Addressing deteriorating water quality

Angela Nugent

CORK is the first county council to approve a comprehensive suite of bye-laws to address agriculture-related water quality problems.

These bye-laws came into force on October 1 last. They were drafted to tackle deteriorating quality in both ground and surface waters, which manifests as high nitrates in drinking water and eutrophication of waterways. Three river catchments - the Lee, Gradogue and Funshion- are involved.

About one-fifth of the land area of the county is affected, as are an estimated 2,500 farmers. Dairying, often combined with beef production, comes to the fore in the listed catchments.

Tillage is significant and pig production is traditional in some areas, particularly around Mitchelstown.

Sustainable farming practices

Frank O'Flynn, environment officer with the council, commented "We expect that, by and large, the bye-laws will not have a major impact on farming. They are a compromise that has emerged from consultation with all the interested parties, including the farming organisations and Teagasc

"Hopefully this compromise will prove workable and deliver the necessary improvements in water quality. The bye-laws are in line with the Code of Good Agricultural Practice to Protect Waters from Pollution by Nitrates".

He continued "However, it is very difficult to make an omelette without breaking eggs. We had to impose some restrictions - eg a ceiling of 210 kg/hectare on organic nitrogen where nitrate levels in groundwater exceed 20 mg/litre and 250 kg/hectare per annum elsewhere in the target areas.

These figures equate to stocking rates of 1 and 1.2 livestock units per acre respectively. The regular soil testing and informal nutrient management planning required are agronomically desirable and cost effective. The 15 mg/litre soil P reading, set as a cut off point for bag P applications and the importation of slurry, does not restrict production.

Teagasc reckons that a response (for most crops) over 10 mg/litre is tenuous. The recording of organic and bag fertiliser usage is in-line with good management practices and is basic to the monitoring of business/enterprise performances".

"Slurry storage (minimum of 12 weeks) and preclusion of slurry/farmyard manure spreading in November, December and January, the main stay of the bye-laws, should facilitate better use of nutrients.

"We did not need the additional bye-laws for those with grossly inadequate farmyard facilities to have problems, the Water Pollution Act would have impacted sooner or later. That said, we prefer persuasion and do not intend to resort to the law lightly".

Measures in-place

The bye-laws now in force in the Lee, Funshion and Gradogue catchments have 10 measures impacting at farm level.

These relate to soil testing of all farms over 20 hectares or with an intensive enterprise, irrespective of farm size.

On request soil test results shall be made available for inspection by Cork County Council farm staff. The ceilings for bag P fertiliser applications are 15 mg/litre in general and 30 mg/litre in the case of peat soils.

The spreading of bag nitrogen is precluded from the first of October to the first of January. A ceiling of 60 kg/ha is imposed on bag nitrogen usage between the first of January and end of February. If bag nitrogen is used then the spreading of slurry in this period is precluded.

There are ceilings on the use of slurry. These are related to the nitrate contents of ground water in the locality. The ceilings are 250 kg/ha/year in general and 210 kg/ha in specific areas where nitrate readings exceed 20 mg/litre.

The zones of contribution to the various bore holes will be identified. The council hopes to have these areas identified and mapped within the year.

It is not an easy task for ground water flows are not linear, rather they depend on the bedrock, topography, flow rates etc. Geological Survey of Ireland personnel is currently mapping zones of contribution in Cork, including areas of the Funshion.

Landowners importing slurry must notify the County Council and such slurry can only be spread on land with a soil P reading of less than 15 mg/litre.

All fertiliser applications should be in line with Teagasc recommendations. The recording, on a monthly basis, of all the chemical and organic fertilisers applied is required.

These records cover amounts, dates and locations of applications and the nutrient content of the chemical fertilisers used. Recording of fertiliser sales by merchants within the county is also required. These records will be available to Cork County Council farm staff.

The bye-laws require provision of at least 12 weeks storage for slurry and facilities for the separate collection and disposal of clean yard water.

There is a requirement to have all slurry/farmyard manure land spread by October 31 each year. Adherence to Codes of Good Practice when spreading slurry is embodied. Where the slurry is spread on tillage ground then incorporation "as soon as possible" is required.

Buffer zones are in force - 10 metres for streams and drains, 15 m for lakes and main river channels, 50 metres for domestic wells and 100 m for sources of public water.

Co-operation sought

Frank O'Flynn appeals for adherence to the bye-laws and for co-operation. The co-operation of all players in the industry is sought but that of farmers is paramount. Agriculture is the main player in the water quality deterioration in the 3 catchments.

Frank urged farmers "Stay within the bye-laws. They allow sound economic farming that is environmentally responsible. Stocking up to 1 livestock per acre is OK, once you go over that level it may get difficult in some areas. We don't necessarily make apologies for that".

The hope is that awareness raising and education will engender a sense of responsibility.

Owen O'Sullivan, an environmental technician with Cork County Council, is now visiting farms in the listed catchments. He reports that about 50 per cent of the farmers visited, generally those with enterprises of significant scale, are aware of the bye-laws, often those with small farms are not. This is a concern that will be tackled.

Frank O'Flynn added "Our emphasis is on awareness raising, education and voluntary action. Hopefully these with bring the majority on board. The farming organisations and professional bodies such as Teagasc are involved. Legislation and prosecutions are not our first choice.

"However, if the county council does not succeed in improving water quality then other agencies will get involved to drive the process. Yes, Nitrate Vulnerable Zones are in the pipeline and will provide further armament but really it is environmentally responsible farming practices that matter. There have been significant farmyard improvements in recent times in the high groundwater nitrate zones.

"Farmers must realise that the protection of water quality is in the interest of their family and community".

The Environmental Department of Cork County Council currently employs 4 farm staff. Under the Phosphorus Regulations there is a proposal to employ a further 2 farm staff members.

Farm staff have authorised access to farms under Section 28 of the Water Pollution Act. However, the reality is that most farmers prove approachable, interested and indeed hospitable to County Council staff visiting their farms.

Nitrates in drinking water of major concern

In the Lee, Funshion and Gradogue catchments deteriorating water quality is showing through in relatively high levels of nitrates in ground water and the eutrophication of surface waters.

The former is a human health hazard, the latter an environmental hazard. Currently the EU's Drinking Water Directive is being breached and remedial measures are a necessity not a choice. The Nitrates Directive also overhangs the debate and the designation of Nitrate Vulnerable Zones is anticipated.

The nitrates content of drinking water sourced from bore holes, fed from groundwater, is of most concern for County Council personnel. Such sources supply about 25 per cent of drinking water requirements and are particularly important in some areas of the county eg north Cork.

The groundwater in some subcatchments (limited areas) show readings of 60, 70 and 80 mg of nitrates per litre. In extensive areas the readings are 20 to 25 mg/litre. The overall picture is 70 to 80 per cent of bore holes with over 25 mg of nitrates per litre of water. Unfortunately the nitrate levels continue to rise by 2 to 4 mg/litre per year.

The EU has set a guide level of 25 mg of nitrates in drinking water, at which point remedial measures should be introduced, and a maximum level of 50 mg.

Insidious and harmful

Nitrates in drinking water are insidious and their impact not immediately apparent.

Such water is generally clear, odourless and tastes and boils okay. Yet is may be very dangerous to human health with implications of blue babies, Hodgkins lymphoma, stomach cancers etc. Consumers are generally much more aware of the bacteriological quality of drinking water than its nitrate content.

Frank O'Flynn said "The jury is still out on the full implications (of high nitrates in drinking water) for human health and we don't have all the answers. However, all the experience would indicate trouble".

He parallels the current nitrates in drinking water debate with that of smoking 20 years ago. Then some medics suggested that smoking contributed to disease, now that link is well recognised.

Possibly in five to 10 years time high nitrates in drinking water may be proven to be very dangerous to human health.

Meanwhile the precautionary principle must operate. Frank said "We (county council personnel) are very concerned. We simply do not want to be responsible for any damage to human health".

Farmyard facilities and slurry management

Frank O'Flynn, environment officer with Cork County Council and an agriculturalist, emphasises adequate farmyard facilities, their management and particularly environmentally responsible slurry spreading.

Best use is made of the nutrient content of slurry if it is applied in the growing season to soils that are not overly enriched. This is hardly rocket science.

Yet some farmers continue to spread slurry out of season and without due regard for the potential impact on water quality.

Recycling slurry back onto its land of origin eg silage fields is ideal. Depending on location this option may not be available to intensive enterprises.

Tillage ground, the source of the cereal content of rations, is often well removed from these pig and poultry units.

Sugar beet crops can make good use of slurry. Do not apply large quantities to bare ground in the autumn. Rather spread in line with your nutrient management plan, as near as possible to the planting/sowing date and incorporate through ploughing.

Notification of slurry importations and the 15 mg/litre soil P ceiling on such slurry spreading have implications for some pig units in the specified catchments.

Traditional spread lands, where fertilisers and slurry were spread annually without recourse to nutrient management planning, may now have excessive P levels. Hence the hunt for new spread lands. The problems are localised.

The 12 week slurry storage requirement of the bye-laws is less than the 16 weeks generally required with new planning permissions.

The 12 weeks are seen as covering the critical months of November, December and January.

Frank O'Flynn emphasises slurry management, rather than absolute storage capacity, saying "If the tanks are full in November it does not matter how much storage you have in theory, it is zero at the start of winter".