reached about 0.45% in 2000 –Fraction of the river miles assessed by the conventional criterion (More Likely Than~) reached about 1.8% in 2002

34. Conclusion Model Comparison Model Comparison –Space/Time analysis produces more accurate estimation than the conventional purely spatial analysis –Space/Time analysis produced very different estimate –In purely spatial analysis, non-assessment river miles reach about 99% NJ DEP will be able to better assess PCE concentration in all river reaches by using this method and new criterion NJ DEP will be able to better assess PCE concentration in all river reaches by using this method and new criterion