The infringements were revealed after inspectors checked almost 20 inner-city projects, he said.
The resulting litter and dust was annoying many citizens.
The director said city regulations stipulated that project developerscould use the pavements for building materials between 10pm and 6am butthen had to leave them clean for pedestrians.
Instead, their workers left an abundance of illegal barriers andtemporary tents with pavements destroyed to install pipes.
An example was a project in Ba Trieu street .
There, the developer had been fined 5 million VND (263 USD) and required to remove the pipes.
"These developers should be condemned for their bad behaviour," the director said.
"If they honoured the regulations, contractors and workers would, in turn, care about surrounding environment.
"Inspectors make regular checks and require the contractors to repairthe damage but some still ignore the instructions and prefer to pay thefines."
The Infrastructure Development andConstruction Joint Stock Company, which had failed to install safetylamps and allowed its work to encroach the pavement, had ignoredrepeated requests for payment of its fines.
Thedirector blamed a shortage of inspectors, his department has almost 30,and the failure of local authorities to enforce the rules for the litterand pollution.
His department had proposed thatrelevant authorities refuse to allow offenders to hire pavement spaceand impose fines of between 15-20 million VND (789-1,052 USD) for anytransgressions, he said.
The department would continue to inspect the laying of underground cable and construction work until Monday, August 30.
Ensuring quality and progress as well as ensuring limitedenvironmental pollution and encroachment would be the criteria for theinspections.
Hanoi has spent 1 trillion VND(52.6 million USD) on ten construction projects for the anniversarywhich falls on Sunday, October 10./.