Doug Davidge's job as an Environmental Assessment Officer has changed dramatically since he joined Environment Canada in Whitehorse 16 years ago.

In those days, a field trip to sample the water in Yukon streams and lakes meant packing three or four testing instruments, along with crates of large bottles and bags to contain samples of water, sediment, and biological specimens.

Analysis of the samples happened well after the field trip, in a laboratory hundreds of kilometres away. In order to make sure the lab analysis was accurate, the samples had to be treated according to very exacting standards in the field. Then it was a matter of waiting for results.

Field trips today involve less equipment and less waiting, says Davidge. More and more of the analysis can be done on site. Some samples are still sent to laboratories, but modern lab techniques can get the same information from much smaller samples than were used 16 years ago.

Water sampling is generally part of baseline studies, to assess the state of a stream prior to development, or environmental impact studies related to development. Field technicians collect samples of water, sediment, and biological specimens in order to get as complete a picture as possible of the condition of the stream at the time the samples were taken.

In most cases, Davidge says, water quality studies look at dissolved metals, nutrients, temperature, pH, dissolved oxygen and conductivity (a way to measure total dissolved solids in the water).

"Fifteen years ago we would have taken three or four instruments, but now we may only take one because the new equipment does all the things the three or four used to do."

The new electronic water sampling equipment not only does more work; it works faster. The multi-probe water quality instruments of today produce almost instantaneous results, says Davidge. Sometimes multi-probes are hooked into a computerized system that allows sampling at time intervals or depth intervals.

"A very flexible rate of sampling can be programmed into the instrument," Davidge says.

Usually the field technician goes to the sampling site, takes samples over a period of time, and moves on to another site, Davidge says. The information from the sampling instrument is then downloaded into a laptop computer or in some situations, can be sent by telephone lines or satellite to a base computer.

Sometimes automated water sampling systems are used. The automated equipment can be programmed to collect a pre-determined amount of water from a site at set intervals for two or three weeks. It pumps water into sample containers and stores them until a human water sampler arrives to collect them for analysis.

"It eliminates or reduces the risk to the field technician," says Davidge. "We don't have to be exposed to adverse weather or water conditions for long periods of time."

In addition, leaving an automated sampling device at a test site is cheaper than having a field technician spend two or three weeks in the bush in order to sample the stream a few times a day. The automated equipment makes longer-term monitoring economically feasible, Davidge says.

Electronic equipment has changed the job requirements of the field technician substantially. When Davidge packs for a field trip today, he has to include a laptop computer, which interfaces with the test instruments to set them up and to download information, and batteries to power the electronic gear.

"The job is actually more technically demanding now," Davidge says. "You have to be able to understand how the instruments work. If the readings are to be valid, the instrument has to be maintained and calibrated."

"A computer background is very important in the work of field technicians involved in environmental monitoring," he says.

For more information about environmental monitoring, contact the Environmental Protection branch of Environment Canada, Whitehorse.