Regulations and applications of SUDS technology in Scotland

Transcription

1 Namur workshop, November 2014 Regulations and applications of SUDS technology in Scotland Dr BJ D Arcy Independent environmental consultant Research Fellow Abertay University Chair Scottish Green Infrastructure Forum b.darcy@btinternet.com

2 Scottish Environment Protection Agency, SEPA Formed (créé) in 1996, by merging 10 river 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 qualityof the water environment, and is the flood warningagency in Scotland (not flood measures). SEPA has driven SUDS technology in Scotland.

3 SUDS: sustainable urban drainage systems Engineered techniques which together or 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 alternatives. Concentration (ug/l) Cr, Pb, As, V, Cu Cr Pb As V Cu Discharge /10/ :24 28/10/ :36 28/10/ :48 28/10/ :00 28/10/ :12 28/10/ :24 28/10/ :36 Time Plus proche de la nature Discharge (m3/s)

4 SUDS aspirations for multiple benefits

5 Source control SUDS & green infrastructure for restoration of urban water cycle & as climate change countermeasures Attenuate peak flows close to source reducing need for pumping from storm tanks Cooling effect (evapotranspiration) for heat island problems Recharge groundwater Slow & prolong the rate of drainage to rivers Gestion sur la parcelle!

6 Regulation & bringing the technology The multi-stakeholder challenge for regulating stormwater Who should be responsible for the SUDS infrastructure? The relationship between regulation and other persuasion factors Qui est responsable? into practice

7 Stormwater as a regulatory challenge Discharge from a surface water sewer First flush? Flood risk Illegal effluents or misconnections Flood risk authority Water utility Pollution control agency La même eau mais différentes responsabilités! Local council: Public health Building control

8 Who owns the infrastructure? A qui appartient l infrastructure? Motorways and major trunk roads... government Roads & streets... Local authority Public sewers...the water utility Within each property The land owner or business

9 Who is responsible for the pollution? The water utility makes the discharge from sewer networks The local council for road drainage Traffic provides some of the pollution Human activity provides contamination too

10 Who should own and maintain SUDS features? Propriétéet responsabilitéde l entretien Public drainage features Water utility (= Intercommunales) or local council (= Commune)? Which is more important the stormwater engineering or maintaining the grass and other plants, amenity & appearance? Private sites (house plots, individual businesses & commercial units) Need building control validation as fit for purpose Can we split those remits?

11 Co-develop regulatory options: Sustainable Urban Drainage Scottish Working Party Environmental Problem Definition and Characterisation Assess Effectiveness Socio-economic considerations Co develop with target sector ideas for resolution of problem Co-promote solutions with target sector Dialogue entre les parties : régulateur et parties prenantes (promoteurs, constructeurs, etc.)

12 SEPA: Environmental Driver Doing SUDS in Scotland Developer Planning Authority Retrofits Building Control Scottish Water Site Owner

13 WEWS Act 2003 gave remit for SUDS to Scottish Water Scottish Water 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. SUDSWP agreed on this option, but others in SW resisting the remit. Local councils 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. Flood Risk Management Act 2009 gave new powers & duties to Local councils.

14 WFD requires management of diffuse pollution Diffuse pollution...surface water drainage Many individually minor sources that collectively determine water quality on routine basis Best practice approach needed across sectors Need water qualitytreatment by SUDS for runoff. Anthropogenic baseline qualitynot the same as liability to major spill incidents.

15 Diffuse sources of pollution mustbe regulated: a WFD requirement 5% directly controlled by site licence 95% not directly regulated By discharge licence The challenge for pollution control: Number of sources vastly outnumbers those classically controlled by regulation hitherto A totally different regulatory approach is therefore required: light touch + sectors engagement Effective uptake of measures will only be achieved by sector led initiatives

16 Regulations & guidance to bring in SUDS technology in Scotland From 1995 in Scotland, implemented COPA (1974) provisions for control of surface water runoff; required SUDS technology. WEWS Act 2003, & GBRs (2006) SUDS for Roads (2010) Building Regulations (2005) Permitted development, 2009 consultations Stormwater management plans & integrated drainage ( )

17 Requiring SUDS, & Regulating Oil & chemical contamination risks for stormwater GBR 10 The dischargemust not contain runoff from the followingareas constructed after ( ) Fuel delivery areas loading/unloading bays where potentially polluting material handled Oil & chemical storage, handling & delivery areas Developments since shall use SUDS (paraphrased)

18 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, or onto any surface which drains to it. Sewage or trade effluent must not be discharged into a surface water drainage system. But still need passive treatment infrastructure

19 Regulation to require SUDS technology Technical & policy Guidance (Planning, Roads, Water Utility, EPA, Building Standards) Economic environment Establishment of a Market for the technology Consistent uptake of technology Alternatives, not add-on costs Reductions In water charges Affordable, widespread uptake of technology

20 No maintenance, no functionality GBR 10 requires maintenance of surface water treatment systems of all kinds. But... Inspection? Enforcement?

21 Enforcement makes a difference A n n u a l T P lo ad (t o n Long-term changes in P input (Loch Leven)

22 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 resources Edinburgh council environmental wardens: remit includes littering, dog fouling, car exhausts...diffuse pollution?

23 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 water overflows)(compliance with GBR 10) Q & S process: public s to address existing impacts of SWOs. Serious limitations and long timescales. Local Authorities: Planning & Bld. Control 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 Enterprise CBI, RIAS, Homes for Scotland

24 House plot or unit plot SUDS small scale features at each development unit. AIMS: 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. Provide basic 1 st level of self purification by soil & vegetation, grass, or stone filter drains or permeable surfaces.

25 How to stop foul into surface wrong-connections? Make it in your face

26 Innovation: bringing unit plot SUDS technology into practice Benefits 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 Cost savings for public purse where 2 o measures required downstream on surface water network. Regulatory regime required 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 development mitigation techniques Offence provisions if damaged/by-passed

27 Conclusions Regulationestablishes a market for the technology and consultancy expertise Guidanceneeds 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 factorsneed to be addressed to allow at least cost-neutral take-up of the technology Plot by plot techniques for stormwater offer costeffective benefits for stormwater quality and flow attenuation Need an inspection & enforcement regime