PowerPoint-Pr

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Water management strategies to combat harmful
cyanobacteria in water How can we design
regulatory systems which are adequate to control
this hazard ? Ingrid Chorus UmweltBundesAmt
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Classical approach
Focussing on substances, their toxicty,
standards, monitoring in the product,
implementation
How do we monitor and implement the standard ?
How much do we tolerate (standard)?
Whats the hazard (substance)?
? How well can this work in practice for
protecting humans from exposure to toxic
cyanobacteria ?
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What are the hazards due to cyanotoxins ?
Toxic mechanisms well described for
microcystins, anatoxin-a, saxitoxins,
cylindrospermopsin
WHO provisional TDI available for microcystin-LR
TDI proposed for cylindrospermopsin
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Effects of cyanobacterial crude extracts on
embryonic development of fish and amphibians A.
Oberemm, IGB
Inhibition of early zebrafish development
following exposure to aqueous crude extracts (0.1
dw/v)
Super Blue Green Algae
control (prim-6, approx. 26 h)
Planktothrix agardhii
Aphanizomenon flos-aquae
(Müggelsee 1995)
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I. Similar malformations of fish and amphibian
hatchlings exposed to aqueous crude extracts
zebrafish (Danio rerio)
Anabaena flos-aquae NRC 44-1 (0.1 dw/v)
axolotl (Ambystoma mexicanum)
Anabaena flos-aquae NRC 44-1 (0.1 dw/v)
II. Destruction of outer egg structures of
zebrafish embryos exposed to aqueous crude extract
Planktothrix agardhii (0.01 dw/v)
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Odds ratio for illness through recreational
exposure the Pilotto et al. 1997
epidemiological study
(5000 cells few µg / L Chl.a)
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What are the hazards due to cyanotoxins ?
Toxic mechanisms well described for
microcystins, anatoxin-a, saxitoxins,
cylindrospermopsin
What do we monitor, how do we manage ?
Countries (e.g. Poland, Spain, Czech Republic,
France have set standards for MCYST-LR in
Drinking-water (1 µg / L)
! Further unknown toxins !
WHO provisional TDI available for microcystin-LR
TDI proposed for cylindrospermopsin
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Current monitoring and managment recreational
waters
WHO Guidelines for safe practice in managing
bathing waters which may contain cyanobacterial
cells and/or toxins
Guidance level how derived health risks recommended action
20 000 cells/ml or 10 µg/l Chl.a with cyanos dom human bathing epidemiological study short-term adverse health outcomes, e.g. skin, gastro - irritations, probably low frequency post on-site advisory signs inform authorities
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Guidance level how derived health risks recommended action
100 000 cells/ml or 50 µg/l Chl.a with cyanos dominant provisional TDI for MC-LR, data on other cyanotoxins potential for long-term illness short-term adverse health outcomes, e.g. skin, gastro irritations, watch for scums restrict bathing further investigation post on-site advisory signs inform authorities
20 000 cells/ml or 10 µg/l Chl.a with cyanos dom human bathing epidemiological study short-term adverse health outcomes, e.g. skin, gastro - irritations, probably low frequency post on-site advisory signs inform authorities
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Guidance level how derived health risks recommended action
scums in bathing area animal fatalities human illness cases potential for acute poisioning potential for long- and short-term illness, see below immediate action to prevent contact prohibition of swimming and water-contact activities public-health follow-up inform authorities
100 000 cells/ml or 50 µg/l Chl.a with cyanos dominant provisional DW guideline value for MC-LR, data on other cyanotoxins potential for long-term illness short-term adverse health outcomes, e.g. skin, gastro irritations, watch for scums restrict bathing further investigation post on-site advisory signs inform authorities
20 000 cells/ml or 10 µg/l Chl.a with cyanos dom human bathing epidemiological study short-term adverse health outcomes, e.g. skin, gastro - irritations, probably low frequency post on-site advisory signs inform authorities
Approach addresses cyanobacteria in general, but
uses microcystin TDI for target-setting
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Background information. Carrying capacity total
P gt 20-40 µg/L, bloom history health complaints

• Scums

• Secchi depth lt 1 m

Visual inspection

• Cyanobacteria dominant (microscopy)
• and
• Chl.-a gt 40 100 µg/L

Approach addresses cyanobacteria in general, but
implicitly uses microcystin TDI for target-setting

• Microcystin analysis

gt 10 and lt 100 µg/L
gt 100 µg/L
gt 10 µg/L
Issue warning temporarily restrict use
Issue warning consider temporary restriction of
use
Include cyanos in surveillance inform users
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Discomfort Can we really assess cyanotoxin risks
and keep people safe by monitoring at regluar
e.g. 14-day intervals for compliance to
standard(s) ?
Would it really improve if we had standards for
more of them?
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We need local expertise to understand this type
of situation, to be able to predict scums and to
be able to respond rapidly
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Classical approach
Focussing on substances, their toxicty,
standards, monitoring in the product,
implementation
How do we monitor and implement the standard ?
How much do we tolerate (standard)?
Safety is achieved through multi-barrier
approaches to avoid cyanobacterial proliferation
i.e. managing processes
Whats the hazard (substance)?
? How well can this work for protecting humans
from exposure to toxic cyanobacteria ?
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New Approach Water Safety Plan
Operational Monitoring Process rather than
Product, using HACCP principles, familiar from
food industry
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• Steps of a Water Safety Plan
• Hazard analysis and risk assessment
• Determine Control Measures
• Determine operational limit not to be exceeded at
  each
• Determine monitoring system for that limit
• Determine corrective action
• Validation of System and Verification of its safe
  operation
• Documentation and Communication

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WSP is specific to the respective setting
WSP is developed by a team of local experts who
know the system ( external expertise)
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1. Hazard analysis What information is
available for analysing the cyanotoxin hazard in
the given system ?
Data on its occurrence in the specific setting
Generic information
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Example Schlachtensee Phytoplankton-biomass
before restoration was successful, i.e. TP gt 100
µg/L (blue Cyanobacteria)
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Use generic information to assess the hazard
Generic knowledge expect microcystins ! Expect
further toxic effects !
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Fastner et al. 2001

expect higher microcystin content in cells with
Planktothrix agardhii (and highest with P.
rubescens)
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Example Havel River beaches with scums
measured concentrations
1997 ½ of 27 samples gt 100 µg / L ¼ of 27
samples gt 1000 µg / L 2 samples gt 10 000 µg /
L (provisional WHO GV for MC-LR in DW 1 µg / L)
? High risk of human exposure to hazardous toxin
levels !
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• 7 Steps of
  WSP
• Hazard analysis and risk assessment
• Determine Control measures
• Determine operational limit not to be exceeded at
  each
• Determine monitoring system for that limit
• Determine corrective action
• Validation of System and Verification of its safe
  operation
• Documentation and Communication

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• 7 Steps of
  WSP
• Hazard analysis and risk assessment
• Determine Control measures
• Determine operational limit not to be exceeded at
  each
• Determine monitoring system for that limit
• Determine corrective action
• ! Multiple Barriers catchment, water-body,
  treatment !
• Validation of System and Verification of its safe
  operation
• Documentation and Communication

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Multiple Barrier System against disease agents in
drinking-water Barriers are possible in 1.
Catchment 2. Water-body 3. Offtake
system 4. Treatment 5. Distribution
Control points for cyanobacteria in each
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Fourth barrier Drinking-water treatment
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Example 2 Rostock treatment plant microcystin
concentrations in raw and filtered water
Microcystis or Planktothrix agardhii in the raw
water (biovol. 19 mm³/L in one case, otherwise lt
2 mm³/L flocculation and rapid filtration
Chorus (ed.) 2001
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• Steps of WSP
• Control measure filter
• operational limit turbidity (fluorescence)
  threshold level
• monitoring system continuous on-line turbidity
  (fluorescence) reading
• corrective action if limit is exceeded immediate
  filter backwashing

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• Verification of CCPs safe operation
• microcystin analysis in raw and finished water,
• particularly in critical situations
• e.g. at high cell density in raw water
• or shortly before filters are backwashed
• (risk of cell lysis on filters !)

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• Verification of CCPs safe operation
• microcystin analysis in raw and finished water,
• particularly in critical situations
• e.g. at high cell density in raw water
• or shortly before filters are backwashed
• (dissolved MCYST risk of cell lysis on filters
  !)
• 7. Documentation filter operation, turbidity
  readings, backwash intervals, standard operating
  proceedures

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Third barrier Offtake system
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Second barrier Water-body management to avoid
cyanobacterial growth
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• Example Niewe Meer in Amsterdam artificial
  mixing against Microcystis spp.
• Control Measure ? Mixing depth and intensity
• Operational limit not to be exceeded ? Minimal
  pressure and operation time of aerators
• Monitoring system for that limit ? Continuous
  aerator operation record
• Corrective action ? Maintenance or replacement of
  defect aerators within ? days

See Visser et al.
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6. Verification of whether CCP is working
check for Microcystis in Niewe
Meer Validation of system analysis and choice of
CCP periodic assessment for shift to other
toxic cyanobacteria
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6. Verification of whether CCP is working
check for Microcystis in Niewe
Meer Validation of system analysis and choice of
CCP periodic assessment for shift to other
toxic cyanobacteria

• Documentation and Communication
• aerator operation, response of temperature
  profiles, development of Microcystis and other
  phytoplankton
• Communication of success and costs to public

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First barrier Catchment management
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• Target control nutrient loading to achieve
  in-lake concentrations too low to sustain
  hazardous cyanobacterial populations

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Example 1 Schlachtensee Phytoplankton-biomass
at TP 30 40 µg/L blue Cyanobacteria)
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First barrier Catchment management is the
WSP-concept applicable and helpful ?

• Target Total P lt 30 40 µg/L in the lake
• Control Measures ? Usually more than one
• Operational limits ?
• Monitoring systems ?
• Corrective action ?

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First barrier Catchment management is the
WSP-concept applicable and helpful ?

• Target Total P lt 30 40 µg/L in the lake
• Control Measures ? Usually more than one
  sewage effluent fertiliser and manure
  application land use and erosion protection
  measures
• Operational limits ?
• Monitoring systems ?
• Corrective action ?

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First barrier Catchment management is the
WSP-concept applicable and helpful ?

• Target Total P lt 30 40 µg/L in the lake
• Control Measures ? Usually more than one
  sewage effluent fertiliser and manure
  application land use and erosion protection
  measures
• Operational limits ? maximum TP concentrations in
  sewage effluent nutrient budgets vegetation
  cover
• Monitoring systems ? Yes, but often not online
• Corrective action ? Usually not as immediate as
  in technical systems

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WSP in Catchments ?, cont

• Difference to technical systems usually there is
  not the one Control measure in catchment
  management
• Benefits of applying WSP to catchment management
  more stringency
• through WSP teams,
• concept of control measures and operation limits
  for them
• sysematic approach stringency of monitoring
  their compliance and taking corrective action

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WSP in Catchments ?, cont

• Difference to technical systems usually there is
  not the one Control Measure in catchment
  management
• Benefits of applying WSP to catchment management
  more stringency
• through WSP teams,
• concept of operation limits
• stringency of monitoring their compliance and
  taking corrective action
• Stringency of
• 6. periodic validation and verification
• 7. documentation and communication

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Multiple Barrier System against disease agents in
water Barriers are possible in 1.
Catchment 2. Water-body 3. Offtake
system 4. Treatment 5.
Distribution recreational use
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EU Bathing-water directive 1976 current revision

• Draft Directive of the European Parliamentt and
  of theCouncil concerning the management of
  bathing water quality (Political agreement 16
  July 2004)
• Statements related to cyanobacteria
• Monitoring actions and frequency should be
  related to the bathing waters history and
  classification, and regional climatic conditions,
  putting emphasis on bathing waters where risks
  may occur. Conformity should be a matter of
  appropriate management measures and quality
  assurance, not merely of measuring and
  calculation. A system of bathing water profiles
  is therefore appropriate to provide a better
  understanding of risks as a basis for management
  measures.

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EU Bathing-water directive 1976 current
revision, ff.

• Article 1 purpose and scope1. This Directive
  lays down provisions for
• the monitoring and classification of bathing
  water quality(
• the management of bathing water quality and
• the provision of information to the pubic on
  bathing waters.

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EU Bathing-water directive 1976 current
revision, ff.
Article 14 a Cyanobacterial risks 1.   For
bathing waters whose profile indicates a
potential for cyanobacterial proliferation,
appropriate monitoring shall be carried out to
enable timely identification of health
risk. 2.    For bathing waters subject to
cyanobacterial proliferation, a management plan
shall be established for immediate response to
prevent exposure, including information of the
public.  
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EU Bathing-water directive 1976 current
revision, ff.
Article 19 Technical adaptations to the
Directive  1. The methods of analysis for the
parameters set out in Annex I may be adapted to
scientific and technical progress in accordance
with the procedure referred to in Article 20(2).
2. Scientific results obtained on virus
detection, toxic cyanobacteria and algae may also
be integrated completing the list of parameters
in Annex I, in accordance with the procedure
referred to in Article 20(2).  3. The Commission
may in accordance with the procedure referred to
in article 20(2), adopt technical guidelines on
selected issues of implementation relating to
bathing water management strategy, information
and reporting strategy ....
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Summary changes through the Water Safety Plan
approach

1. Hazard assessment is more comprehensive better
   options for taking experience and emerging
   knowledge into account
2. Monitoring and surveillance focuses on the
   process are the processes working to control
   the hazard, are the barriers intact ?
3. Surveillance of authorities shifts focus to
   processes rather than product
4. Systematic approach regular review of the
   systems
5. Improved documentation, transparency and
   communication

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Thank you !