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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 - PowerPoint PPT Presentation


  • Conventional and Alternative Treatment Strategies for Emerging ContaminantsOHIO AWWA Southeast District Fall Meeting November 21, 2013

    Chad Roby, P.E. and Patrick Eiden, P.E.HDR Engineering, Inc.

  • AgendaIntroduction Emerging Contaminants

    EDC/PCCPs, Perchlorate, Chromium, and NDMAHealth effectsOccurrenceRegulatory Issues Contaminant Removal in Water Treatment ProcessesPublic InteractionsConclusions

  • 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 SourcesThey Come from You, not from Wastewater Treatment Plants

  • Concept Continuous Input of CECs

  • Contaminant Candidate List

    Regulation DeterminationAdverse health effects OccurrenceMeaningful opportunity for reducing risks to health

    CCL 1 (60 contaminants) March 1998 CCL 2 (51 contaminants) February 2005 CCL 3 (116 contaminants) October 2009

    Whats 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 functionAndrogen: male sex hormones Mimics: estrogenic and androgenic compounds

    Pharmaceuticals and Personal Care Products (PPCPs)Non-steroidal anti-inflammatoryAnti-epilepticAntibioticsAnti-anxietyAntioxidantsPain relieverAnti-cholesterolSun Screen

  • Why are EDCs/PPCPs a Concern?Direct impacts on ecological healthWell documented: feminization of fish, etc.

    Direct impacts on human health?

    Public perception and concernA very sensitive issue

    Indicator of antibiotic overuse?

    Integrated Water EnvironmentDrinking Water, Wastewater and ReuseWater Resources

  • CECs - EDCs/PPCPs are Present in Source Waters Kolpin et al 2002USGS Surface Water Survey (2000)30 States139 StreamsSample for 95 compoundsAt least one compound detected in 111 streams (80%)82 of 95 compounds detected at least once

  • ORSANCO/EPA Study158 compounds measuredReport: 2010

  • Feminized Fish are Found Throughout the United States Nine river basinsMississippiColumbiaRio GrandYukonColoradoMobileApalachicolaSavannahPee DeeFeminization found25% of fish species31% of sites

    Hinck et al 2009Large and small mouth bass

  • EDCs and PPCPs in US Drinking WatersSnyder, et. al, 2008

  • How Effective Are Our Treatment Plants at Removing Contaminants of Emerging Concern

  • WRF Study on EDCs and Related Compounds WRF 4162Target Compounds

    Umass Bench scale study

    EDCsPharmaceuticalsWW AssociatedN-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)PerchlorateAtenolol (blood pressure)Ranitidine (ulcers, GERD)Ciprofloxacin (antibiotic)

  • Some EDCs are Currently RegulatedExamples:Pesticides: atrazine, chlordane, DDT, endrin, lindane, methoxychlor, simazine, and toxapheneNonpesticide organics: benzo(a)pyrene, bis(2-ethyhexyl) phthalate, dioxin, and PCBsInorganic chemicals: cadmium, lead, and mercury

    Values are based on toxic or cancer effects

  • Groundwater with Chlorine DisinfectionGood 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 ChlorinationGood removal of most compounds except TECP

  • Surface Water - Conventional Treatment with Anthracite/Sand Filtration, Pre/Post ChlorinationMostly 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 WTPsWRF #4221, 2013

  • Unregulated Contaminant Removal at Full-Scale WTPsWRF #4221, 2013Other ObservationsSource water with more NPDES permitMore contaminants detectedGreater mass of containmentsSize of watershed Hydrology plays important role in detection

  • Path Forward?Water utilities presently face a dilemma when trying to proceed with planningLack of firm scientific consensus on the importance of drinking water as a route of exposure for these compoundsRegulatory evaluations underwayNo clear path for utilities10,000 chemicals - Endocrine Disruptor Screening Program (EDSP)Even effective treatment doesnt capture all compounds

  • EDCs and PPCPs - Removal by Advanced Treatment ProcessesGranular Activated Carbon FiltrationCan be effective if run in adsorption modeExpensiveOzonation and BiofiltrationCan be effective if filters operate biologicallyMembranesOnly the high pressure types are effective (e.g., reverse osmosis)Expensive if just used for PPCPsAdvanced 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 E +1.20 VClO4- +8H+ + 8e- => Cl- + 4H2O E +1.38 V

    UsesExplosivesFireworksMedicinal (hyperthyroidism)Analytical chemistry

    Primary health effect: Interferes with iodine uptake into the thyroid gland

  • UCMR - Perchlorate Occurrence by PWSas of August 2004Natural and manmade sourcesLow levels detected in 26 states

  • Perchlorate Regulatory StatusNo MCL or MCLGRegulations in progressDirected 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

  • Chromium: General Information

    SymbolCrDiscovered in1797Atomic Number24Atomic Weight51.9961Oxidation States6, 3, 2, 0UsesHarden steelPlatingCatalystPigmentsDietary supplementTypical sourceChromite (FeCr2O4)

  • Summary of Cr(VI) Health EffectsNational 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 findingsToxStrategies 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 g/L (0.1 mg/L)California MCL = 50 g/LWHO Standard = 50 g/LNo federal regulation (MCL) for hexavalent chromium (Cr(VI))California Public Health Goal for Cr(VI) 0.02 g/L Potential adverse health effects due to Cr(VI) NOT Cr(III)

  • Chromium Detection LocationsReference USEPATotal Chromium

  • Ref: Seidel, 2011Ohio (Region 5)

  • Potential Treatment TechnologiesEasier to Reduce Cr(VI) to Cr(III) than Oxidize Cr(III) to Cr(VI)

  • NDMAN - Nitrosodimethylamine (NDMA)

    Polar, highly soluble and semi-volatile

    Degrades in the presence of sunlight Particularly sensitive to ultraviolet radiation

  • NDMA SourcesAn 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 TreatmentBy-product of disinfection with chlorine/monochloramineGenerally thought monochloramine will produce more NDMANDMA formation has been associated withAnion exchange resinsDimethylamine (DMA) containing polymersSystems with nitrificationWastewater 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 201263% from surface water

  • NDMA Regulatory StatusConsidered by USEPA as a probable human carcinogenAssociated with tumors of the lung and kidneys in mice No MCL or MCLG is established for NDMAIncluded in UCMR2 and CCL3USEPA estimates a 10-6 risk in drinking water at 0.7 ng/LCalifornia has an action level of 10 ng/L 10 parts per trillion!

  • NDMA Will They or Wont They?Posted on March 4, 2013 by Sarah Clark Lots of p


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