The Kenya Pipeline Company has defended its decision to utilise part of the decommissioned 14-inch oil pipeline to convey water from the Mzima Spring Water intake point to Mombasa.
KPC commissioned the multi-product white oil pipeline in 1978 to transport gasoline, kerosene, Jet A-1, and diesel from Mombasa to the hinterland.
The pipeline had a design shelf life of 25 years but remained in service for 42 years, leading to several operational challenges, including frequent leakages.
To assess the integrity of the pipeline, KPC conducted an inline inspection and a close interval potential survey in 2018.
The survey revealed extensive external and internal corrosion coupled with bends and crack-line anomalies.
Following the increased frequency of pipeline leaks and hydrocarbon releases, which endangered safety and adverse environmental aspects, coupled with the escalating cost of maintenance, a decision to decommission Line 1 was reached.
Subsequently, KPC considered several decommissioning options for the line.
The first option on the table was to remove the entire line, disposing of the pipes as scrap metal before restoring the right of way.
The second option was to abandon the pipe underground, while the third was to re-use the whole pipeline or some sections of it to supply water.
At the time of the study, the proposed length of reuse sections of the pipeline was 215km from the Mzima Springs water intake point to Mombasa.
KPC commissioned Kurrent Technologies Ltd, a Nema-registered firm of experts, to prepare and submit to the authority the Environmental Impact Assessment Study Report.
This is in accordance with the directives of the National Environment Management Authority and the Environmental Management and Coordination Act of 1999.
The report has since been submitted to Nema.
KPC said abandoning the pipe along the right of the way would have required minimum cost to monitor potential pollution and minimal environmental disturbances since there would be no site construction or demolition activities leading to insignificant environmental impacts.
KPC said there would have been minimal social impacts.
The company said abandoning the pipeline would have challenges as scrap dealers would have had a field day, leading to insecurity, environmental, and safety issues as there is an active oil pipeline nearby.
As a mitigation measure, KPC would have been required to spend more on community awareness and security.
KPC said abandoning the pipeline would have had the potential of contaminating soil and water due to the release of residual petroleum compounds from the pipeline and the decomposition of metal.
The company would have been required to monitor the decommissioned pipeline mainly in areas with historical pollution, river crossings, and other sensitive ecosystems.
In a study, the company observed that the asset value of Line 1 is Sh 5,770,462,500, while the cost of uprooting it was estimated to be Sh4,136,808,333.
“The estimated disposal value of Line 1 scrap material was KES 2,216,528,448.00. Based on the above, the sum of the asset value plus the cost of uprooting less the disposal value is a net loss of KES 7,690,742,385.00,” KPC says.
Additionally, pipeline recovery and extraction are similar to the construction of a new pipeline and involve excavation work, cutting of the pipeline, dismantling and demolition of the pump stations, transportation and disposal of the pipes and other waste, backfilling of the trenches, and site restoration.
In general, the drawbacks of complete pipeline removal include significantly higher costs in terms of capital and manpower expenditure and increased risk of environmental and human safety hazards during removal.
KPC cites another drawback as the disruption of surrounding ecosystems with possible contamination from residual pipeline contents leaked during excavation.
The study report said the population in the area of jurisdiction was 4.4 million, with a total population of approximately 55 percent (2.4 million) served by piped water.
“The current water demand for water in the region is approximated at 329,306 m3/day against a production of 180,000 m3/day.”
The Coast region mostly depends on bulk water supply system schemes presently comprising Mzima Pipeline, Marere Pipeline, Tiwi Boreholes, and Sabaki-Mombasa Pipeline, supplying Mombasa and 13 townships in Kwale, Kilifi, and Taita Taveta counties.
The remaining six townships are supplied from local sources.
Mwache Dam in Kwale was under construction at the time of the study as an additional key bulk water supply system scheme for domestic water supply and irrigation.
On the quality of water being supplied using the pipeline, KPC says pigging using water was undertaken from Mombasa to Nairobi to clean the pipeline.
The inline water was tested for petroleum compounds after every pigging up to 10 times until the water met the regulatory requirement for drinking water.
KPC is still engaging experts to have the appropriate internal and external coating of the pipeline applied to ensure water quality and pipeline integrity and meet Kenyan standards on drinking water quality.