Neath Port Talbot Council officers have stopped and spoken to 65 traders as part of a joint operation against rogue traders.
The council partnered with South Wales Police, Dyfed Powys Police, and HM Revenue and Customs.
The two-day operation dubbed Operation Crossfield saw the council officers advising traders on contracts and consumer rights.
They also checked for proper waste carrier and scrap metal licences.
At the same time, other partnership teams led their own inspections on vehicle safety and ensuring vehicles were not running on illicit fuels.
Waste management centres throughout the county borough also underwent on-site checks.
Some vehicles were found with serious safety defects like worn tyres, unsecured loads and, alarmingly, parts likely to detach.
Until these vehicles were repaired or made safe, they were not permitted to move.
South Wales Police doubled down on the operation by taking active measures against drug and traffic-related offences.
Cllr Cen Phillips, cabinet member for nature, tourism and wellbeing, said: "These joint operations show how seriously the council takes Consumer Protection offences or fly tipping."
The public were reminded to be discerning when dealing with waste carriers.
Householders should engage only reputable licensed traders to avoid possible liabilities in case of fly-tipping.
Moreover, consumers were also enlightened about their rights when contracting tradespeople.
For instance, if a job costs over £42, the law requires that traders provide cancellation rights with a grace period of 14 days.
Other advice for consumers included taking time to appraise proposed work, obtaining several quotes before entering an agreement, and making staged payments for large jobs.
They should also scrutinise claims of membership to trade organisations.
For any complaints about traders, they can contact the Citizens Advice consumer helpline on 0808 223 1144 (Welsh) or 0808 223 1133 (English).
More information regarding waste carriers including the waste carrier database, can be found via the Natural Resources Wales website.
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