Construction of New Sewer: Safety, Health, and Best Practicable Means

This report provides a detailed overview of the construction of a new sewer, emphasizing adherence to 'best practicable means' and comprehensive safety protocols. It outlines the necessary consultations with authorities, neighbors, and interested parties, along with the importance of maintaining ongoing communication and information exchange. The report addresses the technical aspects of sewer construction, including requirements for sealing redundant pipework, testing retained pipes, and the use of appropriate materials to prevent future issues. It also highlights crucial safety and health precautions for construction workers, detailing various occupational hazards associated with different trades and offering strategies for controlling these risks. These strategies include decreasing exposure to hazards through engineering controls, environmental controls, and the use of personal protective equipment. The report also stresses the importance of providing proper eating and sanitary facilities, implementing effective safety programs, and preventing accidents and injuries through clearly defined policy statements and emergency preparedness.

DRAFT PAPER
Construction of New Sewer
In constructing the new sewer, the contractor will have to:
 demonstrate ‘best practicable means’. He will have to consult the States Authorities well
in advance of works commencing to discuss the proposed task and the scope of liaison
and ‘Scheme of Protective Works’ to be submitted for protecting nearby residents and
commercial occupiers.
 Identify neighbors and interested parties (including where appropriate Ward Members)
and consult with them beforefinalizing the Scheme of Protective Works.
 Maintain dialogue and information exchange with the state’s Pollution Team, neighbors
and interested parties throughout the proposed works;
 Respond to complaints and resolve where practicable; and
 Ensure neighbors and interested parties are kept informed of works as they progress and
are consulted where necessary.
 Contact must be made with the Water and sewerage Authorities before any work
commences. undertaken on connections to sewers or drains running under the public
highway. The following general requirements will have to be met:
 All redundant sewer communication pipe work must be sealed off at the sewer. The
remaining pipe work should be removed or filled with a suitable weak concrete, cement
grout or other suitable material. This is to prevent any infestation by rodents and avoid
the risk of future possible subsidence.
 All retained sewer communication pipes should be tested and a CCTV survey carried out
to ensure they are suitable for the new development and in good condition.

 In order to prevent rodents or sewer gases reaching the site, temporary sewer
communication pipes must be provided with a ‘cascade’ cast iron interceptor trap to
British Standard specification.
 It is strongly recommended that all under-ground drainage systems are installed using
pipes made of a robust material such as cast iron, and that inspection chambers etc. are
properly sealed with bolted down covers. This will prevent later problems from damage
by vibration or rodent access.
 Wherever it is at all possible, the drainage system serving the proposed development or
refurbishment should gravitate to the sewer. This will eliminate the need for pumping of
foul drainage to the sewer and the associated problems which regularly occur with this
type of installation.
 It is highly recommended to work on sewer lines from 10pm when roads are less busy.
This will ensure minimal disruption of traffic.
Safety and Health Precautions
Workers in the construction field build, maintain, repair, modify, renovate, and demolish various
construction facilities such as buildings, offices, health facilities, tunnels, roads and other civil
works. The International Labour Organization (ILO) classifies the construction sector asan
undertaking by the government and private sector to erect buildings for purposes of habitation or
commercial use as well as public works such as water systems and roads, dams, bridges and
airports. In some construction sites in the US and other developed countries, construction
workers are also involved in cleaning hazardous wastes in sites.
Construction accounts for 4% of the US GDP. For this reason, a lot of construction work is
ongoing. In construction, workers are exposed to many risks and health hazards at work. Levels

of exposure differ from work to work, by the day and hour. Exposure to a risk may be of short
duration but is likely to occur. Hazards may not be primarily caused by a worker’s mistake, but
also bystander hazards exposed by those people who work at nearby sites. Severity of a hazard
depends on the magnitude and duration of exposure. It is possible to minimize bystander hazards
if one knows the trades of workers at nearby sites. Some of possible risks when carrying out the
project are:
Occupations Hazards
Brickmasons Cement dermatitis, awkward postures, heavy
loads
Stonemasons Cement dermatitis, awkward postures, heavy
loads
Hard tile setters Vapor from bonding agents, dermatitis,
awkward postures
Carpenters Wood dust, heavy loads, repetitive motion
Drywall installers Plaster dust, walking on stilts, heavy loads,
awkward postures
Electricians Heavy metals in solder fumes, awkward
posture, heavy loads, asbestos dust
Electrical power installers and repairers Heavy metals in solder fumes, heavy loads,
asbestos dust
Painters Solvent vapours, toxic metals in pigments, paint

additives
Paperhangers Vapours from glue, awkward postures
Plasterers Dermatitis, awkward postures
Plumbers Lead fumes and particles, welding fumes
Pipefitters Lead fumes and particles, welding fumes,
asbestos dust
Steamfitters Welding fumes, asbestos dust
Carpet layers Knee trauma, awkward postures, glue and glue
vapour
Soft tile installers Bonding agents
Concrete and terrazzo finishers Awkward postures
Glaziers Awkward postures
Insulation workers Asbestos, synthetic fibres, awkward postures
Paving, surfacing and tamping
equipment operators
Asphalt emissions, gasoline and diesel engine
exhaust, heat
Rail- and track-laying equipment
operators
Silica dust, heat
Roofers Roofing tar, heat, working at heights
Sheetmetal duct installers Awkward postures, heavy loads, noise
Structural metal installers Awkward postures, heavy loads, working at

heights
Welders Welding emissions
Solderers Metal fumes, lead, cadmium
Drillers, earth, rock Silica dust, whole-body vibration, noise
Air hammer operators Noise, whole-body vibration, silica dust
Pile driving operators Noise, whole-body vibration
Hoist and winch operators Noise, lubricating oil
Crane and tower operators Stress, isolation
Excavating and loading machine
operators
Silica dust, histoplasmosis, whole-body
vibration, heat stress, noise
Grader, dozer and scraper operators Silica dust, whole-body vibration, heat noise
Highway and street construction workers Asphalt emissions, heat, diesel engine exhaust
Truck and tractor equipment operators Whole-body vibration, diesel engine exhaust
Demolition workers Asbestos, lead, dust, noise
Hazardous waste workers Heat, stress
Chemical hazards
Chemical hazards mostly are airborne. They can appear as dust, fumes, vapors, gases or mists.
Exposure to chemical hazards is by inhalation although some airborne risks may settle on the
skin and get absorbed into the body. Hazards that can penetrate the skin include pesticides, and
some inorganic solvents. Some chemical hazards occur in liquid or semi-liquid state e.g.
adhesives, glues and tars or as powders such as dry cement.

Physical hazards
Physical hazards are there in all construction projects. These risks include heat, cold, radiation,
vibration, barometric pressure and noise. Machines used in construction such as excavators and
breakers are a possible source of noise. Noise not only affects the person on site but also people
who neighbor the site. Pneumatic hammers and other hand tools, as well as earth moving
equipment and large tracks also expose workers to segmental or whole vibration of the body.
The machines that have transformed construction into an increasingly mechanized activity have
also made it increasingly noisy. The sources of noise are engines of all kinds (e.g., on vehicles,
air compressors and cranes), winches, rivet guns, nail guns, paint guns, pneumatic hammers,
power saws, sanders, routers, planers, explosives and many more. Noise is present on demolition
projects by the very activity of demolition. It affects not only the person operating a noise-
making machine, but all those close-by and not only causes noise-induced hearing loss, but also
masks other sounds that are important for communication and for safety.
Heat and cold hazards may also pose risks because the project will be carried out when people
are exposed to the weather. Roofers are often exposed to the sun, and most times they have are
not protected. This may lead to heavy radiation and convection heat currents in addition to
metabolic heat arising from heavy physical labor. People who operate heavy equipment may sit
beside a hot engine for a long time and may work in enclosed cabs which have windows but no
ventilation.

Fig 1: Carrying without appropriate work clothing and protective equipment
Controlling Occupational Hazards
Decreasing exposure to concentration
This requires consideration of the source to exposure, and the environment in which a hazard
occurs, as well as the people who are exposed to the hazard. Decreasing exposure can be done
through engineering controls at the source environmental controls to remove the hazard from the
environment and personal protection that is provided to workers.
Engineering controls
This involves some sort of engineering change such as substituting a more hazardous substance
with a less hazardous one. For instance, if we can use Non-respirable synthetic vitreous fibres
instead of asbestos, water to substitute organic solvents in paints and using non-silica abrasives
to replace sand in abrasive blasting (sand blasting).
The process of work can also be changed such as replacing pneumatic hammers with impact
hammers. Impact hammers generate less vibration and noise. Shear cutting can help to replace

sawing or drilling which generates harmful dusts, noise and particulate matter. Technological
improvements help to reduce the risks of health problems. Use of better equipment is also
important. For instance, use of a two-handed screw driver with a longer handle can help to
reduce stress on the wrists by increasing torque.
Environmental Controls
Environmental controls help to remove hazardous materials from the environment. Use of local
exhaust ventilation (LEV) can be used at a job with a ventilation duct and a hood to trap fumes,
dust and vapors. LEV would however have to be mobile and flexible to accommodate changes
such as change in location of tasks which lead to emission of toxic substances. LEV can involve
independent power sources, mobile trucks that collect dust and are fitted with fans and filters,
mobile water supplies and flexible ducts.
The simple and effective method for controlling exposure to radiant physical hazards (noise,
ultraviolet (UV) radiation from arc welding, infrared radiant (IR) heat from hot objects) is to
shield them with some appropriate material. Plywood sheets shield IR and UV radiation, and
material that absorbs and reflects sound will provide some protection from noise sources.
Personal Protection
Use of personal protective gear is important in construction sites. All workers should wear
helmets and safety boots to prevent them from getting injured while on site. In addition, it is
important to prevent injury on people who carry heavy things such as stone by providing them
with safety clothing which they can place on their backs and shoulders.
Construction worker without a safety helmet and boots

Eating and Sanitary Facilities
There should be eating and sanitary facilities in site to reduce exposure to hazards. Lack of a
toilet on site may lead to diseases such as cholera and typhoid. In addition, there should be
sufficient supply of water where people can wash hands after visiting the toilet. Workers may
oftenswallow toxic substances transferred from their hands to cigarettes and food if they don’t
wash their hands. There also needs to be changing facilities at a worksite so that workers do not
transfer contaminants to their homes.
Safe Construction Work
Effective safety programs have several common characteristics. They are profound in
organizations, from the highest ranking office to the workers doing hands on jobs. It is important
to implement codes of practice at the site and calculate costs of injury and illness. Everybody at
the site receives relevant training on how to manage safe construction work. Inexperienced
workers should receive on-the-job training from the more experienced workers. Injury rates will
be significantly lower if this is implemented.

Preventing Accidents and injuries
There should be clearly defined policy statements in the organization conducting construction
procedures. A policy statement is a specific code of practice which defines hazards and their
control for occupations and works at the site. It is important also to clearly define roles and
responsibilities at the site. Failure to meet these standards by anyone on site should be punishable
by fines and penalties. People who meet standards should be rewarded.
It is critical to prepare for emergencies at sites. Emergency drills should be conducted
occasionally to teach workers on what do in case of an accident. Preparation includes assigning
responsibilities, providing first aid, immediate medical attention and having standby
communication with ambulances, hospitals and medical practitioners who can be consulted.