City of Columbus Division of WaterHap Cremean Water Plant UV Disinfection Project

OAWWA 78th Annual ConferenceCincinnati, OHSeptember 15th, 2016

UV Technology as a Cost Effective Secondary Barrier for Cryptosporidiumand Other Pathogens

Acknowledgements

• Operation and Maintenance Staff• Administrators

City of Columbus, Division of Water

• Michael McWhirter & Kwasi Amoah, MWH, now part of Stantec• James Collins & Stephane Jousset, ARCADIS

HCWP Design Team

• Chris Schultz and Trent Branson, CDM Smith• Paul Swaim, CH2M

DRWP Design Team

Agenda

1 UV Treatment Process Selection

2 Facility Backgrounds

3 Location Selection

4 Design Flow

5 Technology Selection

6 Design UVT

UV Treatment Process Selection

1

Ongoing monitoring indicates presence of Cryptosporidium.

HCWP SOURCE WATER (Oocysts/L)

GENOTYPINGDETECTION ONLY

0.038 – Bin 1

0.028 – Bin 1

CURRENT PROJECTION FOR ROUND 2 SAMPLING

AVERAGE OF ALL DATA (SINCE DETECTIONS BEGAN)

.015 – Bin 1

.049 – Bin 1

Conventional treatment meets disinfection and removal requirements.

The City of Columbus is installing a secondary barrier at their plants.

LT2ESWTR…future?

Backup for

turbidity

Safeguard to public health

Secondary Barrier

Monitoring

Sampling

Reporting

Future Considerations for Cryptosporidium –more to come?

Alternative Methods used for Cryptosporidium Removal.

Process $ Physical vs. Chemical

Advanced Oxidation Processes (AOP)

10x Chemical

Ozone 5-10x Chemical

Reverse Osmosis (RO)

20-40x Physical

UV Disinfection 1x Physical

UV Disinfection is an inactivation process.

- DNA transformation

- Germicidal range

UV Disinfection is effective against an array of pathogenic organisms.

• Cryptosporidium and Giardia• Bacteria (Legionella, Escherichia coli, etc.)• Viruses (Influenza, Hepatitis B Virus, Adenovirus, etc.)• Mold Spores (Manure Fungi, etc.)• Algae (Green Algae, Protozoa, etc.)Source: Water Research Center “Drinking Water Treatment with UV Irradiation”http://www.water-research.net/index.php/water-treatment/water-disinfection/uv-disinfection

Official OEPA credit can be achieved with UV Disinfection.

OAC 3745-81-68 • Microbial toolbox options for

meeting Cryptosporidium treatment requirements.

Facility Backgrounds2

Columbus has three drinking water plants.

There are two ongoing UV Disinfection projects in Columbus.

Parallel Pre-Design and UV

Equipment Pre-Selection

Both Dublin Road and Hap

Cremean

Currently in Detailed Design

MWH is designing HCWP UV Disinfection.

Hap Cremean is a conventional surface water treatment plant… and so much more!

Location Selection2

Three potential locations were evaluated for UV.

Location Evaluated?

Combined Filter Effluent (New Building)

Individual Filter Effluent (Filter Galleries)

Downstream of the Clearwell

Unfiltered Application ×

Groundwater Application* ×

Uncovered Reservoir Application* ×*Not Applicable at HCWP

Each location was evaluated based on four parameters.

Hap Cremean installing UV in the filter gallery. Dublin Road constructing a new UV facility.

Design Flow3

The UVDGM flow requirements through filter galleries and other locations.

Location Flow Requirement

Combined Filter Effluent (New Building)

Combined rated capacity of all duty filters

Individual Filter Effluent (Filter Galleries)

Rated design flow for individual filter

Downstream of the Clearwell Rated capacity of the HSP station

The potential future flow rate was used for design.

•3.2 gpm/sf (6.5 MGD per filter)Current Filter Rating

•Up to 70 MGD•11 filters available with 1 in backwash (6.4 MGD)

Maintain Flexibility for Half Plant Operation

•5.4 MGD (23 filters online)•6.3 MGD (20 filter online)

125 MGD During Construction

•4 gpm/sf (8.1 MGD per filter)•Possible under a range of conditionsFuture Filter Rating

Technology Selection4

Medium pressure (MP) and low pressure – high output (LPHO) technologies were evaluated.

Power Output

Number of Lamps

Lamp Life

Labor Requirements

MP LPHO

Both technologies were allowed to bid at HCWP.Parameter MP LPHO

Demonstrated UV Technology

O&M Requirements

Headloss Implications

Mercurial Content

Potential Auxiliary Benefits

Operational Flexibility

Cost Evaluation

Environmental Considerations

Design UVT5

What is UVT? -DEMONSTRATION

Historical data recommended a design UVT of 90.0 %/cm.

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

UV

T (

%)

Cumulative Frequency

2000-20142010-2014

95%

99%

Data was collected through preliminary design to confirm design UVT.

Ozone has given a 3.0-4.0 %/cm boost in UVT.

80

82

84

86

88

90

92

94

96

98

100

Indi

viud

al F

ilter

Effl

uent

Onl

ine

UVT

(%

)

Online Analyzer Data

Grab Sample Data

Ozone off line

There are many reasons why UV is a great choice for PWSs.

Protects public health Inexpensive

Easy to operate and maintain

Easy method to meet additional

disinfection requirements.

Questions?Contacts:

C.R. Weaver: (614)645-7100 or CRWeaver@columbus.govSarah E. Hayes: (614)324-2224 or sarah.hayes@mwhglobal.com