Think green<br><i><u>Tips for all construction sites</u></i>
TCE Consulting Engineers has carried out assignments on project management and construction supervision at many Indian and foreign project sites, including Mumbai Sewage Disposal Project for Municipal Corporation of Greater Mumbai. The MSDP is a World Bank aided Rs 860-crore project commissioned recently (1995-2003). It involved 10 sites, some 250 km of sewage lines and several tunnels and shafts. Environment management was a prime requirement.
A.S. Prabhudesai, Chief Engineer, Construction Department, TCE, has 28 years experience in construction activities, in India and abroad and is site-in-charge at MSDP.
Prof. B.P. Nansi talked with Prabhudesai regarding the environment management during construction at MSDP.
International funds like World Bank insist that Environment Management Plan (EMP) be in place and followed at project sites aided by them. Such EMPs are applicable at other sites too. In fact, we are supposed to take care of the environment anyway.
Measures for protecting the environment during construction are not difficult. All we need is awareness and will. Here are some measures that were taken at the project site during construction. The measures are excellent guides for green construction.
All contractors were to make their EMP and follow. The EMP was reviewed and approved by the site-in-charge.
The contractor would appoint a special EMP officer to implement the EMP.
Periodic auditing was done. External auditing was also done.
Regular follow-up meetings were held. If non-conformities existed, they had to be corrected.
Public, and especially the community surrounding the project site, is a project stakeholder. Community get-togethers were held to explain how the project is going to genuinely benefit the community. At one site, fishermen feared the damage to fish crop. It was explained to them that the project would discharge the sewage farther away and further deep; the result would be a better fish crop.
Domestic facilities and toilets
- Canteen waste and garbage was collected regularly and dumped at the Municipality- identified dumpsites.
- Pucca toilets were built for the site personnel and for general community use. The project requested some NGO's to maintain the facility and it is working well.
There was strict procedure to register the worker's name etc., and issue an ID-card, before anybody would take up the work at the underground location.
Borrowed earth and any other construction material were obtained from the designated sites only. Any work done at the supply site was carefully executed. Care was taken to see that the hill slope was not disturbed. Also, care was taken that the course of any water flow on hills did not alter.
The project involved excavation for tunnels and shafts. The project also needed rocks for lining of lagoons. So the project recycled its own excavated rock (about 20,000 M3). The blasting was controlled to get the desired size of rocks.
Construction solid waste
Debris, excavated earth and all other construction solid waste were regularly collected in dedicated trucks. The debris was watered to avoid any dust fly-off en route and covered. The waste was dumped at the disposal sites identified by municipality/collector.
- Drainage control and monitoring was done regularly so that local wells did not get polluted.
- The sub-soil water obtained due to any excavation was pumped into a detention tank. The overflow was then put into a water-body. The grit, earth, pebbles etc., flowing along with the water would settle in the detention tank and would not pollute the discharge receiving water-body. The settled muck was disposed off at the designated places.
The site regularly monitored air quality.
Safety officer monitored gases continually and would give permit to enter a tunnel or a shaft after the safe level was observed.
Water was sprinkled regularly on roads and open areas around site
The project monitored noise level continuously. At one site, the neighbouring residents complained of noise disturbance. Some corrections that were taken:
- Suitable revised working hours of noise-making equipment
- Use of electrical motors in place of diesel engines
- Sound proof cover around the noise-making machines
Continuous monitoring was done and vibrations were kept within limits.
The site did not dispose off, on its own; the bio-medical waste generated in the site-run dispensary and the first aid centres, but regularly submitted to a near-by hospital for disposal along with the hospital waste.
Dustbins were placed to avoid littering. Site was cleaned regularly
For every tree felled, five trees were planted. Trees were planted around the site also.
Measures for protecting the environment during construction are not difficult. All we need is awareness and will. And the knowledge that this is the only planet we have.
(Oct 01-15, 2004)