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Microconstituents: Science, Regulation and Implication

PNCWA Annual ConferenceOctober 26, 2010

Presented byDan Cutugno

PBS Engineering + EnvironmentalPortland OR

Microconstituents DefinedWater Environment Federation definition

“…natural and manmade substances, including elements and inorganic and organic chemicals, detected within water and the environment for which continued assessment of the potential impact on human health and the environment is a prudent course of action”

Also referred to as “Micropollutants”

USEPA and other entities have adopted the term

“Contaminants of Emerging Concern”

Types/Groupings of Microconstituents

•

Pharmaceutical and personal care products (PPCPs)

• Pesticides, industrial chemicals(BPA, PBDEs, PFOS, etc.)

• Persistent / bioaccumulative toxics (PBTs)• Nanomaterials• Endocrine disruptors• Disinfection byproducts• Natural compounds (e.g., microbial toxins)

Sources of Microconstituents

Source: Stensel, H.D., Univ. of WADepartment of Civil and Environmental Engineering

Contaminants of Emerging Concern

Potential Sources, Routes and Sinks

Source: USGS

Sources of Microconstituents

Source: USEPA

Microconstituents: Science, Regulation and Implication

SCIENCE

Microconstituents: Science

•

Chemistry of the compounds•

Behavior / Fate in treatment processes

•

Behavior / Fate in the environment•

Effects on Biological Systems

Microconstituents Important chemical properties

•

Many are polar, non-volatile–

Remain in aqueous phase

–

Are either removed by treatment or discharged

•

Remainder are lipophilic–

Sorption to solids

•

River sediments, WWTP Biosolids•

Potential re-release from solids or uptake by benthic organisms

–

Tendency to bioaccumulate in environment

Microconstituents and Wastewater Treatment

•

Sub-ug/l (10s to 100s of ng/l) concentrations well documented

•

Incomplete (50-90%) removals via conventional treatment is typical–

Sorption to solids can be significant

•

Complex chemistries involving original forms and various derivatives

•

Chlorination byproducts

•

Requires advanced treatment technologies

Wastewater Treatment – Conventional Removal Mechanisms

•

Microbial degradation–

New / trace chemicals never “seen”

by

WWTP bugs–

Levels too low to induce enzyme systems

•

Sorption onto filterable solids–

More typical for non-polar compounds

–

Implications for sludge management/disposal

Microconstituents in Biosolids

Source: USGS

Microconstituents: Example Relevant Studies

USGS StudyLooked for 95 contaminants in 139 streams

in 30 states (1999-2000)

Pharmaceuticals, hormones, and other organic wastewaterContaminants were measured in 139 streams during 1999 and 2000

USGS StudyMost frequently detected chemicals•

coprostanol (fecal steroid)

•

cholesterol (plant and animal steroid)•

N-N-diethyltoluamide (insect repellent)

•

caffeine (stimulant)•

triclosan (antimicrobial disinfectant)

•

tri (2-chloroethyl) phosphate (fire retardant)•

4-nonylphenol (nonionic detergent metabolite)

Most frequently detected chemical groups:•

Steroids, nonprescription drugs, insect repellent

Highest Concentrations (ppt levels)•

Detergent metabolites, steroids, and plasticizers

2008 WA Dept of Ecology/EPA Study

•

PPCPs in 5 POTWs•

172 compounds detected (typical)

•

21% removed by conventional treatment•

53% removed by advanced treatment (nutrient removal/filtration)

•

20% in biosolids•

carbamazepine, fluoxetine, and thiabendazole pass through

2008 WA Dept of Ecology/EPA Study

•

carbamazepine, fluoxetine, and thiabendazole pass through

Advanced Wastewater Treatment Technologies

•

Nutrient Removal–

Increased biological activity -

“co-metabolism”

of

microconstituents•

Activated Carbon–

Generally not cost effective

–

Residue management•

Ultra filtration–

High energy costs

–

Residue management•

Ozonation–

Generally most cost effective

Treatment to Remove Microconstituents

•

Not likely to be widely mandated•

Case/Location Specific–

Where intensive water re-use may occur

–

Pre-treatment of specific sources?–

May be driven by public perception more than science or economics

Behavior / Fate in the Environment

Release Scenarios

Source: Water Env Assoc of Ontario

Behavior / Fate in the EnvironmentContinuous discharge in WWTP effluent results in

continuous “background”

in receiving streams

–

Chemicals essentially become “persistent” pollutants even if their half-lives are short –

–

“pseudo persistence”

•

Continual, multigenerational exposure for aquatic organisms

•

“Environmentally Relevant Levels”

•

Synergistic effects, ecosystem stress

Effects on Aquatic OrganismsPotential “novel”

mechanism for bioaccumulation

Some PPCPs w/low octanol-water partition coefficients (high polarity) have been found to concentrate in aquatic organism

Examples:–

estrogens (concentrated in fish bile 60,000 X)–

gemfibrozil (concentrated in fish tissue, 113 X) –

diclofenac (concentrated in fish organs, up to 2,700 X)–

fluoxetine (concentrated in muscle, liver, and brain of fish)

Potential mechanism: drugs being designed to take advantage of gaining intracellular access via active transport

Source: C. Daughton, USEPA

Microconstituents: “Case Study”

Nonylphenol•

Commonly used surfactant in US

e.g.,nonylphenol ethoxylate

•

Moderately soluble, resistant to natural degradation in water

•

Estrogenic, persistent, bioaccumulate

•

Tends to accumulate in O2

poor envs

Nonylphenol

•

POTW effluent -

often found as a breakdown product from surfactants and detergents.

•

POTW Biosolids –

anaerobically treated sludge found to contain very high levels

•

Banned in Europe in 2003•

EPA released “Action Plan”

in Aug 2010

–

Encourages voluntary phase out–

Use TSCA mechanisms to regulate as needed

•

Industry push-back: APE Research Council

Nonylphenol as Case Study

•

Persistent, biologically active•

Widespread use -

est. 380 million lbs in 2010

•

Increasing evidence for concern–

Complex data subject to interpretation

•

Increasing attempts to control•

Initial resistance from manufacturers, users

•

“Tipping point”

reached–

Political momentum, public perception

–

Alternative formulated by necessity•

Alcohol ethoxylates

Microconstituents: Science, Regulation and Implication

REGULATION

Microconstituents:

REGULATION

Source Control “End-of-Pipe”

Microconstituents: RegulationSOME EXISTING REGULATIONS•

Food Quality Protection Act (FQPA)

Endocrine Disruptor Screening Program (EDSP)•

Federal Fungicide, Insecticide, and Rodenticide Act (FIFRA)

•

Toxic Substances Control Act (TSCA)•

Clean Water Act (CWA)

Ambient Water Quality Criteria & Standards

•

Safe Drinking Water Act (SDWA)•

Drinking Water Standards & Health Advisories

Microconstituents Regulation

•

Source Control Regulations –

Toxics Reduction (e.g., Oregon TUHWR, WA P2)

–

Toxics tracking/managemente.g., federal TSCA, European REACH

–

Toxic waste managemente.g, federal, state RCRA

•

Other source control mechanisms–

“Green”

chemistries, product substitutions, etc.

–

drug “take back”

initiatives

Microconstituents Regulation

•

End-of Pipe Regulations

–

Clean Water Act

–

Safe Drinking Water Act

Microconstituents: Regulation

Safe Drinking Water Act (SDWA)•

Unregulated Contaminant Monitoring (UCM) Program

•

Candidate Contaminant List (CCL) - every 5 years

•

EPA selects up to 30 contaminants for monitoring by large and some small drinking water systems

SDWA -

CCLOctober 2009 –

CCL3

•

104 chemicals, chemical groups•

12 microbiological contaminants

•

One perflourinated compound added–

perfluorooctane sulfonic acid (PFOS)

•

Ten pharmaceuticals were added: –

One antibiotic

–

erythromycin

–

Nine hormones

–

17 alpha-estradiol, 17 beta- estradiol, equilenin, equilin, estriol, estrone,

ethinyl estradiol, mestranol, and norethindrone

Microconstituents: Regulation

General developments at the State level•

Development of priority lists

•

Some initiatives to ban / restrict certain chemicals (e.g.PBTs)

•

Increased monitoring•

Development of guidelines for ww reuse

•

Drug take back programs / events

Microconstituents: Regulation

Specific state initiatives•

CA: Recycled Water Policy (2009)–

Monitoring Strategies for Chemicals of

Emerging Concern (CECs) in Recycled Water (June 2010)

•

OR: SB737 -

Municipal Persistent Pollutant Reduction Plans

•

MA: Emerging Contaminant Screening Process

Microconstituents: Science, Regulation and Implication

IMPLICATIONS

Reasons for Concern

•

Large quantities of source chemicals •

Type and quantities of chemicals in municipal WWT systems is growing

•

Sewage systems not equipped for complete removal

•

Risks are uncertain•

General demand for water increasing–

Pressure to re-use

Microconstituents: implications

Human Health•

Generalizations not meaningful

•

Varies by contaminant group–

Drug levels <<< therapeutic dosages

–

Endocrine disruptors: potential risks, esp. for certain risk groups (e.g., infants)

–

PBTs: bioaccumulation, risk thru ingestion•

Synergistic effects ?

Microconstituents: implications

Aquatic Ecosystems•

Potential effects more troubling–

Aquatic organisms can suffer continual, multigenerational exposure ("pseudo-

persistence" )–

inhibition of aquatic defensive mechanisms (e.g., “xenobiotics”

getting into cells)

–

Potential for additive (cumulative) and interactive (synergistic) effects from multiple exposure

Microconstituents: implications

Aquatic EcosystemsPotential for slow, gradual degradation:•

subtle changes (e.g., neurobehavioral), even at ppb levels (μg/L)

•

Stress on Ecosystems– Long-term, subtle effects on

populations– Loss of biodiversity?

46

So Is There a Problem?•

Define “problem”

–

what is “risk”

•

To humans, from–

drinking water: probably not

–

food chain: probably not (?)–

Direct contact (surface water): no

•

To aquatic organisms, from–

Continuous exposures: yes (?)

•

Part of a trend: chemical life cyclesnot adequately understood or addressed

•

Too much uncertainty –

is this the problem?

So Is There a Problem?•

Part of a trend: chemical life cyclesnot adequately understood or addressed

•

Too much uncertainty –

is this the problem?–

“precautionary principle”

AcknowledgementsThe presenter wishes to thank the following individuals for

providing verbal input and technical information used in this presentation

Christian Daughton, Ph.D., Environmental Sciences Division, U.S. Environmental Protection Agency, Las Vegas, Nevada.

Dave Reckhow, Ph.D., Department of Civil and Environmental Engineering, Univ. of Massachusetts at Amherst Amherst, MA

Phil Singer, Ph.D., Dept. of Environmental Sciences & Engineering, School of Public Health, Univ. of N Carolina, Chapel Hill, NC

Shane A. Snyder, Ph.D., Arizona Laboratory for Emerging Contaminants (ALEC), Univ. of Arizona, Tucson, AZ

Paul Westerhoff, Ph.D., Civil, Environmental and Sustainable Engineering Program, Arizona State University, Tempe, AZ

Q & ADiscussion

Thank you