Hexavalent Chromium Treatment Goals Community and National Cost Implications

Transcription

1 Hexavalent Chromium Goals and National Implications American Water Works Association Water Quality Technology Conference Toronto, Canada November 5,

2 Acknowledgement American Water Works Association Steve Via Water Research Foundation Alice Fulmer Project Steering Committee Heather Collins Matthew Corson Technical Input Tarah Henrie Joe Marcinko 2 2

3 Outline 1. s California Factors 6. Scenarios Evaluated 7. California

4 s 1. Develop estimates of the ranges of national, and California, capital and annual O&M costs for implementing treatment to different potential drinking water limits 2. Identify community level cost estimates of treatment 3. Identify data and information gaps that could be filled by future work 4 s Calif. s 4

5 Mine database for EPs with reported levels For each EP size and target, identify technology with the lowest annualized cost National = Sum of costs of treatment systems for all EPs Develop Capital and O&M s as a function of Size EP = Entry Point 5 s Calif. s 5

6 National Cr bases Two national databases were used: 1. USEPA s 6 year review (6 YR) database of Total Cr levels at PWS EPs ( ) 2. WRF National Chromium & Boron Survey (NCBOS), (2003) 6 YR database is large (162,823 datapoints) However, large fractions have high MRLs (1 to 50 µg/l) NCBOS database is smaller (342 datapoints) But MRLs are lower (0.2 to 0.6 µg/l) 6 s Calif. s 6

7 Three bases Applied 1. 6 YR base, with ND Values set at 0.25 MRL 2. 6 YR base, with ND Values set at 0 µg/l 3. NCBOS base 7 s Calif. s 7

8 Cr All US PWS Sizes 8 s Calif. s 8

9 Cr Small US Systems 9 s Calif. s 9

10 Cr % Small US Systems 10 s Calif. s 10

11 Four were Considered: 1. Disposable Weak Base Anion (WBA) Resin 2. Regenerable Strong Base Anion (SBA) Resin 3. Reduction Coagulation Filtration (RCF) 4. Reverse Osmosis (RO) 11 s Calif. s 11

12 Two Scenarios Considered Scenario 1 a. Residual streams are discharged untreated to the onsite sanitary sewer b. Spent WBA resin is disposed of in a municipal landfill Scenario 2 a. Residual streams are treated onsite with coagulation and clarification b. Sludge is dewatered on site and disposed of as nonhazardous waste (national cost) or hazardous waste (California cost) c. Recovered brine and concentrate are hauled off site for disposal in an appropriate facility d. Spent WBA resin is disposed of as Low Level Radioactive Waste (LLRW) s Calif. s 12 12

13 WBA System Scenario 1 Scenario 2 13 s Calif. s 13

14 SBA System Scenario 1 Scenario 2 14 s Calif. s 14

15 RCF System Scenario 1 Scenario 2 15 s Calif. s 15

16 RO System Scenario 1 Scenario 2 16 s Calif. s 16

17 Basis of s (all costs adjusted to 2011) Technology Capital Basis Annual O&M Basis RCR & WBA Engineer s Estimate Engineer s Estimate SBA RO Engineer s Estimate Existing SBA plants in NV &ME Engineer s Estimate Operating Plants in Florida Engineer s Estimate USEPA 2001 Equations 17 s Calif. s 17

18 Capital Range SBA 18 s Calif. s 18

19 Annual O&M Range SBA 19 s Calif. s 19

20 National Capital Scenario 1 20 s Calif. s 20

21 National Capital Scenario 2 21 s Calif. s 21

22 National Annualized Scenario 1 22 s Calif. s 22

23 National Annualized Scenario 2 23 s Calif. s 23

24 California Capital Chart has been subsequently refined in preparation for publication. 24 s Calif. s 24

25 California Annualized Chart has been subsequently refined in preparation for publication. 25 s Calif. s 25

26 Level Assumptions: 1. Well with Level of 30 µg/l 2. Well Utilization Rate = 90% 3. Available Land to build a treatment system 4. All four technologies can remove down to 1 µg/l 5. By pass flow is used to minimize treatment system size 6. Blended water goal = 80% of MCL 26 s Calif. s 26

27 Level (Range between Scenario 1 and Scenario 2) Table has been subsequently refined in preparation for publication. 27 s Calif. s 27

28 & Information Needed 1. Better understanding of treatment performance under different water quality conditions 2. Better understanding of the national and total Cr levels at low(er) levels 3. Optimization of treatment systems to minimize residuals handling & disposal cost 28 s Calif. s 28

29 Questions? (818) s Calif. s 29