Company Announcement - GIBB, South Africa’s leading black-owned consulting firm has been awarded the first environmental project for the Port of Beira in Mozambique to assess the spillage of coal where ship-to-ship transfer takes place, to determine the magnitude and extent of the dispersion of coal. Beira serves as a large coal terminal, however the actual port is very shallow which makes it difficult for large tanker ships to enter, and requires the coal to be transferred to smaller feeder ships at the port, which then meet the larger tankers out at sea where trans-shipment takes place.

Roland David, Environmental Sector Unit Manager at GIBB says, “These trans-shipment activities give rise to the spillage of coal which could then be dispersed along the seabed which in turn affects those benthic flora and fauna most susceptible to coal dust coverage and possible anoxic conditions that might arise during coal oxidation within close proximity (0–100 m) to the coal-loading activity.”

“The understanding of coal dispersion will allow the client to better understand its impact on the environment, which in turn will enable them to adjust their operations to ensure that the release of coal into the ocean is minimised. The government of Mozambique will also be able to measure the impact of these operations on the marine environment,” comments David. GIBB’s analysis involves the sampling of the open ocean trans-shipment area once per year, for three years. “The analysis will provide accurate data on how to decrease and manage the amount of coal dispersion in the surrounding environments, thereby reducing negative environmental impact,” states David.

The distribution of coal is determined by particle settling velocity and current velocity, with coal concentration decreasing rapidly away from the terminal. Coarser sediment fractions contain the highest coal concentrations and carbon/nitrogen ratios when compared to finer fractions. Coal particles with >2.36 mm diameter, and settling velocities ≤10.54 cm/s, settle out close to the point of release (depending on currents), whilst small (<53 μm) and weakly oxidized coal particles travel further and take longer to settle out (settling velocities ≥0.16 cm/s). This results in a wider dispersal of coal particles, and a corresponding decrease in the coal concentration.

“As with similar projects in Africa, logistics can be an issue. The challenges are that the small vessel is very difficult to work from and the seas can be quite tumultuous and unpredictable. These issues combined means that the collection of data can be quite dependent on sea conditions and can make for very difficult, uncomfortable site work. Further to that, the surveying needs to be completed very quickly in order to make the project profitable,” shares David.

“This is the first marine project won by GIBB which shows their commitment to increasing their service offerings. GIBB is continually looking at innovative ways to provide quality services to their clients all over Africa,” concludes David.