Free Chlorine and Chloramine Distribution Optimization in ...Free Chlorine and Chloramine...
Transcript of Free Chlorine and Chloramine Distribution Optimization in ...Free Chlorine and Chloramine...
Free Chlorine and Chloramine Distribution Optimization in a Consecutive System.
A Lesson in the Multi-Parameter Approach
Laura Blood, Renee Diehl-PADEPKate O’Neill, Loyal Fredley-Veolia Water
Ed Eisenbrown –New Sewickley Township
• Where we are in the world
• Brief description of the system
• Scope of study
• How we did it
• Initial Results
• Follow up steps
• Where are we now?
• Questions and Suggestions
Distribution System Optimization StudyOutline
New Sewickley Township Water Authority 2
New Sewickley TownshipBeaver County, Pennsylvania
Purchased surface sources: Beaver River and Service Creek Reservoir
New Sewickley Township Water Authority 3
Map courtesy of Wikipedia New Sewickley Township, Beaver County, Pennsylvania
Distribution System Optimization StudyTwo separate systems with different water quality optimization issues:
New Sewickley Township Water Authority 4
BFMA (Freedom
Tank)
Emergency Sodium Hypochlorinator
Hillman/Harvey Run Road Pump Station
Highview Circle Tank300,000-gal with SolarBee
mixing system
Tri-County Tank435,000-gal with passive Red Valve mixing system
M
M
Tri-County Pump Station
Liberty Hills Interconnection
AWA
Distribution System Optimization Study
SCOPE?
Distribution System :• Historical residual disinfectant
data, and disinfection byproduct data (trihalomethane-TTHMs and haloacetic acid-HAAs)
Tank Assessment:• Operations-Historical tank
cycling data to assess turnover and mixing
Distribution System :• Investigative sampling in suspected
areas of high water age
Tank Assessment:
• In-tank sampling to assess water quality
New Sewickley Township Water Authority 5
Distribution System Optimization Study
Focus?
High water age
Increased disinfection byproduct formation (THMs and HAAs)
Adverse health effects-suspected carcinogens and reproductive and
developmental disorders
Increased risk of microbial
contamination
Adverse health effects-
pathogenic bacteria,
fungus etc.
Nitrification
(if chloraminated)
Decrease residuals
Taste and odor issues
New Sewickley Township Water Authority 6
You are not my friend
Contaminant Distribution Optimization Goal
Monochloramine >1.50 mg/L
Since NSTMA’s entry point residual from the chloraminated portion of the system fluctuates around 0.50 mg/L total
chlorine, it was recommended that they adopt the > 0.50 mg/L total chlorine optimization goal in place of the
monochloramine goal.
Free Ammonia-Nitrogen Distribution: [< ] 0.05 mg/L (AWWA alert level) [< ] 0.10 mg/L (AWWA action level)
Free chlorine (in 95% of routine samples per month)
> 0.20 mg/L(Freidman et al 2010)
Total chlorine (chloramines)(in 95% of routine samples per month)
> 0.50 mg/L(Freidman et al 2010)
Trihalomethanes (TTHMs)(based on locational running annual average)
< 0.07 mg/L (0.06 long term) [Freidman et al 2010]
Haloacetic Acids (HAA5s)(based on locational running annual average)
< 0.05 mg/L (0.04 long term)[Freidman et al 2010]
Heterotrophic plate count (HPC) NA-Trends means more than value. Beaver Falls Municipal Authority (BFMA) goal of 20 CFU/ml
Nitrite [<] 0.010 mg/L (AWWA alert level)[<] 0.015 mg/L (AWWA action level)
New Sewickley Township Water Authority 7
New Sewickley Township Water Authority 8
Distribution System Optimization StudyHistorical Data
BFMA starts using chloramines 4th
quarter 2010
New Sewickley Township Water Authority 9
TTHM long term optimization goal
HAA5 long term optimization goal
New Sewickley Township Water Authority 10
TTHM long term optimization goal
HAA5 long term optimization goal
AWA installed
tube settlers
Storage Tank AssessmentData
Tank Cycling Assessment Graphs and Summary Data (May 1-15th 2014):
Freedom Tank
Volume (MG) 1.0
Diameter (ft.) 53
Max Operating Water Depth (ft.)
59
Inlet Diameter (ft.) 1.0
Mixing Performance Ratio (Goal > 1.0)
0.46
Avg. Turnover Time (Goal < 5 days)
11.2
New Sewickley Township Water Authority 11
Tank Cycling Assessment Graphs and Summary Data (May 1-15th 2014):
Highview Circle Tank
Volume (MG) 0.30
Diameter (ft.) 25
Max Operating Water Depth (ft.)
79
Inlet Diameter (ft.) 0.83
Mixing Performance Ratio (Goal > 1.0)
0.44*
Avg. Turnover Time (Goal < 5 days)
6.4
*Mixing performance ratio does not account for the SolarBEE mixer
Storage Tank AssessmentData
New Sewickley Township Water Authority 12
Tank Cycling Assessment Graphs and Summary Data (May 1-15th 2014):
Tri-County Tank
Volume (MG) 0.435
Diameter (ft.) 34
Max Operating Water Depth (ft.)
64
Inlet Diameter (ft.) 0.67
Mixing Performance Ratio (Goal > 1.0)
1.39
Avg. Turnover Time (Goal < 5 days)
3.8
*Mixing performance ratio does not account for the Red Valve passive mixer
Storage Tank AssessmentData
New Sewickley Township Water Authority 13
METHODS:
• Battery-operated submersible purge pump. Calculated flush time
• Sample every 10 ft. in the tank
Storage Tank AssessmentIn-Tank Study
New Sewickley Township Water Authority 14
In-tank Tank Results:• Well mixed and Low residual
Storage Tank AssessmentIn-Tank Study
New Sewickley Township Water Authority 15
0
10
20
30
40
50
60
0 0.05 0.1 0.15 0.2
He
igh
t (f
t)
Concentration (mg/L)
Highview Circle TankHeight (ft) vs. Water Quality
Parameters (mg/L)
Free Chlorine Total Chlorine
Free Ammonia Monochloramine
0
10
20
30
40
50
60
0 0.05 0.1 0.15 0.2
He
igh
t (f
t)
Concentration (mg/L)
Tri-County TankHeight (ft) vs. Water Quality
Parameters (mg/L)
Free Chlorine Total Chlorine
Storage Tank AssessmentIn-Tank Study
New Sewickley Township Water Authority 16
In-tank Nitrite greater than AWWA alert level indicating excess nitrite
0
10
20
30
40
50
60
70
0.000 0.010 0.020 0.030 0.040 0.050 0.060 0.070
He
igh
t (f
t)
Nitrite Concentration (mg/L)
Highview Circle TankHeight (ft) vs. Nitrite(mg/L)
Storage Tank AssessmentIn-Tank Study
New Sewickley Township Water Authority 17
Tank TTHM (mg/L) HAA5 (mg/L) HPC (CFU/mL)
Tri-County Tank 0.0595 0.0015 1
Highview Circle Tank 0.0738 0.0041 340
METHODS:
• Targeted areas of suspected high water age; dead ends, areas of low demand etc.
• Attached hydrant sampler. Estimated flush time to ensure water from the main
• Sampled at least 6 sites
• 3 of the sites chosen were tested for disinfection by-products and heterotrophic plate counts (HPCs)
Distribution AssessmentField
New Sewickley Township Water Authority 18
Site 30.04 ppm Cl222 CFU/ml0.02 NO2
74.7 ppb THMs
Site 20.03 ppm Cl2
0.004 NO2 Entry Point0.49 ppm Cl2
0.039 NO2
Site 50.58 ppm Cl2270 CFU/ml
0.015 ppm NO2
77.0 ppb THMs
Site 60.05 ppm Cl2
0.002 NO2
Site 40.05 ppm Cl2
0.015 NO2
Highview CircleTank0.03 ppm Cl2340 CFU/ml0.006 NO2
73.8 ppb THMs
New Sewickley Township Water Authority 19
Site 30.48 ppm Cl2
Site 20.10 ppm Cl278 CFU/ml
70.9 ppb THMs
Entry Point0.57 ppm Cl2
Site 50.06 ppm Cl2
Site 70.02 ppm Cl2
Site 40.06 ppm Cl220 CFU/ml
64.2 ppb THMs
Tri-County Tank0.17 ppm Cl2
1 CFU/ml59.5 ppb THMs
Site 60.12 ppm Cl2
Site 80.21 ppm Cl2
Site 90.04 ppm Cl2
Liberty Hills Entry Point
0.14 ppm Cl2
Site 110.03 ppm Cl2
New Sewickley Township Water Authority 20
Tank Study Results Distribution Study Results
Harvey Run (Chloramines)
• Relatively uniform water quality
• 0.03-0.07 mg/L total chlorine
• Nitrite ranged from 0.006 (effluent) to 0.021-0.051 mg/L within the tank
• Turnover 6.4 days
• Total chlorine residuals range from 0.03 to 0.58 mg/L
• HPC-ranged from 22-340 CFU/ml
• DBPs- HAA5s not detected. THMs range from 0.073-0.077 mg/L
• Free ammonia ranged from 0.02 to 0.13 mg/L
• Nitrite ranged from 0 to 0.04 mg/L
Tri County (Chlorine)
• Relatively uniform water quality
• 0.13-0.17 mg/L total chlorine
• Turnover 3.8 days
• Total chlorine residuals range from 0.04-0.57 mg/L
• HPC-range from 1 to 78 CFU/mL
• DBPs-HAA5s not detected. THMs ranged from 0.059-0.070 mg/L.
Distribution System Optimization Study
New Sewickley Township Water Authority 21
Follow up and Next Steps
Board approval for equipment upgrades and monthly monitoring in chloraminated section of system
Experimented with valve operations
Looped the area around the Site 4-Freedom HS
Upgraded chlorination pump
Revised flushing operations
. . . So what has happened since last year?
New Sewickley Township Water Authority 22
0.00
0.50
1.00
1.50
2.00
2.50
Summer 2015 Burn Out Cycle-Entry Point
Total Chlorine
Free Chlorine
Monthly data since May 2015 including a burn out
New Sewickley Township Water Authority 23
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Co
nce
ntr
atio
n (
mg/
L)
Time
Monochloramine
Entry Point
Site 2-1130 Hillman St
Site 3-Freedom HS
Site 4-1320 Robinson St
Site 5-1175 9th St
Site 6-Orchard St
Tank
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Co
nce
ntr
atio
n (
mg/
L)
Time
Total Chlorine
Entry Point
Site 2-1130 Hillman St
Site 3-Freedom HS
Site 4-1320 Robinson St
Site 5-1175 9th St
Site 6-Orchard St
Tank
New Sewickley Township Water Authority 24
0
0.02
0.04
0.06
0.08
0.1
0.12
Co
nce
ntr
atio
n (
mg/
L)
Nitrite
Entry Point
Site 2-1130 Hillman St
Site 3-Freedom HS
Site 4-1320 Robinson St
Site 5-1175 9th St
Site 6-Orchard St
Tank
0
0.1
0.2
0.3
0.4
0.5
Co
nce
ntr
atio
n (
mg/
L)Free Ammonia
Entry Point
Site 2-1130 Hillman St
Site 3-Freedom HS
Site 4-1320 Robinson St
Site 5-1175 9th St
Site 6-Orchard St
Tank
NH3 + O2 NO2
(Nitrite)- + 3H+
NO2- + H2O
NO3- (Nitrate) + 2H+
New Sewickley Township Water Authority 25
New Sewickley Township Water Authority 26
Distribution System Optimization StudyReferences and Tools
Distribution System Optimization StudyReferences and Tools
•Nitrification Prevention and Control in Drinking Water. AWWA Manual M56. 2013.
•Partnership for Safe Drinking Water http://www.awwa.org/Portals/0/files/resources/water%20utility%20management/partnership%20safe%20water/files/utilitybenefitsNov12.pdf
•PADEP Distribution System Optimization http://www.portal.state.pa.us/portal/server.pt/community/distribution_system_optimization/21175/distribution_optimization_goals/1588922
•Heterotrophic Plate Counts and Drinking-Water Safety. World Health Organization. 2003. Ed. J. Bartram et al. IWA Publishing. http://www.who.int/water_sanitation_health/dwq/HPCFull.pdf
New Sewickley Township Water Authority 27
Connection Collaboration Communication
Questions and Suggestions