Rural Diffuse Pollution Control Options - Essay Example

Diffuse pollution has a deeper and wider impact because of the relative risks it poses to the environment. There are various options for controlling diffuse pollution which are listed and discussed in the following sections.

Main Options for the Control of Diffuse Pollution

Soil and water pollution is a common feature of population growth which is brought about by industrialization, development in agriculture, and exploitation of natural resources. Man-made chemicals, pest control, discharge from agricultural activities; and chemical waste products from industries all contribute to pollution. Diffuse pollution is a form of pollution that results from long-term contamination from urban or rural human activities. Diffuse pollution originates from different sources. In rural areas, diffuse pollution has a different context when compared to urban diffuse pollution. Rural diffuse pollution problems arise from poaching livestock, spraying of chemicals, the use of fertilizers in farming, soil erosion due to extensive forestry, etc. These problems can be controlled by using the following options:

Problem

Solution Option 1

Solution Option 2

Scientific Basis

Rationale

Livestock fecal pathogens

Adoption of planning tools including nutrient budgets and manure application plans (SEPA 2008)

Fencing livestock to prevent access to streams and ponds  (SEPA 2008)

BOD[1] of milk is 140,000, pig slurry 20,000, cattle slurry 10,000, and dirty water 1000 to 5000 mg/liter (Defra 2009)

 Reduce ammonia and other gases released to the atmosphere; limit nitrate leaching to groundwater; reduce nutrients and contaminants build up in soil (Defra 2009)

Chemicals from pesticides and herbicides

Biobeds for pesticides  (SEPA 2008)

Buffer strips prevent pesticides and fertilizers from seeping into underground water sources  (SEPA 2008)

Nitrogen and phosphorus are harmful chemicals which lost from the soil seep into groundwater and surface waters, and pollute them. Agrochemicals impact the ecology of river waters and drinking water through a mere 0.1μg/1 (Defra 2009)

Nitrate pollution problems come from agriculture. Agrochemicals can be managed by using Best Management Practices (Defra 2009)

Soil erosion from cultivation

In field measures such as conservation tillage; irrigation scheduling; field drainage maintenance  (SEPA 2008)

Buffer zones can prevent runoff of agricultural land spreading to catchment areas  (SEPA 2008)

Eroded soil affects the quality of drinking water, causes serious damage to fisheries, increases unwanted aquatic vegetation, and increases the risk of flooding (Defra 2009)

Soil erosion from forestry

Setting river margins, buffer zones, and river restoration  (SEPA 2008)

Contour plowing reduces soil erosion on sloping land  (SEPA 2008)

Reduction of acidification of surface water in catchment areas

Freshwaters can only stand certain critical loads before their water chemistry deteriorates. This is estimated at 10 km2 grid square 

Critical load assessment helps select margins or zones for replanting to reduce acidification of surface water, and design forestation of the region (Defra 2009)

Experts (D'Arcy 2004; Halm and Grathwohl 2005) are of the view that diffuses pollution control strategies should either reduce or restrict polluting substances. These can be achieved by adopting combination strategies to improve the environment. Intervention should be based on the following hierarchy of preferred control measures:

1. Restrict the use of pollutants or substances which lead to pollution such as pesticides.
2. Reduce the frequency or intensity of activities that cause pollution such as reducing logging to prevent soil erosion.
3. Reduce mobilization of pollutants to the aquatic environment.
4. Interception of pollutants before it reaches catchment areas such as creating buffer zones or strips to prevent livestock fecal deposition in watercourses.
5. Treatment of pollutants by filtering ponds or water areas for degradable pollutants (D'Arcy 2004; Better River Basin 2008).

The most preferred control option(s) for diffuse pollution should fall into the three broad categories of drainage infrastructure, containment, or behavioral change. From the above-listed diffuse pollution control options, the author recommends the following for each problem:

1. Pollution from livestock - fencing livestock is a viable option as it would help contain cattle heads from venturing into catchment areas. This is a less expensive approach for farmers who are already faced with high taxation policies and held responsible for diffuse pollution (Rooney 2005; Lognonne 2005).
2. Chemicals from pesticides and herbicides - could be curtailed by creating buffer strips that act as both a zoning tool and prevention of seepage of pesticides.

iii. Soil erosion from cultivation - can be prevented by buffer zones to collaborate with the above, and prevent runoff of agricultural land into catchment areas. This falls under the containment category of control.

1. Soil erosion from forestry - should use buffer zones to contour sloping land, and reduce soil erosion from depositing in the freshwater surface. This containment measure would also help reduce acidification of surface water.

Apart from the above options, control policies such as the WEWS Act, CAP Reform, and the setting up of specialist units in diffuse pollution areas to monitor catchment areas, and support in the form of advice and training of stakeholder groups are also recommended. These behavioral control options help mitigate diffuse pollution. While there are more control options, the above-discussed ones are most preferred by advisory organizations, agencies, and environmental groups.