Indirect Potable Reuse and Groundwater Injection in the U.S.

Erik Rosenfeldt, Ph.D., P.E.

2015 Education Seminar: Bringing Game Changing Innovation Home to VirginiaApril 29-30, 2015 | Westin Hotel in Richmond, VA

Agenda

• Introduction

• Drivers Behind Potable Reuse

• A quick tour of Reuse in the United States

• Challenges in the Near and Far Future

• Regulatory Structure

• Can we trust the technology?

• Can we trust the operations?

What is Water Reuse/Recycling?

Non-Potable• Irrigation—Golf, Residential, etc.• Cooling Towers, Boiler Feed• Wetland Restoration

Potable• Indirect

• Seawater Intrusion Barrier• Groundwater Replenishment• Aquifer Storage/Recovery• Reservoir Augmentation

• Direct• Pipe-to-Pipe

Water Quality Risks Stem from Source

Potential Risks to Water Supplies are often similar

Risks Pristine Surface Waters

Groundwater Sources

Wastewater Reuse Polluted Surface Waters

Pathogens

Disinfection Byproducts

Secondary Standards

Metals

Industrial Contaminants

EDCs and PPCPs

Emerging Contaminants

De Facto Reuse occurring anyhow

Drivers for Water Reuse

People Are Moving to Water-Stressed Areas

Source: www.sandia.gov

Population Growth is 20% to 50%

in Most Water-Stressed Areas

US population will increase

significantly (double over 100 years)

By 2030, 47% of world population will

be living in areas of high water stress

Need to find water for an equivalent of

the population of San Diego per year

What are the Drivers for Water Reuse?

• Opportunity to Sell Recycled Water Product

• Energy Conservation / Resource Recovery

• Wastewater Disposal / Nutrient Management

• Minimizing Potable Demand

• Delay Potable Water Infrastructure Expansion

• Lack of Adequate Water Supply

• Seawater Intrusion Barriers

• Groundwater Replenishment

• Legislated Conservation/Reuse

• Maintaining Environmental Flows/

Parks/Wetlands

California: Relative Costs of Water Reuse Can Be Cost Competitive

California: Water Reuse Can Be Energy Competitive

Potable Reuse in California

• Long history of indirect potable reuse.

• Significant goals to expand

South Florida Drivers

Regional Water Availability Rule (Demand Not Met)

Ocean Outfall Rule

60% Reuse Requirement(160 mgd of reuse needed)

Georgia Drivers

Land Subsidence

Virginia

The aquifer system in the region has been compacted by

extensive groundwater pumping in the region at rates of 1.5- to

3.7-mm/yr; this compaction accounts for more than half of

observed land subsidence in the region.

California

Examples of Planned Reuse Systems in the US

Early Potable Reuse

• Chanute, Kansas, 1956 Emergency

• Secondary WW, 17-day holding pond

• 5 Months of DPR, 100% Recycle 8 – 15 x

• Denver Water Demonstration, 1985-1992

• Evaluated Secondary WW:• High-pH lime

clarification/recarbonation/filtration/UV/ GAC /RO/ aeration/ozonation/chloramination

• High-pH lime clarification/recarbonation/filtration/UV/ GAC /UF/ aeration/ozonation/chloramination

• Health studies NO adverse outcomes

• OCWD built Water Factory 21 in 1975. First useof RO to recycle water for seawater injection barrier 15 MGD.• (2 years earlier than first membrane seawater

RO)

• 1991- California Dept of Health granted first permit to inject 100% recycled water without blending.

• 25 years of business as usual

Water Factory 21 (1975 – 2004)

Orange County Water District – Groundwater Replenishment

• Pop. 2.5 million

• Annual rainfall < 12 inches

• Groundwater basin lowered fromover extraction by 1920s.

• Reliance on Colorado River and Northern California

• 40% Surface Water

• 60% Groundwater

• By 1950s, over extraction of groundwater had led to seawater intrusion contamination of deep water aquifers.

Advanced Treatment for

Groundwater Replenishment

Advanced Purification Process – Membrane-Based Treatment

“Tastes like water, because it is water”

SE Florida Searches for Reuse Opportunities

ParameterHollywood

(mg/L)

Biscayne

(mg/L)

Floridan

(mg/L)

Sodium ≈640 ≈20 ≈1,100

Chloride ≈1,400 ≈140 ≈2,100

TDS ≈3,500 ≈300 ≈4,500

Unique hydrogeology facilitatesan alternative approach

Opportunity for a revised recharge treatment approach

Reverse Osmosis WTP

AOP

Secondary

or Tertiary

Effluent

Backwash Waste

Reverse Osmosis

Concentrate

Microfiltration

Floridan

Aquifer

Recharge

Treatment designed specifically for emerging contaminants

Texas Cities: Direct Potable Reuse

IPR in Virginia

• Potomac Region (Unplanned and Planned IPR examples)

Challenges Remaining for Potable Reuse

What’s the Greatest Risk in Recycled Water?

• True Risks

• Pathogens

• ALL Regulated Contaminants

• Industrial Contaminants

• Operations

• Perception Risks

• “Emerging Contaminants”

• Notice of Violation

• Aesthetics

Inconsistent Regulatory Approaches

California Title 22 (Potable)• 12-log Virus removal (99.9999999999%)

• 10-log Giardia and Crypto removal

• Sum of all treatment processes

Plus

• 1,4-dioxane and NDMA removal to non-detect

• Removal of contaminants of emerging concern (CECs) base on chemistry, reactivity

Georgia Reuse Regulations• Three Overarching Themes:

• Managed risks and safeguards adequately provided for IPR

• Concept of IPR is based on sound technology and processes

• Growing public acceptance of emerging technology used to assure the safety of IPR

• Concepts of the methods• Requires “Environmental” or “Engineered”

buffer• Required blending according to 7Q10 flows• Treatment technologies considering both

WW and DW treatment

• “Points” provided for treatment barriers

• OK, TX, NC, VA have different approaches

Ensuring Safety of Potable Water?

• Sure technology is capable, but questions remain…

Multi-Barrier Approaches for Potable Reuse Projects (www.waterreuseguidelines.org)

DPR- Raising the Stakes

Can We Trust the

Technology?

Can We Trust

Operations?

Trust but Verify

Convincing a

Skeptical Public

Convincing

Regulators

WRRF-13-03:

Critical Control Point Assessment to Quantify Robustness and Reliability of Multiple Treatment Barriers of a DPR Scheme

Can We Trust the

Technology?

What Does the CCP Approach Provide?

Review and Manage Risks to Protect Public Health

What are the

risks?

Holistic Review/robust methodology – source water to distribution

What are the

right

technologies?

How are we

sure they are

working?

How do we

respond if a

barrier fails?

Contaminants/

Hazardous Events

Treatment

BarriersMonitoring

Operating

Response

Focus is on health relevant contaminants.

WRRF-13-13:

Development of Operation and Maintenance Plan and Training and Certification Framework for Direct Potable Reuse (DPR) Systems

Can We Trust the

Operations?

Where to I Find Trained Reuse Operators?

A gap in training and certification for reuse...

Weekly Alarm Count

0

100

200

300

400

500

600

700

800

900

1000

10/5/09 -

16/05/09

18/5//09 -

25/5/09

25/5/09 - 1/6/09 1/6/09 - 7/6/09 8/6/09 - 15/6/09 15/06/09 -

22/06/09

22/6/09 - 29/6/09 29/6/09 - 5/7/09 6/7/09 - 13/7/09

Week

Ala

rm

s p

er D

ay (

Weekly

Avg

)

Alarms per day Avg Bundamba 1A

Alarms per day Avg Bundamba 1B

Plant 1

Plant 2

Summary

• Potable Water Reuse is NOT a new concept

• De facto reuse widely practiced in the US

• Diverse drivers for each region

• Intentional IPR and DPR is becoming more common

• Multiple technology options• Membrane-based advanced treatment = MF-RO-UV/AOP• Alternative advanced treatment includes ozone, BAC/GAC, IX, and other

processes

• Several Important Challenges Remain• Risk analysis and operation/response plans needed• Regulatory Approaches?• Public Safety Protection of the utmost importance• Public education and outreach is critical

Collaborators

• Hazen and Sawyer Water Reuse Practice Group

• Ben Stanford, Pat Davis, Kevin Alexander, Anni Luck, Troy Walker, Enrique Vadiveloo

• Many more…

• Hazen and Sawyer Applied Research Group

• Ben Stanford, Bill Becker, Wendell Khunjar, Nicole Blute, Troy Walker, Allison Reinert, Grace Johns, Ben Wright

Questions?

erosenfeldt@hazenandsawyer.com