Initiatives to tackle diffuse pollution in the UK

8

Pergamon

Wat. Sci Tech. Vol. 38, No. 10. pp. 131.138,1998.

IAWQ

~ 1998 Published byElsevier SCienceLId. Printed in Greal Britain. Allrights reserved

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INITIATIVES TO TACKLE DIFFUSE POLLUTION IN THE UK Brian J. D'Arcy*, Fauzia Usman*, David Griffiths** and Phillip Chatfield** • Scottish Environment Protection Agency, Clearwater House, Heriot Wan Research Parle, Avenue North. Riccarton; Edinburgh EH14 4AP. UK •• The Environment Agency. Rio House. Waterside Drive. Aztec West. Bristol BS12 4UD. UK

ABSTRACf Initiatives to addressthe problemof diffuse pollution in the UK are reviewed.Characteristics of the problem and key pollutantsare identified: oil. pesticides. sediment,organic wastes.faecal pathogens. nutrient, trace metals and solvents;of importance to potablesuppliesas well as causingenvironmental pollution. Optionsto address the problem include action by central government, limited regulatory activity by environment agencies, and educational campaigns. Examplesof several UK initiatives are given. Factors in considering effectiveness of measures are proposed. (i) in measurable improvements in the environment and (ii) in indirect measures,ego numbers of BMP's provided, kilometres of buffer zone established, tonnage of waste oil recycledetc, © 1998 Published by ElsevierScienceLtd. All rights reserved

KEYWORDS Diffuse pollution; oil; pesticides; nutrients; urban runoff; agriculture; enforcement; economic instruments; campaigns; measuring effectiveness.

INTRODUCTION This paper considers the efforts made by UK environmental regulators to address the problem of diffuse pollution, which is taken to include multiple dispersed sources (such as urban runoff discharging via surface water sewer outfalls, and field drains serving farmland). plus non-point source pollution such as contamination of direct runoff, seepage or groundwater, and aerial deposition. The major pollutants of concern in the UK are listed in Table I. together with sources and an indication of the problems they cause. The nature of diffuse pollution determines the potential of options for its control. For practical purposes many diffuse pollution problems were not controllable by the normal statutory powers that were the principal legal options for pollution control by the environmental agencies in the UK prior to Ist April 1996 (SEPA. 1996). A number of codes of practice and UK initiatives existed prior to the formation of the UK environment agencies on 1 April 1996. For agriculture, existing advice was available in relation to pesticides. fertilisers and the disposal of organic wastes, (MAFF, 1991 and Scottish Office, 1992) but there was little general awareness of diffuse pollution 131

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as a policy area worthy of focused attention and a concerted educational effort. One of the Scottish Environment Protection Agency (SEPA) predecessor agencies, the Forth River Purification Board, produced a video and booklet, "A Clear Future for Our Waters" (FRPB, 1994) that included an early attempt to raise diffuse pollution as a priority issue , indicating that the UK might need to learn from the USA and elsewhere and develop a Best Management Practices (BMPs) approach. The National Rivers Authority (one of the EA predecessor agencies) was at that time thinking along similar lines and commissioned consultants to investigate U.S. experiences with BMPs, but focused mainly on agriculture (Huggins, 1998). For the urban environment, diffuse polIution and the possible use of BMP structures in the UK was not recognised by the regulators as a serious issue until the Forth River Purification Board initiative, (FRPB 1994), although a number of academic institutions were working in this field (Ellis 1989, Pratt, 1989) . There was, however, interest in attenuation of stormwater flows to help reduce flooding and reduce the adverse impact of urban development on stream hydrology (e .g. Thames Water, 1989; CIRIA,1992). Table 1. Diffuse Pollution Concerns in the UK POLLUTANT Oil and other hydrocarbons

EXAMPLE SOURCES Car maintenance. Disposal of waste oils. Spills from storage and handling. Road runoff. Industrial runoff.

Pesticides

Municipal application to control roadside weeds. Agriculture. Private properties?

Sediment

Runofffrom arable land. Upland erosion. Forestry. Urban runoff. Construction industry. Agricultural wastes (slurry, silage liquor, surplus crops). Sewage sludge. Industrial wastes for land application. Failures ofconventional sewerage systems (wrong connections in separate sewer systems). Dog faeces in towns and cities. Application of organic wastes to farmland. Agricultural fertilisers. Atmospheric deposition.

Organic Wastes

Faecal Pathogens

Nitrogen

Phosphorus

Soil erosion. Agricultural fertilisers. Contamination of urban runoff (detergents, organic material).

Trace Metals

Urban runoff. Industrial and sewage sludges applied to land. Contaminated groundwater. Water table rebound following mining (especially coal). Cleaning plant on industrial yards, wrong connections of trade effluent to surface water.

Iron Solvents

ENVIRONMENTAL PROBLEM Toxicity. Contamination of urban stream sediments. Groundwater contamination. Nuisance (surface waters) Taste (potable supplies). Toxicity. Contamination of potable supplies. Destruction of gravel riffles. Sedimentation of natural pools and ponds. Costs to abstractors (eg. Fish farms, potable supplies). Oxygen demand. Nutrient enrichment. Health risks. Non compliance with recreational water standards.

Eutrophication (especially coastal waters). Contamination of potable supplies (rivers and groundwaters). Acidification Eutrophication of freshwaters: - ecological degradation - blue green algae - increased filtration costs for potable reservoirs/rivers Toxicity.

Toxicity. Aesthetic nuisance. Toxicity. Contamination of potable supplies (rivers and groundwaters).

Forestry is a sector that presents classic diffuse pollution risks, and is the only major sector for which those risks have been seriously addressed for some years in the U.K. (Selbe, 1987) . The Forest and Water

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Guidelines (Forestry Commission, 1988, 91, 93), enforced as a condition of grant support, include requirements for buffer strips between new planting and watercourses; blind vegetated zones at the end of drainage channels where upland is ploughed for tree planting; mound -planting in particular sensitive catchments, and for sediment traps to minimise the impact of forest road construction and other forestry activity. Forestry excepted, there were no concerted approaches to tackling diffuse pollution by central government, or by the national regulatory agencies prior to the formation of the environment agencies. THE IMPORTANCE OF DIFFUSE POLLUTION IN THE UK Evidence of the relative environmental impacts of diffuse and point source pollution in the UK has not been systematically collected for the purpose of such a comparison. Data permitting an approximate comparison is available from the PARCOM programme (Paris Convention On Monitoring Inputs to the North Sea), for which the loadings of major nutrients and persistent chemicals discharged to Scotland's coastal waters are measured annually . Monitoring stations on all the major rivers, together with additional data for major point source discharges (trade and sewage effluents), provide the information summarised in Table 2. For many Scottish rivers the river-borne loadings approximate to diffuse inputs. For 13 substances, the contribution of diffuse sources exceeded that from point sources. The clearest example of a largely diffuse input is nitrogen, for which 91 % of the total input to Scottish coastal waters was from river-borne loadings. Two other elements emphasise the importance of diffuse sources, in these instances associated with vehicles and urbanlhighway runoff: lead. 71-77% diffuse sources , and cadmium, 77-95% diffuse sources. Table 2. Pollutant inputs to Scottish coastal waters (1995 data) PERCENTAGE OF TOTAL POLLUTANT LOADS DERIVED FROM DIFFUSE SOURCES RANGE(%) POLLUTANT 73.3 to 93.5 Hg 77.1 to 94.8 Cd 71.0 to 77.4 Pb oto 96.0 PCB 58.0 to 74.5 G-HCH 91.4 to 91.4 NOl-N 35.9 to 36.8 PO.-P 38.1 to 38.2 P The ranges refer to values reported for individual major Scottish rivers at point of discharge into coastal waters. Quantifying the importance of diffuse pollution in the UK is currently being attempted by a project under the auspices of the Chartered Institution of Water and Environmental Management (CIWEM) and the UK Branch Committee of the International Association on Water Quality (IAWQ) . Quantifying the environmental and economic importance of all the issues listed in Table I, will be a major support for the efforts to deal with the problems, as outlined in this paper. OPTIONS TO ADDRESS THE PROBLEM OF DIFFUSE POLLUTION IN THE UK Table 3 lists options for the control of diffuse pollution. One option, that has been found to be effective for some problems, is to ban or restrict the use of specific chemicals; for example the persistent pesticides such as DDT, aldrin and dieldrin that have been implicated in the demise of populations of predatory birds and otters.

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Table 3. Options fot the control of diffuse pollution I. Regulate to ban specific chemicals or restrict their use

Organochlorine pesticides (DDT, aldrin, dieldrin); tributyl tin, PCBs.

2. Regulate discharges

Urban surface water drains (industrial; housing; highways).

3. Planning controls

Conditions on urban developments stating that postdevelopment flows shall not exceed pre-development ones. Strategic conditions in local plans favouring a Best Management Practice approach to urban drainage for new developments.

4. Economic Instruments

Leaded petrol. Nitrogen perhaps?

5. Trade Licensing

Pesticide distributors' premises approval scheme (voluntary, but mandatory for membership of trade association).

6. Linkage to subsidy payments, e.g, European Union (EU) agriculture

Farming and Wildlife Advisory Group (FWAG) recommendation that buffer strips be associated with eligibility for EU arable Area Payments Scheme.

7. Government sponsored environmental schemes

Scottish Countryside premium Scheme (CPS): payments for farmers to create and maintain riparian habitats

8. Environmental Education

Agriculture and forestry codes of good practice; partnership projects - SAC:FWAG:SEPA Buffer Strips Initiative; IAWQ video project (Nature's Way); Oil Care Campaign.

Allcock and Balls (1998) consider the importance of this approach for the active constituent of antifouling paint, tributyl tin (TBT), noting that the prevention of problems by one pollutant does not preclude the occurrence of pollution by replacement chemicals, if the need for a chemical with comparable properties is still to be met. Obviously, as a pollution control strategy, banning a chemical after it has been shown to be a problem is a recognition of failure. Therefore, the agricultural and food industries put a lot of effort into screening proposed pesticides prior to authorisation for agricultural use. Tester (1996), described the legislation and procedures for approving agricultural pesticides in the UK. Control of pollution from specific chemicals can also be achieved by taxation policies. There has been a decline in lead loadings discharged by UK rivers to the North Sea, following action by the UK government to introduce a substantial tax differential that penalises leaded petrol, in favour of unleaded petrol. A similar experience has been reported in Sweden. A leading contender for similar action may be nitrate fertiliser for agriculture. At least one major vegetable and cereal grower in central Scotland has advocated a nitrogen tax, to bring the rising trend of nitrate application under control, arguing that only the most efficient farmers will continue to buy large quantities, and even they will carefully target applications for maximum uptake by crops, and minimal losses through leaching . But Swedish experience found that a simple tax increment on the price of fertiliser was not effective; when introduced in Sweden, the consequent price increase was less than one caused by a rise in energy costs for the manufacturers of fertiliser (oil price increase), (Christine Jakobsson, personal communication). Comparison of the lead and nitrate examples therefore indicates that, for taxes to be

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effective economic instruments, they must be used to establish a price differential. There must be a choice for the consumer, between a cheaper, less polluting product, and the more expensive (taxed) polluting one. Additional means of addressing diffuse pollution problems (table Ill), that are options for national government, include the linking of environmental benefits with agricultural payments, for example under the EU Common Agricultural Policy (CAP). CAP reform, to bring about such a mechanism for funding environmental protection, is a priority issue for environmental concerns in the UK. The current EU agrienvironment programme will need to be hugely expanded (as a replacement for CAP subsidies) before nationally significant environmental benefits can accrue. REGULATION BY UK AGENCIES Some options exist for direct control by the regulatory agencies (SEPA and EA). and for indirect control via the good offices of the planning authorities and the water authorities; particularly with regard to urban runoff and the promotion of Best Management Practices (BMPs). The UK legislation provides for inclusion in a notice or consent, a description of the treatment structures to be employed for a development. For surface waters this would normally be a description of the BMP proposals presented by the developer after informal consultations with the agency and other interested parties. Indirect control may be effected via the powers of the planning authorities (local councils). On 1st April 1996, all the local and regional councils in Scotland were rationalised to form a single-tier level of administration. As a result the new unitary authorities (local councils) are currently reviewing their Local Plans and SEPA is attempting to persuade them to include paragraphs about the need for BMP structures as a matter of course. The above paragraphs refer to the situation for new urban developments. Formal consents can also be required for existing urban surface water discharges and, for a few so far, of the worst case industrial estates, retro-fitting of soft-engineering end-of-pipe treatment options is currently being attempted. In the rural environment, the Environment Act (1995) provides for the control of serious pollution incidents (under the offence provisions). The legislation does not really provide measures to deal with the risks of diffuse pollution, especially where due to such problems as soil erosion and gradual enrichment of groundwaters and coastal waters by nitrate. NON-REGULATORY OPTIONS TO CONTROL DIFFUSE POLLUTION Diffuse pollution as an important issue is a relatively recent or new concern for regulators and polluters. Awareness of possible options whereby polluters can minimise pollution from diffuse sources has been even lower. For that reason, the UK regulators worked, with other partner organisations, under the auspices of the International Association on Water Quality, IAWQ, to produce the Nature's Way video; highlighting diffuse pollution problems and possible solutions to them. The project was launched in June 1996, drawing extensively on international experience (IAWQ 1996). Presentation of Nature's Way to a target audience (including the regulators' own staff) has been a key activity subsequently; via small local seminars, through to major conferences. Effectiveness of delivery has been aided by seeking partner organisations within the key target professions, to co-present the video and/or supporting papers (for example the Scottish Agricultural College, SAC SEPA joint conferences on diffuse pollution and agriculture, Petchey et al., 1996 and in prep, 1998: strongly supported by both UK agencies and by government agriculture advisors in England and Scotland). Similar efforts have been made for urban pollution, actively involving planners, landscape architects, consulting engineers and water companies (e.g, Edwards Jones and D'Arcy, 1998 and Pratt (ed) 1998). In Scotland, a national Sustainable Urban Drainage Working Party has been established, comprising representatives of SEPA, the water authorities, local councils, housebuilders, and the construction industry

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(D'Arcy and Roesner, 1998). This provides a means of achieving consensus and consistency amongst all stakeholders. In Scotland, joint training seminars have been held for field staff from SEPA, and from the national networks of field advisors of two agricultural groups in Scotland: SAC, who provide technical advice on farming matters, and FWAG, the Farming and Wildlife Advisory Group. The SEPA. SAC, FWAG partnership also published a booklet (with supporting poster display for agricultural shows, farm open days etc) - Buffer Strips: Good Agricultural Practice - in 1995, reprinted in 1996. The Environment Agency also published a Buffer Strips booklet for farmers. The Buffer Strips initiatives provide flagships on which the novel (to the UK agricultural community) concepts of diffuse pollution and rural BMPs have been launched. Both agencies have been working with government and farming organisations to ensure that diffuse pollution in general is now firmly on the agricultural agenda in the UK. One of the most significant diffuse pollutants is oil (D'Arcy and Bayes, 1995). The Oil Care Campaign was initiated prior to the formation of the environment agencies and is led by the EA. Other parties are SEPA, oil refiners and distributors, engine oil retailers, waste oil recovery businesses, and local councils (waste disposal authorities). The project raises awareness amongst relevant trade associations and companies, as well as the public, and has led to the proliferation of oil recycling banks. A National Oil Bank phone line, whereby the public can telephone one UK number for advice on the location of the nearest oil recycling facility was initiated in 1995. ASSESSING EFFECTIVENESS Many of the initiatives to address diffuse pollution in the UK are very recent. A major joint project to evaluate their effectiveness is currently underway, funded by the Environment Agency, SEPA, and the Scottish and Northern Ireland Forum for Environmental Research (SNIFFER). That project will evaluate the Oil Care Campaign, which has been established in England and Wales for several years but is only being actively launched in Scotland in 1998; the "Nature's Way" IAWQ video project; and the Environment Agency's "Polluter Pays" project. Effectiveness of educational and other initiatives can be evaluated on two levels: (i) (ii)

the quality of the environment (e.g. length of good quality watercourses; numbers of downgraded lakes; number of pollution incidents per year) indirect measures (e.g. the number of urban BMP structures provided; number of oil recovery banks established; length of buffer strips established along target rivers)

The usefulness of (i) presupposes that the polluted watercourses are only adversely affected by the target issue: often not so. Acceptance of the measures in (ii), presumes a degree of effectiveness in their ability to protect the environment. For urban BMPs, the UK environment agencies are jointly sponsoring, with Abertay University (Waste Water Technology Centre) a major project to evaluate the effectiveness of the BMP structures in Scotland. An initial awareness survey by Abertay University and SEPA indicated a high level of apparent knowledge of BMPs, but subsequent investigations showed that in many instances knowledge was very superficial and often inadequate (McKissock et al. 1998). Measures of activity arising from campaigns, often taken as indicators of success, are of course worthwhile objectives but do not necessarily indicate success in protecting the environment. For example the number of partner organisations buying into the project; sales of videos/booklets; attendance of target audiences at seminars and conferences. The best measures of real environmental progress for diffuse pollution in the UK to date, are the declines in contamination of the environment by chlorinated hydrocarbons, and lead. These are a function of a

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governm ent bans. and a tax differential. respect ively. On a local level. in relation to agricultural pesticide problems. Fig. I compares biological field scores in two small waterc ourses. draining intensively farmed arabl e catchm ent s in East Scotland . Both streams have been the object of intensive joint campaigns by SEPA . SAC and FW AG to educate farmers about pesticide pollution (described in D'Arcy et al. 1996). The Figure show s that the effort s in the DreeJ Burn have been effective. but to date little progres s has been discern ible on the West Peffer Burn. It is too earl y to draw finn conclu sions, but it may be significant that one farm was prosecuted prior to the launch of the friendly persuas ion. partnership approach on the Dreel Bum. That was probabl y very effect ive in persuading the farmer s in the catchment that the subsequent initiative warranted active participation and action to follow -up advice subsequently given by the SAC advisors. Biological Field Scorea (BMWP) For Two Scottish Agricultural Streams 60 50

f

-+-West PefferBurn ...... Or..IBurn

40

...0

f/)

i

III

30 20 10

......._ _........~

Ol--......-

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Figure I. Biological fileld SCores (BMWP) for two Scou ish agricu ltural streams ,

CONCLUSION The effective control of diffu se pollut ion requires the follow ing: I. 2. 3. 4.

Cle ar messages for pollu ters as to the environmental damage resulting from their activities. Cle ar and read ily available guidance on prevent ative measures and practic es. Inform ation on cost-effectiveness of prevention option s. Powerful incentives to prevent pollution (including disincent ive for ca using it) are more costeffe cti ve than mere presentat ion of facts and figures in favour of prevention practices .

The incentives include : avoiding prosecut ions, realising cost-savings, and tax differe ntials . REFERENCES Allcock, R. and Balls . P. W. (1998). Penis growth in female dogwhelks: the implications for polluti on control (in prep). CIRIA ( 1992). Scope for Control of Urban Runo ff. Constru ction Industry Research and Informat ion Association Report No 122, 3. 4. CIRIA , London, UK. D'Arcy, B. J. and Bayes , C. D . (1995 ). Industrial Estate s: A Problem. Proceedings of the Standi ng Conference on Stormwater Source Co ntrol Vol X ; meeting of 9 December 1994. School of The Built Environment. Co ventry University, Coventry , UK. February 1995. D'Arcy, B. J.. Ridg way, I. M.• Marsden, M. W. and Sargent. R. J. ( 1996) . Diffuse Pollution and Agr iculture in the Forth Catchmen t. In Petche y et 01. (eds.) Diffuse Pollution and Agricullure ; SAC. Aberdeen, UK . D'Arcy, B. J. and Roesne r. L. A. ( 1998). Scotti sh Experiences with Storm water Management in New Devel opmen ts. Paper pre sented at Engineering Found ation Conference. Sustain ing Urban Water Resources in the 2 1st Centurtrn 7- 12 September 1997 . Malm o. Sweden . D'Arcy, B. J. (\ 998 ). Urban Best Management Pract ice. In Prall C J (eds.) Proceedin gs OfTh . Fift eenth Meeting Of The Standing Conf erence On Stormwater So urce Cont rol, School of the Built Environment. Coventry Universi ty. Edwards Jones , E. and D'Arcy, B. J. (1998) . Lands cape Design and Urban Drainage. Proc..din /is of Conf erence al Heriot Wall Unive rsity, 18-19 September 1997. Department of C ivil and Offsh ore Engineering , Heriot Wall. Edinburgh , UK.

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Ellis, J. B. (1989). Urban Discharges and Receiving Water Quality Impacts. Pregamon Press, Oxford, UK. Forestry Commission (1988,1991,1993). The Forests and Water Guidelines, HMSO, London, UK. FRPB (1994). A Clear Future for Our Waters. Video and booklet, Forth River Purification Board, Edinburgh, UK. Huggins, B. (1998). The Hampshire Avon Project. In Petchey, D'Arcy and Frost (Eds.). Diffuse Pollution and Agriculture II. Proceedings ofa SAC:SEPA conference, 9-11 April 1991. SAC. Aberdeen, UK. IAWQ (1996). Nature's Way: Designing for Pollution Prevention. Video and booklet produced by the International Association on Water Quality, London, UK. MAFF (1991). Code of Good Agricultural Practice for the Protection of Water. Ministry of Agriculture, Fisheries and Food, and Welsh Office Agriculture Department. MAFF Publications, London, SE991TP, UK. McKissock, G., Jeffries, C. J. and D'Arcy, B. 1. (1998) An Assessment of Drainage Best Management Practices in Scotland. Journal of CIWEM (in press). Nisbet, T. R. (1996). The Efficacy of the Forests and Water Guidelines in Controlling Diffuse Pollution. In Petchey, D'Arcy and Frost (Eds.) (1996). Diffuse Pollution and Agriculture. Proceedings of a SEPA:SAC conference in Edinburgh, April 1995. Scottish Agricultural College, Aberdeen, UK. Petchey, A. M., D'Arcy, B. J. and Frost, C. A. (1996). Diffuse Pollution and Agriculture. Proceedings of Conference held in Edinburgh, 12-14 April 1995. Scottish Agricultural College, 1996. ISBN: 1 854825155. Pratt, C. J. (1989). Urban Stormwater Reduction and Quality Improvement through the use of Permeable Pavements. Water Science and Technology 21, 169-118. Pratt, C. J. (1998). (Ed.) Proceedings of the Standing Conference on Stonnwater Source Control; Vol X, School of The Built Environment, Coventry University, Coventry, UK. SEPA (1996). State of the environment report. Scottish Environment Protection Agency, October 1996, Stirling, UK. Scottish Office (1992) Prevention of Environmental Pollution from Agricultural Activity. Code of Good Agricultural Practice, Scottish Office, Edinburgh, UK. Selbe J F (1981). Forestry and the Water Industry: A Report of a FClWRc collaborative workshop held at York in 1986. Water Research Centre, Medmenham, UK. Thames Water, Hydro Research and Hertsmere Borough Council (1989). Guidelines for the Design of Attenuation Storage Systems. Contlo Conference, 1989.