The sunny-day lives of Shuswap water quality monitors
This blog series is all about the day Erin Vieira, program manager for the Shuswap Watershed Council, joined members of the Shuswap water monitoring group for a day of monitoring in Salmon Arm Bay. Erin usually works from her office in Kamloops (where she doesn’t usually wear a PFD, despite this photographic evidence). Spending a day on the water with water quality staff was a great learning experience and a nice change of scenery!
Haven't yet read Parts 1 & 2? You can start here!
Part 3: The End of the Pipe
Posted July 26, 2017
With all gear and samples stowed on board, our deep station monitoring is finished for today. Typically, several deep stations are monitored in one day, but today the crew has to investigate an arising issue elsewhere.
We head toward our next monitoring locations in Salmon Arm Bay. We’re going to collect samples from three "impact assessment sites" that are required as part of monitoring the impacts of the Salmon Arm municipal wastewater treatment plant. We will collect samples from a "far field" site near Christmas Island that’s several hundred metres from the plant’s discharge pipe; a "near field" site 100 metres from the discharge pipe, also known the "initial dilution zone"; and a site that’s at the end of the discharge pipe.
Upon arriving at the far field site, many of the same procedures at the Sandy Point deep station are repeated: the sonde gives us readings for dissolved oxygen and temperature; water samples are collected in bottles to be analyzed for nutrients, bacteria, ions, and metals; and a Secchi Disk measurement is taken. An additional water sample is collected at this site for nonylphenols. This is a new monitoring project for 2017; nonylphenols have not been monitored in the Shuswap until now. This is a project of interest being led (and paid for) by the Shuswap Watershed Council; this monitoring is not required by government regulators.
Nonylphenols is the name given to a group of synthetic compounds that are commonly found in industry and consumer products such as plastics, rubber, detergents, shampoos, cosmetics, household cleaners, latex paints, lubricants, pesticides and surfactants. In addition to being commonplace and therefore likely to be present in wastewater, they can be toxic to aquatic life at certain concentrations in the environment. The purpose of the nonylphenols monitoring project is to determine if they can be detected at any of the impact assessment sites; and if so, what the concentrations are and how they compare to water quality guidelines.
The collections at the three impact assessment sites are relatively quick – the water is shallow. Our monitoring on Shuswap Lake is wrapped up for the day. We head back to the launch, where I’m free to return to Kamloops – full of new knowledge and appreciation for the labour and technology that goes into monitoring the Shuswap… and feeling thankful that I got to participate on a warm day in June, and not a cold day in November.
Part 2: Into the Deep
Posted July 19, 2017
The measurements from the sonde indicate that the "thermocline" is located between six and seven metres today. The thermocline is the place in the water column where the water temperature changes abruptly. The first six metres of water are within a fraction of a degree of each other; then, at 7 metres, we see that the temperature has dropped by four degrees. The temperature continues to drop rapidly with increasing depth, then at 12 metres it tapers off and once again there is little change to the bottom of the lake.
This is an important concept in lake ecology. In essence, the lake waters are divided into three regions: the "epilimnion" is the upper-most region; the "metalimnion" or thermocline is the middle region; and the "hypolimnion: is the lower-most region. Throughout the year, the degree to which these regions mix with each other and the depths they occupy in the water column will change. There’s a lot more that could be said about these, but I’ll leave it there for now.
Next, the water technician takes a Secchi disk measurement. A Secchi disk is a simple and commonly used device in water quality monitoring. It is a dinner-plate-sized disk divided into four wedges alternating black and white, and attached to a rope. It gets lowered into the water slowly, and the depth at which the contrasting black-and-white wedges are no longer visible under the water is the Secchi disk depth. It is a low-tech method for measuring water clarity.
It’s now time to collect deep station water quality samples. The biologist and tech switch positions in the boat. The biologist readies the collection device: a Van Dorn water sampler. It’s essentially a tube with closing mechanisms on each end. He will lower the Van Dorn to the desired depth, trigger a mechanism to seal the sampler, and then haul it up to the surface. Then, he’ll transfer the water samples to pre-labelled bottles. The samples will soon after be analyzed for nutrients, ions, metals and bacteria. In perfect weather conditions, a water sample would first be collected from the epilimnion and then the hypolimnion. However, the wind is picking up, so the hypolimnion sample will be collected first while the tech keeps the vessel from drifting.
Both hypolimnion and epilimnion samples are collected, from approximately 56 metres and 6 metres deep respectively. The biologist transfers the water into the appropriate bottles and stores them in a cooler. Later, in a laboratory, these samples will undergo various analyses to determine the presence and concentrations of ions, nutrients, metals, and bacteria. As he’s transferring the samples, I’m alerted to another challenge of water quality monitoring: we’re in a confined space, and it’s rocking back and forth. This boat is equipped with two winches, toolboxes, safety equipment, coolers for the samples, and three people – there isn’t much room to move around, and handling the samples requires balance and movement to counter the effects of the waves.
The final collection before we depart the deep station is zooplankton – the tiny animals that live in the water. The technician lowers a large cone-shaped net into the water to 25 metres, and slowly hauls it up. At bottom end of the net is a collection cup teeming with tiny creatures that to my naked eye don’t look like much more than some silt and sludge. The sample is transferred to containers, and it will later be analyzed for taxonomy (i.e., species) and approximate abundance.
Next week: we’ll learn about monitoring the impacts of the municipal wastewater treatment plant, including a special project for nonylphenols
Posted July 12, 2017
It’s 9:40 am. I’m waiting at the Salmon Arm boat launch for my hosts, two staff from the BC Ministry of Environment, to arrive. They’re driving in this morning; I’ve just arrived from Kamloops. It’s currently 21C with a steady breeze blowing. It’s supposed to get up to 26C today – pretty perfect conditions for being on the water. This will be my first time water quality sampling in about 10 years.
They pull up with their vessel in tow. One of my hosts immediately has to take a phone call related to a report of an algae bloom elsewhere in the BC Interior. Our day on the Shuswap may get cut short if the emerging issue needs to be investigated.
We load the boat with our supplies: sample containers, coolers with ice packs, sampling equipment, lunches and water, notebooks. They launch the boat, and I climb aboard.
There are three of us on board: a biologist who will double as the captain for most of the day, a water technician and myself. The first order of business is to go over safety procedures with me, as I’m the only inexperienced person on board. We are donning our Personal Flotation Devices – sleek, comfortable, red, inflatable PFDs. We review the safety equipment on board, we go over procedures to follow in the event of a fire and how to use the radio to call for help, and I’m given an overview of the vessel’s navigation system.
We proceed slowly out of the Salmon Arm marina. We are heading for a "deep station" near Sandy Point, a short boat ride from the marina. The deep stations – there are several of them throughout the watershed – are long-term monitoring locations where water quality samples are collected and analyzed for various parameters such as nutrients, ions, metals, dissolved oxygen, temperature, pH, plankton and more. Water quality monitoring at deep stations provides a very good picture of the overall health of the Shuswap lake system. Despite being called a station, there isn’t actually anything there of course – it’s just a location.
We arrive at the deep station, guided by the navigation system. This is the deepest spot in Salmon Arm Bay at 63 metres. The water technician prepares the profiling equipment: it’s an electronic device called a sonde that has multiple probes attached that measures dissolved oxygen, temperature, turbidity, pH, and specific conductance. She lowers the sonde into the water, one metre at a time, and takes a reading from the hand-held controller that’s attached to the sonde via a very long cable.
This procedure takes about 20 minutes. I’m alerted to one of the challenges of sampling on open water: it’s windy, and the captain is constantly countering the effects of the wind on our vessel to keep us from drifting away from the station. We’re bobbing on the waves, and the water tech is recording water quality parameters in a log-book for various depths in the water column.
These measurements need to take place first as they inform the depths from which the other water quality samples will be taken.
Next week in Part 2: we’ll learn about thermoclines, Secchi Disks, and how to collect water that’s 56 metres below the surface …