Solid Energy's random drug and alcohol tests nabbed 28 offenders in the year to July, more than a third less than the previous year.
Fifteen were Solid Energy employees, equating to about 1.4 per cent of Solid Energy's 1036-strong workforce at June 30, according to information obtained under the Official Information Act.
Thirteen worked for contractors.
Six of the 28 had offended before. Three of them subsequently resigned and three were dismissed, said Solid Energy senior solicitor Rob Page.
Another 17 were either dismissed or were no longer working at the sites and 11 were referred to a rehabilitation programme.
Solid Energy declined to reveal how many workers it caught at each worksite, citing privacy reasons. It would also not say what drugs were detected.
"Releasing this type of information has the potential to reduce the effectiveness of the drug and alcohol testing regime which could subsequently affect the health and safety of all workers employed or engaged at our sites," said Mr Pope.
It caught 45 offenders in the year to June 30, 2012.
Mr Page said the company carried out 1773 random tests in the year to June 30, 2013, 475 fewer than the previous year.
The tests included pre-employment testing of employees, testing of contractors' employees before they worked on site, post-incident testing of employees and contractors, and random testing of employees and contractors.
- Westport News