EIA Issues and Measures
An important element of the EIA process is to mitigate potential impacts. From inception of the base project, some probable impacts were identified and mitigation measures were agreed upon.
The following are some of the environmental limits and operational guidelines that have been agreed with FEPA.
Discharges to water: Outfall to Bonny River
|
SPECIFICATION |
REQUIREMENTS |
|
Temperature |
Maximum limit 40 oC |
|
PH |
6.5 – 8.5 |
|
Oil & Grease |
Maximum limit 10 mg/l |
|
Ammonia |
Maximum limit 5 mg/l |
|
Nitrate (NO3) |
Max limit 50 mg/Nm3 |
|
Sulphide |
Maximum limit 0.2 mg/l |
|
Total Suspended Solids |
Max limit 30 mg/ Nm3 |
|
Total Dissolved Solids |
Max limit 2000 mg/ Nm3 |
|
Biological Oxygen Demand |
Maximum limit 25 mg/l |
|
Chemical Oxygen Demand |
Maximum limit 125 mg/l |
|
Residual Chlorine |
Maximum limit 0.2 mg/l |
|
Dissolved Oxygen |
1 – 5 mg/l |
|
Domestic Sewage handling |
All domestic sewage to be treated;
Overflowing septic tanks are not permitted on site |
|
HCl from Incinerator |
Max limit 250 mg/Nm3 |
To ensure compliance, NLNG adopted the principle of minimisation through abatement at source of aqueous effluents, which have the potential of causing negative impact on the environment. Where this is not feasible, application of end-of-pipe technology is acceptable; eventual environmental effects as a consequence of the ultimate discharge shall be minimised.
NLNG has a modern dentrification/nitrification basin biotreater, which is the first unit of its kind to be operated in Nigeria. Waste water and sewage from the Bonny plant as well as all domestic sewage from the adjacent Residential Area and Joint Venture Construction Camp is treated in this facility so that only clean water flows into the river. The biotreater plant is in continuous operation. It is designed to meet the stringent effluent water quality specifications as agreed in the EIA Environmental Premises.
Solid Waste Management
|
SPECIFICATION |
REQUIREMENTS |
|
Chemical containers / drums |
Avoid recycling for domestic use |
|
Scrap metals |
Recycle via approved and registered contractors |
|
Batteries |
Collect and store in separate containers;
No incineration of batteries |
|
Incombustibles |
Collect and store separately to avoid incineration |
|
Hospital waste |
To be incinerated |
|
Asbestos (CAF gaskets) |
Not to be incinerated |
|
Total Suspended Solids |
Max limit 30 mg/ Nm3 |
|
Handling of containers with disposable waste |
Store in protected area |
|
HCl from Incinerator |
Max limit 250 mg/Nm3 |
|
General waste management |
Develop and implement a Waste Management Plan in conjunction with relevant Authorities |
|
HCl from Incinerator |
Max limit 250 mg/Nm3 |
The principle adopted here is correct handling, treating and disposing of solid waste to avoid/eliminate liabilities in the future and to meet requirements for due diligence.
NLNG operates an incinerator at its Bonny plant to dispose of domestic waste as well as combustible industrial waste. The wetland nature of Bonny Island does not allow the creation of a landfill site. Therefore, all other solid wastes are temporarily stored on the plant site before being transported to the mainland to FEPA approved locations.
Solid wastes such as wood, metal scraps, empty plastic drums e.t.c, were labeled and kept at the plant site whilst other options such as recycling or return to vendor were being investigated. An early success was achieved with the implementation of a disposal scheme for the Iron Oxide sludge from the borehole water treatment plant. This material is now worked into concrete bricks for construction purposes.
Emissions to Air
|
SPECIFICATION |
REQUIREMENTS |
|
Use of natural resources and energy sources |
Efficient use in day-to-day operations.
|
|
CFC's and Halons |
Not allowed.
Use HFC-134a or equivalent for AC refrigerant |
|
Venting of Hydrocarbons |
No venting, except for emergency relief systems in exceptional cases |
|
Flaring |
A "no flaring" principle shall apply to normal plant operations.
Controlled flaring is allowed during start-up and shut-down activities. |
|
NOx emissions from furnaces and gas turbines |
Max limit 350 mg/Nm3 (as dry gas, 11% vol O2) |
|
Carbon Monoxide (CO) emissions |
Max limit 250 ppm mg/ Nm3 (as C) |
|
Hydrocarbons |
Max limit 50 mg/ Nm3 |
|
Dioxins from Incinerator |
Control via automatic incinerator operation, ensuring:
- temperature> 850 oC, and
- residence time > 2 s at min 6% oxygen
- rapid cooldown fluegas below 400-250 oC band
|
|
HCl from Incinerator |
Max limit 250 mg/Nm3 |
Principle adopted is minimisation through abatement at source of gaseous emissions which have the potential of causing negative impact on the environment.
Additionally, dispersion modelling of emissions shall demonstrate that ground level concentrations at the workplace and in the nearby settlements do not exceed the tolerance limits for ambient air pollutants according to ACGIH Occupational Threshold Limit Values.
Baseline studies were carried out on air quality and noise measurements to confirm that the plant meets Project Specification requirements regarding Emissions and Discharges Limits as per EIA premises. The project was signed off as meeting emission and noise limit premises.
Conservation
The impacts of the project on wildlife and forests have been identified. To this end, the company has commenced the establishment of a nature reserve to protect some areas of Bonny ecosystem.
In pursuing the environmental policies, public consultation and enlightenment is considered fundamental to fostering good relationships with our neighbours. Forest enlightenment campaign has been kicked off in partnership with the Bonny Environmental Consultants' Committee (BECC) as part of EIA mitigation measures. Several billboards informing community to protect forests were erected at strategic locations of the Island.
Use of wildlife resources is prohibited and wildlife concentrated in fenced premises was relocated to the forest before construction work commenced.
