Industry Perspective onIndustry Perspective on CIS Mixing Zone Guidance CIS Mixing Zone Guidance

Using the CIS Mixing Zone Guidance Using the CIS Mixing Zone Guidance

JRC Workshop ISPR, Italy 5-6JRC Workshop ISPR, Italy 5-6thth April 2011 April 2011

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The Eurelectric Representatives on the CIS Drafting Group:The Eurelectric Representatives on the CIS Drafting Group:

Neil Edwards (RWE Npower, Asset Operational Support)Neil Edwards (RWE Npower, Asset Operational Support)

&&

Keith Sadler (E.ON New Build & Technlogy)Keith Sadler (E.ON New Build & Technlogy)

OutlineOutline

• Experience of the Drafting ProcessExperience of the Drafting Process• Why is the Guidance Vital for Industry?Why is the Guidance Vital for Industry?• Benefits from the GuidanceBenefits from the Guidance

– Timeframes, Costs/BenefitsTimeframes, Costs/Benefits• Key Aspects of the GuidanceKey Aspects of the Guidance• Example – power station applications:Example – power station applications:

– Tier 0/1Tier 0/1– Tier 2Tier 2– Tier 3/4Tier 3/4

• ConclusionsConclusions

Experience of the Drafting Experience of the Drafting ProcessProcess

• Diverse mix of interests & experience Diverse mix of interests & experience represented on drafting grouprepresented on drafting group– some had limited experience of mz regulation in some had limited experience of mz regulation in

practice to date in EU or elsewherepractice to date in EU or elsewhere

• Positive commitment to work togetherPositive commitment to work together• Lengthy, iterative & repetitiveLengthy, iterative & repetitive• Fundamental debate:Fundamental debate:

– simple cheap, rigid, inflexible rules simple cheap, rigid, inflexible rules – or flexible best practice guidelines for case by or flexible best practice guidelines for case by

case basis case basis

• Limited WrFD related guidance precedents Limited WrFD related guidance precedents (eg CIS 7, 19 & 25 on ‘Monitoring’)(eg CIS 7, 19 & 25 on ‘Monitoring’)

Why is the Guidance Vital for Why is the Guidance Vital for Industry?Industry?• For many BAT compliant installations/processes For many BAT compliant installations/processes

aquatic emission streams contain substances at aquatic emission streams contain substances at concentrations >EQSconcentrations >EQS– Especially with modern methods setting far more Especially with modern methods setting far more

precautionary EQS concentrations than previouslyprecautionary EQS concentrations than previously

• If MZ were not allowed EQS would be ELV which If MZ were not allowed EQS would be ELV which could:could:– rule out some technology that could otherwise be rule out some technology that could otherwise be

BAT/BPEOBAT/BPEO– add unwarranted costadd unwarranted cost– lead to unwarranted environmental impacts in non-lead to unwarranted environmental impacts in non-

aquatic media eg aquatic media eg • offsite transport, treatment & disposal, life cycle offsite transport, treatment & disposal, life cycle

considerations, energy use, sludge/landfill considerations considerations, energy use, sludge/landfill considerations etcetc

Benefits from the GuidanceBenefits from the Guidance

• TimeframesTimeframes– Speeds determinations since principles are already Speeds determinations since principles are already

established in authoritative sourceestablished in authoritative source

• Costs & BenefitsCosts & Benefits– Minimise costs for regulated, regulator and Minimise costs for regulated, regulator and

stakeholdersstakeholders• Focuses efforts to appropriate aspects of applicationsFocuses efforts to appropriate aspects of applications

– Promotes consistent and predictable determinationsPromotes consistent and predictable determinations• Regulated can better integrate constraints into choice of Regulated can better integrate constraints into choice of

options & designsoptions & designs• Sets out key points to address in complex & marginal casesSets out key points to address in complex & marginal cases

– Allows exercise of expert judgement Allows exercise of expert judgement

Key Aspects of the Key Aspects of the GuidanceGuidance

• The acceptability of a mixing zone should be The acceptability of a mixing zone should be determined by the significance of its impacts not by determined by the significance of its impacts not by its dimensionits dimension– Recognises response of biota in the field not the same as in Recognises response of biota in the field not the same as in

laboratory toxicity testinglaboratory toxicity testing• eg avoidance rather than toxicity in some specieseg avoidance rather than toxicity in some species• eg influence of out of mz biological systems on interior of mzeg influence of out of mz biological systems on interior of mz

• Tiered approach – risk-based cost effective regulationTiered approach – risk-based cost effective regulation– allows comprehensive assessment allows comprehensive assessment – focuses regulators, regulator and stakeholder effort on focuses regulators, regulator and stakeholder effort on

discharges and aspects that need careful considerationdischarges and aspects that need careful consideration– Flexible to meet range of pan-European circumstances Flexible to meet range of pan-European circumstances

• Incentivise use of case-specific sound science & dataIncentivise use of case-specific sound science & data• Progressive Mixing Zone extent reduction not to be Progressive Mixing Zone extent reduction not to be

used to force emission reduction …used to force emission reduction …– … … which should follow from IED BAT, PS/PHS which should follow from IED BAT, PS/PHS

reduction/cessation trajectory measures etcreduction/cessation trajectory measures etc

How & When Will Industry Use How & When Will Industry Use MZ Guidance?MZ Guidance?• Factor into feasibility, technology, location & Factor into feasibility, technology, location &

case-specific design optimisation choicescase-specific design optimisation choices– New plantNew plant– Existing plant modificationsExisting plant modifications

• Permitting processes for new plant or existing Permitting processes for new plant or existing plant modificationsplant modifications

• Assessment of existing plant if physical, chemical, Assessment of existing plant if physical, chemical, biological or regulatory context changesbiological or regulatory context changes

• Mixing zones considered from the earliest phase Mixing zones considered from the earliest phase & throughout new project development& throughout new project development– Baseline surveys, option choices, detailed design, Baseline surveys, option choices, detailed design,

modelling, permit applications, modelling validation, modelling, permit applications, modelling validation, impacts assessment monitoring impacts assessment monitoring

Tier 0/1Tier 0/1

• Screening out emissions for which detailed Screening out emissions for which detailed consideration is not appropriate egconsideration is not appropriate eg– Discharge does not contain relevant substanceDischarge does not contain relevant substance– Discharge has relevant substance but below Discharge has relevant substance but below

EQSEQS– Discharge has relevant substance at and Discharge has relevant substance at and

above EQS but emission is ‘trivial’ in the above EQS but emission is ‘trivial’ in the context of receiving waterscontext of receiving waters•Load considerations only - no need for dispersion Load considerations only - no need for dispersion

calculationcalculation

Timescale: Built up iteratively during course of project as process design is refined. A week or so of effort overall. Often needs revision as detailed design evolves to ensure consistent inventories

Costs: <£10k€

Tier 2Tier 2

• Use of precautionary default MZ extent criteria Use of precautionary default MZ extent criteria – eg min{10*river widths,1 km}eg min{10*river widths,1 km}

• Simple calculations of discharge plume mixing Simple calculations of discharge plume mixing giving spatial distributions of concentrations which giving spatial distributions of concentrations which take some limited account of case specifics (eg take some limited account of case specifics (eg CORMIX, Fischer, Plumes …)CORMIX, Fischer, Plumes …)– Discharge volume flow, concentration and outfall Discharge volume flow, concentration and outfall

arrangements + ambient depth, flow & concentrationarrangements + ambient depth, flow & concentration• Can establish no credible threat to vulnerable Can establish no credible threat to vulnerable

receptors or water body objectives …receptors or water body objectives …• without without detaileddetailed representation of the case eg assume representation of the case eg assume

– straight bank, uniform bed, uniform steady flow, simple mixing straight bank, uniform bed, uniform steady flow, simple mixing modelmodel

• … … but sometimes scale and specifics such that but sometimes scale and specifics such that insufficient confidence to permit or refuse permit insufficient confidence to permit or refuse permit with this level of consideration with this level of consideration

Timescale: May be used to scope outfall options, location & initial design. Each run takes a few mins to define, seconds to run, interpretation can be tricky. A week or two per written up study + subsequent stakehodler dialogue

Costs: k€5-20/study

Tier 3/4Tier 3/4

• Detailed receptor mappingDetailed receptor mapping

• + detailed dispersion modelling+ detailed dispersion modelling– Appropriate to case – often 3d such as Delft3dAppropriate to case – often 3d such as Delft3d

• + specific receptor sensitivity assessment+ specific receptor sensitivity assessment

• + specific receptor impact assessment+ specific receptor impact assessment

• + acceptablity determination process + acceptablity determination process

Timescale: Developed with stakeholder input over months - years (eg best practice 1 complete year of baseline data for a new plant EIA)

Costs: €100k-€1M/study depending on details

Wide Range of Cases!Wide Range of Cases!

A Power Station A Power Station on an Estuaryon an Estuary

• Hypothetical exampleHypothetical example

– Typical major estuary with port, sewage treatment Typical major estuary with port, sewage treatment works, heavy industry (some with discharges to water)works, heavy industry (some with discharges to water)

– Coal-fired power station with flue gas desulphurisation Coal-fired power station with flue gas desulphurisation (limestone gypsum process) (limestone gypsum process)

– Ash lagoon & coal stock drainage to small natural water Ash lagoon & coal stock drainage to small natural water course …course …• … … which also receives effluent from a nearby light which also receives effluent from a nearby light

industrial estate & agricultural land (dairy) upstreamindustrial estate & agricultural land (dairy) upstream– Once through cooled (50 m3/s) - discharge to estuary of Once through cooled (50 m3/s) - discharge to estuary of

• heat heat • chlorination oxidant (UK annex VIII)chlorination oxidant (UK annex VIII)• water treatment plant effluent water treatment plant effluent • FGD effluent via cooling water dischargeFGD effluent via cooling water discharge

Tier 0/1 assessmentTier 0/1 assessment

• Screening for substances for detailed Screening for substances for detailed assessment (H1 in England & Wales)assessment (H1 in England & Wales)– Limits detailed assessment to 3 of 20 substances Limits detailed assessment to 3 of 20 substances

in initial list of substancs entering drainage ditchin initial list of substancs entering drainage ditch– Limits detailed assessment of discharge to Limits detailed assessment of discharge to

estuary to heat and chlorination oxidant onlyestuary to heat and chlorination oxidant only• Find concentrations increments from water treatment Find concentrations increments from water treatment

plant and FGD effluent are small and screen out with plant and FGD effluent are small and screen out with Tier 1 criteriaTier 1 criteria

– Eg point of discharge concentrations small compared to Eg point of discharge concentrations small compared to EQS-AA EQS-AA EQS-MACEQS-MAC or ambient (if ambient concentrations > EQS & need or ambient (if ambient concentrations > EQS & need

to consider ‘no deterioration’ policy)to consider ‘no deterioration’ policy)

Tier 2 assessmentTier 2 assessment• Use eg CORMIX to indicate no Use eg CORMIX to indicate no

issue with drainage ditch issue with drainage ditch influence on estuaryinfluence on estuary– Use of precautionary extent Use of precautionary extent

acceptability criteriaacceptability criteria• Eg 1km for ‘wide’ estuary & no Eg 1km for ‘wide’ estuary & no

‘special’ receptor within the ‘special’ receptor within the predicted zone of exceedence predicted zone of exceedence

• Alternatively could use full Alternatively could use full detailed modelling if available detailed modelling if available (but may not be suitable (but may not be suitable directly if developed for other directly if developed for other purposes) purposes)

Tier 3/4Tier 3/4

• Detailed receptor mappingDetailed receptor mapping• Detailed dispersion modelling Detailed dispersion modelling

appropriate to case: appropriate to case: •often 3d such as Delft3doften 3d such as Delft3d

• + specific receptor sensitivity + specific receptor sensitivity assessmentassessment

• + specific receptor impact assessment+ specific receptor impact assessment• + acceptablity determination process + acceptablity determination process

Tier 4 – Fieldwork (flows, Tier 4 – Fieldwork (flows, plumes, mixing, ambient plumes, mixing, ambient concentrations)concentrations)

Tier 4 – Fieldwork receptorsTier 4 – Fieldwork receptors

Biotope MappingBiotope Mapping

Receptor Sensitivity Receptor Sensitivity MappingMapping

Hydraulic Modelling Hydraulic Modelling TechniquesTechniques

Numerical ModellingNumerical ModellingLow water spring

Early ebb neap

Numerical Modelling- Numerical Modelling- AnimationAnimation

• EQS-MAC concentration exceedence EQS-MAC concentration exceedence variationvariation– bed and surface– through an equinox spring neap cycle

•shoreline discharge over an intertidal area with wetting & drying

Consequence Assessment Consequence Assessment • Case-specific assessment Case-specific assessment

of the envisaged impact of the envisaged impact of the proposed mixing of the proposed mixing zone on the specific zone on the specific receptors potentially receptors potentially affectedaffected

• Impact characterisationImpact characterisation– Positive/neutral/negativePositive/neutral/negative– Scale (spatial, temporal)Scale (spatial, temporal)– Significance (conservation Significance (conservation

value)value)• Integrated assessmentIntegrated assessment

– Will conservation objective Will conservation objective and/or water body objective and/or water body objective be compromised by the be compromised by the candidate mixing zonecandidate mixing zone

ConclusionConclusion

• CIS MZ Guidance:CIS MZ Guidance:– Fit for purposeFit for purpose– Encourages efficient & flexible risk-Encourages efficient & flexible risk-

based regulation focusing on key based regulation focusing on key aspectsaspects

– Vital to allow application of technologies Vital to allow application of technologies & options that might otherwise be ruled & options that might otherwise be ruled out leading to unwarranted costs or out leading to unwarranted costs or unwarranted impacts on other media unwarranted impacts on other media

Thank you for Thank you for your attention!your attention!

Coal Stock Drain

Ash Mound drain

Site drain

Power Station Cooling System

Water Treatment Plant effluent, FGD effluent, DeNox effluent …

Sewage Treatment Works

EQS exceedenceEQS exceedence

• Does not mean necessarily harm to all Does not mean necessarily harm to all receptors when EQS concentration receptors when EQS concentration exceeded eg Chloroform (EQS Datasheet exceeded eg Chloroform (EQS Datasheet 2005)2005)– 2008/105/EC EQS 2.5 ug/l (protection of 2008/105/EC EQS 2.5 ug/l (protection of

bacteria in sediment breaking down organic bacteria in sediment breaking down organic matter) but notematter) but note• NOEC fish NOEC fish 1.463 mg/l1.463 mg/l EQS*585 EQS*585

• NOEC invertebrate NOEC invertebrate 6.3 mg/l 6.3 mg/l EQS*2520EQS*2520

• NOEC algae NOEC algae 3.61 mg/l 3.61 mg/l EQS*1444 EQS*1444