Update on Chesapeake Bay Model Upgrade Projects

1. Briefing to Potomac River Integrated Monitoring Stakeholders March 20, 2006 Presented by: Steve Bieber Metropolitan Washington Council of Governments Update on Chesapeake Bay Model Upgrade Projects

2. Potomac Upgrade Better spatial scale to simulate water quality responses to management efforts at a local scale. Better simulation of algal species and their impacts on water quality. Sediment and pH-alkalinity dynamics critical to the Potomac and Anacostia will be modeled. Chesapeake Bay Upgrade Sediment types and physical processes affecting sediment loads will be incorporated. Water quality responses to sediment control actions will be more accurately reflected. Improved sediment controls may reduce the need for WWTP upgrades. Project Description

3. Water Quality Issues Unique to Potomac • Large pool of particulate inorganic phosphorus (PIP) that may not become available for algal growth • Large blooms of Microcystis (blue-green algae) • Algal growth more limited by phosphorus than by nitrogen, especially in tidal fresh portion • Potential for nitrogen fixation • DC waters listed as impaired due to high pH • pH-Alkalinity influence on sediment phosphorus flux

4. Blue Plains Users & COG U.S. EPA U.S. Army COE State of Maryland District of Columbia State of Virginia ICPRB Univ. of Maryland VIMS LimnoTech Hydroqual Smithsonian ERC USGS Occoquan WML Project Partners

5. Benefits of Upgrade to Potomac Model • Scientific • Better understanding of load-response relationships in Potomac River and Estuary • More accurate representation of nutrient cycling, transport and delivery to the main Bay • Design tool for fine scale monitoring programs in nearshore areas and local embayments • Management • Explicit representation of Potomac water quality issues • Improved capability for load allocations to sources within the tidal fresh Potomac • Improved capability for investigating trade-offs among nitrogen, phosphorus and solids loads

6. Status • Commencement of the project outlined in the Corps PMP was April 2004. • Scheduled completion is April 2007. • We are 22 months into a planned 36 month project. • Congress was good to us this year. Planned commitments from DC and EPA will fulfill major project goals.

7. Estuarine Phosphorus Model • Simulate the relationship between phosphorus loading and production and biomass of living resources in the Potomac River Estuary. • This is key to predicting the frequency and severity of harmful algae blooms. • One year of really exciting field work has been completed. • A new estuarine phosphorus model has been proposed. • A second year of process-oriented field work is planned.

8. pH - Alkalinity • This task involves developing a mathematical modeling framework that relates pH to nutrient loading, primary production, and other factors. • This relates directly to the investigation of harmful algae blooms in the Potomac. • The Potomac Estuary is listed as impaired for violating the pH water quality criteria. • Field investigation of pH effects on sediment phosphorus release commenced April 2004. Completion summer 2005. • No modeling activity has commenced due to lack of funding. • Funding by DCDHMH is in progress. Two funding increments. • Delivery date should be pushed back to April 2008

9. Erosion Rate Measures • This task involves the measurement and analysis of sediment erosion rates in the Potomac and upper Chesapeake Bay. • Two years field work completed by VIMS, Horn Point, ERDC – mostly in the Potomac. • Third-year effort is devoted to data analysis.

10. Light Attenuation • This task involves fundamental measures of the effects of suspended solids on light attenuation. • Two years field work completed by Smithsonian. • Chuck Gallegos is working on a FORTRAN code to complete this project.

11. Particle Settling Velocity • The goal of this phase of the project is to produce statistically sound relationships that relate concentration and sinking of mineral solids (TSS-POC) with seasonal and regional variations in plankton community structure and dynamics. • Analysis of field data has been completed. • Three protocol lab experiments have been completed. One more in progress now. • Hope for delivery of an algorithm in an April-May time frame.

12. CE-QUAL-ICM • The model is up and running for 1994-1999. • Substantial effort has been devoted to data acquisition and processing. • Reformulation and/or recalibration is required to bring DO into calibration • Scheduled completion = 50%. Actual = 50%.

13. Phase V Watershed Model • We have 1994-1999 flows mapped to new grid. Used to drive CH3D • We lack Phase V loads for WQM. • We lack Phase V flow and loads for 2000

14. Other Activities • Anacostia Monitoring –Three-year project proceeding as planned. • Fall-line monitoring –Ongoing program. • Surface Waves – Basic wave model is complete. Results have been passed to VIMS for insertion into boundary layer model.

15. Other Activities (Cont’d) • Bank Loads – Spatially detailed estimates of shoreline erosion are being created for the upper bay and Potomac. • Loads for the Maryland portion of the bay, including Potomac north shore, are being evaluated by Jeff Halka of MGS. • Loads for the Virginia portion of the bay, including Potomac south shore, are from existing reports.

16. Other Activities (Cont’d) • Anacostia Stream Bank Erosion – better estimates of sediment inputs from streams. Report is completed. • Boundary layer dynamics - The boundary layer model is “almost completed.” Incorporates currents from CH3D and waves from wave model. • Algal Speciation –No activity and no funding identified.

17. Summary • Progress for the core of this project, suspended solids, is on schedule and proceeding well. • Peripheral efforts are behind (pH) or unfunded (algal species modeling).

18. Summary • Funding to project completion has been identified. • The next year is “crunch time.” • More detailed info available at http://www.chesapeakebay.net