Acid-Sensitive Lakes Nine hundred and thirty-three lakes located in Saskatchewan, Alberta and the Northwest Territories were sampled to establish current acidification status. Of the 933 lakes, 244 (or 26%) are considered acid sensitive, almost always because of naturally low calcium and magnesium (or "base cation") concentrations. The most acid-sensitive lakes (i.e., those with extremely low base cation concentrations) are located on the Canadian Shield in both Alberta and Saskatchewan and east of the oils sands development area. Fifty-one of the 244 acid-sensitive lakes were sampled twice annually (spring and fall) to identify chemical changes through trend analyses. Results revealed that 55% of these lakes had concentrations of some metals in excess of Canadian Council of Ministers of the Environment guidelines. Of the 291 samples taken in the 51 lakes, iron concentrations were greater than guidelines in 36% (105 samples), aluminum in 33% (97 samples), lead in 0.3% (1 sample) and copper in 0.3% (1 sample). The metals in these lakes occur naturally and are expected to be found in a wide range of concentrations given the geology and physiography of the Canadian Shield. It remains to establish the relationship between acid sensitivity, geology and high metal concentrations.

Wild fish community data (species, abundance, diversity, length, weight) for 2013 and 2019 are now available for tributaries of the Athabasca River (rivers Steepbank, Ells, Firebag, High Hills, Dunkirk, Horse, Muskeg, Tar and Calumet) and 2017 data for rivers and creeks adjacent to Christina Lake (Christina River, Sunday Creek, Birch Creek, Sawbones Creek, Jackfish Creek and Unnamed Creek). The composition and diversity of the fish communities in these waterbodies have been evaluated over time to identify changes in the presence and abundance of fish species in these waterbodies adjacent to SAGD oil sands mining activity and at sites that are outside of the Athabasca Oil Sands deposit and not influenced by mining activities. Not all waterbodies are adjacent to mining activities and these provide some information as to the natural variability and stability of these fish communities over time. This involved establishing baseline conditions in fish communities in the fall of 2013, 2017 and 2019. This baseline data has assisted in tracking changes in fish communities of these waterbodies over time. Fish community assessments (non-lethal sampling) were carried out in a reach of river using a Smith-Root 12B backpack, Smith-Root LR-24 backpack and or seine at the sites identified in Section 2.3. Length, weight, species identification, and external assessment were performed on fish collected. Fish were then returned to the water at the site of capture. This fish community assessment work commenced September 17th to 27th, 2013, October 3rd to 8th, 2017 and September 24th to October 2nd, 2019. This monitoring activity compliments and supports the Wild Fish Health program.

Wild fish health data (length, weight, gonad size, etc.) are now available for trout perch collected from the Athabasca and Peace Rivers; white sucker collected from the Athabasca River; longnose sucker collected from the Peace River; slimy sculpin collected from the Steepbank River; lake chub from Alice Creek, the Ells and Dover Rivers; and longnose dace from the Mackay River. Contaminants data available for walleye collected from the Athabasca and Peace Rivers. For each of these data sets, upstream reference areas are provided for comparison to downstream developed sites. Reference data are currently being evaluated for variability between years to develop triggers, and these triggers are essential to eventually quantify potential effects at exposed sites. Using existing critical effect sizes developed in the Environmental Effects Monitoring programs for pulp and paper and metal mining effluents, condition endpoints in white sucker were increased within the deposit. Slimy sculpin condition and reproductive endpoints are also exceeding effect sizes downstream of development sites. This data is now being used to predict future fish health endpoints within sites, between sites and relative to reference variability to help assess change in fish health.

Oil Sands Sediment Exposures of Embryo-larval Fathead Minnows Dataset contains laboratory-studied fathead minnow egg and larval survival rates when exposed to sediments collected from 18 sites in the Athabasca watershed (2010-2014). A controlled laboratory study examined the impacts on fathead minnow eggs and larval development when exposed to collected sediments at concentrations of 1, 5 and/or 25 g/L. Sediments and water were renewed daily, and eggs were assessed as they hatched (in about 5 days), and as the larval fish grew to 8-9 days post hatch (dph), and 15-16 dph. The data in the file present the mean survival (and standard deviation). Two sediment sites caused decreased survival of fathead minnow fry: The Ells River lower site, and the Steepbank River Lower site. These data show that sediment from these sites can affect larval fish survival in the lab. The next steps are to compare these findings to the health data from wild fish collected from these same tributary sites. Toxicity Testing of Groundwater near the Oil Sands Development Dataset contains toxicity studies of groundwaters collected near the Athabasca and Ells rivers. Groundwaters were collected in the summer of 2013 from 4 sites below the riverbeds at depths of 0.5 to 1 metre. Sites were chosen to represent groundwaters close to oil sands tailings ponds and further from tailings ponds and mining activities. Under controlled laboratory conditions, fathead minnow eggs were exposed for 5 days (until hatch) to the groundwaters at standard dilution concentrations of 6, 12, 25, 50, and 100% of the groundwater sample to compare egg and larval fish survival. The data presents the average survival until hatch of 3 repeated exposures (and standard deviation) and 9 repeated exposures for controls. Some groundwater is toxic to minnows and some is not. No correlations were found between toxicity and proximity to a tailings pond. Assessing Toxicity of Oil Sands Related Substances Laboratory fish were exposed to melted snow from sites located close to oil sands mining and upgrading facilities and from sites far away from mining activities to assess the toxicity of substances found in the snow. In addition, river waters, bed sediments, suspended sediments, groundwater and atmospheric depositional samples (pre-melt snow collections) were also tested for toxicity. Fish exposed to undiluted snowmelt showed biological effects. Fish exposed to river water from the region collected during snowmelt conditions showed no effects.

As part of a three year study funded by Environment and Climate Change Canada and Natural Resources Canada (ecoENERGY Innovation Initiative, project UOSGQ963; http://www.nrcan.gc.ca/energy/funding/current-fundingprograms/eii/4985) data were gathered to assess and monitor water quality conditions in northeastern British Columbia (BC). Defined in this datasetas portions of the Petitot, Fort Nelson, and Hay River basins, northeast BC is a region subject to both historical conventional oil and gas development and more recent unconventional oil and gas (UOG) development. UOG development in this area is presently focused on the Horn River Basin, Cordova Embayment and Liard Basin shale formations (BCOGC 2010, 2013a). Otherwise, UOG development in BC is centered in the Montney Play, located further south (Adams et al. 2016). Surface water quality assessment and monitoring focused on two river basins in this area: the Petitot River Basin and the Fort Nelson River Basin. Baseline and/or best available surface water quality information was gathered from January 2012 to March 2015. Benthic macroinvertebrates were collected over the same period to complement the water quality study through development of a Canadian Aquatic Biomonitoring Network (CABIN) bioassessment model. Routine Water Quality Monitoring study objectives were to gain a better understanding of water quality conditions in the Petitot River Basin by collecting baseline data using a standard suite of physical-chemical variables and establishing a representative long-term site. Routine water quality sampling sites were selected at locations with known exposure to UOG activity and varying watershed areas; submersible loggers were also installed to collect specific conductance and temperature data. Synoptic Water Quality Monitoring study objectives were to establish patterns of spatial and temporal water chemistry through synoptic water sampling at high and low flow periods and examine potential relationships between UOG activity and surface water quality. Sample sites were selected at microbasin drainage outlets to represent a range of upstream activity and potential contamination. A series of samples were also collected along the mainstem Petitot River at 20-kilometre intervals from the Alberta border to the Highway 77 bridge to capture potential “step-changes” in water chemistry as the river flows through the northeast BC gas production area. Biological Monitoring study objectives were to establish baseline reference conditions based on benthic macroinvertebrate communities and habitat characteristics, and develop a predictive bioassessment model to assess the ecosystem health of streams in the Liard, Fort Nelson, and Petitot River basins exposed to UOG activity. The biological monitoring study design followed CABIN sampling methodology for benthic macroinvertebrate collections in streams and rivers (Environment Canada 2012, http://www.ec.gc.ca/rcba-cabin). Sampling was conducted at 53 reference sites unaffected or minimally influenced by human activity. Thirty five test sites were also selected across a gradient of UOG activity, based on well densities. A preliminary predictive bioassessment model for northeast BC was established and is available through the CABIN website for future assessment of water quality and ecosystem health in the region.

Atmospheric Contaminant Deposition using Snowpack The data set includes snow samples (metals, water chemistry and polycyclic aromatic hydrocarbons [PAHs]). Data from 2012-2014 snowpack samples collected from ~90-130 sites located varying distances from the major oil sands development area show deposition patterns and levels consistent with earlier studies carried out in 2008 (Kelly et al. PNAS, 2009 and 2010). As with earlier findings, concentrations of numerous metals, water chemistry parameters (Ni, Pb, Zn, V, La, Al, Fe, total Hg, methyl Hg, total suspended solids [TSS], particulate organic carbon [POC], particulate organic nitrogen [PON], total phosphorus [TP]) and PAHs decrease with distance from the major mining extraction and upgrading facilities. Canadian Council of Ministers of the Environment (CCME) guidelines do not exist for snow.

Sediment from Lakes Polycyclic aromatic hydrocarbons (PAHs), 47 elements including numerous metals, and visible reflectance spectroscopy or VRS-chla have been determined in sediment core samples collected in 2012, 2013 and 2014 from 16 small (surface area 4-97 ha; maximum depth ~1-5 m deep), hydrologically simple lakes located 30 to 120 km from major oil sands development areas. Canadian Council of Ministers of the Environment (CCME) guidelines are available for 13 of the 53 PAHs reported here. Sediment concentrations did not exceed Canadian Council of Ministers of the Environment (CCME) probable effects levels (PELs), which define the level above which biological adverse effects are expected to occur, for PAHs in any lake. Exceedances of the CCME interim sediment quality guidelines (ISQG) for the protection of aquatic life occurred for 4 PAHs (naphthalene, 2-methyl naphthalene phenanthrene, and benzo(a)pyrene) in 8 lakes. CCME sediment quality guidelines are available for 7 of the 47 elements reported here. Exceedances of the CCME ISQG for metals were found for arsenic in 3 lakes, cadmium in 8 lakes, mercury in 3 lakes and zinc in 9 lakes. Exceedances of the CCME PELs for metals occurred in 2 lakes for arsenic and 1 lake for zinc. Further assessment of the data is ongoing to examine reasons for exceedances as well as spatial and temporal trends of the PACs and elements. Analyses of lake primary productivity, using visible reflectance spectroscopy or VRS-chla as a proxy, show consistently greater productivity (i.e. VRS-chla concentrations) in the top sediment core slices relative to the bottom, regardless of lake morphological and limnological characteristics and landscape position. Potential drivers of these changes are being examined.

Assess the importance of atmospheric deposition of contaminants as a contributor to ecological impacts of oil sands development and identify sources. • Use snowpack measurements sampled across a gridwork to develop maps of winter-time atmospheric contaminant loadings for the region ~100 km from the major upgrading facilities • Assess long-term trends in winter-time atmospheric deposition • Determine the potential impact of wintertime snowpack mercury loads on tributary river water mercury concentrations (Spring Freshet) using Geographic Information System and hydrological modelling approaches • Compare snowpack loadings to those obtained from precipitation monitoring and compare spatial patterns to PAC air measurements obtained from passive sampling network

The objectives of the fish component of the integrated oil sands monitoring program are to provide the necessary data/information to address key questions related to both environmental health of fish populations and fish health issues that can be used to inform human use and consumption. The questions underlying the fish monitoring design are related to the status and health of wild fish populations in the Lower Athabasca River including and in an expanded geographical extent. Data is being collected to provide a baseline against which future changes in fish populations will be evaluated, and compared to data from historical studies to assess change over time to the current state. Data is also being collected in areas of new oil sands development, to develop baseline data for future site-specific comparisons, contribute to an expanded geographic basis of the overall monitoring plan, and contribute to an improved ability to examine cumulative effects.

Shallow groundwater and the interaction of these waters with surface water in the mineable area of the Athabasca oil sands region are being examined to assess the role and importance of groundwater in the regional river ecosystems. Groundwater quality chemistry data is available from 182 shallow groundwater samples collected below the Athabasca, Ells, Muskeg and Steepbank rivers and 2 monitoring wells near an existing tailings impoundment. Additionally 5 surface water samples were also collected for comparative purposes. All samples were collected between 2009 and 2011 and include analyses for up to 60 parameters, including electrical conductivity, pH, temperature, and dissolved oxygen concentration, major ions, trace metals, total concentrations of naphthenic acids, fluorescence intensity using synchronous fluorescence spectroscopy (SFS) and others. Statistical analyses indicate that shallow riparian groundwater proximate to a tailings pond and groundwater collected away from the any tailings pond were indistinguishable for nearly all parameters assessed with a few exceptions. The analyses also identified a small subset of groundwater samples that have some chemical similarities to OSPW (Oil Sands Process-Affected Water). Further investigations may be required to evaluate the nature and ecological significance of groundwater at these locations. Further context, interpretation and discussion of this data may be found in “Profiling oil sands mixtures from industrial developments and natural groundwaters for source identification,” which was published in Vol. 48 (5), pp. 2660–2670, January 2014 in the journal Environmental Science and Technology and “Assessing risks of shallow riparian groundwater quality near an oil sands tailings pond” published in 2016 in the journal Groundwater (Vol. 54, No. 4, pp. 545-558).