Buckhorn Disinfection Byproducts / Backwash Disposal Project Board of Directors Meeting June 14,...
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Transcript of Buckhorn Disinfection Byproducts / Backwash Disposal Project Board of Directors Meeting June 14,...
![Page 1: Buckhorn Disinfection Byproducts / Backwash Disposal Project Board of Directors Meeting June 14, 2012.](https://reader036.fdocuments.in/reader036/viewer/2022070407/56649e255503460f94b14ad7/html5/thumbnails/1.jpg)
Buckhorn Disinfection Byproducts / Backwash
Disposal Project
Board of Directors MeetingJune 14, 2012
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Project Purpose and Issues
Backwash Management Strategies
DBP Reduction Alts and Recommendations
Recommended Phasing Plan
Presentation Outline
![Page 3: Buckhorn Disinfection Byproducts / Backwash Disposal Project Board of Directors Meeting June 14, 2012.](https://reader036.fdocuments.in/reader036/viewer/2022070407/56649e255503460f94b14ad7/html5/thumbnails/3.jpg)
Project Purpose: Assure Compliance with Stage 2
Disinfection Byproduct (DBP) Rule (a)
& Develop An Integrated Backwash Management Strategy
Key Project Issues: Elevated DBPs in the Buckhorn WTP
Distribution System Insufficient Pond 7 Storage Capacity
for Backwash Waste Water Disposal
Project Purpose and Issues
(a) Effective October 1, 2013.
![Page 4: Buckhorn Disinfection Byproducts / Backwash Disposal Project Board of Directors Meeting June 14, 2012.](https://reader036.fdocuments.in/reader036/viewer/2022070407/56649e255503460f94b14ad7/html5/thumbnails/4.jpg)
1. Expand Pond 7 to Contain 100-Yr Storm Event per WDR
2. Remove Solids at WTP to allow Recycle to WTP and/or Discharge Treated Backwash Water (BWW) to Pond 7
a) No WDR Required
3. Select Best Long-Term and Most Cost Effective Backwash WaterManagement Strategy
Backwash Water Management Strategies for the Buckhorn
WTP
![Page 5: Buckhorn Disinfection Byproducts / Backwash Disposal Project Board of Directors Meeting June 14, 2012.](https://reader036.fdocuments.in/reader036/viewer/2022070407/56649e255503460f94b14ad7/html5/thumbnails/5.jpg)
Comparison of Solids Removal Alternatives
Alternative
Comparison Criteria (Score 1 to 5, 5 = best)
ScoreRegulatory Construction Cost
ApplicabilityParticulate Chemical
Compliance Removal Compatibility
1. Bag Filter w / Recycle 35
($255k) 1 1 5 15
2. Bag Filter w / Discharge 21
($760k – $910k) 3 1 5 12
3. Mech. Dewatering w / Recycle 33
($525k) 1 1 1 9
4. Mechanical Dewatering w / Discharge 22
($660k) 1 1 5 11
5. Conventional Drying Beds 31
($1,525k) 3 5 416 (site
constraints)
6. Proprietary Drying Beds 54
($355k) 5 5 4 23
7. Reuse Old Plant (Conv. Drying Beds) 31
($1,515k) 2 5 4 15
8. Leachfields 15
($200k) 1 5 5 17
9. Micro Screen 32
($595k – $900k) 2 3 5 15
10. Expand Pond 43
($500k - $650k) 3 5 5 20
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Proposed Flow Schematic
![Page 7: Buckhorn Disinfection Byproducts / Backwash Disposal Project Board of Directors Meeting June 14, 2012.](https://reader036.fdocuments.in/reader036/viewer/2022070407/56649e255503460f94b14ad7/html5/thumbnails/7.jpg)
Potential Site Layout
Recommended DeskinsTM System
(Solids Removal and Dewatering)
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Stage 2 DBR Rule Compliance
Historical TTHM/HAA5 Results
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TOC Removal Coagulation/Filtration Adsorption Oxidation
Reduce Chlorine Dose Maintain Disinfection CT Maintain Residual Disinfectant throughout System
Distribution System Modifications Reduce Water Age Tank Materials
DBP Removal Strategies
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Buckhorn WTP Distribution System
DBP Sample Location
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Comparison of DBP Reduction Alternatives
DBP Reduction Alternative
Capital Cost(1-5, 5 = Lowest)
Operating Cost(1-5, 5 = Lowest)
DBP Reduction(1-5, 5 = Greatest)
Complexity(1-5, 5 = Simplest)
Total Score
TOC REMOVAL
Chlorine Dioxide
2($180,000)
1($30,000/yr)
3 3 10
ACH4
($25,000)3
($20,000/yr)4 5 16
Ferric Chloride
3($45,000)
2($25,000/yr)
3 3 11
REDUCE CHLORINE RESIDUAL
Clearwell Baffling/Chlorine Booster Stations
1($160,000)
3($20,000/yr)
5 2 10
pH Adjustment
Location
4($20,000)
5($0/yr)
3 5 17
Reduce CT Provided
5($0)
5($0/yr)
3 5 18
DISTRIBUTION SYSTEM MODIFICATIONS
Tank Mixing3
($175,000)5
($0/yr)2 4 14
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ACH DBP Reduction
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Recommended Phasing PlanGoal: ACH feed system operational Summer
2013; highest DBP concentrations have historically occurred during summer seasona
Step / Activity Est. Construction Cost ($)
2012 2013
J J A S O N D J F M A M
1. Solids Removal Project
355,000 Design B Construct & Startup
2. Full Scale Testing to Minimize Chlorine Dose
0b
3. Tank A Modifications
50,000 D B Construct
4. ACH Improvements 25,000 D B C & SU
Total Est. Construct Cost
430,000
a First set of Stage 2 DBP compliance testing to be conducted prior to October 1, 2013
b Testing conducted by Agency operators and staff
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Questions ?