Maria Meyer P.E.

Treatment Supervisor

Richard Miller Treatment Plant

Greater Cincinnati Water Works Service Area

Where is Our Water Coming From?

• About 84% of the water comes from the Ohio River.

– Treated at the Richard Miller Treatment Plant.

• The remaining water comes from the Great Miami Aquifer.

– The groundwater is treater at the Charles M. Bolton Plant.

Industrial Ohio River – Barge Traffic

Contaminant Discharges Into the Ohio River

Spills Upstream from Plant Intake

Other Challenges - Runoff, Cyanobacteria

Groups of Chemical Contaminants Found in Source Waters

• Natural Organic Matter

• Pharmaceuticals

• Personal Care Products

• Synthetic/Volatile Organic Chemicals

• Herbicides, Pesticides

• Endocrine Disruptive Compounds (EDCs)

• Cyanotoxins

• Generally, their concentrations in the Ohio River are low.

• The river water gets screened by chemists multiple times around the clock for certain/regulated organic contaminants.

Best Available Technology for Removal of Organic Chemicals

• Activated Carbon

• Complex pore structure

• Adsorbs most chemicals

• Granular and Powder

• Granular Activated Carbon (GAC) can be reactivated (reused)

GCWW: GAC Research (1978 – 1990)

GAC Facility In Service Since 1992

GAC Process At The Richard Miller Plant

Solids Removal - Clarification Organics

Removal Disinfection

Fluoridation

GAC

Full-Scale GAC Contactors

12 Contactors

65 ft. x 30 ft. 1950 ft2

11.5 ft. of carbon

EBCT 15 min.

Flow Rate 7.1gpm/ft2

GAC Performance: Total Organic Carbon (TOC) Removal

Jan Feb Mar AprMay

JunJul

AugSep

OctNov

Dec

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

TO

C m

g/L

Ohio River

Coag/Sed

Sand Filter Effluent

GAC Effluent

GAC Contactors: TOC Breakthrough Curves

Benefit of GAC on Trihalomethane (THM) Precursor Removal

Benefit of GAC on Haloacetic Acid (HAA) Precursor Removal

Atrazine Removal by GAC AWWA Atrazine Study

GCWW Data 2003

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

3/19 4/2 4/16 4/30 5/14 5/28 6/11 6/25 7/9 7/23 8/6 8/20 9/3 9/17

pp

b

RAW Sand Filter Eff. GAC Eff. MCL

MCL

2003 AWWA Study

Removal of Various Synthetic & Natural Organic Chemicals

Source: USEPA/USGS Study 2007

Removal of Chemical Contaminants Found in Ohio River

• Annual screening of 96 chemicals (Pharmaceuticals, EDCs, Herbicides, Pesticides etc.) in the river and the processed water after GAC.

• The GAC consistently removes the Synthetic Organic Contaminants.

Research on Emerging Contaminants

• Research in-house for emerging contaminants.

• In-house Rapid Small Scale Column Test (RSSCT) capability.

• In-house pilot-scale GAC columns.

• Participation in several research projects for removal of contaminants.

• Jar tests for PAC effectiveness.

Research on Removal of Pharmaceuticals and EDCs by GAC

• Pilot study 10% breakthrough, EBCT 15 min

Source: S.Summers et al, WRF # 4235

Additional Benefits of GAC at RMTP

• Removal of tastes and odors from the water.

• Provides an additional step of turbidity removal (water clarification).

• Improves the UV transmittance of the water and helps the downstream Ultraviolet Disinfection process.

• The water processed through the GAC requires less chlorine for disinfection.

• Improved control of the GAC performance during seasonal events and spills, due to the in-house GAC reactivation.

Summary

• The GAC provides GCWW protection from spills and SOCs while providing reduction in Disinfection Byproducts.

• The drinking water is tested daily for several contaminants to ensure its safety and compliance with regulations.

• Ability to research and enhance the removal of emerging contaminants with a multi-barrier approach.

• GAC greatly improves our customers’ perception of our water quality.