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“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
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“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 Runoff & Seepage EDCs/CECs & PPCPs Reuse Domestic Water Usage Receiving Water Bodies WWTP Domestic Sewage WTP Land (Biosolids) Land Application Ecosystems
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
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 CECs - EDCs/PPCPs are Present in Source Waters …
ORSANCO/EPA Study 158 compounds measured Report: 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 Large and small mouth bass 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 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
Surface Water – Conventional Treatment with GAC Filtration, Pre/Post Chlorination • Good removal of most compounds except TECP
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 Full-Scale 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 Full-Scale 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 • 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)
ClO4- Contaminated Water ClO4- Contaminated Water Electron Donor Resin Dispose Dispose Destruction Or Biomass ClO4- Brine Filtration Disinfection Treated Water Treated Water Destruction Methods: Biological Reduction Catalyzed Thermal ClO4- Contaminated Water Treated Water Uncontaminated Water Biological Reduction (fixed and fluidized bed) Ion Exchange Blending Basic Approaches Treatment of Perchlorate in Drinking Water ClO4- Contaminated Water Concentrate Treated Water Reverse Osmosis
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) Cr(III) Reduce or Oxidize Anion Exchange Membrane Precipitate Soften EDR Deposit on Surface Electro Coagulation No Treatment Adsorption Filter Coagulate/ Co-precipitate Filter Delivered water Cr(III) only Potential oxidation to Cr(VI) in distribution system Delivered water Cr(VI) only Easier to Reduce Cr(VI) to Cr(III) than Oxidize Cr(III) to Cr(VI)
CH3 O = N-N CH3 NDMA • N - Nitrosodimethylamine (NDMA) • 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 • Wastewater effluent organic matter (EfOM) • Evidence of continued formation in distribution system Presence of nitrogen with oxidant
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
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 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 DayThe 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