1. U.S. Department of the Interior U.S. Geological Survey Evaluations of Heavy Metal Listings on the State of Massachusetts Integrated List of Waters Assabet and Concord Rivers March 2008 – January 2009 Project Personnel Andrew Massey Kim Campo Cooperating Agency U.S. EPA Mass. DEP

2. 2 of 13 Objective “...to document current water quality conditions and assess whether or not the original listing remains appropriate or alternatively to support delisting if appropriate.” Assabet R. below Rt. 9, 8/25/2008

3. 3 of 13 Progress Last Quarter Sample Analysis Dissolved metals and total metals results received from EPA All laboratory analysis is complete  Data Compilation Data from five monthly-lab reports compiled Plotting and validation of results nearly complete  Results Interpretation Field QC (blanks and reps.) is excellent; 25% of samples Lab QC (dups., spikes and reagent blanks) good for dissolved, less good for totals 300 site-specific hardness-dependent metals criteria

4. 4 of 13 6 Impaired Segments, 12 Monitoring Sites Sampled monthly June-October, 2008 (fixed frequency)Sampled monthly June-October, 2008 (fixed frequency) Wade and bridge sampling; 10 points per cross-sectionWade and bridge sampling; 10 points per cross-section USGS Clean-hands/dirty-hands methodsUSGS Clean-hands/dirty-hands methods Approach

5. 5 of 13 Approach (continued) Samples and Analysis Total & Dissolved metals*EPA LabTotal & Dissolved metals*EPA Lab Total Suspended SolidsEPA LabTotal Suspended SolidsEPA Lab Dissolved Organic Carbon Alpha Labs (EPA contract lab)Dissolved Organic Carbon Alpha Labs (EPA contract lab) Field Parameters: 3 points at each transect**Field Parameters: 3 points at each transect** *Detection limits less than EPA Recommended Water Quality Criteria standards; Includes Calcium and Magnesium to determine Hardness Dependent Criteria **To confirm well-mixed water throughout the cross-section

6. 6 of 13 A cross-sectional flow-integrated sample obtained by the EWI method will produce a water sample volume that is proportional to the amount of flow at each of several, equally spaced, predetermined verticals in the stream cross section. Equal Width Increment-wade sampling Concord R. below River Meadow Bk. @Lowell, 8/28/2008

7. 7 of 13 Sampled Flows

8. 8 of 13 Hardness-Dependent Water Quality Criteria Several Metals’ toxicities are a function of hardness Increasing hardness has the effect of decreasing toxicityIncreasing hardness has the effect of decreasing toxicity Water quality criteria to protect aquatic life calculated at different concentrations of hardness (measured as mg/L CaCO 3 )Water quality criteria to protect aquatic life calculated at different concentrations of hardness (measured as mg/L CaCO 3 ) Cadmium, Chromium, Copper, Lead, Nickel, Silver and ZincCadmium, Chromium, Copper, Lead, Nickel, Silver and Zinc CMC: Criteria Maximum Concentration is an estimate of the highest concentration of a material in surface water to which an aquatic community can be exposed briefly without an unacceptable effect. CCC: Criterion Continuous Concentration is an estimate of the highest concentration of a material in surface water to which an aquatic community can be exposed indefinitely without an unacceptable effect.

9. 9 of 13 Assabet and Concord Rivers, 2008 Hardness-dependent dissolved metals Summary statistics All concentrations are micrograms per liter ChromiumCopperLeadNickelZinc Min:0.51.60.21.42.5 Mean:0.592.910.682.668.83 Median:0.592.450.752.207.00 Max:0.8121.11421 CCC Range:47-955-121-431-6770-152 Total n:60 NA's :4629142 Std Dev.:0.081.770.291.745.62 DRAFT- SUBJECT TO CHANGE

10. 10 of 13 Boxplots of hardness-dependent Dissolved metals concentrations DRAFT- SUBJECT TO CHANGE

11. 11 of 13 Site-specific Water-Quality Criteria DRAFT- SUBJECT TO CHANGE

12. 12 of 13 Site-specific Water-Quality Criteria DRAFT- SUBJECT TO CHANGE

13. 13 of 13 Looking forward… Data transfer Transmit results to Massachusetts DEP and U.S. EPA for their evaluation No USGS Report planned at this time Submit proposal for state-wide assessment of metals-impaired segments Larger effort addressing impaired reaches in watersheds statewide Year-round sampling (what’s happening during other time frames?) Focus on Total metals; 2008 results to show 1:1 relation; where deviations occur, total-metals concentrations are higher and therefore protective (conserves time and equipment by eliminating sample filtration during on-site sample processing)