Transcript 9 Derogations - sanepid.opole.pl

Dr. K. Luden
German guidance document on §9
dealing with derogations
Dr. Katrin Luden
Warschau Feb. 2009
1
Dr. K. Luden
Drinking water directive 98/83/EC
§9 Derogations
Member States may provide for derogations from the parametric values
set out in Annex I, Part B, (chemical) or set in accordance with Article
5(3) (others), up to a maximum value to be determined by them, provided
no derogation constitutes a potential danger to human health and provided
that the supply of water intended for human consumption in the area
concerned cannot otherwise be maintained by any other reasonable means.
Derogations shall be limited to as short a time as possible and shall not
exceed three years, towards the end of which a review shall be conducted
to determine whether sufficient progress has been made. Where a Member
State intends to grant a second derogation, it shall communicate the
review, along with the grounds for its decision on the second derogation,
to the Commission. No such second derogation shall exceed three years.
Dr. K. Luden
Drinking water directive 98/83/EC
Derogations
If the competent authorities consider the non-compliance with
the parametric value to be trivial, and if action taken in
accordance with Article 8(2) is sufficient to remedy the
problem within 30 days, the requirements of paragraph 3
(specify grounds, parameters, timeframe…) need not be
applied.
possible only when no derogation for [..] more than 30
days on aggregate during the previous 12 months
Dr. K. Luden
Drinking water directive 98/83/EC
(1) param. Ann. 1Part B (chemical) first and second
derogation
(2) third derogation
(3) specification of grounds, parameters, maximum
values, area, food productions, monitoring,
remediation plan duration
(4) trivial derogations
(5) 30 days
(6) information of the affected population
Dr. K. Luden
German drinking water ordinance
§ 9 Measures in case of non-compliance with limit
values and requirements
•
Health office gets to know of non compliance immediate decision of whether this is liable to
cause a hazard to human health; orders of
investigation to find the cause of non compliance
•
If hazard to human health is feared: alternative
supply (if possible) or continuous water supply
under security measures
•
Hazard to human health cannot be ruled out by
above measures: interruption of water supply
Dr. K. Luden
German drinking water ordinance
§ 9 Measures in case of non-compliance with limit
values and requirements
(4) In all cases of non compliance health office orders
remedial action
(5) If the non compliance is considered no risk to
human health the health office sets a maximum
value and a time allowed for the correction within
30 days; does not apply to E. coli, Enterococci (and
Coliform bacteria)
(6) In case of non compliance for chemical
parameters: derogation permissable for 3 years
(information of the federal ministry of health)
Dr. K. Luden
German drinking water ordinance
§ 9 Measures in case of non-compliance with limit
values and requirements
(7) Review of the permitted derogation and second
permit of derogation
(8) Under exceptional circumstances application of a
third permit for derogation filed with the EU
(9) Same applies to indicator parameters
(10) Specified information in the permits of derogation
as in EU directive
(11) Information of the consumers/public
(12) Not applicable to water in bottles or containers
Dr. K. Luden
§9 Guidance document
Part 1 Microbiology
Indicator organisms
E. coli, Enterococci and Coliform bacteria
Pathogens liable to damage human health
Legionella
Part 2 Chemistry
Concentration of chemicals possibly dangerous to human
health
Carcinogens
Disinfection products
…
Dr. K. Luden
§9 Guidance document
General information
Invariably every single time a limit value is exceeded
(plausibility of the results critically reviewed)
immediately the question whether this poses a risk to
human health has to be answered
All decisions by the health office have to be based on that
§16 of the German DW-ordinance requires action plans
for derogations
Disruption of a water should be an emergency measure
only
Dr. K. Luden
§9 Guidance document
Dangers of an interruption of the water supply
Incalculable epidemic risk due to non sufficient supply of
water for hygienic matters (body hygiene, laundry,
dishwashing or sewage system)
Risk due to lack of water for firefighting
The more people are affected by the interruption the
higher the potential hazard and damage to be
balanced against the potential benefit
Dr. K. Luden
Indicator parameters
Limit value exceeded for microbiological indicator
organisms:
? Is there a potential danger to human health?
yes
> act as described for E. coli
no
> measures for identifying the cause and
eliminating it, legal constraints, derogation permit
Examples:
Colony counts
C. perfringens
Turbidity
Dr. K. Luden
Colony counts
Abnormal change:
Health authorities and water company investigate the
cause and decide on necessary measures e.g.
flushing of the pipes
increase of concentration of disinfection chemicals
further investigation of additional parameters like
potentially pathogenic organisms like P. aeruginosa,
Aeromonads, Legionella)
Dr. K. Luden
C. perfringens
Confirmed detection of C. perfringens:
 Even with chlorination occurrence of Cryptosporidia,
Giardia or Viruses not excluded
 Immediate investigation on cause and its elimination
 Possibly analysis for Cryptosporidia and Giardia
 Analysis of fecal indicators in the source water
advisable
 boiling of water should be recommended or bottled
water should be used as foodstuff (10 to 30
Cryptosporidia cysts and 3 to 5 Giardia cysts per
100 l can cause an outbreak)
Dr. K. Luden
E. coli, Enterococci (Coliform bacteria)
Coliform bacteria:
 Without potential hazard to human health
 Not an undisputable evidence of fecal contamination
 Nevertheless unwanted contamination therefore
identification of the organism necessary
 Investigation of the cause (e.g. with the help of an
institute for hygiene)
 Measures for continuation of water supply
Dr. K. Luden
E. coli, Enterococci (Coliform bacteria)
E. coli and Enterococci:
Limit value exceeded: always potential risk to human
health given
 Switch to a different water supply if possible
 Disinfection (may be not sufficient for Cryptosporidia,
Giardia, C. perfringens and some viruses) and
information of the public,
 boiling for 3 minutes as a measure of self protection
 If disinfection not possible: restriction of use (boiling,
toilet…)
 If those measures are not sufficient: interruption of
water supply (only in extreme situations)
Dr. K. Luden
Pathogens
Pathogens posing a hazard to human health:
Possible causes:
direct influence of manure
accidents or catastrophes
direct connection between drinking water and sewage
pipes
…
If there is only an isolated detection of a pathogen
plausibility of the test result should be confirmed by
another lab or repeated analysis
Procedure as for E. coli
Dr. K. Luden
Legionella
The technical specifications of DVGW and a publication
dealing with Legionella in hospitals etc. are referred
to
Dr. K. Luden
Chemistry



Tables with maximum parametric values concerning
toxic concentrations specific for adults or infants and
small children
Distinguished between compounds with or without a
threshold effect
Dealing with potentially carcinogen compounds
Questions:
Is there a hazard to human health?
Is the hazard “bigger” than from interruption of the water
supply?
What measures for protection (alternative water supply)?
Dr. K. Luden
Example
Several incidences of coliform bacteria within the
distributions system of a water supplier (city of 50.000).
Also higher total plate counts than usual.
Hazard to human health?
Where is the source of the contamination?
What measures have to be taken?
Dr. K. Luden
Example
An “ancient” water tower (1897) was
identified as source of the
contamination: dead flies on the
surface of the waterbody
Some of the coliforms were identified
as potentially pathogenic (E. chloacae
and S. marcescens): boiling
recommendation
Dr. K. Luden
Example
Problem
Measures
Dead flies on water surface
remove/cleaning of sides in zone
of water level higher colony
counts
Old pipes  no air/water flushing
possible
Flushing in direction towards the
tower (change of flow direction) 
higher colony counts
Shutdown of the water tower for
cleaning and disinfection not
possible, needed for maintaining
pressure in the pipes of the city
New water works, pressure
maintaining pumps  needed time
during which a continuous
overflow was maintained
Derogation for several months until pumps were installed.
Dr. K. Luden
Example 2
Problem
Measures
Within a water supply zone (city)
several occurrences of coliform
bacteria in monitoring results.
Sporadic in a storage tank at the
water works
Boiling recommendation as well as
flushing and pressure tests in the
piping
Cleaning and disinfection of the
tank
Samples were taken at hydrant
below the surface
Chose more reliable sampling
points (e.g. behind the water meter
in households)
area was disconnected from the
water supply (high stagnation
Fair area between the water works times reflux possible…)
and the affected area.
Flushing and installation of
devices to prevent reflux into the
pipes
Dr. K. Luden
Thank you for your attention!