“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.
EPA Synopsis of Microconstituent Sources
They Come from “You”, not from Wastewater Treatment Plants
Concept – Continuous Input of CECs
WWTP WTPReceiving Water Bodies
Domestic Water Usage
Domestic Sewage
Land (Biosolids) Land
Application
ReuseRunoff & Seepage
Ecosystems
EDCs/CECs & PPCPs
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
What’s the EPA doing?
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 …
Kolpin et al 2002
USGS Surface Water Survey (2000) 30 States 139 Streams Sample for 95
compounds At least one compound
detected in 111 streams (80%)
82 of 95 compounds detected at least once
ORSANCO/EPA Study
158 compounds measuredReport: 2010
Feminized Fish are Found Throughout the United States
Nine river basins Mississippi Columbia Rio Grand Yukon Colorado Mobile Apalachicola Savannah Pee Dee
Feminization found 25% of fish species 31% of sites
Hinck et al 2009
Large and small mouth bass
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 Pharmaceuticals WW Associated
N-N-diethyltoluamide (DEET) Atorvastatin (weight loss) N-Nitrosodimethylamine (NDMA)
Tris(2-chloroethyl)phosphate (TCEP) (flame retardant)
Naproxen (arthritis)
Estrone (estrogen) Sulfamethoxazole (antibiotic)
Trimethoprim (urinary tract)Perchlorate 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
Treatment
filtered finished
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Atenolol Ranitidine Sulfamethoxazole Trimethoprim Ciprofloxacin DEET Naproxen TCEP Atorvastatin Naproxen-Neg
Surface Water – Conventional Treatment with GAC Filtration, Pre/Post Chlorination Good removal of most compounds except TECP
Treatment
settled filtered finished
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Atenolol Ranitidine Trimethoprim Estrone DEET TCEP Atorvastatin
Surface Water - Conventional Treatment with Anthracite/Sand Filtration, Pre/Post Chlorination Mostly good removal except DEET, TCEP
Surface Water – Ozone/Biofiltration
(WRF 4162)
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
Unregulated Contaminant Removal at Full-Scale WTPs
WRF #4221, 2013
Unregulated Contaminant Removal at Full-Scale WTPs
WRF #4221, 2013
Other Observations Source water with more NPDES permit
More contaminants detected Greater mass of containments
Size of watershed Hydrology plays important role in detection
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 Explosives Fireworks Medicinal (hyperthyroidism) Analytical chemistry
Primary health effect: Interferes with iodine uptake into the thyroid gland
UCMR - Perchlorate Occurrence by PWSas 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
ClO4-
Contaminated Water
Uncontaminated Water
Treated Water
ClO4-
Contaminated Water
Ion Exchange Biological Reduction (fixed and fluidized bed)
Blending
Treated Water
DisposeDestruction
ClO4-
Brine
Destruction Methods:Biological ReductionCatalyzed Thermal
DisposeResin
Or
ClO4-
Contaminated Water
Treated Water
Electron Donor
Biomass
FiltrationDisinfection
ClO4-
Contaminated Water
Treated Water
Reverse Osmosis
Concentrate
Chromium: General Information
Symbol Cr
Discovered in 1797Atomic Number 24Atomic Weight 51.9961
Oxidation States 6, 3, 2, 0Uses Harden steel
PlatingCatalystPigments
Dietary supplementTypical 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
Ref: Seidel, 2011
Ohio (Region 5)
Potential Treatment Technologies
Filter
SoftenPrecipitate
No Treatment
Coagulate/Co-precipitate
Filter
AnionExchange
Membrane
Reduce or Oxidize
Delivered water Cr(VI) only Delivered water Cr(III) onlyPotential oxidation to Cr(VI) in distribution system
ElectroCoagulation
EDR
Cr(VI) Cr(III)
Adsorption Deposit on Surface
Easier to Reduce Cr(VI) to Cr(III) than Oxidize Cr(III) to Cr(VI)
NDMA
N - Nitrosodimethylamine (NDMA)
Polar, highly soluble and semi-volatile
Degrades in the presence of sunlight Particularly sensitive to ultraviolet radiation
O = N-N CH3
CH3
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
Wastewater effluent organic matter (EfOM)
Evidence of continued formation in distribution system
Presence of nitrogen with oxidant
NDMA – Cancer Effects
NDMA Results from UCMR2
Russell et all, JAWWA 2012
63% from surface water
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
NDMA Profile Through Treatment Plant
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Public Perception
Public Perception - The Terminology Can Create or Exacerbate Fears 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 PublicityPublicity (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 1-800-882-9539.
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 - 4-nonylphenol 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]
Patrick Eiden, [email protected]
