regulations and applications of suds technology in
TRANSCRIPT
Namur workshop, November 2014
Regulations and applications of SUDS technology in
Scotland
Dr BJ D’ArcyDr BJ D’Arcy
Independent environmental consultant
Research Fellow Abertay University
Chair Scottish Green Infrastructure Forum
Scottish Environment Protection Agency,
SEPA www.sepa.org.uk
• Formed (créé) in 1996, by merging 10 river purification boards, HMIPI, and some waste purification boards, HMIPI, and some waste regulation functions from local authorities.
• Remit: the single statutory environmental regulator in Scotland, responsible for all aspects of the environment: water, waste, land and air quality (qualité eau, déchets, sols et air).
• SEPA regulates the quality of the water • SEPA regulates the quality of the water environment, and is the flood warning agency in Scotland (not flood measures). SEPA has drivenSUDS technology in Scotland.
SUDS: sustainable urban drainage systems
Engineered techniques
which together or
individually aim to
Cr, Pb, As, V, Cu
300
350
400
1.000
1.200
1.400
Cr
Pb
As
V
Cu
Discharge
individually aim to
attenuate peak flows
and clean-up runoff, with
the aim of replicating
natural hydrology.
La meme techniques: LID, WSUD,
urban BMPs, -techniques
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28/10/2007 02:24 28/10/2007 03:36 28/10/2007 04:48 28/10/2007 06:00 28/10/2007 07:12 28/10/2007 08:24 28/10/2007 09:36
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(m3/
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Plus proche de la natureurban BMPs, -techniques
alternatives.
Plus proche de la nature
SUDS aspirations for multiple benefits
Source control SUDS & green infrastructure for
restoration of urban water cycle & as climate
change countermeasures
• Attenuate peak flows close to • Attenuate peak flows close to
source – reducing need for
pumping from storm tanks
• Cooling effect
(evapotranspiration) for heat
island problems
• Recharge groundwater• Recharge groundwater
• Slow & prolong the rate of
drainage to rivers
• Gestion sur la parcelle!
Regulation & bringing the technology
into practice
• The multi-stakeholder challenge for regulating challenge for regulating stormwater
• Who should be responsible for the SUDS infrastructure?
• The relationship between regulation and between regulation and other persuasion factors
• Qui est responsable?
Stormwater as a regulatory challenge
Discharge from a surface water sewer
First flush?
Illegal effluents or misconnections
Flood risk authority
Floodrisk
surface water sewer
Pollution control agency
Flood risk authority Water utility
Local council:Public health
Building control
La même eau mais différentes responsabilités !
Who owns the infrastructure?
• A qui appartient
l’infrastructure?l’infrastructure?
• Motorways and major trunk roads ... government
• Roads & streets... Local authority
• Public sewers...the water
utilityutility
• Within each property
The land owner or
business
Who is responsible for the pollution?
• The water utility makes
the discharge from the discharge from
sewer networks
• The local council for
road drainage
• Traffic provides some of
the pollutionthe pollution
• Human activity provides
contamination too
Who should own and maintain SUDS features?
Propriété et responsabilité de l’entretien
Public drainage features
• Water utility (=
Private sites (house plots, individual businesses & commercial units)
• Water utility (=
Intercommunales) or local council (= Commune) ?
• Which is more important –the stormwater engineering or maintaining the grass and other plants, amenity &
individual businesses & commercial units)
Need building control validation as fit for purpose
other plants, amenity & appearance?
• Can we split those remits?
Co-develop regulatory options: Sustainable
Urban Drainage Scottish Working Party
Environmental
ProblemDefinition and
CharacterisationProblem Characterisation
Co – develop with
target sector ideas for
resolution of problem
Assess
Effectiveness
Socio-economic
considerations
Co-promote
solutions with
target sector
Dialogue entre les parties : régulateur et parties prenantes
(promoteurs, constructeurs, etc.)
“Doing SUDS” in Scotland
SEPA: Environmental Driver
Developer
Building
Control
Planning
Authority
Developer
Retrofits
Scottish
Water
Site
Owner
WEWS Act 2003 gave remit for SUDS
to Scottish Water
Scottish Water
• Formed from the drainage
Local councils
• Broad remit allows for • Formed from the drainage
functions of local authorities –
took all the drainage engineers
• Legal remit for SUDS allows a
capital programme for retrofits
and improving existing
polluted watercourses.
• Broad remit allows for multiple benefits and objectives in theory
• Broad remit and local political influence puts drainage and SUDS programme at risk of loss of budget to other issues.
polluted watercourses.
• SUDSWP agreed on this
option, but others in SW
resisting the remit.
programme at risk of loss of budget to other issues.
• Flood Risk Management Act 2009 gave new powers & duties to Local councils.
WFD requires management of diffuse
pollution
Diffuse pollution.....surface water drainage
• Many individually minor “sources” that • Many individually minor “sources” that collectively determine water quality on routine basis
• Best practice approach needed across sectors
• Need water quality treatment by SUDS for
runoff.
Need water quality treatment by SUDS for
runoff.
• Anthropogenic baseline quality NOT the same as liability to major spill incidents.
Diffuse sources of pollution must be regulated:
a WFD requirement
The challenge for pollution control:
5% directly control:
• Number of sources vastly outnumbers those classically controlled by regulation hitherto
• A totally different regulatory approach is therefore required:
5% directly
controlled by site
licence
• A totally different regulatory approach is therefore required: light touch + sectors engagement
• Effective uptake of measures will only be achieved by sector led initiatives
95% not
directly regulated
By discharge licence
Regulations & guidance to bring in
SUDS technology in Scotland
• From 1995 in Scotland, implemented COPA (1974) provisions for control of surface water From 1995 in Scotland, implemented COPA (1974) provisions for control of surface water runoff; required SUDS technology.
• WEWS Act 2003, & GBRs 10-11 (2006)
• SUDS for Roads (2010)
• Building Regulations (2005)• Building Regulations (2005)
• Permitted development, 2009 consultations
• Stormwater management plans & integrated drainage (2009-2010)
Requiring SUDS, & Regulating Oil & chemical
contamination risks for stormwater…GBR 10
The discharge must not contain
runoff from the following areas constructed after (1.04.2006)runoff from the following areas constructed after (1.04.2006)
• Fuel delivery areas
• loading/unloading bays where potentially polluting material handled
• Oil & chemical storage, handling & delivery areas
Developments since 1.4.2006 shall use SUDS (paraphrased)
Regulating wash waters & sewage to prevent
contamination of stormwater drainage system: GBR 11
• “Oil ..(& other pollutants) must
not be disposed of into a
surface water drainage system, surface water drainage system,
or onto any surface which
drains to it.”
• “Sewage or trade effluent
must not be discharged into a
surface water drainage
system.”system.”
• But still need passive
treatment infrastructure…
Regulation to require
SUDS technology
Technical & policy
Guidance (Planning,
Roads, Water
Utility, EPA,
Building Standards)
Economic
environment
Consistent uptake
of technology
Alternatives,
not add-on
costs
Reductions
In water
charges
Establishment
of a
Market for the
technology
charges
Affordable, widespread uptake
of technology
No maintenance, no functionality
• GBR 10 requires
maintenance of maintenance of
surface water
treatment systems
of all kinds.
But...But...
• Inspection?
• Enforcement?
Enforcement makes a difference
25
5
10
15
20
An
nu
al
TP
loa
d (
ton
ne
s)
Long-term changes in P input (Loch Leven)
01850 1875 1900 1925 1950 1975 2000
95% indirectly controlled - by GBRs, not licences –
but need an inspection & enforcement regime
Cannot visit each of the premises:
need a sampling approach - &
partnerships for most efficient use of partnerships for most efficient use of
resources
Edinburgh council Edinburgh council
environmental wardens:
remit includes littering,
dog fouling, car
exhausts...diffuse
pollution?
How to achieve an inspection regime for individually minor,
but collectively significant sources and features?
Scottish Water• responsible for discharge quality from public SWOs (Storm
Local Authorities:•Planning & Bld. Control•Roads; SUDS & FloodsStorm
water overflows)(compliance with GBR 10)•Q & S process: public £s to address existing impacts of SWOs. Serious limitations and long timescales.
•Roads; SUDS & Floods•Integrated drainage•Environ Health•Building control•Dog fouling & street littering•Transportation & traffic
SEPA•Regulation of GBRs•Serving notices•Administration of river restoration funds (DP & habitat benefits?)
Other possible partners:Scottish govt. as observers for one or two pilot projects?Scottish EnterpriseCBI, RIAS, Homes for Scotland
House plot or unit plot SUDSsmall scale features at each development unit.
AIMS:
• Attenuate peak runoff close to source (roof and • Attenuate peak runoff close to source (roof and yard rainfall runoff)
• Make it difficult to put foul drainage into the surface water system: above ground features close to house, &/or stone-fill filter drains that would quickly block if sewage drained into them.would quickly block if sewage drained into them.
• Provide basic 1st level of self purification by soil & vegetation, grass, or stone filter drains or permeable surfaces.
How to stop foul into surface wrong-connections?
Make it in your face…
Innovation: bringing unit plot SUDS
technology into practice
Benefits
• Significant flow attenuation at source
Regulatory regime required
• Building regulations – allow • Significant flow attenuation at source
• Maintenance the responsibility of plot occupant (designed to inconvenience at that level if neglected)
• No costs to public utilities/authorities
• Building regulations – allow direct connections of roof drains to SUDS
• Planning guidance explaining concept & then being basis of a planning condition “shall be drained by house plot SUDS technology”
• Recognition as permitted • Cost savings for public purse
where 2o measures required downstream on surface water network.
• Recognition as permitted development mitigation techniques
• Offence provisions if damaged/by-passed
Conclusions
• Regulation establishes a market for the technology and consultancy expertise
• Guidance needs to be modified to allow uptake of the • Guidance needs to be modified to allow uptake of the technology (some guidance precedes regulation during introductory phase of technology, but this stage is most important for standards and consistency)
• Economic factors need to be addressed to allow at least cost-neutral take-up of the technology
• Plot by plot techniques for stormwater offer cost-effective benefits for stormwater quality and flow effective benefits for stormwater quality and flow attenuation
• Need an inspection & enforcement regime