Part II - Water Pollution from Waste Mismanagement

As I began to mention in my last post, the way in which the cattle interact with their environment is very important for the quality of local water resources.

The intensity of grazing in a region can increase the potential for contamination. Donkor et al. (2002) found that because of the compaction of the land due to cattle moving around the area and hooves compressing the soil, runoff is relatively higher in an area of heavy grazing compared to a lightly grazed region. So the contaminated agricultural waste that I discussed previously is even helped to the water source indirectly due to the cattle!

A now antiquated, but in my eyes very relevant study from Schepers and Francis in 1982 illustrated the problem clearly. They conducted a study of a 32.5 ha cattle pasture in Nebraska, recording the levels of nutrients in the runoff in areas where cattle were grazing and not grazing.

They determined that the influence of grazing cattle had a huge impact on the levels of nitrates, soluble phosphorus, chemical oxygen and chloride concentrations in the runoff.

Dissolved nutrients in runoff was seen to increase from 6% (where no cattle resided) to 78% when livestock were grazing in the area!

Cattle also usually have direct access to water as part of some farming practices. This direct access allows immediate deposition of waste into the water system. Cattle can also severely effect the river bank ecosystems by overgrazing and from aforementioned soil compression.

Cattle interacting directly with a water source. Source omafra  

Whats more crucial is the fact a fully functional riverbank zone is pivotal for maintaining a stream ecosystem, which can aid in maintaining the quality of water by acting as a natural buffer to incoming nutrients and materials.

River bank degradation. Source Getty images

So…. animals facilitating waste entry into the water system and manure mismanagement can be caused by a variety of processes - the specific effects of these pollutants are going to be tackle in my future posts, so stay tuned!

P.S (I realise that most of the factors discussed in this post also relate very closely to land degradation, I am also planning on exploring this environmental impact in more detail at a later date)