The RMP Mercury Strategy

Jay A. DavisSan Francisco Estuary Institute

Presented at:The RMP Mercury Coordination Meeting

Feb 2008

Origins

• SF Bay pollutant enemy #1• Profusion of mercury

proposals• Tom Mumley’s idea• RMP Mercury Group

– Stakeholder planning group– Key input from Regional

Board

RMP Mercury Strategy • Concise, living document• Overarching goal to support water quality

management decisions• Articulates prioritized information needs of

managers• Focus on methylmercury

– Premise: possible to identify key fractions and processes to achieve a more rapid solution

• Augments existing RMP Status and Trends monitoring

Management Questions for Mercury

1. Where is mercury entering the food web?2. Which processes, sources, and pathways contribute

disproportionately to food web accumulation?3. What are the best opportunities for management

intervention for the most important pollutant sources, pathways, and processes?

4. What effects can be expected from management actions?

5. Will total mercury reductions result in reduced food web accumulation?

Q1: Patterns in Uptake

• Major focus for next 3 years• Spatial and temporal• RMP Small fish• RMP S&T: sport fish, bird

eggs, water, sediment• Other studies

– FMP– SBMP– USGS

Q2: High Leverage Pathways • Ideally follows Q1• Some work now, greater focus after

a few years• RFP• Two potentially very valuable but

somewhat risky studies– Blum isotopes– Hintelman DGTs

• Other studies– Sac Regional– WERF….

Q3: Opportunities for Intervention

• Ideally follows Q2

• RMP focus on internal sources

• Other programs on external sources– Lester’s Prop 13 Study

Q4: Effects of Management Actions

• Management actions including remediation, restoration, etc.

• Models – continual development– MeHg mass budget a start

• Monitoring– Regional monitoring– Local monitoring as actions are

taken

Q5: Effect of Total Mercury Reductions

• Not part of the 1-4 sequence

• No specific studies currently planned

RMP Plan for Mercury Studies Table 1. Mercury and methylmercury studies and monitoring proposed for the RMP from 2008 to 2012. Numbers

indicate proposed budget allocations in 1000s. Matching funds from other programs indicated in parentheses.

Element Questions 2008 2009 2010 2011 2012 Food Web Uptake (Small Fish) Mercury 1 150 150 150 100?a 100?a High Leverage Pathways and Processes

Mercury 2 100 100 150f 150f

Methylmercury Model Development Mercury 3, 4 25 25 Surface Sediments (THg, MeHg) Mercury 1 160b 160b 160b 160b 160b Water (THg, MeHg) Mercury 1 140b 140b 140b 140b 140b Sport Fish Mercury 1 215b 41b 218b Avian Eggs Mercury 1 120b 120b Effects on Birds 70c

(34)d 50b (20)d

50b (20)d

50b (20)d

50b (20)d

Sediment Cores (THg) 100b 100b Small Tributary Loading (THg) 100b 100b 100b 100b 100b River Loading (THg) 140b Guadalupe Loading (THg) 65b Guadalupe Model (THg) 75 Watershed Load Model (THg) 40 Remote Sensing 14 a The need for continuing this work will be evaluated after three years. This estimate assumes continuation of trend monitoring with small fish. b Hg and MeHg are part of a longer list of pollutants covered by this budget. c A study by USGS: Mercury-Selenium Effects on Reproductive Success of Terns and Stilts in San Francisco Bay. d Matching funds from USGS. e Useful in evaluating the “monitoring target” for avian eggs in the mercury TMDL. f Assumes increased emphasis on mercury Question 2 after obtaining answers to Question 1 through small fish work in 2008-2010.

Benefits

• Clear direction for obtaining needed information

• More effective use of RMP funds

• Framework for evaluating and communicating progress

Filling the Gaps

• Are there better ways of answering our questions?

• Are any important elements missing?– Systematic monitoring of restoration?

• Can we be coordinating existing elements better?