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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
UK WIR
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)
UK WIR
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
UK WIR
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
UK WIR
SAGIS is separated into 18
Regional Models (Anglian
model in this case). The
tool is based on a GIS
interface and Access
databases.
UK WIR
This zoomed in image shows the
waterbodies, rivers and features
(discharges abstractions etc.).
UK WIR
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
UK WIR
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
UK WIR
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
UK WIR
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
UK WIR
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
UK WIR
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
UK WIR
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
UK WIR
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
UK WIR
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
UK WIR
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
UK WIR
Conclusions