Water Quality Sampling Update – Aug. 25, 2016
Surface Water Monitoring
The Water Security Agency (WSA) has results for 120 surface water quality samples. Samples were tested for a comprehensive suite of parameters (substances) including Petroleum Hydrocarbon F1 to F4 fractions, the BTEX compounds (Benzene, Toluene, Ethylbenzene and Xylene) and a set of 20 different compounds known as Polycyclic Aromatic Hydrocarbons (PAH) in each of the 120 samples.
So far WSA has seen one exceedance in raw water for any treated drinking water quality standards, guidelines or screening values. This exceedance was for Benzo(a)pyrene at North Battleford along the northeast bank of the river and was just above the current drinking water quality guideline value of 0.01 ug/L and measured 0.02 ug/L (parts per billion).
There are 16 samples that have shown exceedances for the guidelines for protection of aquatic life, 11 were for Toluene, three for Pyrene, one for Benzo(a)pyrene and one for Fluoranthene. There were 43 “detections” which were below any guideline values for various petroleum constituents.
WSA has also been collecting sediment samples (mud, silt and sand) from the river bottom, from the Point of Entry all the way down the river system.
WSA found detectable amounts of F3 and/or F4 hydrocarbons in the five sites monitored but not at each location on a river transect site were monitoring was carried out across the width of the river. There were F2 hydrocarbons at the upper sites (near the point of entry and near #21 highway bridge).
There was also some PAH compounds present near the point of entry and #21 highway bridge in the sediments. Since the F2, F3 and F4 and PAH compounds tend to attach to organic materials found in the sediments and are essentially non-soluble in water, these are expected to be found in the sediments and less so in water. There were a total of 6 exceedances of the Canadian Council of the Ministers of the Environment (CCME) Interim Sediment Quality Guidelines at two of the stations (four exceedances at the sites near the Point of Entry and two exceedances at #21 Hwy).
The CCME interim sediment quality guidelines are intended to protect organisms that live in or on the bottom sediments and thereby the aquatic food chain, but are not of direct concern for people.
WSA continues to sample water and sediment quality in the area.