UK WIR

Emerging Contaminants How the UK water industry has responded

Dr Arthur Thornton

Research and Innovation

Atkins

UK WIR

Substances of emerging concern

1. “Emerging substances” – how are

they identified?

2. Understanding sources

3. Perspectives from the UKWIR CIP

4. CIP findings

5. Further investigations – CIP2

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Emerging contaminants - identification

● How do we define emerging contaminants?

● The “list of lists” syndrome – where each list is based on different and sometimes poor defined (and even more poorly communicated) criteria

● Scoring systems abound with sensible but differing weightings (some more questionable)

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What are the criteria for “emerging” classification? [really “emerging concern”]

● Likely effects – phys chem. properties - persistence, bioavailability, toxicity

● Likely presence – amount of use, mode of use , control of use

● Already have monitoring data – hence profile – measured elsewhere? (note – EU approach re steroids – concern but evidence across the EU sparse or patchy – so on watch list

● Change of uses

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Example criteria – but what weighting?

● Production (use)

● Kow - Octanol-water

partition coefficient

● Abiotic degradability

● Biodegradability

● Endocrine disrupting

effects

● Immune system

disrupting effects

● Tissue (dermal)

lesion

● Mutagen

● Carcinogen

● Reproduction / development

effects

● Lowest acute toxicity data

(LC50, EC50)

● Lowest chronic toxicity data

(ecotoxicological)

NOEC/LOEC

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Other factors not often included in scientific assessments

● What about value to society as a negative weighting? - eg use of EE2, copper, zinc, plastics

● Also amenability to implement control – diffuse sources / natural sources (PAHs, E2)

● Effects? But which target organism(s) – aquatic life / humans via drinking water

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GIS

WwTW discharges

Other point sources

Agricultural

Minewater

Intermittent urban

Highway runoff

Atmospheric

Natural

Septic tanks

Sources to WwTW

SAGIS

Refined source apportionment

Re-vamped SIMCAT

GIS interface

and user friendly

outputs

Comprehensive range

of bespoke diffuse

element inputs

River Monitoring data

New, more accurate

and diverse data from

CIP

Modelling Sources of Contaminants

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SAGIS is separated into 18

Regional Models (Anglian

model in this case). The

tool is based on a GIS

interface and Access

databases.

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This zoomed in image shows the

waterbodies, rivers and features

(discharges abstractions etc.).

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CIP ISSUES – five main questions

● Trace contaminants in surface waters - what is the extent of job to be done (and Water Industry rôle)?

● Which substances are of primary concern? – and which of low priority?

● How well are these substances removed by current treatment processes?

● What new processes might be of value?

● What are the main sources of these substances to sewer – other control options

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Questions addressed in 3 main strands

• Effluent quality – 162 works ca fortnightly over one year –

representative of treatment for 70% of popn (not coastal / v small

wks) 0.25M results

• Wastewater treatment process effectiveness – 28 works, influent,

mid process and effluent samples – over approx one year 0.25M

results

• Sources to sewer - urban catchment

studies to look at upstream sources

– 9 towns 0.3M results

• 75 substances – metals, organic chemicals

(industrial and household), pharmaceuticals

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What’s new / different / special about the CIP?

Other investigations

● Focus on particular works/treatment processes

● Single substance groups (eg steroids, metals or some pharms)

● Problems (particular discharges or incidents)

● Local, small scale

● Research driven (policy aim uncertain)

● Comparability issues

The CIP

● Addresses the national status quo re processes

● Covers all main substance groups

● Not influenced by specific local problems or unduly biased by single sector

● Massive scale provides power and greater certainty

● Policy aims defined at outset

● Coherent measurement strategy (LODs, sampling sample numbers - fosters comparability)

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CIP priorities

● PAHs

● TBT

● Nonylphenol

● DEHP

● Copper , Nickel, Zinc

● Triclosan

● BDEs

● Steroids

● Diclofenac

● Pharmaceuticals (various but not exhaustive list)

● New list P(H)Ss – PFOS, HBCDD, cypermethrin?

Current Likely future

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Note “Un-prioritised”!

● Bisphenol-A ● EDTA ● Mercury ● Lead ● Silver ● AMPA ● Bentazone ● Glyphosate ● A number of other biocides – not used

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Treatability

●

Majority of

substance

concentrations

reduced

substantially....

.

But often not

sufficiently re

EQS NID

NIT

PBD

PBT

CUD

CUT

ZND

ZNT

CDD

CDT

HGD

HGT

FED

FET

ALD

ALT

ALR

AGD

AGT

DEHP

BDE28

BDE47

BDE99

BDE100

BDE153BDE154

NOP

TBT

ANT

FLU

NAP

BAP

BBF

BBK

BGHIP

ICDP

TSS

AMONBOD

COD

TP

PHOS

GLYPH

TRICL

BENTZNBISPA

MCPP

EDTA

IBPF

PRPL

ERMYOFLX

OXTCY

SLCYA

FLXT

E1

E2

EE2

NOP1ET

NOP2ET

NOP3ET

DCF

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

Frac

tio

nal

re

mo

val i

n t

reat

me

nt

-O

VER

ALL

Influent - effluent removal - median and interquartile range

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Source issues Sources of the majority of substances of interest found to be

predominantly domestic

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

TRICL BISPA EDTA IBPF PRPL ERMY OFLX OXTCY FLXT E1 E2 EE2 DCF

Fra

ctio

na

l co

ntr

ibu

tio

n t

o l

oa

dDomestic sewageL'boro

Grantham

Stirling

Fazakerley

Consett

Blackburn

Eastleigh

Huddersfield

Maidenhead

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Example-nonylphenol in WwTW effluents

Shows value, variance, skewness, likely range in

effluent

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

Co

nce

ntr

atio

n µ

g/l

WwTW code

NOP medianmean

EQS

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The three scenarios: The three scenarios determined post

dilution:

● 10% Available EQS: No deterioration Policy, PHS cessation, Background

● 50% Available EQS: Taking a view on ‘significant contribution’

● 100% Available EQS: Maximum allowable (cannot permit breach)

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Tertiary technologies

● Pilot plant studies used to determine removal rates for substances of interest

● Costs derived, incorporating pilot plant information

● CO2 emissions estimated based on

power consumption

●Assumptions detailed in Appendix

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Control options

● Substance specific: Existing controls, use controls, control at source

● End of pipe: Site specific, treatment process efficiency v substance

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Triclosan

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0 1000 2000 3000 4000 5000

Tric

losa

n µ

g/l

Cumulative Number of WwTW

current

ban in PCPs

NTF low, AOP med, MF/RO high

source plus NTF

source plus NTF low, AOP med, MF/RO

highsource plus NTF low, AOP med and high

Maximum obseveredconcentration0.44 µg/l

Controls are non-medical

Personal Care Products

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CIP Phase 2

● Clear direction from Government

● Greater focus on individual high risk sites – as determinant of and justification for potentially high levels of investment

● Require clear evidence of need for measures

● Press ahead with investigations of prioritised list of substances

● Plus review of pharmaceuticals (UKWIR project) and inclusion of new substances

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CIP Phase 2

●Remains EQS driven

● In - river confirmation:

• Of compliance status

• Of contribution made by discharge as basis

for direction and apportionment of

measures

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Contribution example

Graph shows mean

concentrations with

90% confidence

intervals

0

5

10

15

20

25

30

35

upstream effluent downstream

dis

solv

ed

co

pp

er

µg/

l

Contribution

EQS (BLM)

Apparent mean dilution 3.6 x

Contribution

= 29 % EQS

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Technology & Catchments

● Major trials of treatment innovations – at pilot and demonstration scale

● Approach to management of catchment as a whole rather than by individual discharges

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Conclusions

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Conclusions