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


Map courtesy of Wikipedia New Sewickley Township, Beaver County, Pennsylvania

Distribution System Optimization StudyTwo separate systems with different water quality optimization issues:


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



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


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)



Distribution System Optimization StudyHistorical Data

BFMA starts using chloramines 4th

quarter 2010


TTHM long term optimization goal

HAA5 long term optimization goal


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



Highview Circle Tank

Volume (MG) 0.30

Diameter (ft.) 25


79



0.44*


6.4

*Mixing performance ratio does not account for the SolarBEE mixer




Tri-County Tank

Volume (MG) 0.435

Diameter (ft.) 34


64



1.39


3.8

*Mixing performance ratio does not account for the Red Valve passive mixer



METHODS:

• Battery-operated submersible purge pump. Calculated flush time

• Sample every 10 ft. in the tank

Storage Tank AssessmentIn-Tank Study


In-tank Tank Results:• Well mixed and Low residual



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



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)



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


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


Site 30.48 ppm Cl2


70.9 ppb THMs

Entry Point0.57 ppm Cl2

Site 50.06 ppm Cl2

Site 70.02 ppm Cl2


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


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.



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?


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


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 3-Freedom HS


Site 5-1175 9th St

Site 6-Orchard St

Tank


0

0.02

0.04

0.06

0.08

0.1

0.12

Co

nce

ntr

atio

n (

mg/

L)

Nitrite

Entry Point


Site 3-Freedom HS


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 3-Freedom HS


Site 5-1175 9th St

Site 6-Orchard St

Tank

NH3 + O2 NO2

(Nitrite)- + 3H+

NO2- + H2O

NO3- (Nitrate) + 2H+



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


http://www.awwa.org/Portals/0/files/resources/water utility management/partnership safe water/files/utilitybenefitsNov12.pdf

http://www.portal.state.pa.us/portal/server.pt/community/distribution_system_optimization/21175/distribution_optimization_goals/1588922

http://www.who.int/water_sanitation_health/dwq/HPCFull.pdf

Connection Collaboration Communication

Questions and Suggestions

Free Chlorine and Chloramine Distribution Optimization in ...Free Chlorine and Chloramine...

Documents

Transcript of Free Chlorine and Chloramine Distribution Optimization in ...Free Chlorine and Chloramine...