Central Environmental Authority Parisara Piyasa

104, Robert Gunawardena Mawatha Battaramulla Sri- Lanka

Telephone No: 872415, 872263, 872606 Fax No: 01-872605

POLLUTION CONTROL GUIDELINES (FOR SMALL SCALE INDUSTRIES)

NO. 2 - SAW MILLS

Central Environmental Authority Ministry of Forestry & Environment 2001

Pal.

No. 2 - Saw Mills

CEA Library

1 1 in in 07138R

Pollution Control Guidelines

No 2 - Saw Mills

Prepared for the Central Environmental Authority by the Environmental Resources Management Lanka (Pvt.) Ltd. With financial Assistance/ from the World Health Organization (WHO)

1997/2001

First edition 2001

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C h s I T j No. |

Published by the Central Environmental Authority Parisara Piyasa 104, Robert Gunawardena Mawatha Battaramulla Sri-Lanka

Telephone: 01-872415,01-872263, 01-872606

Fax: 01-872605

This document may be reproduced in full or in part, with due acknowledgement to the Central Environmental Authority

Preface

During the last two decades, rapid industrial development and population growth have contributed to the deterioration of the environmental quality in Sri Lanka.

In recent past, the Central Environmental Authority has initiated a number of important measures towards sustainable development by protecting, managing and improving our environment. Most notable legislative measures were the amendments to the National Environmental Act No 47 of 1980 which was subsequently amended by Act No 56 of 1988 and Act No 53 of 2000 reaching the basic goals of industrial pollution control in Sri Lanka.

The Central Environmental Authority has been entrusted with the task of preparing industrial pollution control guidelines for the industrial sectors. With an objective of fulfil l ing this tasks, industrial pollution control guidelines were prepared in 1992 for the eight high polluting major industrial sectors i.e. Natural Rubber Industry. Concentrated Latex Industry, Desiccated Coconut Industry. Leather Industry, Dairy Industry. Textile Processing Industry, Pesticide Formulating Industry. Metal Finishing Industry.

The following nine guidelines have now been prepared to cover the small scale industrial sectors in Sri Lanka.

No. No, No. No. No. No. No. No. No.

2 3 4 5 6 7 8 9

Paddy Mills Saw Mills Metal Crushers Garages and Service Stations Lime Kilns Coconut Shell Burning Industries Grinding Mills Coir Mills Bakeries

The main purpose of the preparation of these guidelines was to assist Local Governmental Authorities and industrialists in industrial pollution control to meet the requirements of the Environmental Protection Licensing scheme.

These nine guidelines have been prepared by the Environmental Resources Management Lanka (Pvt) Limited for the Central Environmental Authority with financial assistance of the World Health Organisation (WHO).

This document contains pollution control guidelines for Saw Mills.

Thilak Hewawasam Chairman

CONTENTS

Page

1.0 Introduction 1

2.0 Process description 2

3.0 Waste generation and environmental impacts 3

4.0 Mitigatory measures for environmental pollution 5

5.0 Occupational health & safety 10

6.0 Reference to current law 10

7.0 Conclusions and recommendations 12

8.0 Sources of information and analytical facilities 1 3

9.0 Sri Lankan standards for discharge o f pollutants 1 5

1.0 Introduction

Saw milling is a primary wood industry. The capital required for saw milling industry is low in comparison to capital required for other primary wood industries such as for plywood and paper production. Saw milling industry is the largest user of round wood in Sri Lanka. Saw mills are mostly owned by families and small trade organizations, as it is possible to start a sawmill with simple machinery and minimal investment of capital. Saw milling industry produces raw materials for many other industries. The main end users are activates in construction work, joinery work, and furniture manufacturing Work etc. The end users in Sri Lanka are identified as follows. (FSMP 1994)

Construction and joinery Furniture , Others

75% 15% 10%

The important factors, which determine the cost of sawn timber production, are cost of logs, loss in conversion and cost of sawing. The cost of logs in Sri Lanka is very high since wood is scarce. Today we have importing of logs to the country due to this scarcity.

The saw milling industry in Sri Lanka is wide spread throughout the country as in other developing countries. There is a clear concentration of establishments of various sizes in Colombo area, especially in Moratuwa which has a long history of carpentry.

Structure of furniture industry Type

Small scale (less than 5 employees)

"Number of plants

8500

Sawn wood consumption m'/annum

5000

Medium scale 600 60000 Large scale ( over 100 employees)

10 15000

Source: Demand for industrial forest product and round wood Table -1

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2.0 Process Description

The process carried out in saw mills, which lead to significant environmental impacts, are illustrated in fig.l

Unit Process Environmental Impacts

Logs 1

r

Primary sawing | p Saw Dust Noise

• Vibration

Sawmill J f

Sawmill J Sawmill J

Sawn timber 1 r

Secondary sawing 1 ^ Saw dust Noise

\ \ Vibration

Final product (Sawn timber)

Fig. 1

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3.0 Waste Generation and Environmental impacts

3. J Dust pollution.

Air pollution is the presence of solids, liquids, or gasses in the ambient air in amounts, which are injurious or detrimental to man, animal, plants or property.

The off cuts and sawdust are the wastes generated at a sawmill. The generation of sawdust would be around 10% of processed volume basis. In saw milling industry poor saw milling techniques cannot be justified under any circumstances when logs are valuable species such as Teak, Mahogany etc. the waste of which in economic terms is colossal. Proper saw milling practices help to conserve natural resources as they reduces waste.

Generally in Sri Lanka sawdust is dumped in the direct surroundings of the mills and bumed. Huge piles of smoldering saw dust are the results. Using valuable land areas to dump saw dust is an uneconomic use of land available, especially in an area where land values are very high. The degradation period of sawdust is relatively long and thus the dumping sites will be unsuitable for construction purposes or for any cultivation purposes. A more serious problem will be created if sawdust is disposed into natural water bodies. This will result in high bottom deposits, emission of bad odours, anaerobic conditions at the lower levels and discoloration of water. Heaps of sawdust are a source of aesthetic pollution. This is taking place with respect to Bolgoda Lake and Lunawa lagoon in the Moratuwa area.

The danger from inhalation of dust or fume is best appreciated when the function of the lungs is considered in detail. The basic lung area is approximately 80m2 and just as this provides an excellent surface area to introduce medication to body, it is also a very receptive area for foreign bodies. The average lung capacity is approximately six litres and the average factory worker breathes between 8 and 10m2 of air in an eight- hour day. If the concentration of the pollutant therefore is one gram per cubic meter, a factory worker may inhale 10 grams of dust during eight- hour day. Much of this will be trapped in the body's defense mechanism, the nasal hair, and by deposition on the mucus-lined walls of the

the nasal hair, and by deposition on the mucus-lined walls of the primary bronchi, the afrways feadlrtg to the lungs. A srgnrncam percentage however could reach the lower lung and become trapped there. When the dust concentration is high and subsequent lung contamination is great, the sacs at the bottom of the lung, known as the alveoli, become closed after sometime by a process known as fibrosis. Fine particles may cause damage to the external body, for example irritation or abrasion of the skin and eyes. Inhalation of dust in case of timber mills can introduce various chemical residues contaminated in timber and can also result in respiratory problems like asthma and allergies.

Dust is a nuisance to the neighbors in term of setting on wells and vegetation. Wind action causes dust movements in the neighborhood. I f the nuisance continues it will create an unsatisfactory relationship with neighbors.

3.2 Noise pollution

The sawing process generates noise. The major contributor to the noise pollution is the high frequency sound emanating from the saw during the sawing action. The noise generated from the driving machinery is relatively low.

Noise pollution is an adverse environmental impact and a work place occupational problem. Depending on the level of noise the damage can be acute or chronic. Acute damage may occur to eardrum, but this occurs only with very loud sudden noises. More serious is the chronic damage to the tiny hair cells in the inner ear. Prolonged exposure to noise of a certain frequency pattern may cause either temporary hearing loss, which disappears in a few hours or days, or permanent loss. Loud sounds affect the circulatory and nervous systems, although the results are difficult to assess. It Interferes with speech, radio and T.V listening, disturbs sleep and relaxation, affects performance as reduced work precision and increased reaction time, causes annoyance, irritation and is a public nuisance.'

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4.0 Mitigatory measures for environmental pollution

4.1 Saw Dust

4.1.1 Minimization of saw dust generation

• Use low gauge small diameter saws to saw small diameter logs rather than using high gauge large diameter saws.

• Practice efficient and adequate maintenance of machinery and good saw maintenance.

• The log should be tightened on each side of the log not more than 0.5 metres from the ends to prevent lateral movement of the log.

• The log should be held firmly by logs on the carriage; the number of spikes depends on the length of the log.

• The height of the spike should be at least 3/4 of the log. • Avoid bad sawing practices such as poor log alignment and

improper log turning. • Try to use saws that minimize losses in conversion e.g. use of

band saws instead of circular saws. 4.1.2 Proper disposal of sawdust.

It is proposed that sawdust be burned in a properly constructed burning device with a stack as instructed below and shown in the figure 4.1 and 4.2 Sawdust should not be disposed of in a manner where it would get into natural waterways and cause pollution.

However burning o f sawdust is an unsatisfactory solution. There are many options available although they need to be developed. Some examples are given in the following table 2.

Option Applicability Assistance/Information Electricity generation Group of sawdust generators can get together

and efficiently generate energy Energy Conservation Fund

As fuel for domestic stove A simple stove can be made easily and packed sawdust wil l bum for 4-5 hours.

NERD Center

Industrial Combustion Used as a fuel in the wood drier Crematorium Low cost crematorium which is cheaper when

compared to LP gas operated plants NERD Center

Bakery Ovens This can be used in a small bakery. Considerably reduces the energy cost

NERD Center

Vegetable Dryer Can be used to dry vegetables which are in excess in the harvesting season

NERD Center

Briqueting Refuse derived fuel pellets result in this process which can be used in solid fuel fired units

Agricultural Use As animal litter and it gives cleaner eggs Mushroom culture Sawdust shows to be a good medium for

mushroom culture IDB

Composting Saw is a good compost provider Board production MDF, Fiber board and partition board etc.

Table 2

Construction of the burning device

• Assess the volume of sawdust generation per day. • The capacity of the burning device should be equal to the

volume of the dust generated per day. • Any excess sawdust should be stored in a covered building and

burnt in the facility when possible. • Build a tapering chimney 30 feet high out of 225mm (9inch)

brickwork. The top width of the chimney should be around 0.6m while the bottom width should be equal to the width of the outer wall of the kiln.

• The stack also could be constructed with metal, (using metal sheets or empty tar barrels, but such use will have a short life span i f not properly maintained)

• The stack height depends on the site conditions and is intended for the proper dispersion of smoke emitted during burning of sawdust. The minimum height can be 30 feet or 2.5 times the height of nearby building ( i f there is any) which could be affected from the smoke from the incinerator.

• Resulting ash can be used as a soil conditioner or should be disposed after mixing with sand.

4.2 Mitigation of the impacts from the noise

• Construct high boundary walls around the premises. • Use noise absorbing materials such as gypsum boards in order

to absorb noise • Locate the industry away from noise sensitive areas such as

schools, hospitals etc. • Locate the motors in sound proof housings. • Sawing and other noise generating activities should be

restricted to the day time preferably to the time period from 6.00 am to 6.00 p.m.

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PROPOSED SAWDUST BURNING FACILITY

Stack 3cr

/ Feed Port

/ Ash Removal Port

Not to Scale Figure 4.2

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"PROPOSED SA W T J U ^ B U S I N G F ^ C I I ^

30"

A s h Removal Port

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5.0 Occupational health and safety

"Health is a state of complete, physical, mental and social well-being and not merely the absence of disease or infirmity"

World Health Organization (WHO)

It is important that the 'work environment' is properly maintained. Workforce education is vital for this purpose. The benefits of this type of an approach would result in overall positive environmental management by the system concerned. Steps to be followed are given below,

• The health and safety requirements of the workers should conform to those prescribed in the Factories Ordinance.

• Provide workers with dust masks that can filter the fine dust • Provide workers with earplugs • Insist that workers should wear the protective equipment • Educate workers on the importance of work safety.

6.0 Reference to current law

Industrial establishments cannot operate without having appropriate permission from relevant local authority. It is necessary initially to obtain siting and planning permission and then relevant approval from the local authorities. The functions if improperly executed, can be subjected to prosecution under the public nuisance ordinance. It is important that owners plan and run industrial institutions accordingly

PUBLIC NUISANCE

" Public nuisance is an act or illegal omission, which causes any common injury, danger or annoyance to the public or to the people in general who live in or occupy property in the vicinity" e.g. Noise, Air or water pollution etc. Discharging effluent into a natural waterway endangering public health or Quarrying activities using explosives etc. in a manner that endangers neighbours or the public.

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Thus proper adherence to guidelines is important.

In respect of public nuisance, whether it is caused by air pollution, water pollution, sound pollution or other means the police wil l act as follows

• Prosecute the offenders under Section 261 of the Penal Code for causing a public nuisance.

• File motion in the Magistrate's Court under Section 98 of the Criminal Procedure Code to abate the public nuisance.

ENVIRONMENTAL PROTECTION LICENSE (EPL)

It is an offence for any industry to discharge, deposit or emit waste into the environment without an environmental protection license issued by the Central Environmental Authority or in some cases by the local authority. The public may complain about Environmental Protection License violations to the Police, local authority or the Central Environmental Authority.

Region Site Clearance

EPL

North Western Province

Local Authority

Provincial Environmental Authority

Other Provinces

Local Authority

CEA

Thus the industry should be established away from any primary residential zones and all relevant constructions should conform to the zoning plan and existing rules and regulations of the relevant local authority.

The owners should comply with the rules and instructions or conditions laid down by the CEA and the respective local authority.

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7.0 Conclusions and Recommendations Maintain the saws in time and adopt good saw doctoring practices. Raise the skill levels of the sawers and saw doctors. Use thin kerf saws, use of accurate saw guards and provide devices for log turning and alignment.

' The log should be an integral part of the carriage and play or vibration should not be allowed.

• Lateral displacement of the log should not be allowed. • Increase managerial skills of managers. • Encourage the employers who are interested to the

environmentally friendly works. • Al l factory owners should apply for the environmental

protection license using the questionnaire that has been prepared by the CEA. The questionnaires could be obtained from the local authority of the area or the CEA.

• Depending on the degree of pollution, only those applications coming under Low Polluting Industries/ Processes should be received by the local authority.

• A license is valid only for a period of 3 years from its date of issue. The owner of the industry should apply for renewal of license to the relevant local authority, one month before the expiry date.

• The EPL issued should not be considered as an approval for the industry to be operated at a particular location. It is only a permit to discharge effluent/emissions or emitting of noise levels according for stipulated standards.

• Written approval (i.e. trading or operating license) of the relevant local authority should be obtained for operational purposes.

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8.0 Sources of information and analytical facilities

• Central Environmental Authority(CEA), Parisara Piyasa, 104, Robert Gunawardena Mawatha, Battaramulla. Tel - 872415,872263, 872606

• Relevant Local Authority

• Local Environmental Development Officers

• Industrial Development Board of Ceylon (IDB), 615, Galle Road, Katubedda, Moratuwa. Tel-612603

• National Engineering Research and Development Center (NERD), 2P/17B, IDB, Industrial Estate, Ekala, Ja-ela Tel-236384, 236307

• University Of Sri Jayawardenepura, Department Of Forestry And Environmental Sciences, Gangodawila, Nugegoda Tel-854685

• Energy Conservation Fund, Room No: 2-203, BMICH, Colombo-07. Tel-682534

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Industrial Technology Institute (ITI) -(former-CISIR), 363,Bauddhaloka Mawwatha, Colombo-07. Tel-693807-9, 698621

National Building Research Organization (NBRO), 99/1, JawattaRoad, CoIombo-05. Tel-588946,501834

Industrial Services Bureau-North Western Province, No: 141, Kandy Road, - 037- Kurunegala Tel 23721/2

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9.0 Sri Lankan standards for discharge of pollutants

P. 1 Maximum permissible Noise Levels at Boundaries.

Areas Equivalent Continuous

Sound pressure level (dB) Areas Day time Night time

Rural residential Area 55 45 Urban residential Area 60 50 Noise sensitive Area 50 45 Mixed residential 63 55 Commercial Areas 65 55 Industrial Area 70 60

9.2 Ambient Air Quality Standards

Pollutant Averaging Standard Measurement time ug/m 3 Method**

Suspended Annual 100 Particulate 24 hr 300 Hi-volume Matter 8hr 350 Sampling (SPM) 3hr 450 and Gravimetric

I hr 500

> 03 hour average - 03 consecutive hourly

> 08 hour average - 06 hourly average

> 24 hour average - 18 hourly average > Monthly average - 21 Daily average > Quarterly average - 03 consecutive monthly

Average each quarter > Yearly average - 09 monthly average each quarter

Least 02 monthly average each quarter

> By wet chemistry methods or by automated analyzers

Note These standards are to be reviewed and revised as necessary, based on the results o f Ambient Monitoring Program.

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