ENVIRONMENTAL IMPACT ASSESSMENT
(EIA) REPORT
FOR
BIOJOULE KENYA LTD
FOR
PROPOSED (AD) BIOGAS
PLANT, NAIVASHA
BY
Environmental Cost Management (ECM) Centre Limited (Reg: 196)
JUNE 2013
Environ mental Cost Management (ECM) C entre Limited
Theta Lane off Lenana Rd, Kilimani, P.O. Box 101 35-001 00, GPO Nairobi, Kenya
Tel: 254-30 016 61, 0 20-27 1299 9, 07 349 4788 2, 07 20-82 8621 Fax :02 0 -271 2299 9,
E-ma il: ecm@ ecmcentre. com
I
Prepared by:
Environmental Cost Management (ECM) Centre Limited (Reg: 196)
Signed………………………………..date…………………………….
Proponent:
Biojoule ltd
Signed………………………………..date…………………………….
Operating Terms
AD Anaerobic digestion
DM Dry Matter
kWh Kilo watt per hour
MWh Mega Watt per Hour
KP&LC Kenya power and lighting Company
EXECUTIVE SUMMARY
Vegpro Limited deals in fresh produce, flowers and logistics from Kenya. After the fresh produce and
flowers for export are produced, wastes such as spent vegetable, rose plants (leaves, stems, etc.),
vegetable out grades, rose rejects and farm produced “green crops” that are left are first decomposed
and used as fertilizer for the farm. These wastes will henceforth collectively be referred to as
feedstock. Vegpro ltd also obtains waste from Vandenberg ltd Farm that is located nearby.
Approximately 23,024 tonnes per year of fresh feedstock is available at a dry matter (DM) content of
23.7%, giving 5,448 tonnes per year of dry matter (DM). In order to utilize the feedstock and
diversify revenue sources, the company proposes to set up a biogas plant within Gorge farm, at the
south-western end, a spot which is about 200 meters from an existing KP&L sub-station.
Photo 1: Aerial layout of the farm showing the earmarked site(in green)
The objective of the project is to satisfy the ever increasing demand for electricity in Kenya with a
clean alternative to the more fossil-fuel based electricity component of the Kenyan national grid. The
project aims to generate electricity. Some of the electricity will be used for the operation of the plant
itself, the farm with the balance being exported to the grid. Energy from Thermal sources like Coal,
Diesel is expensive and a source of pollution and contributes to the CO2 emissions. Electricity
generated from this plant will replace these sources sustainably.
It is recognised that a project of such magnitude as the proposed biogas plant could have certain
adverse environmental impacts if appropriate measures to protect the environment are not
undertaken.In order to ensure lasting co-existence of the site activities with other social and economic
activities in the area, and compliance with the Environmental Management and Coordination Act,
1999, Vegpro Limited commissioned this environmental assessment for the project.
The results of this study show that the proposed biogas plant does not have a potential for serious long
term negative environmental impacts and overall has a positive environmental and socioeconomic
benefit to the local community.
The project is sitting on a site where development had already been undertaken and the surrounding
areas are large scale agricultural activities, where agricultural equipment is already employed.
The major impacts that may be caused by the project will be short term and mainly during
construction. These include noise and air pollution due to heavy construction equipment, soil
excavation, excessive requirement of water and possible more energy requirements. For water and
energy usage, alternative sources should be sought without affecting the surrounding area.
The potential adverse environmental impacts during operations, such as wastewater, solid waste and
drainage systems, adequate mitigation measures will need to be put in place. Plans are also in place to
adequately mitigate the health and safety impacts of the project. The recommendations have been
provided in the Environmental management Plan (Section 7) as proposed actions. This report presents
the findings under the following headings:
• Environmental impact assessment objectives and scope;
• Nature of the project;
• Methodology;
• Policy and legal issues;
• Baseline conditions of the site;
• Anticipated environmental impacts;
• Environmental management plan;
• Annexes.
Contents ENVIRONMENTAL ASSESSMENT OBJECTIVES AND SCOPE OF WORK ............................... 8
Introduction ................................................................................................................................... 8
Assessment Objectives .................................................................................................................. 3
Scope ............................................................................................................................................ 3
Terms of Reference ....................................................................................................................... 3
Responsibilities ............................................................................................................................. 4
Methodology Outline ..................................................................................................................... 5
Environmental Screening ............................................................................................................... 5
Environmental Scoping.................................................................................................................. 5
Desk Study ................................................................................................................................ 5
Baseline Data/Information Gathering ......................................................................................... 6
Site Assessment ......................................................................................................................... 6
Reporting ................................................................................................................................... 6
POLICY AND LEGAL FRAMEWORK ........................................................................................... 7
General Overview .......................................................................................................................... 7
Policies .......................................................................................................................................... 7
National Environment Action Plan (NEAP) ............................................................................... 7
National Policy on Energy ......................................................................................................... 8
Kenyan Economic Strategy for Wealth and Employment Creation (2003-7) ............................... 8
Policy Guidelines on Environment and Development ................................................................. 8
Legal Aspects ................................................................................................................................ 9
The Environment Management and Co-ordination Act, 1999 ..................................................... 9
Electric Power Act, 2006 ......................................................................................................... 10
The Factories Other Places of Work Act (Cap 514) .................................................................. 10
The Water Act 2002 ................................................................................................................. 11
The Public Health Act (Cap. 242) ............................................................................................ 12
Local Government Act (cap 265) ............................................................................................. 13
EIA/ EA Regulations ............................................................................................................... 13
BASELINE INFORMATION & DATA .......................................................................................... 14
Project Site and Topography ........................................................................................................ 14
Drainage System and Hydrology.................................................................................................. 14
Vegetation ................................................................................................................................... 14
Rainfall and Climate .................................................................................................................... 15
Soils ............................................................................................................................................ 15
Water Resources .......................................................................................................................... 15
Bio-diversity................................................................................................................................ 15
Air Quality .................................................................................................................................. 15
Land Use Activities ................................................................................................................. 16
Areas of Cultural Importance ................................................................................................... 16
Environmentally Sensitive and/or Significant Areas ................................................................. 16
Economic Development ........................................................................................................... 16
Social Issues ............................................................................................................................ 16
PROJECT DESCRIPTION AND MAGNITUDE OF OPERATIONS .............................................. 17
General Description, Ownership and Project Location ................................................................. 17
Nature of the Project and Proposed Development ......................................................................... 18
Feedhopper Unit with Shredder and Feeder .............................................................................. 19
Hydrolyser 1 ............................................................................................................................ 19
Hydrolyser 2 ............................................................................................................................ 19
Digester ................................................................................................................................... 20
Recyclate Tank ........................................................................................................................ 20
Central Building ...................................................................................................................... 20
Biogas Store ............................................................................................................................ 21
Main Pump Assembly .............................................................................................................. 21
Main Plant Control System ...................................................................................................... 22
Solids Separator ....................................................................................................................... 22
Electricity Generating Sets (CHP Units)................................................................................... 23
Main Flare ............................................................................................................................... 23
Site Description ........................................................................................................................... 24
Process Description ..................................................................................................................... 24
Sources of Raw Materials ............................................................................................................ 26
Waste Generation ........................................................................................................................ 26
Project Construction .................................................................................................................... 26
Construction Inputs .................................................................................................................. 26
Construction Activities ............................................................................................................ 26
Current Status of the Project and Construction Period .............................................................. 27
Project Implementation and Operation ......................................................................................... 27
Project Budget ............................................................................................................................. 27
Project Lifetime and Decommissioning........................................................................................ 27
ANALYSIS OF ENVIRONMENTAL IMPACTS ........................................................................... 28
STAKEHOLDER COMMENTS ..................................................................................................... 31
TABLE 1: ENVIRONMENTAL ASPECTS, IMPACTS AND MITIGATION ................................ 33
ENVIRONMENTAL MANAGEMENT PLAN ............................................................................... 35
CONCLUSION ............................................................................................................................... 37
ANNEX: ............................................................................................ Error! Bookmark not defined.
ATTACHMENTS .............................................................................. Error! Bookmark not defined.
ENVIRONMENTAL ASSESSMENT OBJECTIVES AND SCOPE OF
WORK
Introduction
Vegpro Limited deals in fresh produce, flowers and logistics from Kenya. The company
operates two firms i.e. Gorge Farm and Longonot Farm in Naivasha located 15KM from Naivasha
town along Moi South Lake Road. Vegpro Ltd is a leading producer of vegetables and cut flowers.
After the fresh produce and flowers for export are produced, wastes such as spent vegetable, rose
plants (leaves, stems, etc.), vegetable out grades, rose rejects and farm produced “green crops” that
are left are first decomposed and used as fertilizer for the farm. These wastes will henceforth
collectively be referred to as feedstock.
Photo 2: Photo showing vegetables in the farm
Approximately 23,024 tonnes per year of fresh feedstock is available at a dry matter (DM) content of
23.7%, giving 5,448 tonnes per year of dry matter (DM). In order to utilize the feedstock and
diversify revenue sources, the company proposes to set up biogas plant within its Gorge farm, at the
south-western end, a spot which is about 200 meters from an existing KPLC sub-station. (see photo 1)
Photo 3: Photo Showing the process waste
used as feedstock
Photo 4: Photo showing sweet corn process
waste
Extensive testing of this material in laboratory scale digesters at Southampton University, UK, has
shown that this feedstock will yield 421M3/hr of biogas of which 232 M
3/hr will be methane. These
methane is used in electricity generation. Some of the electricity generated will be used for the
operation of the plant itself, on the farm with the balance being exported to the grid.
The project proposal is for an on-farm anaerobic digestion (AD) plant comprising a system of
hydrolysers and a digester to produce biogas, an engine driven electricity generating set (genset) and
other associated equipment to operate and manage the process. The whole project is designed to be
sited on a pre-leveled area on the farm. This project will establish an environmentally friendly and
sustainable form of electricity (and heat) production from the feedstock, also known as substrate once
loaded into the digestion system. The AD process uses naturally occurring bacteria and other
microbes to convert organic matter in the feedstock into:
• Biogas, which is an energy rich mixture of methane and carbon dioxide which is
suitable for use as a fuel to generate electricity and heat.
• Nutrient rich solid and liquid fertilisers to be used on the farm in place of purchased
chemical fertilisers.
The resulting biogas is burned in an engine driven generating set (genset) to produce electricity,
mostly for use on the farm with the balance available for export to the grid. The genset also produces
heat in the form of engine cooling water and some of this will be used to heat the hydrolysers to 50-
55C and to maintain the digester at a temperature of ~ 40-45C. The pre-hydrolysis of the feedstock
material in the two hydrolysers ensures
significantly higher biogas production and
shorter residence times than conventional
AD plants, maximizing biological
degradation and stabilization, minimizing
capital costs and plant footprint and
increasing electricity (and heat)
production.
Photo 5: AD plant photo (the
surface tanks and with top
storage domes)
Photo 6: Standard Biogas generator set
It is recognized that projects such as the proposed biogas plant by Vegpro Limited could have
certain adverse environmental impacts if appropriate measures to protect the environment are
not undertaken. In order to ensure lasting co-existence of the site activities with other social and
economic activities in the area, and compliance with the Environmental Management and
Coordination Act, 1999, the site operators commissioned this environmental assessment for the
project.
Assessment Objectives
The objective of this assessment is to determine and assess the impacts of the proposed project and to
develop appropriate mitigation measures. The assessment also aims to ensure compliance with the
provisions of the Environmental Management and Coordination Act, 1999 and to prepare
an Environmental Management Plan which can be used as the basis for future audits.
Scope
The Kenya Government has put forward measures aimed at protecting the environment by listing
projects which must undergo environmental impact assessment under schedule 2 of EMCA 1999. For
a proposed project to get a license form NEMA, they are required to either submit a project or EIA
report depending on the magnitude and nature of the project. This EIA report covers the following
aspects of the proposed cogeneration project:
• The baseline environmental conditions of the area
• Description of the nature and design of the project
• Description of the major activities at the site during construction, operation and
decommissioning phases of the project
• Provisions of the relevant environmental laws
• Identification of materials to be used and by-products and wastes
• Identification and discussion of the potential adverse impacts to the environment from
the site
• Establish appropriate mitigation measures for these impacts
• Provision of an environmental management plan.
Terms of Reference
The terms of reference for the EIA included the following:
• Hold appropriate meetings with the management to establish the procedures, define
requirements, responsibilities, and a timeframe
• Provide a description of the nature, design, activities of the proposed Biogas Plant
with a focus on potential impacts to the surrounding environment
• Inspect the site and its surroundings in collaboration with the management
• Carry out a systematic environmental assessment at the site following the gazetted
regulations
• Conduct a stakeholder meeting for the identification of social and community
concerns
• Produce an environmental assessment project report that should contain among
other issues identification of key environmental aspects, recommendations on
appropriate mitigation measure to minimize or prevent adverse impacts and ensure
health and safety of the workers and neighbouring communities
• Develop an environmental management plan.
Responsibilities
While the environmental impact assessment expert provided the technical understanding on
the baseline environmental status, potential impacts, management options and legal framework,
the client provided the following:
• Site map(s) showing roads, service lines, buildings’ layout and the actual size of the
site
• Full details of nature of the project, design, materials usage and by-products, site
operational outline and any wastes to be generated
• Anticipated measures for handling wastes on the site
• Anticipated management programme for the proposed development
• Arrangement with surrounding community/stakeholder meetings
The output from the environmental expert included the following:
• An environmental impact assessment project report comprising of an executive summary, study approach, operational nature of the project, baseline conditions, impacts
and appropriate mitigation measures
• An environmental management plan as part of the report recommendations
Methodology Outline
The general steps followed during the assessment were as follows:
• Preliminary assessment of the site
• Environment screening, in which the project was identified as among those requiring a project
report under schedule 2 of Environmental Management and Coordination Act (EMCA),
1999
• Environmental scoping that provided the significant environmental issues related to proposed
project and the site activities
• Desk studies and interviews with the site managers
• Detailed physical inspection of the site and the surrounding areas
• Community/stakeholder comments gathering
• Reporting
Environmental Screening
This step was applied to determine whether an environmental assessment project report was required
and what level of assessment was necessary. This was done in reference to requirements of the EMCA
(1999) and specifically the second schedule. Issues considered included the physical location,
sensitive issues, nature of the project, project design and nature impacts.
Environmental Scoping
The scoping process helped narrow down onto the most critical issues requiring attention during the
assessment. Environmental issues were categorized into physical, natural/ecological, social, and
economic aspects.
Desk Study
The desk study included documentary review on the nature of the site activities, project
design, operational requirements, policy and legislative framework as well as the environmental
setting of the area among others. It also included discussions with managers and staff.
Baseline Data/Information Gathering
Site information was gathered through observation and research. The site was visited for inspection of
the physical environment and status of the immediate surroundings. A pre-prepared data sheet was
used to record information gathered during the visit of the sites. The field data sheet addressed various
aspects of the project site and the general environment and had been adopted from the international
environmental protocol then adjusted to incorporate issues listed in the EIA regulations in the
Kenya Gazette Supplement No. 56 of 13th June 2003.
Project design documents, including main drawings, were reviewed. Physical investigation took into
consideration the environment where the plant will be located. The hydrology and surface geology of
the area, the drainage system, and the typical socio-economic activities around the site were
investigated. Also investigated were the public services provided in the area including the drainage
systems, water supply/abstractions, and access roads.
Site Assessment
Field visits were meant for physical inspections of the site characteristics and the environmental status
of the surrounding areas to determine the baseline data and potential impacts. The assessors
were conducted around the site by the General Manager of Gorge Farm. Community/stakeholder
consultation comments were also solicited during this stage through visits to individual
stakeholders/neighbours.
Reporting
In addition to briefing the management, this project report was prepared. The contents were
then presented to the client for submission to the National Environmental Management Authority
(NEMA) as required by law.
POLICY AND LEGAL FRAMEWORK
General Overview
Environmental impact assessment (EIA) is a tool for environmental conservation and is
used for the identification of significant environmental aspects and impacts of proposed projects
which when addressed ensure sustainable operations with respect to environmental resources and co-
existence with other socio-economic activities in the neighbourhood. At the national level,
Kenya has put in place necessary legislation that requires environmental impact assessments to be
carried out on specified types of operations and projects and reports to be submitted to the
National Environment Management Authority (NEMA) for approval and issuance of relevant
licenses.
To facilitate this process, regulations on EIA and environmental audits have been established
under the Kenya Gazette Supplement No. 56 of 13th June 2003. Besides, a number of other national
policies and legal statutes have been reviewed to enhance environmental sustainability in
national development projects across all sectors. Some of the policies and legal provisions that are
deemed relevant to the proposed project are briefly presented in the following sub-sections. For the
purposes of this report, emphasis has been put on those policies and legal provisions that relate to the
design, installation and operation of the proposed facilities.
Policies
National Environment Action Plan (NEAP)
According to the Kenya National Environment Action Plan (NEAP, 1994) the Government
recognized the negative impacts on ecosystems emanating from industrial, economic and
social development programmes that disregarded environmental sustainability. Following on
this, establishment of appropriate policies and legal guidelines as well as harmonization of the
existing ones have been accomplished and/or are in the process of development. Under the NEAP
process, EIA was introduced and among the key participants identified were the industrialists,
business community and local authorities.
National Policy on Energy
The National Policy on Energy, Sessional Paper 4 of 2004 recognizes that the success of
socio-economic and environmental transformation strategies pursued by the government at present
and in the future is to a large extent depended on the performance of the energy sector as an economic
infrastructure. The paper encourages the use of environmentally friendly and efficient
technology for the generation of electricity; and the generation of electricity from renewable energy
sources through a wider adoption and use of renewable technologies and thereby enhance their role in
the country’s energy supply matrix. This enhancement will reduce the country’s dependence on oil
based thermal generation. The proposed project is therefore in line with the policy.
Kenyan Economic Strategy for Wealth and Employment Creation (2003-7)
The strategy also identifies implementation of renewable sources of energy projects as part of
the key reforms necessary in the energy sector, which is in line with the proposed project. The
proposed project will improve the revenue base of Vegpro Limited with possible increase in job
creation for more people in the region. At the same time the project will lead to economic
improvement of the country through increased power availability.
Policy Guidelines on Environment and Development
Among the key objectives of the Policy Paper on Environment and Development (Sessional
Paper No. 6 of 1999) are:
• To ensure that from the onset, all development policies, programmes and projects take
environmental considerations into account,
• To ensure that an independent environmental impact assessment (EIA) report is prepared for
any industrial venture or other development before implementation,
• To come up with effluent treatment standards that will conform to acceptable health
guidelines.
Under this paper, broad categories of development issues have been covered that require
sustainable approach. These issues include the waste management and human settlement sectors. The
policy recommends the need for enhanced re-use/recycling of residues including wastewater, use of
low non- waste technologies, increased public awareness raising and appreciation of clean
environment. It also encourages participation of stakeholders in the management of wastes within
their localities. Regarding human settlement, the paper encourages better planning in both rural and
urban areas and provision of basic needs such as water, drainage and waste disposal facilities among
others.
The proposed project does not use any water for its operations except for personnel and washing
down, which is in very limited quantities, which support this policy guideline. No waste is generated
as both the liquid and solid fertilizers will be used in the farms.
Legal Aspects
Application of international conventions and national statutes and regulations on
environmental conservation and pollution prevention suggests that organizations have a legal duty and
responsibility to conserve resources and discharge only wastes of acceptable quality to the receiving
environment and without compromising public health and safety. The key international and national
laws of relevance that govern the management of environmental resources in the country have been
briefly discussed in the following paragraphs. Note that wherever any of the laws contradict each
other, the Environmental Management and Co-ordination Act, 1999 prevails.
The Environment Management and Co-ordination Act, 1999
This Act has sections which regulate the environmental aspects of the energy sector. Part II
of the Environment Management & Co-ordination Act, 1999 states that every person in Kenya is
entitled to a clean and healthy environment and has the duty to safeguard and enhance the
environment. To achieve this, the Act directs that any operator of any proposed significant
undertaking should carry out an environmental impact assessment and prepare an appropriate
report for submission to the National Environmental Management Authority (NEMA), who in turn
may issue a license as appropriate.
The second schedule of the same Act lists management of power projects among the projects
that must undergo an environmental impact assessment before implementation.
Part VIII section 72 of the Act prohibits discharging or applying poisonous, toxic, noxious or
obstructing matter, radioactive or any other pollutants into aquatic environment. Section 73 requires
those operators of projects, which discharge effluent or other pollutants to submit to NEMA accurate
information about the quantity and quality of the effluent. Section 80 demands that all owners of an
industrial establishment or trade emitting a substance or energy causing or likely to cause air pollution
to apply for an emission license from the Authority. However, NEMA has not yet established the
emission standards.
Biogas projects are renewable sources of energy which utilize feedstock. The waste
generated is mainly converted to both liquid and solid fertilizer, which are then re-used in the farms.
Electric Power Act, 2006
Section 121 (1) c of the Electric Power Act, 1997 empowers the Electricity Regulatory
Commission (ERC) to “formulate, enforce and review environmental, health, safety and quality
standards for the energy sector, in coordination with other statutory authorities”; ERC is therefore the
Lead Agency in respect of the electric power sub-sector, while section 9 (3) of the Act requires ERC
to take into account the need to protect the environment, conserve natural resources, and protect the
health and safety of service users and the public at large, among other things; when evaluating
applications for licenses.
The Act also empowers the board to ensure the licensees provide information to the
public on the environmental performance and sources of their electric power.
To ensure compliance, a copy of this EIA report will be issued to the ERC to verify
conformance before issuing of the license.
The Factories Other Places of Work Act (Cap 514)
Section 13 states that every factory shall be kept in a clean state and free from effluvia arising
from any drain, sanitary convenience or nuisance including accommodation of dirt and refuse. Section
17 of the same Act requires that where any process is carried out which renders the floor liable to be
wet to such an extent that the wet is capable of being removed by drainage, effective means shall be
provided and maintained for safe draining off the wet. Section 51 requires suitable means of removing
dust or fumes from work places. Section 53 of this Act requires that workers employed in a process
involving exposure to wet or to any injurious or offensive substances, suitable protective clothing and
appliances (gloves, footwear, goggles, and head coverage) shall be provided.
Section 4 of Kenya subsidiary legislation of 2004, Legal Notice No. 31 of Kenya Gazette
Supplement No.25 of 24th May, 2004 of the Factories Act Cap 514, requires that, all factories or other
workplace owners to establish a safety and health committee, which shall consist of safety
representatives from the management and the workers. The number of the committee members will
range from 3 to 7 depending on the size (number) of employees. The Act also requires the
management to appoint a competent person who is a member of the management staff to be
responsible for safety, health, and welfare in the factory or workplace. Section 13 goes ahead to state
that a health and safety audit of the workplace be carried out in every twelve months by a
registered health and safety adviser. If the owner(s) or management contravenes any of the rules,
he/she shall be guilty of an offence.
Under environment health and safety performance in the electric power sub-sector, the
electricity generating stations are regarded as factories. The Factories Act has provisions dealing with
the safety and health of persons working in factory premises, which description encompasses
electricity generating plants. The provisions of the Factories and Other Places of Work Act (Cap
514) and the attendant subsidiary legislations are enforced by the Department of Occupational health
and Safety of the Ministry of Labour. The Electricity Regulatory Commission will therefore liaise
with the Department of Occupational Health and Safety to ensure that the safety and health of persons
working in utilities in the electric power sub-sector are safeguarded at all times.
Vegpro Ltd biogas project will be governed by this Act and since the project deals
with power generation, appropriate measures will be put in place to ensure safety of workers and
property as a whole.
The Water Act 2002
Part II section 18 of the Act provides for national monitoring and information systems on
water resources. Following on this, sub-section 3 allows the Water Resources Management Authority
to demand from any person or institution, specified information, documents, samples or materials on
water resources. Under these rules, specific records may need to be kept by a factory operator and
the information thereof furnished to the authority.
Section 73 of the Act allows a person with license (licensee) to supply water to make
regulations for purposes of protecting against degradation of water sources. Section 75 and sub-
section 1 allows the licensee to construct and maintain drains, sewers and other works for
intercepting, treating or disposing of any foul water arising or flowing upon land for preventing
pollution of water sources within his/her jurisdiction.
The proposed project will not create any further water demand from the current rates because
its operations do not require any water furthermore using the liquid digestate will reduce the amount
of water required to irrigate farm crops and chemical nutrients added to irrigation water
The Public Health Act (Cap. 242)
Part IX section 115 of the Act states that no person/institution shall cause nuisance or
condition liable to be injurious or dangerous to human health. Section 116 requires Local Authorities
to take all lawful, necessary and reasonably practicable measures to maintain their jurisdiction
clean and sanitary to prevent occurrence of nuisance or condition liable for injurious or dangerous to
human health.
Such nuisance or conditions are defined under section 118, and include waste pipes, sewers,
drains or refuse pits constructed or situated in such a state as in the opinion of the medical officer of
health to be offensive or injurious to health. Any noxious matter or waste water flowing or
discharged from any premises into a public street or into the gutter or side channel or watercourse,
irrigation channel or bed not approved for discharge is also deemed as a nuisance. Other nuisances are
accumulation of materials or refuse which in the opinion of the medical officer of health is likely to
harbour rats or other vermin.
Section 130 provides for making and imposing regulations by the county councils and others
the duty of enforcing rules in respect of prohibiting use of water supply or erection of structures
draining filth or noxious matter into water supply as mentioned in section 129. This provision is
supplemented by Section 126A that requires county councils to develop by-laws for controlling and
regulating among others private sewers, communication between drains and sewers and between
sewers as well as regulating sanitary conveniences in connection to buildings, drainage, cesspools,
etc. for reception or disposal of foul matter.
Part XII Section 136 states that all collections of water, sewage, rubbish, refuse and other
fluids which permits or facilitate the breeding or multiplication of pests shall be deemed nuisances
and are liable to be dealt with in the manner provided by this Act.
Vegpro Ltd will ensure that there is no holding for both fresh feedstock and the solid or liquid
waste (fertilizers) generated. All feedstock will be fed into the digesters and the remaining will be
decomposed at the existing composting operation. For the fertilizers, all will be used in the farms
immediately they are produced. This will ensure the plant areas are kept in such a way that they do
not constitute a health hazard.
Local Government Act (cap 265)
Section 163 allows the County Council to prohibit all businesses, which may be or become a
source of danger, discomfort or annoyance due to their noxious nature through smoke, fumes, dust,
noise, or vibrations
Section 165 allows the local authority to refuse to grant or renew any license which is
empowered in this act or any other written law on the grounds that the activity does not conform to
the requirements of any by-laws in force in the area of such local authority or the granting of the
license would be contrary to the public interest.
The chosen AD process operates in a closed and sealed system with limited potential for
odour escape; exclusion of air is a fundamental requirement of the process. The methods used to limit
the ingress of air also prevent the leakage of odour.
EIA/ EA Regulations
The environmental impact assessment guidelines require that the study be conducted in
accordance with the issues and general guidelines spelled out in the second and third schedules of the
regulations. These include coverage of the issues on schedule 2 (ecological, social, landscape, land
use and water considerations) and general guidelines on schedule 3 (impacts and their sources, project
details, national legislation, mitigation measures, a management plan and environmental schedules
and procedures.
BASELINE INFORMATION & DATA
Project information was gathered through site visit for comprehensive investigation of the
physical environmental status of the farm operation(s) and that of the immediate surroundings and
discussions with the company managers, staff, and other stakeholders.
Project Site and Topography
The Vegpro LTD Biogas Plant will be located within its Gorge farm, at the south-western
end, a spot which is about 200 meters from an existing KPLC sub-station (see phot 1). The area is flat,
well drained and is currently composed of soft loamy agricultural soils like the rest of the existing
farm site.
The area is surrounded by:
• Finlays farm to the south
• Karuturi Housing estate to the west
• The rest of the other sides are Vegpro farms i.e. Longonot farm and Gorge farm.
The current activities going on in the area are normal farm operation including water irrigation. To
access the KPLC sub-station for the power transmission, either Vegpro must use KPLC’s existing
way leaf of must ask either Finlays or Karuturi to provide a way leaf on their areas.
Drainage System and Hydrology
All the surface water drains to an existing drainage system within the farm. The farm has
established an elaborate drainage system for rainwater which is stored in a dam situated at the
eastern side of the location where the plant will be constructed. There will be no waste water
generation other than liquid fertilizer which will immediately be used in the farms.
Vegetation
The proposed site for the project is a farm site and therefore there are no existing vegetation
other than farm weeds.
Rainfall and Climate
The area has a relatively cool weather, with temperatures ranging between 10 0C and 22 0C
over the year. The Because of farming activities the area can be very dusty, especially during dry
season. The wind direct in the area has no distinct direction but changes depending on pressure
changes from time to time during the day.
The rain pattern appears to be spread through the year. Two seasons with the maximum
amounts of rain are between March and May and October and December. The lowest rainfall is
recorded in September at below 200 mm while the highest is recorded in April at slightly below 1200
mm.
(Source: http://www.world66.com/africa/kenya/theriftvalley/naivasha/lib/climate)
Soils
Naivasha is a small town located about 70 km. North West of Nairobi, and sits on the floor of
the Great Rift Valley. The farm being situated near Mt. Longonot, the majestic 11,000 ft. dormant
volcano, thrives in the fertile volcanic soils. (Source: http://www.kiangazifoundation.org/who-we-
are/about-naivasha.html)
The plant is not expected to have adverse impact on the soils in the site because the soil will
only be disturbed during the laying of the foundation and from construction activities.
Water Resources
The main water source for the farm, other than rain water, is Lake Naivasha. The plant will
however not have any effects on the existing water abstraction situation as the plant does not need
water for feedstock digestion.
Bio-diversity
There is no major biodiversity within the farm site where the new equipment will be located.
Air Quality
The air quality will be affected during construction due to a lot of dust from excavation. It is
recommended that the ground be watered prior to excavation activities to preserve air quality.
Land Use Activities
The dominant land use in the area is predominantly commercial scale agriculture. The most
vibrant and fastest growing commercial activity is carried out by the large multinational owned flower
and horticulture farms nestled along the shores of Lake Naivasha. These large scale farms produce
almost exclusively for the European market earning Kenya US$ 150 million per year and employ up
to 60,000 farm workers. These farms draw water for irrigation from Lake Naivasha all year round,
resulting in receding water levels over the years.
(Source: http://www.kiangazifoundation.org/who-we-are/about-naivasha.html)
The proposed site, however, will be located on a very small section of the Gorget farm where
its effect on the farming activity will be completely insignificant.
Areas of Cultural Importance
The proposed project will be located within the existing Gorge farm compound where there
are no areas of cultural importance.
Environmentally Sensitive and/or Significant Areas
The proposed site will be located where there are no environmentally sensitive or significant areas.
Economic Development
The area is currently being used for large scale agricultural activities. The proposed site,
however, will be located on a very small section of the Gorge farm and will not have any effects on
the existing farming activities.
Social Issues
Currently there are no social issues associated with the site.
PROJECT DESCRIPTION AND MAGNITUDE OF OPERATIONS
General Description, Ownership and Project Location
Vegpro Limited deals in fresh produce, flowers and logistics from Kenya. After the fresh
produce and flowers for export are produced, waste/feedstock left are first decomposed at the
decomposing site and used as fertilizer for the farm.
Approximately 23,024 tonnes per year of fresh feedstock is available at a dry matter (DM)
content of 23.7%, giving 5,448 tonnes per year of dry matter (DM). In order to utilize the feedstock
and diversify revenue sources, the company proposes to set up a biogas plant within its Gorge farm,
at the south-western end, a spot which is about 200 meters from an existing KPLC sub-station.
Extensive testing of this material in laboratory scale digesters at Southampton University,
UK, has shown that this feedstock will yield 421m3/h of biogas of which 232m3/h will be methane.
Using the proposed gensets this methane will yield 11,800 Mwhrs per year of electricity. If this
energy was produced using diesel generators it would represent more than 3 Million litres of diesel.
The project proposal is for an on-farm anaerobic digestion (AD) plant comprising a system of
hydrolysers and a digester to produce biogas, an engine driven electricity generating set (genset) and
other associated equipment to operate and manage the process. The whole project is designed to be
sited on a pre-leveled area on the farm. This project will establish an environmentally friendly and
sustainable form of electricity (and heat) production from the feedstock, also known as substrate once
loaded into the digestion system. The AD process uses naturally occurring bacteria and other
microbes to convert organic matter in the feedstock into:
• Biogas, which is an energy rich mixture of methane and carbon dioxide which is suitable for
use as a fuel to generate electricity and heat.
• Nutrient rich solid state and liquid state fertilisers to be used on the farm in place of purchased
chemical fertilisers.
The resulting biogas is burned in an engine driven generating set (genset) to produce electricity,
mostly for use on the farm with the balance available for export to the grid. The genset also produces
heat in the form of engine cooling water and some of this will be used to heat the hydrolysers to 50-
55C and to maintain the digester at a temperature of ~ 40-45C.
The pre-hydrolysis of the feedstock material in the two hydrolysers ensures significantly
higher biogas production and shorter residence times than conventional AD plants, maximizing
biological degradation and stabilization, minimizing capital costs and plant footprint and increasing
electricity (and heat) production. The anaerobic digestion (AD) plant will be owned and run by
Vegpro Limited within its Gorge farm where it will also be located.
Nature of the Project and Proposed Development
The objective of the project is to satisfy the ever increasing demand for electricity in Kenya
with a clean alternative to the more fossil-fuel based electricity component of the Kenyan national
grid. The project aims to generate electricity from renewable sources. If this energy was produced
using diesel generators it would represent more than 3 Million litres of diesel Per year.
The plant will cover an approximate area of 80m by 55m. Construction work will include soil
excavation and concrete work, using heavy construction equipment. This will be followed by
installation of plant machinery before plant operation can commence.
The proposed project, the anaerobic digestion (AD) plant, is a power generation project
involving the generation of electricity using feedstock on site.
The principal components of the complete AD system are:
• A Feedhopper Unit with Shredder and Feeder
• 2 x Hydrolyser Tanks
• 1 x Digester Tank
• 1 x Recyclate Tank
• 1 x Biogas Store
• 1 x Central Building
• Main Pump System
• Main Plant Control System
• 1 x Solids Separator
• 3 x Outdoor packaged gensets
• 1 x Main Flare
Feedhopper Unit with Shredder and Feeder
This unit is a stationary system into which the feedstock is loaded by a conventional
tractor/loader with front bucket. The hopper has a volume comfortably in excess of that needed for a
single feed cycle of the AD plant. At its outlet an uptake auger “feeds” Hydrolyser 1 through a simple
water lock. In normal
operation at Longonot the
Feedhopper unit operates
twice per day for 1-2 hours
during the 2 feed cycles.
Feedstock is moved out of
the hopper and through the
shredder unit where it is
reduced in size to promote
digestion. This material is
mixed with liquid from the
recyclate store and is
pumped into Hydrolyser 1
through the Main Pump.
Hydrolyser 1
Hydrolyser 1 is a concrete tank. It is a sealed unit to prevent the escape of biogas or ingress
of air. It is fitted with 2 x stirrer units, an over/under pressure valve working on the water lock
principal, a heating coil for achieving and maintaining an internal temperature of 50-55C. There are
numerous small ports and tappings for fitting instrumentation such as level and temperature sensors
and transparent viewing ports. There are a number of openings to allow access for maintenance. The
tank has a corrosion resistant coating on the inside to cope with the acid conditions (pH 4 – 6) and a
minimum of 4cm of thermal insulation on the outside. There are also fixed inlet and outlet ports
connecting the tank to the Main Pump via a system of automatic and hand valves and a gas outlet pipe
connected to the Biogas Store.
Hydrolyser 2
Hydrolyser 2 is identical to Hydrolyser 1 except for the position of inlet and outlet ports,
instrumentation, etc.
Photo 7: Photo showing the feed hopper unit
Digester
The digester is a concrete
tank. It is a sealed unit to
prevent the escape of biogas
or ingress of air. It is the
heart of the digestion plant
and is controlled to produce a
high and constant volume of
biogas. To achieve this, the pH must be maintained at 6.5 – 8. It is fitted with 4 x stirrer units and an
over/under pressure valve working on the water lock principal. There are numerous small ports and
tappings for fitting instrumentation such as level and temperature sensors and transparent viewing
ports. There are a number of openings to allow access for maintenance. The tank has a corrosion
resistant coating on the inside and a minimum of 4cm of thermal insulation on the outside. There are
also fixed inlet and outlet ports connecting the tank to the Main Pump via a system of automatic and
hand valves and a gas outlet pipe connected to the Biogas Store. In normal operation the digester is
maintained at a temperature of 40-45C simply by mixing warmer material from Hydrolyser 2 with
existing material in the tank. The 3,000m3 of tank contents and the outer insulating layer ensure a
heat loss equivalent to < 1C per day so no heating of the tank is required and no heating system is
fitted. The four stirrer units operate intermittently and sequentially on an automated cycle to produce
a slow, steady, circular movement of substrate within the tank.
Recyclate Tank
Excess substrate from the digester is piped to the recyclate tank. A simple, screw press type
separator is fitted to the plant so that the mixture of solid and liquid leaving the digester can be
separated into liquid and solid fertiliser fractions. It is necessary to store a small amount of the liquid
fertiliser as some is needed to mix with fresh feedstock in the Feedhopper system during each feed
cycle; this is stored in the recyclate tank which has sufficient liquid for 3 - 4 day’s use.
Central Building
The 2 hydrolyser tanks, the Digester and the Recyclate Tank are positioned on site such that a
building can be erected between them using the outside of the tank walls for part of the building
structure. This building is used to house the Main Pump assembly, the Main Plant Control System
and many of the minor services required by the plant, such as the compressed air system. This design
ensures that the maximum amount of equipment is sited indoors free from the adverse effects of
weather.
Photo 8: Photo showing the digester tanks
Biogas Store
Biogas produced by the digestion plant is stored in a membrane type gas holder which is
situated on the roof of the digester. The store has is fitted with a system of gas content monitors
which detect the rate of gas production relative to use. This signal is used to control the injection of
material from Hydrolyser 2 into the digester to achieve the desired rate of gas production. The
volume of biogas stored is sufficient for ~ 8 hours
operation when meeting the farm’s maximum
electricity demand and longer at reduced demand.
This allows for fluctuations in biogas supply and
demand to be compensated for and for routine
maintenance operations on gensets and hydrolyser
and digester accessories. It also minimises the
flaring of excess biogas, which is wasteful, and
minimises the need to vent gas under emergency
conditions.
Main Pump Assembly
The AD plant is provided with a Main Pump
Assembly situated in the Central building. This
comprises a powerful Rotocut type centrifugal pump
with inlet and outlet manifolds, stone trap, etc. This
pump is capable of chopping any oversize clumps of
material that may have agglomerated in any of the
tanks. The inlet and outlet manifolds have multiple
ports individually connected to all of the tanks and
system inlets and outlets and individually controlled by pneumatically operated valves so that the
pump can be programmed to move tank contents to and from anywhere on the plant. The Main Pump
operates intermittently throughout each 24 hour day to meet the needs of normal operation of the plant
and also allows for individual tanks to be emptied for inspection and repair whilst maintaining plant
operation under a wide variety of circumstances.
Photo 9: Photo showing the storage dome
Photo 10: Photo showing the main pump
passembly
Main Plant Control System
The AD plant is automatically
managed and controlled by a computer
system situated in the Central building.
Sensors in the biogas store, the 2 Hydrolysers
and the Digester monitor the pH, temperature,
movement of feedstock and substrate, tank
levels and biogas production and
consumption. This control system provides
for continuous and fully automatic operation
of the plant to achieve a high and continuous
production of biogas. It also monitors correct
operation of the plant and individual items of plant equipment and ensuring safe plan operation at all
times and alerting operators to any potential problem. The control system also provides an automatic
feed cycle for fresh material, which simply requires the operator to fill the Feedhopper with fresh
feedstock using a bucket loader, and for continuously controlling the operation of the tank stirrers.
The Control System also records and analyses data collected from all of the sensors mounted on the
AD plant so that a complete history of plant operation is available and operating trends can be plotted.
Information is provided to operators via local and remote screen interface(s) allowing the operator to
view all of the current and historical operating parameters in the plant.
Solids Separator
The AD plant is fitted with a simple
screw press type solids separator for
separating the solid and liquid
fertiliser fractions of the material
leaving the digester. The solids
fraction is dropped into a small
bunker adjacent to the Separator and
is ready for immediate use as a
fertiliser or for adding to the farm’s
existing composting operation. The liquid fertiliser fraction and is also available for immediate use
as a fertiliser. However, a proportion of this liquid is required for mixing with fresh feedstock so a
Recyclate Tank is provided to store sufficient liquid for this purpose.
Photo 11: Photo showing the main control system
Photo 12: Photo of the separator
Electricity Generating Sets (CHP Units)
The AD plant will eventually be fitted with 2 site rated outdoor packaged generating sets,
providing an electrical capacity comfortably in excess of biogas production to cover maintenance
periods, etc. The gensets will be fitted with full
heat recovery, distribution and cooling systems so
that they can operate in Combined Heat and Power
(CHP) mode. The gensets will be fully outdoor
packaged to provide full weather protection for the
units and their accessories and full soundproofing
for the protection of the environment. These
gensets have been selected to provide an operating
efficiency (to electricity) of more than 40% over a
wide operating range to maximise electricity
production from the available biogas. Each genset
is equipped with its own microprocessor based control system controlling the gensets themselves and
their ancillary systems (pumps, water coolers, intercoolers, oil coolers, gas carburettors, ignition
systems, etc.). All information from the control system is available on a screen interface and this
information can be provided to remote screens and to the plant’s data logging system.
Main Flare
The AD plant is fitted with a Main Flare. This unit can take
biogas from the plant and burn it under controlled conditions to
achieve complete combustion with low emissions. The flare unit can
be used to burn excess biogas in circumstances where the gensets are
not running but it is desired to keep the biogas plant running at full
output. The flare will also be activated if the Control System detects
excessive gas pressure in the plant.
Photo 13: Photo showing the cogeneration sets
Photo 14: Photo of the flaring
unit
Photo 15: Aerial layout of the farm showing the proposed location of the AD plant
Site Description
The AD plant will be sited in one corner of the Longonot/Gorge site in reasonable proximity
to the adjacent KPLC switchyard. The design footprint of the AD plant and associated access and
maintenance roadways is the minimum required for efficient management of the plant and its
associated processes. In designing the plant care has been taken to keep structures compact and the
overall footprint as small as practical. The overall scale of the plant ensures that there will be no
significant increase in visual impact beyond that created by existing developments on the
Longonot/Gorge and existing sites. The current activities going on in the area are normal farm
operation including water irrigation.
Process Description
The type of AD plant chosen for this project features 2 x Hydrolysers which are separate from
the main Digester tank so that digestion takes place as a staged process with each stage occurring
under optimum but different conditions. The two Hydrolysers are allowed to become acidic through
natural biological action which promotes the breakdown of the substrate and maximises the
production of methane in the digester. The volume of the 2 hydrolysers, 2 x 471m3, gives a nominal
residence time of the substrate in the two tanks as 3 days. The use of 2 hydrolysers instead of a single
larger unit prevents fresh feedstock being passed straight to the digester without being pre-treated.
The residence time of the substrate in the Digester is 15 days.
During plant operation the stirrer units operate intermittently and sequentially on an
automated cycle for approximately 5 minutes every ½ an hour to maintain homogenisation and
temperature of the substrate. Stirrers may also be activated in exceptional circumstances, e.g. if
falling gas production is detected.
The AD plant is designed so that it can operate continuously and automatically at its
maximum capacity or to meet any electrical demand lower than this whilst only intermittently loading
feedstock into the Feedhopper. Continuous operation with intermittent loading is achieved as follows:
• Immediately following a feed cycle the status of the 2 Hydrolysers and the Digester is that
they are all 100% full. During normal operation material is fed from Hydrolyser 2 to the
Digester to maintain the desired biogas production rate as determined by the plants
instrumentation and Control System. This is a semi continuous process and material will
be moved to the digester at roughly 30 minute intervals to achieve steady gas biogas
production. Excess material in the digester leaves through the overflow pipe and water
lock to maintain a constant digester level. During this operating phase the level in
Hydrolyser 2 falls as material is removed; on a plant with 12 hours between feed cycles ~
130m3 of material will have been forwarded to the digester so Hydrolyser 2 will be ~
80% full at the end of this period.
• During (1) Hydrolyser 1 remains full and so all feedstock is subjected to 12 hours of
hydrolysis fermentation.
• When the operator selects the next feed cycle the operating sequence changes temporarily as
follows. Initially the only activity is that Hydrolyser 1 feeds material to Hydrolyser 2
until it is full. This leaves Hydrolyser 1 80% full and Hydrolyser 2 100% full. When this
action is complete Hydrolyser 2 and the Digester return to normal operation exactly as per
(1) above. In addition to this the Feedhopper system is then activated and a mixture of
fresh feedstock and liquid from the Recyclate Store is pumped into Hydrolyser 1. When
Hydrolyser 1 is full the plant returns to normal operation exactly as per (1) above.
• During (3) ~ 20% fresh material and recyclate is introduced to Hydrolyser 1 reducing its
temperature. This is automatically compensated for by the Control System which
introduces genset cooling water to Hydrolyser 1’s heating coils until the desired
temperature has been re-established.
• During this whole process the only action required by plant personnel is to top up the
Feedhopper with fresh feedstock using a bucket loader and to select the feed cycle at
roughly 12 hour intervals. All other plant operation is completely automated.
• The electricity generated will be metered at various locations to determine the quantity used
internally or exported to the grid.
It is expected that apart from the electricity used by the plant itself, the rest will be fed into the
national grid and Vegpro’s electricity consumption will be netted off from what it fed into the grid
Sources of Raw Materials
Every day, the Longonot farm generates approximately 63 tonnes (23,024/365) of feedstock.
Besides this, more than 20 tonnes of feedstock is received daily from Van Den Berg, a neighbouring
flower farm who uses the Longonot farm to dispose their feedstock since they have no space. This
makes more than 80 tonnes per day.
The input to the Biogas plant will be the over 80 tonnes per day of feedstock generated from
the two farms.
Waste Generation
The main wastes to be generated by the biogas plant will be wash water used to clean the
plant. The solid and liquid fertilizers are also by-products of the plant, but will be used in the farm.
The wash water from the plant will be directed to an existing drainage system.
Project Construction
Construction Inputs
Construction will require the following inputs:
• Some raw construction materials such as ballast, cement, stones, sand, and steel since
the foundation is already in place
• Construction labour force (both semi-skilled and skilled)
• Some water for construction purposes, especially for plinths and other equipment mounting
points
• Heavy machinery (hoisting equipment and delivery trucks)
Construction Activities
Construction activities will involve the following:
• Site preparation, including construction of plinths and equipment mounting points
• Procurement and delivery of construction materials
• Storage of materials, including fuels
• Construction, with significant welding activities
• Disposal of construction wastes
• Completion of the development and commissioning
Current Status of the Project and Construction Period
The project has evolved from preliminary through to final detailed design stages. It is not
known how long the construction period is expected to last but construction is expected to begin from
the time a NEMA license is issued. Most of the work will be carried out during standard working
hours (from 0800hrs to 1700hrs).
Project Implementation and Operation
The project implementation and operation phase is covered under 4.4 to 4.6 above.
Project Budget
The total project budget is estimated at USD 1.4million.
Project Lifetime and Decommissioning
This has not been established as at now but a full environmental impact assessment will be
conducted before decommissioning in order to ensure that it is carried out in environmentally
responsible manner.
ANALYSIS OF ENVIRONMENTAL IMPACTS
The Vegpro Biogas Plant will be located within its Longonot farm, at the south-western end, a
spot which is about 200 meters from an existing KPLC sub-station. The area is flat, well drained and
is currently composed of soft volcanic soils like the rest of the existing farm site.
The potential environmental impacts mainly relate to construction, operation and
management of the cogeneration plant as opposed to the project siting and site preparation. These
are:
• The construction activities, waste generation and their management.
• The operations of the biogas plant, waste and their management.
During the construction phase, the most important aspect is occupational health and safety of all
involved in the activity. A lot of soil is expected from excavation, some waste from construction
materials and off cuts are expected. High standards of health and safety and full compliance with the
Factories and Other Places of Work Act will be required as a mitigation measure.
During operation, no significant waste will be generated. However, the following were taken into
consideration when analyzing and assessing the significance of the impacts that may be created:
• Loading and Transportation of Feedstock to the AD Plant
This project will use biomass feedstock materials produced on-farm and that from Van Den Berg.
This material is currently used on-farm in a composting operation. No additional environmental
impacts will arise from transporting the material to the AD plant instead of the composting operation;
all operations will remain on site using normal farming equipment and practices.
• Transportation and End Use of Liquid and Solid Fertilisers
The proposed AD plant produces ~ 15,500m3 per year of mixed solid and liquid fertiliser. This
material is automatically separated into solid and liquid fractions for use as solid and liquid fertilisers.
It is proposed that all of this material will be used on-farm as part of normal farming operations,
displacing the need to transport in some of the chemical fertilisers already used on site. The solid
fertiliser will be transported to cultivated areas or the composting operation using farm vehicles. The
liquid fertiliser will be transported and used by the farm’s existing irrigation system. Any marginal
increases in the use of farm vehicles and irrigation systems will be more than offset by reductions in
the use of delivery vehicles for chemical fertilisers. There will be NO additional environmental
impacts from the on-site transportation of solid and liquid fertilisers produced by the AD plant.
• Odour Production and Control
Odour control is a key feature of the proposed plant’s design. The process chosen is biologically
aggressive in degrading the substrate and this, together with adequate retention time, ensures the
maximum possible yield of gas and the minimum possible odour potential in the final substrate.
Odour control and operating efficiency are closely linked and the chosen technology typically yields
20% more methane than more conventional systems, reducing the potential for odour even further. In
addition to the applicant’s desire to achieve the highest possible plant operating efficiency some odour
abatement measures have been included in the plant design. They are listed in the environmental
aspects and impacts (EA&I) in table 1 below.
• Dust Production and Control
The AD process for the Gorge site is essentially a wet process. Feedstock from the farm needs to
be used in as fresh (wet) a condition as possible to prevent rotting. The feedstock material is 75-80%
water so there is no possibility of dust generation during feedstock storage (short term) and handling.
Similarly, the fertiliser products are both wet, even the solid fraction is 70% water, so no dust can
arise from the storage or use of this material. The proposed AD plant site is rural and contained
within land occupied by the applicant. For these reasons there is NO risk of dust nuisance from this
project and NO special dust control measures are needed on site.
• Noise Production and Control
There are four main items of equipment in the AD plant that could give rise to the generation of
noise; Main Pump, stirrers, Feedhopper and Gensets. The Main Pump is situated in the Central
Building which is formed from the walls of the 4 AD system tank walls. These tanks are full of sound
deadening liquid. The Main Pump operates intermittently and is considered to produce NO noise and
NO abatement measures are necessary.
The stirrers and feedhoppers themselves are propeller like units which operate at very low speed,
~ 40 rpm, and are submerged in liquid. The stirrers themselves produce NO noise. However, the
stirrers are electrically driven via gearboxes and these drive systems are mounted on the outside of the
tanks. The drive systems will produce noise typical of electric motors and gears, which, due to its
frequency content is easily attenuated by ~ 30dB by a typical acoustic enclosure. The proposed AD
plant site is contained within land occupied by the applicant so the risk of unattenuated noise nuisance
at the site boundary is LOW. If noise levels at the site boundary are measured as being unacceptable
typical acoustic enclosures could be fitted to the offending stirrer(s) to achieve acceptable noise
levels.
The Gensets proposed for this project are outdoor packaged in accoustic enclosures and fitted
with roof mounted cooling systems and exhaust systems which discharge > 3m above ground level.
The noise output from the complete genset system is 60dB(A) at 1m from the enclosure wall at 1.2m
above ground level. The proposed AD plant site is contained within land occupied by the applicant so
the risk of genset noise nuisance at the site boundary is LOW. If noise levels at the site boundary or
any receptor are measured as being unacceptable additional noise mitigation measures would have to
be introduced. These could be fences, earth banks, tree plantations, etc. Any of these could also be
used to adjust the visual impact of the development. The most likely impacts are described in Table 1
below. Some are short term and a few are long term.
STAKEHOLDER COMMENTS
Stakeholders / neighbours were visited individually to inform them about the project and its
potential impacts. The method for collecting their concerns was through a face to face interview.
Generally, they were positive and no to the project’s development were raised. A few issues were
however raised by some of them. The following are the details of what the stakeholders felt:
Mr. Gilbert Bii – Van Den Berg LTD
• He felt the positive impact would be the assurance that his feedstock would be going for the
right use.
• He also felt that this would ensure proper usage of waste. This would ensure reduction of lake
pollution since floods would not sweep the feedstock wastes to the lake.
Ms Everlyne Silali – Research Officer, Kenya Wildlife Services (Hell’s Gate)
Responded that there would ease off some power demand burden from KPLC’s main grid.
She however had some concerns as follows:
• Fear of holding raw materials overnight attract their wild animals, especially baboons,
resulting in a conflict between KWS and the Longonot Farm.
• The facility should be properly fenced to make it baboon proof.
• Generation of punget smell in the event of holding of waste.
• Liquid discharge in to the lake through normal drainage system.
• Increased water usage resulting in more water abstraction from lake.
Mr. Johnson Maina – Service Manager, Finlays
He felt this was a good idea which was long overdue. He mentioned they had thought about
the same but never went far as they were still contemplating approaching the other neighbours so they
could pull resources together. To him, this project would increase power availability for all.
He was however, concerned that the transportation of feedstock from Van Den Berg would
litter the main road. This would increase the green leaf litter from that which Karuturi trucks are
already putting.
Mr. Amos Otieno – Farm Manager, Kedong Ranch
He had all the support for the project. No concerns at all.
Robert van Paul, Director Business operations, Sher Karuturi
He said this was a very positive move that should be supported by all. He even felt that
Vegpro should consider incorporation Karuturi so that they can expand the capacity of the plant.
TABLE 1: ENVIRONMENTAL ASPECTS, IMPACTS AND MITIGATION
# Environmental
Issues
Aspect Impact Mitigation
1 Surface
water
quantity &
quality
• Increased
water usage
• Discharge
of effluent
• No quality impact due to water usage as no water is required
for feedstock digestion. Only during construction. • No quality impact due to waste treatment.
• Maintain / improve the current drainage system
2 Air quality • Exhaust
gasses
• dust • Odour
• Pollution of air with exhaust gases from construction machinery during construction
• Pollution of the air with dust from construction machinery during construction
• Pollution of the air with from substrate, during operations.
• Use of properly serviced machinery during construction.
There is no added effect on environment during
operation • Pour water on the ground to avoid dust.
• Continuous regulation of gas production in the Digester to
ensure constant and effective operating conditions
• Regulation of biogas production to ensure minimum
flaring and venting of biogas
3 Soil Soil
excavation • Soil disturbance due to excavation during construction • No mitigation.
4 Noise Noise
generation
• Noise pollution from main pump, stirrers, feedhopper and
gensets
• Noise to be controlled by use of acoustic enclosures for
respective equipment or other noise mitigation measures
would have to be introduced
5 Health
and safety Occupationa
l hazard • Accidents and injuries to worker during
construction and operation of the project
• Fire outbreak
• Increased noise levels from construction equipment
• Identification and elimination of potential hazards
• Provision and use of appropriate and adequate
personal protective equipment. Ensuring contractor
compliance
• Provision of adequate fire fighting equipment
and
emergency procedures as is currently the
case
6 Socio-
economic
impacts
Increased
incomes from
project activities
• Increasing employment opportunities for the local community
• Increased revenue generation for the company which
eventually trickles down to local residents
The company should continue with diversification
programme so as to increase the revenue generation and
economic development.
7 Resource
conservatio
n
Use of
clean
technology
• Use of ash for soil pH stabilisation eliminates the
need for artificial fertilisers
• Water conservation due to reduced water consumption
• Use of renewable resources for electricity generation
reduces the pressure of fossil fuels and vegetation
Putting measures in place to ensure that operational
procedures are followed always and identification of
non- conformity identified and addressed
ENVIRONMENTAL MANAGEMENT PLAN
Item
No. Environmenta
l
Issue
Impacts Proposed Actions
Implementation
Timeframe
s
Cost Responsibility
General Remarks
1 Surface
water
quantity &
quality
• Increased water usage
• Discharge of
effluent
• Maintain / improve the current
drainage system
During
construction Contractor costs
involved are
part of contractor
costs
Contractor Water conservation will
ensure that downstream
flow is increased and
water pollution from
construction activities
does not occur
2 Air quality • Exhaust gasses
• dust • Odour
• Use of properly serviced machinery during
construction. There is no added effect on
environment during operation • Pour water on the ground to avoid dust.
• Continuous regulation of gas production in the
Digester to ensure constant and effective
operating conditions
• Regulation of biogas production to ensure
minimum flaring and venting of biogas
During
construction and
durin
g operation
Vegpro Limited
Contractor
Use of properly serviced
equipment and effective
control of dust and odour
will ensure that that
health of the workers and
individuals living in the
area will not be affected
3 Soil Soil excavation • No mitigation. During
construction All costs
involved are
part of
preliminary
contractor costs
Vegpro Limited
Contractor
Ensure effective
disposal of excavated
soils
4 Noise Noise generation • Noise to be controlled by use of acoustic
enclosures for respective equipment or other
noise mitigation measures would have to be
introduced
During operation Project developer
costs are part
of the wider
Vegpro
operations
management
costs
Vegpro Limited Ensure application of
PPEs
5
Health
and
safety
Occupational hazard • Identification and elimination of potential hazards
• Provision and use of appropriate and
adequate personal protective equipment.
Ensuring contractor compliance
• Provision of adequate fire fighting
equipment and
emergency procedures as is currently the case
Continuous - Vegpro Limited
6 Socio-
economic
impacts
Increased incomes from project activities
The company should continue with
diversification programme so as to increase the
revenue generation and economic development.
Continuous -
7 Resource
conservati
on
Use of clean
technology Putting measures in place to ensure that
operational procedures are followed
always and identification of non-
conformity identified and addressed
Continuous - Vegpro Limited • A legal register will
ensure compliance
with laid down
guidelines at all
times,
• Obtain necessary
permits where
required, e.g. Water
abstraction permit. 8 Compliance
Aspects Compliance with the legal
requirements, market
demands and ethical
obligations.
• Establish a legal register with a focus on the
critical relevant environmental laws,
• Carry out annual environmental audits as
required by law,
• Review all contractual agreements to reflect
the environmental legal requirements,
• Review a corporate environmental policy guideline,
Continuous - Vegpro Limited • A legal register will
ensure compliance
with laid down
guidelines at all
times,
CONCLUSION
The results of this study show that the proposed Vegpro Limited’s Biogas Plant will not have
a potential for serious negative environmental impacts. The project is siting within a large
commercial farm belonging to the company and the neighbours are also commercial entities where
similar activities are taking place.
The project will use renewable waste to produce energy in Kenya where at least 50% of the
energy is hydro based and very susceptible to weather patterns. The other potion is significantly fossil
fuel based thermal energy which is prone to exchange fluctuations and other political instability in
certain regions of the world. Energy source diversification is therefore very beneficial to the whole
country.
The potential adverse environmental impacts such as odour, noise, wastewater or any gas
emissions will be adequately mitigated. Plans are also in place to adequately mitigate the health and
safety impacts of the project.
From a socio-economic point of view, the project has significant economic benefits not only
to the community but also to the whole country.
The recommendations have been provided in the Environmental management Plan as
proposed actions.
