1. DR. PAUL A. BUKAVECKAS VIRGINIA COMMONWEALTH UNIVERSITY Developing water quality standards to Protect the James River against Impacts from Algal Blooms. http://wp.vcu.edu/jamesriver/

2. Today’s Panel The TMDL process: reductions in nutrient loads to reach restoration goals. Water Quality Criteria: their role in establishing nutrient reduction targets. Algal Blooms in the James River Estuary: causes and threats to designated uses. My Presentation: assessing risk from algal blooms in the James.

3. 10/15 15/22 12/10 15/23 Current James River CHLa standards (µg/L) based on season (spring/summer) & salinity Attainability (load reductions) based on CB model; estimated cost to achieve = $1-2 billion. VA response: “let’s make sure first”  Are standards defensible?  Are model forecasts of attainability reliable?

4. James River Algal Blooms Study 6-year (2012-2017), $3 million study funded by Commonwealth of Virginia (administered by Department of Environmental Quality).  understand when, where, and why of algal blooms.  improve water quality models – specifically, their reliability to predict CHLa under changing nutrient load scenarios.  assess whether current CHLa-based regulatory standards are protective of designated uses. How much CHLa is ‘too much’? Changes to regulatory standards, or modeling framework, directly affect allowable nutrient loads.

5. Science Advisory Panel Evaluate existing numeric CHLa criteria for the James. Are they protective of designated uses? Assess modeling framework: Can model performance be improved to reliably predict responses to management scenarios? Data Collection (2012-14): When, where, why of algal blooms. Effects on water quality, human health and aquatic life resources. Modeling Team: model development, calibration and simulations of nutrient load scenarios.

6. Mean CHLa in relation to current criteria for tidal fresh James. Spring Summer

7. Deleterious Effects of Algal Blooms Water quality  transient (night-time) oxygen minima  elevated pH: daytime maxima Water Clarity: algal contributions to suspended particulate matter Phytoplankton metrics  Community indices: PIBI evenness, richness  Harmful algal abundance & Algal Toxins

8. Water Quality Standards for the James Are current CHLa standards protective of designated uses (aquatic life, etc.)? A dual- probability approach: What is the risk of deleterious effects at a given CHLa concentration? What is the likelihood of exceeding that CHLa concentration if current CHLa standard is attained? CHLap (DO<5)p (CHLa)p (combined) 0-301%50%0.5% 31-6010%35%3.5% 61-9050%15%7.5%

9. Effects of Algal Blooms on Water Quality Risk to water quality conditions from daytime pH maxima exceeding 9.0 in relation to CHLa for the tidal fresh and oligohaline segments of the James. Vertical lines denote current criteria. pH > 9 Summer Spring

10. Phytoplankton Community Structure Phytoplankton Index of Biotic Integrity in relation to CHLa and occurrence of communities in ‘least degraded’ (PIBI>2.67) state.

11. Stressors, Criteria & Risk Stressor (e.g., CHLa) Threats to Designated Uses (e.g., low DO) ideal standard

12. Assessing Risk to Aquatic Life Designated Uses based on Combined Probability Approach Tidal Fresh Polyhaline Mesohaline