MechChem Africa November-December 2022

High standards of waste management in Angola’s oil sector Bruce Engelsman, principal engineer at SRK Consulting, talks about the company’s waste management work in Angola’s oil and gas sector.

A s sub-Saharan Africa’s second largest oil producer, Angola has seen the application of world class waste management standards in its oil andgas sector. SRKConsultinghas been involved in landfill design and environmental impact assessments in Angola for almost 20 years, according to Bruce Engelsman, princi pal engineer at SRK Consulting. “Most of the waste from the offshore platforms comprises drill cuttings, which emanate from many ki lometres of off shore exploration drilling,” said Engelsman. “These have to be brought ashore, treated and disposed of responsibly, to manage the hydrocarbon content in this waste stream.” Before the material can be sent to land fill, a specialist Angolan firm extracts the oil in the cuttings, using the latest Danish thermal desorption technology. Hazardous waste fromoffshore and onshore facilities is incinerated, and general domestic waste is sent to landfill. In line with best practice and Angolan regulations, emissions emanating fromtreatment are scrubbed andmonitored as part of closely managed waste disposal. Environmental protection principles are embedded in the country’s constitu tion, which highlights that the State ‘shall promote the protection and conservation of natural resources guiding the exploitation and use thereof for the benefit of the com munity as a whole’. It also gives all citizens the right to ‘live in a healthy and unpolluted environment’ and requires the State to ‘take the requisite measures to protect the envi ronment and national species of flora and fauna ... and maintain ecological balance’. Engelsman explained that Angola has several main service hubs to support its oil and gas sector. One is Luanda, with its extensive port facilities, and the other is in the far north at Soyo, on the Congo River. “These sites boast total waste man agement solutions that use leading-edge technology,” he said. “The treated residue is deposited in landfill facilities designed by SRK, ensuring that best international prac tice is applied regarding environmental and social impact. The total design includes the cells themselves, groundwater monitoring, roads, and other infrastructure. “To ensure a high standard of design,

SRK has in the past applied the minimum re quirements fromSouthAfrica’s Department of Water and Sanitation. In recent years, Angola began developing its own regula tions – especially regarding characterisa tion of waste – so we incorporate these too.” This developing legal landscape for waste management requires, for instance, more detailed investigation of leachable charac teristics as well as the total concentration of contaminants of concern. Two streams of testing are therefore conducted – one for the leachable concentrations and another for total concentrations. Based on the out come of these tests, there are restrictions on what materials can enter the landfill. “Our extensive experience inwastemanage ment in South Africa – in the field of tailings dams, for example – equips us very well for these projects,” said Engelsman. “Tailings

waste has to be classified to assess whether a lining is required under the facility – a decision with significant cost implications.” The Cacuaco facility, with which SRK has been involved for 15 years, is nearing the end of its life. After closure, operations will move to Bengo in the Viana district, on which SRK is currently busy with design

Angola has several main service hubs to support its oil and gas sector, all boasting total waste management solutions. (Image: Unsplash)

34 ¦ MechChem Africa • November-December 2022