ENVIRONMENTAL IMPACT ASSESSMENT (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 40oC
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.
EMISSION 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> 850oC, and
• residence time > 2 s at min 6% oxygen
• rapid cooldown fluegas below 400-250oC 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 EU and local regulatory limits.
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 established 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.
