reuse regulation roundup: the standards for reuse€¦ · • reclaimed and purified wastewater...

Reuse Regulation Roundup: The Standards for Reuse Melanie Holmer, P.E. Water Reuse Leader

• Introduction • Types of water reuse • Standards for reuse • Reuse regulatory outlook

Agenda

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Drivers for water reuse: • extreme weather (drought) • nutrient/permit limits • seawater intrusion • industrial water supply • agricultural water supply • Water supply diversity • Water supply reliability • NEED MORE WATER!

Reuse – it’s not just for golf courses anymore

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Increasing reliability,

resiliency and diversity in the

water supply portfolio

Uses that are not intended for eventual human consumption.

Non-potable reuse

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• Reclaimed and purified wastewater that is intended for human consumption.

• Potable reuse can be: • Indirect. • Direct.

Potable reuse

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The

cont

inuu

m o

f Pot

able

Reu

se

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7

Groundwater Augmentation

Reservoir Water Augmentation

Raw Water Augmentation

Treated Water Augmentation

WateReuse

Indirect Potable Reuse

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Source: www.wrd.org

Purified water

Disinfection/ Treatment

Distribution to customers

Tertiary or Purified Effluent

Groundwater augmentation

Drinking WTP

Purified water

Distribution to customers

This Photo by Unknown Author is licensed under CC BY-SA

Reservoir water augmentation

Indirect Potable Reuse

Direct Potable Reuse

Drinking WTP

Purified water

Distribution to customers

This Photo by Unknown Author is licensed under CC BY-SA

Raw water augmentation

Direct Potable Reuse

Drinking WTP

Purified water

Distribution to customers

This Photo by Unknown Author is licensed under CC BY-SA

Treated water augmentation

What’s the underlying logic behind reuse treatment and distribution regulations?

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• Acute risk is the primary target. Seek to protect against exposure from outbreaks.

• Chronic risk is also important, but not viewed as significant. More emphasis in potable reuse applications. • Regulated organic and inorganic species.

• “No degradation” of GW quality is a common, but not universal, third goal.

Goals for Reuse Regulations

• Start with well-treated secondary wastewater effluent

• EPA-suggested guidelines: • pH = 6-9 • BOD5 ≤ 10 mg/L • Turbidity ≤ 2 NTU • Escherichia coli = NONE • Residual Cl2 ≥ 1 mg/L

A National Guideline on Wastewater Plant Secondary Effluent Quality for Reclamation

• There are no federal reuse regulations

• EPA has relied on framework of the CWA and SDWA and reuse guidelines

• Reuse is implemented state-by-state; rules are set to be protective of end use

The 2017 EPA Potable Reuse Compendium informs current practice on potable reuse: • Regulatory summary • Current practices • Case Studies • Indirect Potable Reuse • Direct Potable Reuse

EPA Guidelines

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Treatment Goals

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Secondary

Primary

Advanced Treatment

Disinfection

Filtration

Coag/Floc/Settling

Disinfection

Source Control

Pathogen reduction

Remove particles to allow for efficient

disinfection Groundwater Recharge Reservoir Water Augmentation

Pathogen reduction and chemical

contaminant removal

“Full Advanced Treatment” Train

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Secondary

treatment

Advanced

oxidation

Pre- Treatmen

t Equalization MF/

UF Reverse Osmosis

15-20% 5-10%

FAT = RO + AOP

The Urban Water Cycle

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River, GW, Reservoir Drinking

WTP / Disinfectio

n

Community

WWTP / Reclamation

To river, ocean, land

Non-potable uses

AWPF

GW aquifer

Reservoir

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River, GW, Reservoir Drinking

WTP / Disinfectio

n

Community

WWTP / Reclamation

SDWA LT2ESWTR

SDWA Lead and Copper Rule

Local Ordinances

CWA (NPDES) To river, ocean, land

Non-potable uses

AWPF

GW aquifer

Reservoir

State Regs

(Anti-degradation)

State Regs

State Regs

State Regs

State Regs

Local Ordinances

Potable Reuse Framework/Regulations

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Non-potable regulations

IPR regulations and policy

DPR reg framework DPR regs / case by case

No reuse regulations, or case by case

Updated based on: 2012 EPA Guidelines for Water Reuse 2017 EPA Potable Reuse Compendium

Studying DPR

Trends • Water quality and/or technology-based requirements in regulations

• Increased agency partnering to develop reuse projects, sometimes on a regional basis

• Shifting public perception of potable reuse towards acceptance

• Advances in RO technology

What’s Next?

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Questions? Melanie Holmer mholmer@brwncald.com