florida dep indirect potable & direct potable reuse presentation 10 sep12

Terry Keep

Florida DEP, September 2012

UV-Oxidation for Direct and Indirect

Potable Reuse

Learning Objectives

• IPR/DPR Drivers

• IPR/DPR economics, business case

• Public Perception/ the Language of IPR/DPR

• History of IPR in California

• Why UV Oxidation/Science of UV Oxidation

• Case Studies: Orange County, CA (IPR) & Big Spring,

TX (DPR)

• Water stress (CA, TX, NM, AZ, Australia, Israel,

Singapore)

• Environmental effects

• Beach closures, coral reef degradation,

• Water Body improvement:

• Coastal: Tourism/beaches, Shell Fish Industry

• Great Lakes: Algal Blooms, beaches, sport fishing

IDP/DPR Drivers

UN Definition:

Water stress occurs when the demand for water exceeds the availableamount during a certain period or when poor quality restricts its use. Waterstress causes deterioration of fresh water resources in terms of quantity(aquifer over-exploitation, dry rivers, etc.) and quality (eutrophication,organic matter pollution, saline intrusion, etc.)

Source: UNEP Freshwater in Europe; glossary

Some Stats:

Canada and the U.S. are the two OECD countries that use the most water.

• USA = 2000 m3/person/year

• CANADA = 1600 m3/person/year

• DENMARK = 200 m3/person/year (Least Consumptive OECD Country)

WATER STRESS

Only about 0.5% of global water is “available” for consumption - all other

water is sea-water or ice.

WATER STRESS

• Growing demand on use of 0.5% of world’s water

due to

– Population growth, 80 MM people per year globally

– Rapidly rising energy demands

• Year 2000*

– 30% of world’s total accessible fresh water was being used

• Future (2025/2030)*

– 70% of world’s total accessible fresh water will be used

– 47% of world population in areas of water stress

* Water, Energy and Security, EESI Congressional Briefing, Dr. Allan R. Hoffman, U.S. Department of Energy, 13 September 2006

WATER STRESS

California

Some of the most populated regions of the state including Los Angeles and San Diego receive the bulk of their water from the Colorado river in the northern part of the state. Crosses St. Andreas fault

• Extreme costs associated with transportation

Texas

Extreme heat and drought conditions causing strain on natural drinking water sources such as water tables and reservoirs

WATER STRESS IN THE U.S.

• Reduce Growth

• Conserve Existing Water Stores

• Develop New Water Sources

• Water Transfer

• Desalination

– Seawater

– Brackish Water

• Non-potable Reuse to Offset DW

• Indirect or Direct Potable Reuse (IPR/DPR)

WATER STRESS: WHAT ARE THE OPTIONS?

FINANCIALS

IPR is cheaper than desalination and recycled non-potable water reuse

• Desal: Higher energy costs

• Purple Pipe: Installing new distribution system

Fermian Business and Economic Institute, 2011

WATER SHORTAGE: WHAT ARE THE OPTIONS?

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Desalination IPR LocalSurfaceWater

WaterTransfer

kW

h/m

3

IPR/DPR = 75% Less Energy than Desalination

IPR/DPR is also less energy

intensive than other water

shortage solutions

IPR is an Attractive Option Both

in Terms of:

1. Costs

2. Energy Use

3. Security (not imported)

City of San Diego report, 2011:

IPR cost includes 10 mile

pipeline to reservoir

ENERGY

Indirect/Direct Potable Reuse: The Business Case

The Business Cases:

• Existing wastewater plant is a

cost to municipality

• Adding more technology &

convert wastewater to a saleable

product and reduce, if not

eliminate, WWTPs operating

costs

11


The Business Cases:

• IPR: Water is returned to aquifer:

no new piping system needed =

low infrastructure cost

• DPR: Water is returned to

distribution system or WTP = no

cost pumping water into aquifer

and pumping it out again.

• Aquifer water quality lower

than treated water

12


• Drinking water quality

affords flexibility in its

usage (not just for golf

courses, lawn watering) i.e.

new building developments

= increase tax revenue

• Sustainable use of limited

resource (new source of

fresh water)

• Lower impact on receiving

waters and wildlife habitat

13

THE PRICE OF UV-OXIDATION

When compared to microfiltration and RO, incorporating UV-oxidation can

be considered a negligible additional expense both in terms of costs and

energy use.

0%

20%

40%

60%

80%

100%

IPR Energy Use

En

erg

y U

se (

% o

f To

tal)

UV-Oxidation

Microfiltration

Other Energy Use

Reverse Osmosis

6.8%

WHAT’S INHIBITING ACCEPTANCE OF IPR/DPR?

Negative public

perception

Many people do not like the idea of their drinking water coming from treated

wastewater even though in many parts of North America it is happening

unintentionally

• Great Lakes

• Major Rivers (Mississippi, Ohio)

The words used to describe IPR are often perceived as “unclean” and

unattractive leading to negative opinions.

• “Waste”water

• “Re”cyled water and “Re”used water

Greater acceptance for “purified” water

DOES WORDING AFFECT OPINION?

“purified”

PUBLIC SUPPORT FOR IPR INCREASES WITH EDUCATION

San Diego County Water Authority: 2011 Public Opinion Poll Report, Rea & Parker 2011

WATER REUSE: WORLD PROGRESS

• Israel reuses over 70% of its WW

• Singapore reuses 15% with plans to double that by end of 2011

• Australia reuses 8%, has a national goal of 30% by 2015

• USA reuses 5-6% of WW for non-potable and potable purposed and this number continues to grow.

Source: Guy Carpenter. WateReuse Association 2010

CALIFORNIA WATER REUSE REGULATIONS

• The state of California is currently

drafting the only law abiding

regulations related to the

application of non-potable reuse

for drinking water augmentation in

North America.

• These regulations primarily

monitor treated wastewater used

for groundwater replenishment.

CALIFORNIA WATER REUSE REGULATIONS

These regulations are part of the California Code of Regulations (CCR):

Title 22

Division 4 – Environmental Health

Chapter 3 – Recycling Criteria

Article 5.1 – IPR for Groundwater Replenishment-Surface Applications

Article 5.2 – IPR for Groundwater Replenishment – Subsurface Applications

U.S. WATER REUSE REGULATIONS - HISTORY

1978 • First groundwater replenishment regulations introduced to Title 22 in California

• Regulations have been evolving for over 30 years

• First groundwater regulations dealt with surface water spread

1989 • Regulations were re-done to incorporate direct groundwater injection

U.S. WATER REUSE REGULATIONS - HISTORY

2001-2002 • Regulations to total organic carbon (TOC) levels and

organic treatment modified due to the emergence of

NDMA and 1,4 Dioxane as contaminants of concern

2002-Present • Regulations continually being updated to reflect

contaminants of emerging concern

Present • Ground water recharge projects must incorporate

advanced oxidation treatment after secondary

wastewater treatment for direct groundwater injection

projects

CCR TITLE 22 – KEY POINTS

Advanced Oxidation (AO)

Definition: Taking secondary treated wastewater and applying reverse

osmosis (RO) and oxidative treatment processes for the further removal or

microorganisms, total organic carbon (TOC), salts and other contaminant

molecules

This is a mandatory treatment step for groundwater replenishment projects

which use direct groundwater injection.

It is also highly recommended for groundwater replenishment projects

through surface water spreading.

CCR TITLE 22 – KEY POINTS

The Treatment Goals of Advanced Oxidation Include but are not Limited to:

• < 10 ng/L NDMA

• 0.5 log reduction of 1,4-Dioxane

• <0.5 mg/L Total Organic Carbon

• 99.5% rejection of salts

Pathogen Removal (Groundwater Injection and Surface Water Spread)

• 12 log enteric virus reduction

• 10 log Giardia cyst reduction

• 10 log Cryptosporidium oocyte reduction

REAL WORLD ADVANCED OXIDATION

AO requires at least three different treatment processes (in addition to secondary wastewater treatment).

Example: The Orange County Water District uses the following three treatment steps for groundwater injection.

1. Microfiltration

2. Reverse Osmosis

3. UV-Oxidation

Microfiltration

Removes 50% or organic material and effectively removes bacteria, protozoa, parasites and viruses

Prevents downstream fouling of reverse osmosis membranes improving their functional lifetime

REAL WORLD ADVANCED OXIDATION

Reverse Osmosis

Removes molecules as small as 100 atomic mass units and 95% of organic contaminants.

Required for advanced treatment according to Title 22

Removal portion of treatment train

UV-Oxidation

Provides an additional barrier for disinfection

Removes molecular contaminants that escape microfiltration and RO through a combination of UV energy and oxidation.

Destruction portion of treatment

WHY UV-OXIDATION

It has been documented that molecules less than 100 atomic mass units in

size and those with high hydrophobicity can pass through microfiltration and

RO without being treated

Contaminants with these characteristics include:

NDMA 1,4-Dioxane

Bisphenol-A Carbamazepine

DEET Estradiol

Ibuprofen Acetaminophen

Clofibric acid Diclofenac

Meprobamate

Triclosan

Oxybenzone

* Poussade, Y; A. Roux, T. Walker and V. Zavlanos. Advanced Oxidation for Indirect Potable Reuse – A Practical Application in Australia. Presented at OzWater 2009.

NDMA – MEASURED POST RO AT BUNDAMBA*

THE ROLE OF UV-OXIDATION

Molecules which elude filtration are eliminated by UV-oxidation through

the combined action of two (2) independent degrading processes.

1. Direct UV-Photolysis

2. UV-Oxidation

O2

UV light is absorbed by the pollutant P:

Degradation rate depends on:

• Quantum yield of P, Φλ

• Molar absorption coefficients of P in the UV range, ελ

• Intensity and spectral distribution of the light source

• Absorption of water background

ProductsPhn (energy)

[radical species]

1. DIRECT UV-PHOTOLYSIS

1. DIRECT UV-PHOTOLYSIS

Chemical bonds arebroken by UV light

UV light is absorbed by hydrogen peroxide:

Degradation rate depends on:

• OH radical rate constant kOH,P

• H2O2 concentration

• Intensity and spectral distribution of the light source

• Absorption of water background

• OH radical water background demand

Products

H2O2

hn (energy)2 •OH

P + •OHkOH,P

[radical species]O2

2. UV-OXIDATION

2. UV-OXIDATION

Hydrogen peroxide

Hydroxylradical

Chemical bonds arebroken by hydroxyl radicals

THE ROLE OF UV-OXIDATION

Some contaminants that escape RO cannot be removed through oxidation

and can only be eliminated through UV-light (photo-chemically labile)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

1,4-Dioxane NDMA Atrazine Geosmin

UV

-Ph

oto

lys

is/U

V-O

xid

ati

on

Co

ntr

ibu

tio

n t

o T

ota

l

Co

nta

min

an

t R

ed

ucti

on

(R

ela

tiv

e t

o A

tra

zin

e)

UV + 10 ppm H2O2

Photolysis

THE ROLE OF UV-OXIDATION – FOCUS ON NDMA

The EPA Integrated Risk Information System (IRIS) classifies NDMA as a class B2 (probable) human carcinogen

• One in a million cancer risk = 0.7 ppt

NDMA was one of the monitored contaminants from the Unregulated Contaminant Monitoring Rule 2 (EPA, 2006)

• See Below

EPA’s Third Regulatory Determination (expected in 2013) considering NDMA regulations.

• Compliance would be expected 2015-1016

TOXOCOLOGY DATA


NDMA PREVALENCE

EPA evaluated nationwide NDMA between 2008-2010

25% of tested facilities had NDMA concentrations over 2 ppt

• 1 in 1,000,000 cancer risk = 0.7 ppt

• California Reporting Concentration = 10 ppt

In Texas, 56% of 81 systems had NDMA concentrations above 2 ppt

In California, 46% of 145 systems had NDMA concentrations above 2 ppt


Due to NDMA’s resistance to chemical oxidation, alternate oxidation based

treatment technologies are not as effective as UV-Oxidation (photo-chemically

labile).

Pisarenko, A.N., et al., 2011. In Press

NDMA – TREATED AT BUNDAMBA (RO Effluent)

* Poussade, Y; A. Roux, T. Walker and V. Zavlanos. Advanced Oxidation for Indirect Potable Reuse – A Practical Application in Australia. Presented at OzWater 2009.

CASE STUDIES

GWR INSTALLATION - ORANGE COUNTY, CALIFORNIA

• 70 MGD (100 MGD peak)

California facility treating

wastewater to drinking water

standards for groundwater

replenishment

• Water is injected (to protect

from seawater) and percolated

(to replenish) into the aquifer

• MF/RO/UV-Oxidation treatment

train (UV system uses

monochromatic amalgam

lamps)

• System Expansion in progress

Orange County’s Water Factory 21

pioneered the use of UV-oxidation.

GWR INSTALLATION - ORANGE COUNTY, CALIFORNIA

NDMA FULL SCALE TESTING - ORANGE COUNTY, CA

0

10

20

30

40

50

60

70

80

1 2 3 4 5 6 7

Run #

[ND

MA

], p

pt

[NDMA], Inf

[NDMA], Eff

6 Reactors On

Flow: >8.5 MGD

4 Reactors On

DISINFECTION TESTING - ORANGE COUNTY, CA

Influent MS2Effluent MS2

0.000

1.000

2.000

3.000

4.000

5.000

6.000L

og

(p

fu/m

L)

MS

2

• 12.5 MGD California facility

also treating wastewater to

drinking water standards for

groundwater replenishment

• MF/RO/UV-Oxidation

treatment train (UV system

uses monochromatic

amalgam lamps)

• 1.3-log reduction of NDMA,

disinfection

GWR INSTALLATION – WEST BASIN MUNICIPAL WATER

DISTRICT, CA

West Basin Municipal Water District

NDMA FULL SCALE TESTING – WEST BASIN, CA

0

20

40

60

80

100

120

140

Influent NDMA Effluent NDMA

ND

MA

Co

ncen

trati

on

(ng

/L)

UV-Oxidation for Potable Reuse

Case Study - Big Spring, Texas

• Located approximately 300 miles west

of Dallas

• Population: 27,000

• Traditional Raw Water Sources:

– E.V. Spence Reservoir (Surface

Water)

• Surrounding Cities/Towns:

– Odessa

– Stanton

– Midland

Big Spring


• Drinking water supply is managed by the Colorado River

Municipal Water District (CRMWD)

• In 2004, the CRMWD evaluated methods of augmenting or increasing

drinking water availability to support growth and provide protection

against the potential of supply shortages due to drought conditions.

• Three approaches were considered:

1. Obtaining Raw Water from Other Groundwater and Surface Water

Sources

2. Reusing Water for Non Potable Uses

– Golf Course Irrigation, Agriculture

3. Reusing Water as Potable Water


Obtaining Raw Water from Alternative Sources:

• Local groundwater supplies are limited and aquifers are

not readily recharged

• Other surface water sources were too far and would

require extensive transportation

• Other surface waters could suffer decreased availability

due to drought conditions


SOLUTION – Potable Reuse (Direct Raw Water Blending)

• CRMWD decided to build a single treatment plant that would treat

secondary wastewater from surrounding communities to an “advanced”

level

• Known as the “Raw Water Production Facility” (RWPF)

• The RWPF will generate “synthesized” raw water that will be added to

the “natural” surface raw water of the E.V. Spence Reservoir

• The synthesized raw water adds to the capacity of the reservoir and

preserves its supply of source water to the drinking water treatment

plants of Big Spring as well as the surrounding communities


Reusing Waste Water for Non Potable Reuse:

• This approach would offset drinking water demand

• Water users were widely dispersed which would require

construction of an extensive distribution system

• Demand was also very seasonal and did not provide a

“year-round” solution


Big Spring Reclamation Project

Source: Freese and Nicholls


RWPF Details

• Advanced Treatment:

MF/RO/UV-oxidation

• UV-oxidation :

– Treatment of NDMA and

1,4-Dioxane

– Pharmaceuticals and

endocrine-disrupting

chemicals not removed

by MF or RO

– Additional disinfection

barrier

Raw Water Production Facility Design Parameters

Design Flow: 1.8 MGD

Target Contaminants:NDMA 1,4-Dioxane

Design NDMA Reduction: 1.2 - Log

Design 1,4-Dioxane: 0.5 - Log

Oxidant: H2O2

Disinfection Method: UV Light


The Trojan Solution

• Trojan Supplied two (2)

TrojanUVPhox™ UV

chambers along with an H2O2

dosing system for the new

RWPF in Big Spring

• Construction is currently in

progress with commissioning

expected in Spring 2013

Testimonial

“The Trojan system offered a cost-effective additional layer of protection against a

number of water quality concerns, with removal/inactivation mechanisms distinct from

the membrane separation processes upstream”

David Sloan – Senior Water Engineer

SUMMARY

• State of California has been regulating IPR and groundwater

recharge installations for over 30 years.

• New regulations state that advanced treatment of wastewater

required both RO and an oxidation treatment step.

• Oxidation step removes molecules that are able to pass through RO

membranes

SUMMARY

• UV-Oxidation treats contaminants through both chemical oxidation and

direct photolysis

• UV-Oxidation (UV-photolysis) the only effective treatment against

emerging contaminants of concern such as NDMA

• After incorporating the required RO treatment and the highly

recommended upstream microfiltration treatment, the additional costs

associated with UV-Oxidation are minimal

florida dep indirect potable & direct potable reuse presentation 10 sep12

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