The Environment Agency (EA) has reminded waste drivers that they must carry with them the correct paperwork after spot checks in Hertfordshire uncovered a series of breaches.
The checks took place in Borehamwood with environment officers joined by the police, DVSA and council officers.
It said 90% of the vehicles it stopped had to be reminded of the law on carrying waste.
The EA said it pulled over 33 van and HGV drivers and asked them to show they were carrying the right documents, while vehicle inspections were also carried out.
Half a dozen drivers had missing or incomplete paperwork and will now be subject to an EA investigation, while follow-up letters will be sent to another 23 as a general reminder to register if they want to transport waste.
Any lorry or van moving waste for commercial reasons must be registered by law to ensure it is disposed of correctly, or else be subject to further action by the agency.
Hannah Wooldridge, EA senior technical officer said: “The results from our latest checks on lorries and vans in Hertfordshire prove the worth of finding out if drivers and operators are working within the law when carrying waste on board.
DVSA traffic enforcement manager Mick Cheeseman said: “There’s no excuse for driving with mechanical defects or with an overweight or insecure load.”