How to Regulate Diffuse Water Pollution from Agriculture

Jeanette Jensen is currently doing a PhD in the area of environmental and water resources law with the title ‘How to Regulate Diffuse Source Water Pollution from Agriculture? A Comparative Analysis of the Australian and the European Union Legal Frameworks’. She recently graduated with a Master of Mining and Energy Laws from the University of Western Australia. She also holds LL.B. and LL.M. degrees from the University of Copenhagen. Prior to commencing her PhD, she worked as a research assistant to Professor Alex Gardner on research project CRC for Water Sensitive Cities and to Professor John Chandler on research project Petroleum Resource Regulation and Policy.

Diffuse source water pollution (DSP), or non-point source pollution, may be defined as ‘all sources of pollution that enter waters other than from identifiable entry points’, and can thus ‘encompass contaminants that enter waters through surface water run-off or by soil percolation through soil’.[1] The agricultural practices that typically lead to these events are the application of fertilisers and pesticides, tillage practices, habitat alteration, animal waste and soil erosion.[2] These activities can cause nutrient pollution in terms of water eutrophication, soil siltation, and chemical deterioration of water,[3] which impacts have wide-ranging damaging effects on the environment and the economy. For example, eutrophic lakes impact recreation, ecosystem integrity, and human and animal health.[4] Cyanobacteria, the active ingredient in most harmful freshwater algal blooms,[5] ‘deposit unsightly, bad-smelling, mucilaginous clumps of dead and senescing cells on the shore and surface of lakes’, can poison livestock, pets, and humans, and some iproduce toxins that kill aquatic animals.[6]

Researchers first recognised DSP around the late 1960s.[7] In 2005, it was considered ‘today’s leading water quality problem, and diffuse source pollution from agriculture and the urban periphery, its most intractable dimension’.[8] This remains the case today.[9] The most well-known Australian example in which agricultural DSP has manifested is the Great Barrier Reef (GBR).[10] The nutrients have caused significant declines in many habitats and species, especially in the inshore southern two-thirds of the Region, declines in ecosystem processes and natural heritage values.[11] Agricultural land use is also one of the main sources of nutrients in Australian inland waters.[12] In March 2016, the spread of blue-green algae over almost 500km of the Murray River claimed reservoirs, rivers, wetlands and parts of Victoria’s two biggest irrigation districts and induced a water crisis, as taps to towns and farms in some areas had to be turned off to avoid potential public health risks.[13]

In south-western Australia, a number of important coastal estuarine systems are threatened by agricultural DSP. The Peel-Harvey Estuary, which is a Ramsar-listed wetland of international importance,[14] has suffered decades of nutrient pollution compromising water quality.[15] Again, agricultural land use along the rivers feeding the Estuary is the main source of the excess nutrients causing severe toxic algal blooms.[16] Another Western Australian example is the Vasse Wonnerup and Geographe Bay wetlands. The State Government has recently allocated $7.15 million to reduce nutrients in the catchment, including from agriculture.[17] Finally, a warning similar to that for the Murray River in Victoria was issued for a possibly toxic algal bloom in Perth’s Canning River in March 2016.[18] In fact, the Swan-Canning river system has experienced annual algal growths over the past two decades.[19]  In summary, while DSP has been recognised for over thirty years to have a severe impact on water quality, it is still ‘the unfinished business of water quality regulation in Australia’.[20] Non-statutory instruments and voluntary measures have been preferred to tackle the problem, however, with limited success.[21]

According to the OECD:

The relative lack of progress with reducing diffuse source pollution reflects the complexities of controlling multiple pollutants from multiple sources, their high spatial and temporal variability, associated transaction costs, and limited political acceptability of regulatory measures.[22]

Indeed, DSP is deemed hard to regulate.[23] The multiple pollutants from multiple sources, which accumulate into a problem, combined with the spatial and temporal variability due to, inter alia, the physical features of the site and climatic conditions make it difficult to identify, measure and attribute individual emissions.[24] This in turn makes it difficult to utilise the traditional pollution abatement mechanisms of liability and enforcement,[25] which have been very successful in reducing point-source pollution, such as industrial waste from a pipe or drain. Its political sensitivity may be accorded to the impact on the industry and its significance for society.[26]

The main culprits of agricultural DSP are nitrogen[27] and phosphorus,[28] and nitrogen and phosphorus fertilisers are commonly considered fundamental to improving crop yields and economic returns.[29] It has been estimated that nitrogen ‘accounts for an estimated 40% of the increase in per capita food production in the past 50 years’.[30] For this reason, the sources of DSP from agriculture can be ‘politically untouchable’.[31] According to Keeney and Hatfield, solutions will ‘involve looking beyond the edge of effects to redesigning agriculture that will tighten up the N[itrogen] cycle’, and ‘policies will need to be developed that assure the farmer and the public that such measures will not cost productivity, and that a redesigned agriculture can provide for future food needs’.[32]

This research project aims to propose how to regulate to solve the problem of agricultural diffuse source pollution in Australia. While the agricultural nitrogen balances are high and in need of attention in many European countries as well, there have been some improvements over the past 25 years attributed to regulatory measures, such as the Nitrates Directive.[33] In Denmark, ‘a fairly strict regulatory regime has resulted in almost a 50 per cent reduction in nitrogen leaching since the mid-80s’.[34] For these reasons, this researcher will conduct a comparative analysis with the European Union legal frameworks with the purpose of exploring what Australia can learn from the EU by comparison and propose reforms based on these findings.


[1] William Howarth, ‘Diffuse Water Pollution and Diffuse Environmental Laws – Tackling Diffuse Water Pollution in England’ (2011) 23(1) Journal of Environmental Law 129, 130.

[2] Neil Gunningham and Darren Sinclair, ‘Policy instrument choice and diffuse source pollution’ (2005) 17 Journal of Environmental Law 51, 52; Cesare Dosi and Theodore Tomasi (eds), Nonpoint Source Pollution Regulation: Issues and Analysis (Kluwer Academic Publishers, 1994) ix, x.

[3] OECD, ‘Water Quality and Agriculture: Meeting the Policy Challenge’ (2012) 42.

[4] John A. Downing, Susan B. Watson and Edward McCauley, ‘Predicting Cyanobacteria Dominance in Lakes’ (2001) 58(10) Canadian Journal of Fisheries and Aquatic Sciences 1905, 1905.

[5] Cloé Garnache et al, ‘Solving the Phosphorus Pollution Puzzle: Synthesis and Directions for Future Research’ (2016) 98(5) American Journal of Agricultural Economics 1334, 1347, citing Anna M. Michalak et al, ‘Record-setting algal bloom in Lake Erie caused by agricultural and meteorological trends consistent with expected future conditions’ (2013) 110(16) Proceedings of the National Academy of Sciences of the United States 6448.

[6] Downing, Watson and McCauley, above n 4.

[7] Vladimir Novotny (ed), Nonpoint Pollution and Urban Stormwater Management (Technomic Publishing, 1995) 1.

[8] Gunningham and Sinclair, Policy instrument choice and diffuse source pollution, above n 2, 52.

[9] EEA, ‘The European environment — state and outlook 2015: synthesis report’ (2015) 64, 66; OECD, ‘Diffuse Pollution, Degraded Waters: Emerging Policy Solutions’ (2017) 3.

[10] Jon Brodie et al, 2013 Scientific Consensus Statement (27 August 2014) Reef Water Quality Protection Plan Secretariat <http://www.reefplan.qld.gov.au/about/scientific-consensus-statement/>; Australian Government and Queensland Government, ‘Reef 2050 Long-Term Sustainability Plan’ (Department of the Environment and Energy, Australian Government, 2015) 10, 24-25, 42 (‘Reef 2050 Long-Term Sustainability Plan’) <http://www.environment.gov.au/marine/gbr/publications/reef-2050-long-term-sustainability-plan>.

[11] Reef 2050 Long-Term Sustainability Plan, above n 10, app C.

[12] J. Ball et al, ‘Inland Waters – Australia State of the Environment Report 2000’ (Theme Report, CSIRO Publishing on behalf of the Department of teh Environment and Heritage, 2001) 57; State of the Environment 2011 Committee, ‘Australia State of the Environment 2011’ (Independent report to the Australian Government Minister for Sustainability, Environment, Water, Population and Communities, 2011) 231, 236; Robert M. Argent, ‘Australia state of the environment 2016: inland water’ (independent report to the Australian Government Minister for the Environment and Energy, Australian Government Department of the Environment and Energy, Canberra, 2017) <https://soe.environment.gov.au> 18, 78.

[13] Chris McLennan, ‘Water crisis worsens as Murray River blue-green algae spreads’, The Weekly Times (online) 8 March 2016 <http://www.weeklytimesnow.com.au/agribusiness/water/water-crisis-worsens-as-murray-river-bluegreen-algae-spreads/news-story/f9f6c3c1b3989eecccd13982d0e46a1d?utm_source=Weekly%20Times%20Now&utm_medium=email&utm_campaign=editorial>.

[14] The Peel-Yalgorup System, of which the Peel-Harvey Estuary is a part, was listed under the Convention on Wetlands of International Importance especially as Waterfowl Habitat 1971, opened for signature 2 February 1971, 996 UNTS 245 (entered into force 21 December 1975).

[15] Keith Bradby, Peel-Harvey – The Decline and Rescue of an Ecosystem (Greening the Catchment Taskforce, 1997) 147.

[16] Peel-Harvey Catchment Council, ‘Peel-Yalgorup System Ramsar Site Management Plan’ (Government of Western Australia, 2009) 24; Australian Government, ‘Australia’s National Programme of Action for the Protection of the Marine Environment from land-Based Activities – Case study 20: Peel-Harvey waterway’ (2006) <>.

[17] Department of Water (WA), Vasse Geographe Strategy <http://www.water.wa.gov.au/water-topics/waterways/vasse-wonnerup-waterways-and-wetlands>.

[18] Andrew O’Connor, ‘Toxic algae bloom warning for Perth’s Canning river’, ABC News (online) 12 March 2016 <http://www.abc.net.au/news/2016-03-12/toxic-algae-bloom-warning-for-perth-river/7242420>; Linda Skates, ‘Swan and Canning Rivers: auditor-general’s report finds declining health in Perth waterways’, ABC News (online) 20 August 2014 <http://www.abc.net.au/news/2014-08-13/spotlight-on-the-health-of-the-swan-river/5668056>.

[19] Neil Gunningham and Darren Sinclair, ‘Non-point pollution, voluntarism and policy failure: lessons for the Swan-Canning’ (2004) 21 Environmental and Planning Law Journal 93, 94-95.

[20] Rebecca Nelson, ‘Regulating Nonpoint Source Pollution in the US: A Regulatory Theory Approach to Lessons and Research Paths for Australia’ (2010) 35 University of Western Australia Law Review 340, 349.

[21] See, eg, Gunningham and Sinclair, Non-point pollution, voluntarism and policy failure, above n 19.

[22] OECD, Diffuse Pollution, Degraded Waters, above n 9, 3.

[23] Gunningham and Sinclair, Non-point pollution, voluntarism and policy failure, above n 19.

[24] Gunningham and Sinclair, Policy instrument choice and diffuse source pollution, above n 2, 52; D.R. Keeney and J.L. Hatfield, ‘The Nitrogen Cycle, Historical Perspective, and Current and Potential Future Concerns’ in J.L. Hatfield and R.F. Follett (eds), Nitrogen in the Environment: Sources, Problems, and Management (Elsevier Science, 2008) 1, 7-10; Helle Tegner Anker, ‘Agricultural nitrate pollution – regulatory approaches in the EU and Denmark’ (2015) 2 Nordic Environmental Law Journal 7, 8; OECD, Water Quality and Agriculture, above n 3, 19.

[25] Gunningham and Sinclair, Non-point pollution, voluntarism and policy failure, above n 19, 95-96; Cesare Dosi and Tomasi, above n 2, x-xi.

[26] Gunningham and Sinclair, Non-point pollution, voluntarism and policy failure, above n 19, 95-96.

[27] D.R. Keeney and Hatfield, above n 24, 1-2.

[28] European Environment EEA, State and Outlook 2015, above n 9, 66; John Lucey, Nutrient losses from intensively grazed dairy pastures (1 May 2015) Department of Agriculture and Food <https://www.agric.wa.gov.au/pasture-management/nutrient-losses-intensively-grazed-dairy-pastures>.

[29] D.R. Keeney and Hatfield, above n 24, 1.

[30] Ibid 1.

[31] Nelson, above n 20, 341.

[32] D.R. Keeney and Hatfield, above n 24, 2.

[33] Council Directive 91/676/EEC of 12 December 1991 concerning the protection of waters against pollution caused by nitrates from agricultural sources [1991] OJ L 34/1; European Commission, Report from the Commission to the Council and the European Parliament on the implementation of Council Directive 91/676/EEC concerning the protection of waters against pollution caused by nitrates from agricultural sources based on Member States reports for the period 2008-2011, COM(2013) 683 final (2013); EEA, State and Outlook 2015, above n 9, 64, 66; 2-11. But see ibid 67.

[34] Anker, above n 24, 7.

Inquiry into National Water Reform – EDOs of Australia submission

EDOWA recently contributed to an EDOs of Australia submission to the inquiry into National Water Reform. The inquiry is being conducted by the Productivity Commission.

The objective of this inquiry is to allow an assessment of progress in achieving the objectives and outcomes of the National Water Initiative (NWI) and the need for any future reform.

The five issues EDOA identified are:

1. Access to information
2. Compliance, enforcement and markets
3. Climate change
4. Protection of environmental water
5. Extractive industries including mining


  1. EDOA recommends that steps are taken to improve transparency and free public access to information.
  2. That detailed and decisive action is undertaken by relevant agencies into the lack of uniform regulation and enforcement measures for all catchments; that action is undertaken into inaccurate water metering and reporting; and that action is undertaken by these same agencies to address related distortions in the water market.
  3. That climate change be addressed within the National Water Initiative in order to maintain water security for the environment, industry and regional communities.
  4. That environmental water held by the Commonwealth Environmental Water Holder (CEWH) is protected from extraction as it flows through the system.
  5. That extractive industries are included within broader, uniform planning and water entitlement frameworks in all jurisdictions.