SpruceRoots Magazine - February 2002

SpruceRoots Magazine - February 2002


Two Beakers: (L) Raw run-off from the dryland sort and (R) run-off after being treated.
by Erica Thompson

“Turning contaminated environments into organic wonder-ands,” is the calling card of a small outfit of biologists and engineers working from the community of Robert’s Creek on the Sunshine Coast. One of their missions is to create solutions that will restore bays, foreshore areas and fish creeks contaminated by debris laden run-off and toxic effluent originating at dryland sorts. Solving environmental problems generated at log sorts is no small feat considering there are 117 active sites on Vancouver Island alone and thirteen operating on Haida Gwaii.

Ecological hazards and expensive problems occurs when water mixes with wood debris generated at dryland sorts. When logs are transferred from trucks to the sort for grading and bundled for the booming grounds, and as waste like cull wood debris, limbs, stumps, and bark is sorted into burn piles, hog fuel piles and wood waste landfills, keeping debris clear from water is the challenge facing most dryland sort operators today. There is no shortage of water in the remote and coastal areas housing the majority of dryland sorts in BC. Heavy Pacific rains, ground and surface water, or water applied as fire hazard and dust control, fall upon the sort and percolate through waste landfills, hog fuel piles, bark, saw dust, chips, shake blocks and burn piles. As the water runs through red cedar, spruce and hemlock remains, toxic chemical compounds – known as wood waste leachate – seep from the wood debris and move into the water flow.

In July 2001, Weyerhaeuser pleaded guilty to charges of polluting fish habitat after toxic wood waste run-off, from MacMillan Bloedel’s Sproat Lake dryland sort, entered salmon bearing Johnston Creek, near Port Alberni, in 1999. The Sproat Lake affair cost Weyerhaeuser $40,000 in fines under the Fisheries Act, not to mention legal fees, under the Fisheries Act. Earlier the same summer, Bayside Sawmills on the Sunshine Coast paid $20,000 in fines after pleading guilty to contaminating fish habitat with run-off from their log yard. As these events indicate, the environmental impacts of sort activities are gaining the attentions of the Department of Fisheries and Oceans enforcement and compliance officers, biologists, engineers, researchers, sort operators and forest industry financial officers alike.

Dr. André Sobolewski is a microbiologist and the founder of Microbial Technologies. He identifies two different sources of problems originating at the sorts which together have damaging effects on marine habitat and living communities located adjacent to the sorts.

“Leachate is generated when a small volume of liquid slowly percolates through a material and dissolves soluble compounds associated with it. Runoff is generated when a large volume of water is applied to a surface – whether rainfall or for dust control – and sweeps across the surface, collecting anything solid or soluble along the way. The main differences are in volumes of water and speed of flow,” says Dr. Sobolewski.

The composition of the leachate changes depending upon which tree species it is derived from, but generally it made up of water-soluble tannins, fatty acids and wood resin acids from terpenes, which are acutely toxic to fish. Black and brown water, a strong petroleum like smell and the formation of white foam typically identify these changes in local water chemistry. Much of the foaming that occurs when wood waste leachate enters receiving waters is due to wood resins. Other compounds, such as terpenes, create oily iridescent slicks in slow moving waters where it is present.

The run-off problem is worsened by the physical layout of dryland sorts which are built sloping towards the water. As rains fall, particles and debris left on the pavement or the ground are flushed as run-off into the foreshore area. As recent work conducted independently by Microbial Technologies and other DFO studies show, the chemical reactions taking place in the water and the floating particles of wood pose hazards to fish, their food source and rearing habitat.

Microbial Technologies’ dryland sort work began two years ago when Dr. Sobolewski was asked to design a wetland dealing with leachate from a wood waste landfill. The wood debris from mills are commonly dumped in a landfill site and water flowing through these sites carries out leachate. In the case of the landfill, the leachate was day lighting (surfacing in the creek from underground) at a creek where coho were spawning, says Dr. Sobolewski. He felt that if Microbial Technologies could design a way to intercept the leachate and detoxify it before it reached the creek, they would be well on their way to finding a solution to the toxic by-products of wood waste.

Microbial Technologies’ Paul van Poppelen, biologist and engineer, works with Dr. Sobolewski on restoring areas affected by dryland sort activities. “We all knew the wood waste leachate, originating in the fermenting piles of wood, hog fuel and chips soaked with water containing fatty acids and resins, is acutely toxic to fish,” says van Poppelen. But the leachate is released in small volumes relative to the massive volumes of debris loaded storm water run-off entering bays and creeks and this problem of run-off has not historically been afforded due attention. Considering the two sources of pollution originating at dryland sorts, van Poppelen and Dr. Sobolewski went about designing a process that can treat them both together, eliminating both sources of contaminants.

Run-off comes off these sites in incredible volumes. “Imagine, many of these sorts are 3 to 4 hectares in size and if you’ve got an average rainfall of 10 mm falling in a couple of hours, you’ve got a lot of run-off,” says van Poppelen. Moreover, you have a lot of very fine debris flowing into that water.

According to the study Mitigation of Fisheries Impacts From the Use and Disposal of Wood Residue in British Columbia and the Yukon by DFO and Environment Canada, in a log yard or dryland sorting operation, every 100 cubic meters of logs scaled, will generate between three to four cubic meters of debris for paved yard surfaces and between five and six cubic meters for unpaved yard surfaces. On Haida Gwaii, between 1992 – 2001, the total district cut saw 15.7 million m3 of timber move across island sorts. Using the figures from the Ministry of Forests, and the fisheries study, 549,500 m3 to 863,500 m3 of debris (depending upon the ratio of paved to unpaved dryland sort surfaces) was generated from local island log sorting.

According to the report, wood debris in foreshore areas and nearby creeks, result in an overall decrease in species diversity, abundance and biomass. The high organic matter content of wood waste leachate steals oxygen from the water as bacteria and fungi break down wood particles, starving fish of oxygen. The growth of bacteria and fungus further restricts water flow and oxygen exchange in streams, affecting the survival of fish eggs and developing alevins. The report also noted that the microorganisms could even grow directly on fish gills furthering their susceptibility to water quality or habitat changes caused by run-off and leachate concentrations in waters.

The smothering effect of accumulating wood debris.

As well, the report points to fish suffering from fused gills after exposure to waters containing wood waste leachate. Also, the study shows that the bioaccumulation of resin acids in salmonids “may reach an overall body tissue concentration of 20 to 30 times that of the surrounding water during short-term sub-lethal exposureÖfish exposed to resin acids have been observed to exhibit symptoms of respiratory distress characterized by coughing and gill ventilation.” As some wood particles sink, they cover food sources and clog gravel critical to healthy spawning grounds, asphyxiating alevins, fish eggs and aquatic plants. Temperatures in creeks have been known to rise appreciably as a result of the biological and thermal decomposition of wood residue and leachate. Nutrients present in wood waste leachate can result in chronic problems such as increased algal or heterotrophic growth smothering aquatic habitat. Wood residue in unstable areas such as the inter-tidal zone or near estuaries, results in the continuous re-suspension of wood particles in the water column, negatively affecting the bivalves, crustaceans, and polychaetes which rely on unobstructed water columns for feeding.

At Microbial Tech’s lab at Robert’s Creek, van Poppelen set out testing water samples he had collected from polluted dryland sort sites. In a sense, it is new research and not just in BC, he says.

“Although a number of people have been studying ‘toxic woodwaste leachate’ for some years, they have been concentrating on the most difficult aspects of this, such as (bio) degradation of resin acids. However, these are generally academic studies, and thus not rooted in practice and day to day observations on the groundÖWe ran samples through tests at the lab and found the tests were deficient. I could see suspended particles in the sample water, though the tests were showing dissolved material.” van Poppelen explains that the wood debris particles carry a negative charge, keeping a distance from each other, and they always remain suspended in the water column.

The membranes of fish gills are positively charged, he says, and the working hypothesis is fish are dying from asphyxiation. “The fish disappear, they don’t wait to die.”

Microbial Technologies’ clean up strategy to deal with the hazards of dryland sort run-off is a two step approach predicated on the belief that by removing the wood particles, the toxicity will be reduced. The two-prong solution is rooted in water filtration and the laws of natural chemistry. Every dryland sort has its own set of circumstances and depending upon the tree species being sorted – some are higher in resins and fatty acids than others - very different types of effluents and debris are created depending on unique approaches to treatment. In the most generic sense, the strategy is to built a catchment pond to collect the water before it runs off the sort surface into the sea. The most important step is capturing the first flush of water carrying debris like finely ground and powdered bark and wood chips rushing off the sort surface as the rains first begin to fall. Containing this debris removes the biggest environmental danger, van Poppelen says, while continuing to treat the remaining flow once the worst is captured.

The run-off and wood waste leachate is directed into the pumping station and from there it is treated. The filtration process sends the toxic and debris laden water through a gravity fed sand-like filtration system. Some of the wood waste decomposes and the same material that is toxic to fish in open waters is released within the confines of a reservoir. Here, they work in a cycle of continuous decomposition breaking down the new waste entering the system. The desired end product of the filtration and chemical processes, is to have the wood waste sediments clump together and as a solid settle in the bottom of the reservoir.

“Water moves through the filter box, into the reservoir and back through the filter continuously changing the chemistry within the reservoir. The over flow water then passes through a wetland which can be a very small buffer or safeguard, before re-entering the sea,” explains van Poppelen.

Microbial’s systems for dryland sorts are built to handle “reasonable rain events” and are able to accommodate higher than average rainfalls. To handle rain events where 40 mm of water is falling over three to four hectares in two hours, you need a pump and filtration system that will handle 250 litres per second, he says.

We call it a ‘vertical wetland, says Sobolewski. The gravity fed pump means the system can be employed in remote areas where the majority of dryland sorts are located – the kind of places where hydro is not a reality for running any type of equipment. Microbial’s restorative solutions are also very cost effective; a financial factor that makes cleaning up dryland sorts an affordable alternative to paying out hefty fines and the bad press that follows a guilty plea for polluting fish habitat.

After the Sproat Lake and Bayside Sawmills affairs, some forest companies on the south coast recognized the warning signs. Two companies, Sechelt Creek Contracting and Terminal Forest Products, sharing a bay in the Thornborough Channel between Gambier Island and Port Mellon, signed up for a pilot project with Microbial Technologies to treat the wood waste problems at their sorts. A FRBC research grant later funded some of this developmental work. Soon after, Howe Sound Log Sort and Fleetwood Forest Products asked Microbial to help them with their wood waste problems.

In the Thornborough Channel bay, people realized they could not continue working this way indefinitely, van Poppelen says. “There was an inch and a half thick mat of wood waste at the low tide level – a common occurrence in booming areas. Crabs will live there, but the shellfish are having a hard time and the place seems like a desert.”

At the pilot project sorts, the filtration and chemical treatment was put into place in January 2001. There were no more solids in the run-off directed into the booming grounds, and by August there was not a speck of wood waste in the water. The tides had taken the old waste away and the bay was totally regenerated within a season.

“We stopped putting the run-off into the booming grounds and the operators were saying not only the herring but also the seals were back,” says van Poppelen. “It is impressive the speed at which you can make them recover, provided the circumstances are right of course, and a little bit of vision and a practical approach.”

“The best testament to the success we have achieved in one particular place is the following comment to me, by a mechanic on one particular dryland sort: “Well, the changes are incredible, and within a year we have fish back in the booming grounds, right up to the foreshore. Even herring. Only you have created a new problem now. As the fish are back close in, the seals have followed. And now when you are working on the boat, every now and then you hear a loud thump, and another ***** seal has jumped up on the boat! Frightens the life out of me.”

Dr. Sobolewski and van Poppelen agree that the majority of problems associated with dryland sorts are heavily influenced by on-site management practices. How operators lay out the wood; what additional activities are happening on site, like hogging and chipping; what machinery is operatin; and where the various activities are located on site relative to drainage patterns all effect the amount of wood waste and effluent entering bays and creeks.

Working with operators to find solutions leads to more than sustainable practices and a healthier marine environment. Often it means good business sense too, as van Poppelen experienced working with one site manager in developing more efficient strategies for managing hog fuel.

“I suggested to the manager at one site, that we should try hogging straight into the trucks. He needed some convincing that this would save money and time as well as provide a cleaner way of dealing with wood residue. He realized he did not need his second loader on site, or the second hogger. In the end, he had 10% more wood fitting into the trailer, from blowing it directly in rather than loading it loose, for which he gets paid more. We saved them money, through doing an environmental review of their practices. It was an economic incentive for them to clean up their sites as well as making it an environmentally sustainable operationÖThis is how I want to work with operators, based on good business sense.”

For Dr. Sobolewski, the efforts to clean up the province’s dryland sorts shows there are changes afoot in the industry.

“Some companies are seizing the initiative in recognizing their environmental impact, and are willing to spend money to address them. I think that, with a bit of patience, we will see a positive change in the forest industry. I have been involved in a similar transition within the mining industry during the past ten years, and I am happy with the changes I have seen and the part we played in this.” •

SpruceRoots Magazine - February 2002