1. Willow Valley Water Company
Alternative Oxidant & Corrosion
Control – Studies, Strategies &
Solutions - May 4, 2012

2. Joel Wade – Global Water Resources

3. Facility Information/Project Background
Primary Technology
Bench Scale Testing
Full Scale Pilot Test
Full Scale Improvements
Results - Capital / O&M Costs
Conclusions & Considerations

5. Challenges withNewlyAcquired WaterSystem
Willow Valley Water Company
Under 2,000 customers
5 - Active Groundwater Wells
Rated Capacity: 2-Sites 890 Kgal/day
Purchased by Global Water - 2006
SWDA - Groundwater Rule – Disinfection
Required.
Tough Water!
Iron – 1.2 mg/l
Manganese – 1.5 mg/l
Total Organic Carbon - 3.2 mg/l

7. ½” Iron
Deposits
3-1/2”
Manganese
Deposits
2” Free Flow
Area of Pipe

8. Built with limited controls and flexibility
Experiencing process stability issues using sodium
hypochlorite as the oxidant at design capacity
Limited contact time further stresses water clarity
Capacity limited by organic and solids loading not
hydraulics
Oxidant: Sodium hypochlorite
Oxidant Contact : 6 min (Unit 17), 0 min (Cimarron)
Filtration: 2 Parallel Units -Manganese Dioxide Coated Media
Disinfection: Sodium Hypochlorite
Disinfection /
Storage /
Pressure
Boosting
Filtration
Oxidant/Contact
Tank
Groundwater
Well

10. 16 - Sample Points
26 - Constituents
12 - Calculated Indices
2 – Chemistry Models
Material Survey
Water Age Model
Pipe Velocity Contours
Trend Map – Cu+ hits

11. Copper 2.5 mg/l
Copper
1.9 mg/l
Copper
2.1 mg/l

12. Residential Address Water Age (Hrs)
System Address #1 - 1568 E. Puma Rd.
60
System Address #2 - 1648 Valley Pkwy
70
System Address #3 - 1770 Emily Dr.
58
System Address #1 - 8170 Aspen
20
System Address #2 - 1093 Pine
20
System Address #3 - 7793 Green Valley
20
System Address #4 - 467 Kingsley
30
System Address #5 - 8663 ASH
35
System Address #6 - 1430 E. Commercial St.
50

13. pH/ORP
Conductivity / Total
Dissolved Solids
Alkalinity – Total /
Phenolphthalein
Total Hardness
Lead/Copper
Sulfate/ SRBs
Dissolved Oxygen /
Carbon Dioxide
Chlorine/Chloride-
Nitrate/ Sulfate
Iron / IRBs
Total Organic Carbon
(TOC) .
Dissolved Inorganic
Carbon (DIC)
Calcium
Bicarbonate/Magnesium
Bicarbonate

14. Parameter Max Min Average
ORP (mV) 553 121 269
Temp (deg C) 25.3 22.1 24.3
pH (units) 8.13 7.4 7.73
Cond (uS/cm) 2500 1388 2004
TDS (ppm) 1770 973 1414
CO2 (mg/l) 25 10 17
DO (mg/l) 10.8 3.7 6.2
TOC (mg/l) 2.7 2 2.4
DIC (mg/l) 75 53 65.4
T-Alk 320 168 255
Ca- Hard 630 148 408
Mg-Hard 246 62 152
Sulfate 710 378 570
Phosphate 2.8 0.84 1.84
Chloride 250 130 192
Manganese 1.24 0.035 0.306
Iron 1.4 0.012 0.295
Lead 0.6 0.012 0.088
Copper 2.57 0.014 0.595

17. Ionic Strength
Dissolved Inorganic Carbon
CaCO3 – Precipitation Potential

18. WQ Index Max Min Average Indicator Range
pH (Units) 8.13 7.4 7.73
pHs (Units) 7.28 6.71 6.89
LSI (units) 1.38 0.45 0.84 -1.0 to +2.0
CCPP Index 78.92 21.4 50.42 4-10 mg/l
Ryznars Index 6.76 5.48 6.03 5 to 10
Aggressive Index 12.97 12.24 12.71 10 - 12 units
Ionic Strength
(mol/l)
0.0416 0.0246 0.0344 0 - 0.05 mol/L
Larson Sklod
Index
4.64 2.21 3.01 0.8 – 1.2
Baylis curve Scale Scale Scale Incrustation /
corrosion
DIC (Calculated)
(mg/l)
81.1 41 63.2 10 – 30 mg/l as C
Alk/Chloride +
Sulfate Ratio
0.33 0.33 0.29 Greater than 5.0

20. Average pH 7.7 – Check!
Average Alkalinity 255 – Good!
Average LSI - 0.84, Slightly Positive – Stable!
Ryznars Index – 6.03 Mid range of stability –
Check!
Baylis Curve – Non-Corrosive – Deposition Zone
Larson Skold – 3.01 Not So Much!
Alkalinity Chloride + Sulfate Ratio 0.29 – Way
Out of Range!

21. Slow oxidation reactions due to high levels of
TOC in the raw water cause overuse of oxidants
related to Iron and Manganese removal.
Increased DIC concentrations related to the iron
and manganese filtration process, may be the
leading cause of increased copper solvency of
the contact water.
High chloride and sulfate concentrations
stripping away protective films, required to
offset high oxidation potential & electro
conductivity.

23. Simple Ratio - ALK/ (Cl- + SO4)
Increase Alk or Reduce Cl-, SO4
-
DIC limits Alk – Beware of CSI!
Use Polyphosphate as protective coating
Eliminate NaOCl- – Reduce Chloride
Hydrogen Peroxide - Not effective with TOC
Ozone – Material compatibility issues, Can reform
MnO4
Sodium Permanganate – Slow acting, Can reform
MnO4
Chlorine Dioxide – Fast Acting, No THMs Ok, Lets
try it!

25. Advantages
Detention Time – ClO2 reactions are
instantaneous, reducing contact time
requirements and is 10 times more
soluble in water than chlorine.
Increased effectiveness with increasing
pH (opposite of chlorine).
More effective than chlorine for virus
inactivation.
Powerful enough to oxidize Iron
Manganese in the presence of high TOC.
Can inactivate THM precursors without
forming THM or HAA5s.
Improves taste and odor from organics,
algae and sulfides.
CLO2 provides a chlorine residual, while
other oxidants may not.
CT requirements are initiated at point of
use, reducing the amount of chlorine
required to meet CT
Cl2 gas can reduce disinfection costs by
2/3
Disadvantages
ClO2 forms chlorite which is
regulated constituent, limiting the
concentration that can be fed.
On-site generation process control
can vary efficiency of product.
Training, sampling and lab efforts
are higher than that of Chlorine.
On-site generation equipment
capital costs are higher than NaOCl-
Cost per lb of oxidant is 4.3 times
higher than the cost of NaOCl- , but
dosage is 2.7 times less than NaOCl- .
ClO2 decomposes in sunlight.
Safety concern of ClO2 is greater
than that of NaOCl- .
When spilled or agitated, liquid ClO2
can produce chlorine gas.

26. Dissolved Mnvs.OxidantDose:Unit-17Well
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
DissolvedMn(mg/L)
Unit 17 - Oxidant Dose (mg/L)
Oxidation of Mn2+ in raw water by Cl2 alone ,ClO2 alone and MnO4 + ClO2. For combined process,
ClO2 dose was 1.5 mg/L. Initial Mn2+ = 1.35 mg/L. Temp. = 10 C, pH = 7.4 - 7.5. TOC = 3.56 mg/L.
Cl2 Alone
Cl2 + ClO2 (ClO2 dose = 1.5 mg/L)
ClO2 Alone
MnO4- + ClO2 (ClO2 dose = 1.5 mg/L)

27. Dissolved Mnvs.OxidantDose:CimarronWell
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
DissolvedMn(mg/L)
Cimarron Oxidant Dose (mg/L)
Oxidation of Mn2+ in Cimmaron raw water by Cl2 alone, Cl2 + ClO2 and ClO2 alone and Detention time =
5 min. Initial Mn2+ = 0.626 mg/L. Temp. = 10 C, pH = 7.3 - 7.4. TOC = 2.45 mg/L.
ClO2 only
Cl2 Alone
Cl2 + ClO2 (ClO2 dose = 1.0 mg/L)

28. LiquidChlorineDioxide–Pentasodium
Tripolyphosphate

29. PilotUnitOverview
CDG Solution 3000 – Liquid Chlorine Dioxide
330-gallon tote
Variable Speed Drive
Peristaltic Pump Skid
Westfall Static Mixers
50 gallon NaMnO4 & Pump
Injection Quills
Rubbermaid Storage Unit
Na4P2O7 – Mixing &
Chemical Feed Station
Concrete Pad

31. Summary
Cimarron Full-Scale Pilot Results
Constituent Before After
Fe Removal (%) 84.3 99.3
Mn Removal (%) 55.5 88.0
TTHM (ug/l) 0.100 0.059
TOC (mg/l) 2.7 2.4
Max Copper Sampled
(mg/l)
1.30 0.35
Unit 17 Full-Scale Pilot Results
Constituent Before After
Fe Removal (%) 91.0 98.1
Mn Removal (%) 70.4 87.1
TTHM (ug/l) 0.120 0.056
TOC (mg/l) 3.4 3.0
Max Copper Sampled
(mg/l)
2.77 0.56

32. Storage
Tank
ToDistribution
System
Well No. 1
Well No. 2
Raw
Water
Treatment System
Bypass
Iron & Manganese
Treatment
Unit 17
Distribution Pump Station
Onsite Chlorine
Dioxide Oxidant
Generator/Feed
System
Tetrasodium
Pyrophosphate
Sodium
Permanganate
Feed
Chlorine Gas
Feed System
Full Scale
Improvements

33. CDG Gas:Solid™ Process
Cl2 + 2NaClO2 2ClO2 + NaCl
Chlorine Gas Solid Sodium Chlorite
SAF-T-CHLOR™
Chlorine Dioxide Gas Solid Sodium Chloride
½ lb gas chlorine passing through Sodium chlorite makes 1 pound of Chlorine Dioxide

37. Unit17

38. Daily Chlorine Dioxide at EPDS – HACH Field Kit
Daily Chlorite at the EPDS – HACH AutoCat 900
Monthly Chlorite – Third Party – Three Samples

39. ParkerTHMAnalyzer

44. FullScaleImprovements

46. Capital Costs – $172,000 ($0.38 per gallon)
Chlorine Gas System - $37,800
Chlorine Dioxide Generator - $67,300
CC Pad & Tuff Shed Structure - $4,500
Sodium Permanganate feed station - $750
Tetrasodium Pyrophosphate Feed Station - $1,500
Backflow, piping and static mixers - $15,000
Electrical Improvements - $5,000
Settling Tanks and Ancillary Equipment – $10,000
In-House Labor - $30,000 - Constructed in 8-Weeks!

47. Site
Location
Production
(Kgal)
Oxidant&
Disinfection
($)
Power
($)
Prod Cost
($/kgal)
Unit 17 (2010) 104,209 11,823 26,152.38 $0.36
Cimarron (2010) 12,306 1,395.02 5,189.71 $0.54
Site
Location
Production
(Kgal)
Oxidant
($)
Disinfection
($)
Corrosion
Inhibitor
($)
Power
($)
Prod Cost
($/kgal)
% Cost
Increase
Unit-17
(3/2012)
5,976 1,848.62 305.31 87.41 1948.81 $0.70 94.4
Cimarron
(3/2012)
872 258.67 42.64 11.78 576.03 $1.07 98.1

48. Cimarron Jan Feb March April May June July Aug Sept Oct Nov Dec Total
Prod (Kgal) 741 671 807 743 898 944 935 1,229 1,121 1,112 801 724 5,792
Prod($)
2010
$400 $362 $436 $401 $485 $510 $505 $664 $605 $600 $433 $391 $5,792
Prod($)
2012
$793 $718 $863 $795 $961 $1,010 $1,000 $1,315 $1,199 $1,190 $857 $775 $11,477
Change
($)
$393 $356 $428 $394 $476 $500 $496 $651 $594 $589 $425 $384 $5,685
Unit 17 Jan Feb March April May June July Aug Sept Oct Nov Dec Total
Prod (Kgal) 5,931 5,857 7,039 7,519 9,303 8,303 9,467 9,975 7,514 6,543 8,728 4,875 91,054
Prod($)
2010
$2,135 $2,109 $2,534 $2,707 $3,349 $2,989 $3,408 $3,591 $2,705 $2,355 $3,142 $1,755 $32,779
Prod($)
2012
$4,152 $4,100 $4,927 $5,263 $6,512 $5,812 $6,627 $6,983 $5,260 $4,580 $6,100 $3,413 $63,738
Change($) $2,017 $1,991 $2,393 $2,556 $3,163 $2,823 $3,129 $3,392 $2,555 $2,225 $2,968 $1,658 $30,958

49. FE & Mn Removal w/o
Copper Corrosion
Alternative Oxidants can
Improve Fe & Mn
Removal w/o TTHM
Check CPI Before
considering Alkalinity
Augmentation
ClO2 + MnO4 – Most
effective in combination
CLO2 Can Be User Friendly

50. St. Mary's WTP - Flagstaff Az.
Valencia Water Company Utilities Staff.
Pureflow Filtration/Reaco Associates, LLC.
Chemical Feeding Technologies, Inc.
Parker Hannifin Corp
CDG Environmental
Steve Osborn, James Taylor – Global Water
Willow Valley Operations Staff

51. Any Questions ??