Make a submission for clean, healthy drinking water and stronger drinking water standards

*Please note submissions have now closed


Everyone has a right to clean, healthy drinking water.

The Government is reviewing the proposed National Environmental Standards for Sources of Human Drinking Water under the Resource Management Act (RMA) 1991. The Ministry for the Environment has released a consultation document for public comment.

It needs to go further to protect drinking water quality. Stronger standards are needed to protect drinking water and our health from nitrate pollution.  

Submissions can help persuade the Government to strengthen the standards. Once the standards are finalised and agreed by Cabinet, they will come into force as regulations under the RMA.

You can make a submission to the Ministry for the Environment (MfE) calling for tougher standards here. Submissions on the consultation document, "Kia kaha ake te tiakina o ngā puna wai-inu Improving the protection of drinking-water sources", close on 6 March 2022.



Points you could make in your submission:

To protect our drinking water, the solutions are clear. The Government must:

  1. Phase-out the use of synthetic fertiliser by reducing the current cap of 190 kg/ha of synthetic fertiliser use in the National Environmental Standards for Freshwater to protect water quality. Increased synthetic fertiliser use, and urine from the intensive dairy cow and cattle grazing that it allows, are the major cause of elevated nitrate nitrogen levels in our drinking water.

  2. Lower the current Maximum Acceptable Value for nitrate nitrogen in drinking water from 11.3 mg/litre to less than 1 mg/ litre, to help avoid further nitrate pollution and possible increased bowel cancer risk.

  3. Strengthen the proposed National Environmental Standards for Drinking Water (NES-DW) by banning synthetic nitrogen fertiliser and intensive animal grazing in at-risk areas, and extending the regulations to include water supplies that serve small numbers of people:

    1. banning the use of synthetic nitrogen fertiliser in Source Water Risk Management Areas (SWRMA) 2 and 3 would protect drinking water intakes.

    2. extending the scope of the NES-DW would protect people who take their drinking water from supplies serving fewer than 500 people. These supplies are currently outside the scope of the proposed regulations so the standards don’t apply. Yet these small scale supplies, usually in rural areas, are some of the most vulnerable to pollution from land use and intensive agriculture. Many rural households source their drinking water from groundwater through a well or from a nearby river or stream.

    3. prohibiting intensive animal grazing in SWRMA 2 and 3 would reduce nitrate pollution from animal urine from intensive stocking

  4. Support national standards and regulations set by Government, rather than leaving it to regional councils to define “risk management areas” for protecting drinking water sources. In the past, this has led to inconsistencies between regions.

  5. Provide extra funding to local councils to properly map and monitor the Source Water Risk Management Areas in their region, so the new regulations are implemented well.

Why nitrate is a problem:

Environmental impacts of nitrate nitrogen

Nitrate pollution of aquifers, rivers, streams and lakes from agricultural land use is one of the most serious pollutants of drinking water in Aotearoa. Excess nitrogen from fertiliser use and the urine from dairy cows and other farm animals leaches through the soils increasing nitrate nitrogen levels in groundwater and rivers and streams.

Nitrogen helps plants grow. It occurs naturally and is added to the soil as fertiliser and through urine and dung from livestock (such as dairy cattle). Nitrogen is highly soluble. When the soil contains more nitrogen than grass or crops can use it leaches through the soil into groundwater and waterways. 

Since 1990 the annual application of synthetic nitrogen fertiliser in Aotearoa New Zealand has increased by 627%.[1] This is higher than anywhere else in the OECD.[2]  The use of synthetic fertiliser has enabled the intensification of dairy farming. It has led to higher stocking rates and a substantial increase in the number of dairy cows.[3]

Nitrogen leaching into soils from agriculture is estimated to have increased by 29% from 1990 to 2012, due largely to more dairy cows (their urine contains nitrogen) and nitrogen fertiliser use. [4]

The largest sources of nitrogen pollution into our rivers are in order of size are: [5]

  1. urine from dairy cattle
  2. urine from sheep;
  3. synthetic nitrogen fertiliser.

According to monitoring, nitrate nitrogen levels in groundwater have likely or very likely worsened between 1999 and 2018 in 47% of 125 monitored wells around the country.[6]

Rates of leaching vary around the country depending on soils, climate and land use. In 2017, areas in Waikato, Bay of Plenty, Taranaki and Southland had some of the highest leaching rates of nitrate nitrogen per hectare.[7] Riparian planting helps trap sediment but makes little difference to nitrate leaching.


Health impacts of nitrate nitrogen

Elevated levels of nitrate nitrogen in drinking water are a human health issue.

The current New Zealand Drinking Water Standards set a Maximum Acceptable Value of 50 milligrams per litre (mg/l) for nitrate, equivalent to 11.3 mg/litre of nitrate nitrogen. This is based on the World Health Organisation (WHO) standard developed to avoid the risk of blue baby syndrome, rather than addressing emerging research on cancer risks. The standard is for acute exposure rather than ongoing or chronic exposure. 

Exposure to nitrate in drinking water has been associated with an increased risk of  bowel (colorectal) cancer. [8]  A 2018 study by Danish based researchers monitoring 2.7 million people over 23 years has suggested links to an increased incidence of colorectal cancer from nitrate nitrogen in drinking water at 0.87 mg/litre.[9]

This is much lower than the maximum value of 11.3 mg/litre of nitrate nitrogen that New Zealand relies on. Californian research has also linked nitrate nitrogen contamination above 5 mg/litre with an increased risk of premature births.[10]

Aotearoa New Zealand has some of the highest rates of colorectal cancer globally, with more than 3,000 people diagnosed and 1,200 deaths annually.[11] It is second only to lung cancer as the most prominent cause of cancer death in Aotearoa.


Maximum limit for nitrate nitrogen in Drinking Water Standards is too high

The New Zealand Drinking Water Standards set a maximum value of 11.3mg/litre of nitrate nitrogen in drinking water.[12]  This is nearly 12 times higher than the rate associated with an increased risk of colorectal cancer. This is despite strong recommendations from public health experts and researchers to reduce this maximum acceptable value to less than 1 mg/L – still higher than the associated cancer rate.

Our smallest communities are disproportionately impacted by nitrates. A 2015-2016 report on drinking water quality found that community water supplies in communities of between 101-500 people have the worst drinking water quality of any water supplies, with only 25% of water sources achieving the required standards for safe drinking water.  The NES-DW needs to cover supplies for communities of fewer than 500 people.


The current cap on nitrogen use on land is too high

The National Environmental Standards for Freshwater (NES-FW) currently cap the use of synthetic nitrogen fertiliser at 190kg per hectare annually. This is too high to protect water quality and drinking water sources.  High fertiliser use to increase grass growth allows for higher cow numbers. Animal urine, especially from large numbers of dairy cows, is a major cause of nitrate leaching and groundwater pollution. The cumulative impact of both fertiliser and urine leaching means dangerously high levels of nitrogen enter our waterways.

The 190 kg/ha cap allows business-as-usual practices to continue, especially in the dairy and horticultural industries. We need to lower the cap progressively, and phase out synthetic nitrogen use completely, to encourage a shift to regenerative agriculture. We can return to use of natural fixers of nitrogen such as clover and legumes, which was widespread in New Zealand before the major increase in synthetic fertiliser use.  

Caps on synthetic fertiliser use, which operate in nitrate vulnerable zones in the European Union and in countries such as Denmark, have significantly reduced surplus nitrogen leaching.

Parliament’s Environment Select Committee is currently considering a 33,325 signature petition by Greenpeace to ban chemical nitrogen fertiliser, and will report on the petition later this year.


Stronger land use controls use needed to protect drinking water sources

To protect drinking water quality the Government proposes limited restrictions on land use activities in the areas close to drinking water intakes. These are called three Source Water Risk Management Areas (SWRMA).

SWRM 1 is the localised area around a drinking water intake. For intakes from groundwater, it is land within a five metres radius from where drinking water is abstracted such as a bore or well head.  For drinking water taken from rivers it is the river and riverbed 1000 metres upstream and 100 metres downstream of the intake and land five metres from the river’s edge. For lake intakes, it is the lake and its bed within a 500-metre radius of the intake, and a five-metre buffer from the lake edge.

SWRM 2 is a larger area around a drinking water intake. For groundwater, it is the land area on top of the aquifers for the distance it takes groundwater to travels to the intake (bore) within a one year period, to a maximum of 2.5 kilometres. For river intakes it is the land area from where water travels to the intake within an 8-hour period; and for lake intakes it is the entire lake area, extending landward 100 metres, and including tributaries.

SWRM 3 is the catchment for the drinking water supply. Government proposes no new land use controls in SWRM 3 because it believes current RMA controls are adequate. 

In the consultation document, the Government only proposes to prohibit the application of synthetic nitrogen fertiliser in Source Water Risk Management Area 1 (SWRM 1). This is too small to protect drinking water sources.


Changes needed

The Government needs to ban synthetic fertiliser use and require only light animal grazing in Source Water Risk Management Area 2 (SWRM2) to reduce the risk of nitrate pollution of drinking water in areas close to the water intakes. 

It should also phase in a ban on synthetic fertiliser use in Source Water Risk Management Area 3.


How to make a submission

You can use the online submission tool at:



[1] Stats NZ

[2] OECD 2017, OECD Environmental Performance Reviews: New Zealand 2017, OECD Publishing. page 36

[3] PCE 2013: Water quality in New Zealand: Land use and nutrient pollution. Page 16.

[4] Ministry for the Environment & Statistics New Zealand (2015). New Zealand’s Environmental Reporting Series: Environment Aotearoa 2015. Page 54

[5] Ministry for the Environment & Stats NZ 2017: New Zealand’s Environmental reporting series: Freshwater and nitrogen leaching.




[9] Espejo‐ Herrera, et al. (2016) “Colorectal Cancer Risk and Nitrate Exposure through Drinking Water and Diet.” International Journal of Cancer, vol. 139, no. 2, 2016, pp. 334–346.

Schullehner, J., Hansen, B., Thygesen, M., Pedersen, C.B. and Sigsgaard, T., (2018) “Nitrate in drinking water and colorectal cancer risk: A nationwide population‐based cohort study”. International Journal of Cancer, 143(1), pp.73-79.

Richards JS “Nitrate contamination in New Zealand drinking water and colorectal cancer risk”. .