Transcript Conventional and Alternative Treatment Strategies for

“Conventional and Alternative Treatment
Strategies for Emerging Contaminants”
OHIO AWWA
Southeast District Fall Meeting
November 21, 2013
Chad Roby, P.E. and Patrick Eiden, P.E.
HDR Engineering, Inc.
Agenda
 Introduction
 Emerging Contaminants
 EDC/PCCPs, Perchlorate, Chromium, and NDMA
 Health effects
 Occurrence
 Regulatory Issues
 Contaminant Removal in Water Treatment Processes
 Public Interactions
 Conclusions
What are Emerging Contaminants?
USGS Definition:
 “Emerging contaminants" can be broadly defined as any synthetic or
naturally occurring chemical or any microorganism that is not commonly
monitored in the environment but has the potential to enter the
environment and cause known or suspected adverse ecological and
(or) human health effects. In some cases, release of emerging chemical
or microbial contaminants to the environment has likely occurred for a long
time, but may not have been recognized until new detection methods
were developed. In other cases, synthesis of new chemicals or changes in
use and disposal of existing chemicals can create new sources of
emerging contaminants.
They Come from
“You”, not from
Wastewater
Treatment Plants
EPA Synopsis of Microconstituent Sources
Concept – Continuous Input of CECs
EDCs/CECs &
PPCPs
Domestic
Sewage
Runoff &
Seepage
WWTP
Reuse
Receiving
Water Bodies
Land
(Biosolids)
Ecosystems
WTP
Land
Application
Domestic
Water
Usage
What’s the EPA doing?
Contaminant Candidate List
• Regulation Determination
• Adverse health effects
• Occurrence
• “Meaningful opportunity” for
reducing risks to health
• CCL 1 (60 contaminants) March 1998
• CCL 2 (51 contaminants) February 2005
• CCL 3 (116 contaminants) October 2009
http://water.epa.gov/scitech/drinkingwater/dws/ccl/
CECs - EDCs/PPCPs (Microconstituents)
 Endocrine Disrupting Compounds (EDCs) (DEET, TCEP)
 Estrogens: regulate and sustain female sexual development and reproductive function
 Androgen: male sex hormones
 Mimics: estrogenic and androgenic compounds
 Pharmaceuticals and Personal Care Products (PPCPs)
 Non-steroidal anti-inflammatory
 Anti-epileptic
 Antibiotics
 Anti-anxiety
 Antioxidants
 Pain reliever
 Anti-cholesterol
 Sun Screen
Why are EDCs/PPCP’s a Concern?
 Direct impacts on ecological health
 Well documented: feminization of fish, etc.
 Direct impacts on human health?
 Public perception and concern
 A very sensitive issue
 Indicator of antibiotic overuse?
 Integrated Water Environment
 Drinking Water, Wastewater and Reuse
 Water Resources
CECs - EDCs/PPCPs are Present in
Source Waters …
 USGS Surface Water
Survey (2000)
 30 States
 139 Streams
 Sample for 95
compounds
Kolpin et al 2002
 At least one compound
detected in 111
streams (80%)
 82 of 95 compounds
detected at least once
ORSANCO/EPA Study
158 compounds measured
Report: 2010
Feminized Fish are Found Throughout the
United States
 Nine river basins
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Mississippi
Columbia
Rio Grand
Yukon
Colorado
Mobile
Apalachicola
Savannah
Pee Dee
Large and small mouth bass
 Feminization found
 25% of fish species
 31% of sites
Hinck et al 2009
EDCs and PPCPs in US Drinking Waters
Snyder, et. al, 2008
How Effective Are Our Treatment
Plants at Removing Contaminants of
Emerging Concern
WRF Study on EDCs and Related Compounds – WRF
4162
 Target Compounds
EDCs
N-N-diethyltoluamide (DEET)
Pharmaceuticals
Atorvastatin (weight loss)
Tris(2-chloroethyl)phosphate
(TCEP) (flame retardant)
Estrone (estrogen)
Naproxen (arthritis)
Perchlorate
WW Associated
N-Nitrosodimethylamine
(NDMA)
Sulfamethoxazole
(antibiotic)
Trimethoprim (urinary tract)
Atenolol (blood pressure)
Ranitidine (ulcers, GERD)
Ciprofloxacin (antibiotic)
Umass Bench scale study
Some EDC’s are Currently Regulated
 Examples:
 Pesticides: atrazine, chlordane, DDT, endrin, lindane,
methoxychlor, simazine, and toxaphene
 Nonpesticide organics: benzo(a)pyrene, bis(2-ethyhexyl)
phthalate, dioxin, and PCBs
 Inorganic chemicals: cadmium, lead, and mercury
 Values are based on toxic or cancer effects
Groundwater with Chlorine Disinfection
 Good removal except for DEET and TCEP
Groundwater II – Prechlorination/Filtration,
Aeration/Post Chlorination
 Good removal of most compounds except TCEP
110
100
90
Percent Remaining
80
Atenolol
Ranitidine
Sulfamethoxazole
Trimethoprim
Ciprofloxacin
DEET
Naproxen
TCEP
Atorvastatin
Naproxen-Neg
70
60
50
40
30
20
10
0
filtered
finished
Treatment
Surface Water – Conventional Treatment with
GAC Filtration, Pre/Post Chlorination
 Good removal of most compounds except TECP
110
100
90
Percent Remaining
80
Atenolol
Ranitidine
Trimethoprim
Estrone
DEET
TCEP
Atorvastatin
70
60
50
40
30
20
10
0
settled
filtered
Treatment
finished
Surface Water - Conventional Treatment with
Anthracite/Sand Filtration, Pre/Post Chlorination
 Mostly good removal except DEET, TCEP
Surface Water – Ozone/Biofiltration
(WRF 4162)
Unregulated Contaminant Removal at FullScale WTPs
 Coagulation/Flocculation – Minimal
contaminant removal 2 out of 37
compounds @ 75%
 Filtration alone – minimal
contaminant removal 4 out of 32
compounds @ 75%
 Ozone – Effective 15 compounds
transformed at > 70%
 GAC – 8 of 28 compounds
removed at greater than 75%, 11
other compounds removed to a
moderate degree
WRF #4221, 2013
Unregulated Contaminant Removal at FullScale WTPs
 Other Observations
 Source water with more NPDES permit
 More contaminants detected
 Greater mass of containments
 Size of watershed
 Hydrology plays important role in detection
WRF #4221, 2013
Path Forward?
 Water utilities presently face a dilemma when
trying to proceed with planning
 Lack of firm scientific consensus on the importance of
drinking water as a route of exposure for these
compounds
 Regulatory evaluations underway
 No clear path for utilities
 10,000 chemicals - Endocrine Disruptor Screening
Program (EDSP)
 Even effective treatment doesn’t capture all
compounds
EDCs and PPCPs - Removal by Advanced
Treatment Processes
 Granular Activated Carbon Filtration
 Can be effective if run in “adsorption mode”
 Expensive
 Ozonation and Biofiltration
 Can be effective if filters operate biologically
 Membranes
 Only the high pressure types are effective (e.g.,
reverse osmosis)
 Expensive if just used for PPCPs
 Advanced Oxidation (ozone/UV and peroxide)
 Expensive and only slightly more effective than
ozone alone
Other Prominent Microconstituents

Perchlorate – Can occur naturally but most
environmental release associated with solid rocket
fuel

Hexavalent Chromium

N - Nitrosodimethylamine (NDMA)
Perchlorate is the most oxidized form of Cl2
 ClO4- +2H+ + 2e- => ClO3- + H2O Eº +1.20 V
 ClO4- +8H+ + 8e- => Cl- + 4H2O Eº +1.38 V
Uses
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Explosives
Fireworks
Medicinal (hyperthyroidism)
Analytical chemistry
 Primary health effect:
Interferes with iodine uptake
into the thyroid gland
UCMR - Perchlorate
Occurrence by PWS
as of August 2004
• Natural and manmade sources
• Low levels detected in 26 states
Perchlorate Regulatory Status
 No MCL or MCLG
 Regulations in progress
 Directed sampling
 Several states, including Arizona, Maryland, Nevada,
New Mexico, New York, and Texas have established
non-enforceable, advisory levels for perchlorate
 Comprehensive Environmental Response, Compensation
and Liability Act (CERCLA)
Basic Approaches Treatment of Perchlorate in
Drinking Water
ClO4Contaminated
Water
ClO4Contaminated
Water
Resin
Electron
Donor
Dispose
ClO4Contaminated
Water
ClO4Contaminated
Water
Uncontaminated
Water
Concentrate
Or
ClO4Brine
Treated
Water
Dispose
Destruction
Biomass
Filtration
Disinfection
Destruction Methods:
Biological Reduction
Catalyzed Thermal
Treated
Water
Treated
Water
Blending
Reverse
Osmosis
Treated
Water
Ion Exchange
Biological Reduction
(fixed and fluidized
bed)
Chromium: General Information
Symbol
Discovered in
Atomic Number
Cr
1797
24
Atomic Weight
Oxidation States
Uses
51.9961
6, 3, 2, 0
Harden steel
Plating
Catalyst
Pigments
Dietary supplement
Typical source
Chromite (FeCr2O4)
Summary of Cr(VI) Health Effects
 National Toxicology Program (NTP) found evidence of Cr(VI)
carcinogenicity in rats
 CA OEHHA established Public Health Goals (PHG) based
on NTP findings (draft)
 USEPA has proposed a revision to Integrated Risk
Information System (IRIS) based on NTP findings
 ToxStrategies Mode of Action Study indicates lower risk of
cancer by ingestion than assumed by OEHHA or USEPA
Current Regulatory Status for Chromium
 Current standards for total chromium
[Cr(III) + Cr(VI)]
 USEPA MCL = 100 µg/L (0.1 mg/L)
 California MCL = 50 µg/L
 WHO Standard = 50 µg/L
 No federal regulation (MCL) for hexavalent
chromium (Cr(VI))
 California Public Health Goal for Cr(VI) – 0.02 µg/L
 Potential adverse health effects due to Cr(VI) NOT
Cr(III)
Chromium Detection Locations
Reference
USEPA
Total Chromium
Ohio (Region 5)
Ref: Seidel, 2011
Potential Treatment Technologies
Cr(VI)
EDR
Reduce or Oxidize
Anion
Membrane
Exchange
Adsorption
Cr(III)
Electro
Coagulation
Precipitate
No
Treatment
Soften
Deposit on
Surface
Filter Coagulate/
Co-precipitate
Filter
Delivered water Cr(VI) only
Delivered water Cr(III) only
Potential oxidation to Cr(VI) in
distribution system
Easier to Reduce Cr(VI) to Cr(III) than Oxidize
Cr(III) to Cr(VI)
NDMA
 N - Nitrosodimethylamine (NDMA)
CH3
O = N-N
CH3
 Polar, highly soluble and semi-volatile
 Degrades in the presence of sunlight
 Particularly sensitive to ultraviolet radiation
NDMA Sources
 An intermediary in the production of storable rocket fuel
 Production ceased in 1976
 Has been found in ground waters not impacted by rocket fuel
production.
 Variety of chemical processing applications particularly plastic
 Present in cured meat and others foods (beer, sausage, etc.)
 By-products from water treatment, particularly disinfection with
chloramines
NDMA Formation During Drinking
Water Treatment
 By-product of disinfection with chlorine/monochloramine
 Generally thought monochloramine will produce more NDMA
 NDMA formation has been associated with
 Anion exchange resins
 Dimethylamine (DMA) containing polymers
 Systems with nitrification
Presence of nitrogen
with oxidant
 Wastewater effluent organic matter (EfOM)
 Evidence of continued formation in distribution system
NDMA – Cancer Effects
NDMA Results from UCMR2
63% from surface water
Russell et all, JAWWA 2012
NDMA to regulate or not?
• Adverse health effects?
• Occurrence?
• “Meaningful opportunity” for reducing risks to health?
US EPA will probably regulate. Possibly
with an action level.
NDMA Minimization/Treatment
 Small size and high solubility make NDMA difficult to treat by
conventional means
 Add chlorine prior to ammonia
 Precursor control through treatment of organic nitrogen
 Preoxidation with chlorine, chlorine dioxide or ozone can
destroy or transform NDMA precursors
 UV or advanced oxidation (UV/peroxide) treatment
 Take advantage of NDMA instability in presence of UV
0
Monitoring
well
Final
Product
Water
UV Effluent
Post H2O2
RO
Permeate
MF Effluent
ppt
NDMA Profile Through Treatment Plant
70
60
50
40
30
20
10
Public Perception
Public Perception The Terminology Can Create or Exacerbate Fears
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Endocrine disrupting compounds
Compounds of emerging concern
Compounds of potential concern
EPOCs — emerging pollutants of concern
Emerging contaminants of concern
PPCPs --- Pharmaceuticals and Personal Care Products
CEPs – Compounds of Emerging Publicity (Shane Synder)
Even the word ‘chemical’ implies danger to the public
What should we say?
 Ensure understanding, without getting overly technical
 Industry professionals should convey their commitment to
advancing understanding of this issue
 Use appropriate terminology and take care not to cause alarm
 Gently demonstrate that the “source” is all of us, and the
solution is not just at the wastewater treatment plant
 Public Service Advertisements about proper disposal of drugs and
chemicals
 Household hazardous waste disposal events
 Drug take back programs
National Prescription Drug Take-Back Day
The National Prescription Drug Take-Back Day
aims to provide a safe, convenient, and
responsible means of disposing of prescription
drugs, while also educating the general public
about the potential for abuse of medications.
You can search by zip code for a collection site
near you. Inquiries can also be made at 1-800882-9539.
http://www.deadiversion.usdoj.gov/
drug_disposal/takeback/index.html
Public Perception - Communication is Key!
 We need to promote greater public understanding about
their water environment in a way that neither creates
undue alarm nor complacency
 Residual amounts of the substances we use are likely to
end up in the water environment even though it may be
at nearly undetectable levels
 Concentration, duration, and dose are MORE
IMPORTANT than detection
Conclusions
 CECs are present in water
environment
 Human health impacts still
developing
 Environmental effects
 Conventional treatment works well
for many compounds
 Communication is KEY
Resources
 USGS
 http://toxics.usgs.gov/regional/emc/index.html
 US EPA
 http://www.epa.gov/endo/
 ORSANCO
 http://orsanco.org/
 HDR EDC/CEC/PPCP Task Force
 Integrated Water Environment
 Drinking Water, Wastewater and Reuse
 Water Resources
Scientists used florescent dye and bromide to track river water
to which two emerging contaminants had been added - 4nonylphenol and 17β-estradiol. This allowed the scientists to
study the natural attenuation of the two compounds as they
were transported down the Redwood River, Minnesota. Photo
credit: Jeffrey H. Writer, USGS.
Questions?
Resources
 USGS
 http://toxics.usgs.gov/regional/emc/index.html
 US EPA
 http://www.epa.gov/endo/
 ORSANCO
 http://orsanco.org/
 HDR EDC/CEC/PPCP Task Force
 Integrated Water Environment
 Drinking Water, Wastewater and Reuse
 Water Resources
Contact:
Chad Roby, P.E.
[email protected]
614-839-5771
Patrick Eiden, P.E.
[email protected]
614-839-5781