Deriving Site Specific Water Quality Objectives for the Battle River

Transcription

1 Deriving Site Specific Water Quality Objectives for the Battle River Chris Teichreb, M.Sc., P.Biol. Alberta Environment and Sustainable Resource Development March 2013

2 Outline Introduction Developing WQO s Battle River WQO s Next steps

3 Introduction What are water quality objectives? Site specific WQO s are a numerical concentration or narrative statement which has been established for specified waters, and which has an action and/or a management commitment. ESRD, 2012 Based on site specific water quality data Details what we want to achieve Fully implemented WQO s have management actions exceedance of WQO = action

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5 Introduction Why develop WQO s? Expanding population and development results in increased pressure on water quantity and quality Battle River water quality often in the fair to poor rating range Poor water quality results in numerous adverse effects: Impacts to aquatic organisms, including fish Risk to irrigated crops and livestock Risk for health consumption increased cost for treatment of poor quality water Decreased recreational and aesthetic benefits

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10 Developing WQO s Background Committee formed in October 2010 included provincial government, industry, and muncipal representatives Process lead by Golder Final report released in March 2011

11 Developing WQO s Steps for developing WQO s 1. Determine appropriate reaches Based on physical and chemical changes, changes in habitat, changes in land-use, etc. Battle River split into 4 reaches Headwaters to upstream of Hwy 2 Upstream of Hwy 2 to upstream of Driedmeat Lake Driedmeat Lake to ATCO generating station ATCO generating station to border

12 Battle River reach map

13 Developing WQO s 2. Determine available data Primarily relied upon data in provincial water quality database Also utilized data available for muncipalities and industry Split data into ice-covered and open-water seasons If any trends in the data were apparent, used most recent data, otherwise entire dataset used

14 Developing WQO s 3. Determine uses to protect Water uses for which guidelines are available determined for each reach Uses include: Protection of aquatic life Irrigation Livestock watering Recreation Industrial Aesthetics Raw drinking water supply Generally, approach is to protect all current and future potential uses

15 Developing WQO s 4. Establish variable s of concern Determine which parameters were of greatest concern for each reach based on risk to uses For Battle River, included: Nutrients (TP, TSP, NH4, NO3, NO2, NO3+NO2, TN) Physical (Temp, DO, ph) Biological (E.coli, Total and fecal coliforms) Major ions and others (TSS, turbidity, Cl, Ca, F, TDS, SO4, TOC, Hardness, Cond., SAR)

16 Developing WQO s 5. Develop decision tree and develop WQO s For Battle River, decision to use maintain or improve approach

17 Decision tree

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19 Battle River WQO s Honoured existing PPWB process Short-term limits based on 90 th percentile On annual basis, 90% of values for a parameter should be below this number Exceedances may indicate increasing concentration May also be indicative of other events (e.g. spills)

20 Battle River WQO s Long-term limits based on 50 th percentile (median) Using all historical data and adding in new data, determine if there is a significant trend No trend or decreasing trend = good Increasing trend = bad Need to investigate to determine cause of trend (natural or human induced?)

21 Battle River WQO s Example Total Phosphorus Guideline of 0.05mg/L for protection of aquatic life Currently exceeds guideline of 0.05mg/L Objective states that total phosphorus levels should remain below 0.05mg/L and a decreasing trend should be observed over multiple years.

22 Battle River WQO s Example Calcium Guideline of 1000 mg/l for stock watering Reach 1 current icecovered median value = 69 mg/l, 90 th percentile = 102 mg/l Objective = remain below 1000mg/L Target = <69mg/L more than 50% of the time, and <102mg/L 90% of the time (ice-covered)

23 Next Steps WQO s developed based on existing data and philosophy of maintain or improve WQO s not yet applied done through water quality management framework Implementation of WQO s has management implications Management response varies depending on the parameter and whether a trigger or limit exceeded Can vary from enhanced monitoring to closure of facilities Includes management of both point and non-point sources

24 Next Steps Data gaps identified in WQO development process Additional monitoring implemented in 2011 to fill in data gaps More monitoring needed WQO s will require updating in the future as new data becomes available Big question: Managing point source water quality relatively easy. How do we manage non-point water quality under a framework?

25 Thanks!