With rapid urbanisation in the coastal areas of South Africa and the accompanying disposal of waste and water into the sea by way of marine outfall pipelines the public have begun to focus their attention on the ecological and socioeconomic difficulties associated with each type of MOP. 

In some instances, there has been vociferous public opposition with regard to a decision to approve a particular MOP or with regard to the extent to which the operating agency of a MOP is complying with the conditions laid down for the approval of the MOP once approved. Despite this certain national and local governmental authorities have insisted that the disposal of waste by way of MOPs remains the only viable option.

The 2012 Green Paper setting out the South African Policy on Ocean Environmental records that there are about 60 licensed marine outfall pipelines which discharge waste water along the South African coast. Twenty discharge sewage, 30 discharge industrial wastes and ten discharges mixed effluent.    

The discharges vary from raw domestic sewage to intractable industrial waste, the majority being small discharges of treated sewage.   

A greater pollution potential is carried by discharges on the beach or streams discharging directly to the surf zone, since under these conditions effluents are not sufficiently diluted.

It is essential to convert to land based schemes. An analysis of ecological and socioeconomic considerations inevitably involves a comparison between MOPs and alternatives such as land based schemes. 

Any analysis of the cost-effectiveness of a scheme must weigh the costs/benefits of pollution of land against pollution of sea.  In addition, the water component of any material discharged to sea must be seen as a resource.  As the cost of new water and that of recycled water converge, it will become more cost effective for the operating agencies of MOPs to rather choose land based options to avoid discharging the water component of any material to sea.

To date there seems to be a lack of strategic planning and meaningful public participation in environmental assessments before MOPs are officially approved.  Once MOPs are approved, there is clearly also a need to satisfy the public that the operating agency of the MOP is complying with the conditions subject to which the MOP was approved.  

In South Africa and internationally, decision-making in relation to environmental issues requires statutory procedures of public participation to be followed.  

A survey of existing marine outfall pipeline(s) ("MOP" or "MOPs") found off the South African coastline with specific reference to types of MOPs:  

To survey existing MOPs, it is necessary to first define a marine discharge.

A 'marine discharge' defined:

A marine discharge is commonly defined as:

"any discharge directly into the sea below low-water level by means of a pipeline".   

Offshore pipelines and surf zone pipelines': 

Pipelines are often also divided into two categories:

• 'offshore pipelines', being pipelines that discharge effluent beyond the surf zone; and

• ‘Surf zone pipelines', being pipelines that discharge effluent in the surf zone. Generally, they are constructed during spring low tides or successive low tides by attachment to a rocky outcrop in the surf zone.  Usually the pipeline material is either concrete or steel.  In addition, concrete is often cast over the pipeline for protection. 

The three main types of marine discharges: 

Pipeline discharges are generally conveniently categorized into three types:

• Municipal sewage;
• Industrial discharges; and
• Discharges from fish processing.
Other types of discharges:

Other types of discharges include:

• Discharges into estuaries, rivers, etc;
• Discharges through pipelines that release effluent onto the beach or onto a rocky foreshore, or through pipelines that release effluent above high -water level;
• discharges through an open furrow or canal; and
• storm water discharges.