"That's five in every hundred people. There's still a need to do random tests. It's like random alcohol stops on the roads - it's a deterrent and proactive measure.
"We have a culture in New Zealand where we don't tell on work mates because it's deemed narking. Random testing takes that away."
McLeod Cranes managing director Scott McLeod said his company had a zero tolerance drug and alcohol policy.
"In the event that someone receives a non-negative, they get stood down until we find out the result of the test. In the event of a positive, then we would be looking at a dismissal.
"In our industry, we are high risk ... if someone makes a mistake, there is no second chance. When something goes wrong, it would be a catastrophe, there would be a crane lying across a building or something like that."
Employees are tested and given medicals pre-employment, then annually. Random testing is also carried out.
Mr McLeod said it was common for some work sites to do pre-contract testing and some customers also did random testing.
Te Tuinga Whanau Support Services Trust director Tommy Wilson said he had not seen any decreases in people presenting to the trust with drug problems, including alcohol.
"They may see it decreasing in hospital or in court, but here it hasn't dropped off. I don't see any drop off in the number of desperate, addicted people coming in here."
Mr Wilson said there was no point "fingerpointing" any drug when the biggest drug problem was not being addressed - alcohol.
"We have to address all drugs."
Hanmer Clinic director David Benton said presentations of people using synthetic cannabis seemed to have dropped off.
Methamphetamine was still prevalent in about 10 to 20 per cent of clients. "Our major presenting drug is alcohol and that would be true of the general population as well."
