SafeWork Laboratories offers comprehensive wastewater testing via our new Greywater Testing service. We screen for traces of drugs and alcohol in wastewater samples to find evidence of substance abuse.

Our Greywater Testing can provide you with valuable insights into possible drug use in your organisation. You can use these information to develop the best Workplace Drug and Alcohol Policy for you and your employees.

  • Provides reliable and objective chemical data
  • Estimates drug use without relying on self reporting
  • Captures drug use in a catchment in real time

What is Greywater Testing?

Man collecting wasterwater for greywater testing

Greywater testing is the process of screening liquid household waste (greywater) for substances that may be harmful to the environment. Regulators primarily use wastewater analysis to study trends in illicit drug consumption in urban settings (Daughton, 2001; Zuccato et al., 2008; van Nuijs et al., 2011).

However, the practice has since been extended in recent years. Scientists apply wastewater testing to estimate illicit drug use in other areas as well. This includes target sites such as small communities and workplaces, and specific neighbourhoods (Hall et al., 2012; Prichard et al., 2014).

Greywater testing involves sampling a source of greywater and estimating the quantity of drugs consumed by a defined community. Researchers measure the levels of illicit drugs and their metabolites found in urine that end up in wastewater (Zuccato et al., 2008).

Benefits of Wastewater Testing

Man analysing wastewater samples

Wastewater analysis offers an efficient way of gathering objective and reliable chemical data on drug use in a given catchment. The results are not subject to response and non-response bias. The process also reveals the true spectrum of drugs being consumed. This is important since users are often unaware of the actual mix they take.

Through greywater testing, researchers can collect information on trends almost in real time. With these results, they can measure the effectiveness of drug use intervention strategies in the workplace.

Wastewater analysis also provides better monitoring of changes in illicit drug use trends. Researchers can use it to detect fluctuations in weekly patterns.

For example, some testing sites in urban areas may show higher cocaine metabolites and ecstasy loads on certain days. This could occur during or just after weekends and holiday. Meanwhile, other areas may show even distributions of amphetamine and methamphetamine loads throughout an entire week.

How Greywater Samples are Tested

Wastewater samples undergoing laboratory test

Experts recommend taking wastewater samples at the start of workers’ shifts and right before they end. Collectors need to take samples for a minimum of 7 days. But for a more intensive and comprehensive approach, researchers need samples over a period of 14 days.

There are two sets of wastewater samples collected for Greywater Testing:

Preliminary Sample

  • Used for rough analysis of drugs present in wastewater
  • Does not need flow rate records or demographic data
  • Samples stored in standard plastic (PVC) containers with no additives
  • Samples need to be refrigerated immediately <10℃

Wastewater Study Sample

  • Used to determine drug use rates for the study site
  • Requires 200ml wastewater samples
  • Samples stored in standard plastic (PVC) containers
  • Requires flow rates and demographic data

After gathering samples, collectors will take the wastewater to a laboratory for Liquid Chromatography – Tandem Mass Spectrometry (LC-MS-MS). Liquid Chromatography allows researchers to separate a wide range of drug compounds from the wastewater. Meanwhile, Mass Spectrometry allows them to identify the types of drugs that were present in the samples.

Collectors typically gather preliminary samples at least a fortnight before starting the study proper. They will then proceed with collecting the actual Wastewater Study samples.

SafeWork Laboratories Drug and Alcohol Testing in the Workplace

Drugs and alcohol testing in the workplace

SW Labs’ Greywater Testing is the perfect partner for standard drug and alcohol testing in the workplace. Wastewater testing allows you to find out if a member of your staff is abusing drugs and/or alcohol. It can also reveal what specific illicit drugs your employees might be using while at work.

Once you have an idea of the scope of substance use in your company, you can implement workplace drug testing. Our drug and alcohol testing programs can help you identify who among your workers might be suffering from substance abuse. We’ll let you know whether or not they are fit enough to do their job safely and effectively.

Through our wastewater testing service, you can also tell just how effective your workplace drug use intervention strategies are. We can help pinpoint the strengths and weaknesses of your programs, so you can implement changes where necessary.

Drugs Detected in Wastewater Testing

Samples of drugs tested in greywater testing

Our Greywater testing can detect a wide range of illicit drugs typically abused by users. These include:

Amphetamine-class Stimulants

  • Methamphetamine (crystal meth or ICE)
  • Amphetamine
  • MDMA (XTC also known as ecstasy)
  • MDA

Cocaine metabolites

  • BZE


  • Standard Opiates
  • Codeine
  • Morphine

Prescription Opiates

  • Oxycodone
  • Fentanyl

Test results typically become available within 3 weeks after we receive the wastewater samples. However, the testing period will depend on how intensively the requirements are for the data being analysed. For instance, fractionating data for subsite analysis and multisite comparisons often increases the total analysis time.

Once we have the wastewater test results, we will also provide a formal report to Chevron.

More Information

For more information on SafeWork Laboratories’ Wastewater Testing, contact us on the number below or send us an email

1300 795 227