As part of the copper site-specific objective, NPDES dischargers are required to calculate annually the three-year rolling average of dissolved copper concentrations in water in each segment of the Bay, based on RMP data.a This table presents the segment average and corresponding trigger levels in the Basin Plan. The average includes data from randomized as well as historical sites in the segments, although it excludes data from the historical reference site outside the Golden Gate. 

 

 

 

 

 

 

 

 

 

 

 

Bay Segment Trigger (μg/L) 2011-2015 Rolling Average (μg/L) Number of Samples Included in Average Notes
Lower South Bay 4.2 3.62 15  
South Bay 3.6 2.77 12 Historical Station BA30 included
Central Bay 2.2 1.45 12 Historical Station BC10 included
San Pablo Bay 3 2.00 9  
Suisun Bay 2.8 2.29 9  

Sample Locations

In 2011, the RMP reduced the frequency of water and sediment sampling to biennial. Water samples are now collected during odd-numbered years. Therefore, the current copper 3-year rolling averages include 2011, 2013, and 2015 data. 

Key Materials

2015 Update to Copper Rolling Average - Presentation

Past Results:

Bay Segment Trigger (μg/L) 2010-2013 Rolling Average (μg/L) Number of Samples Included in Average Notes
Lower South Bay 4.2 3.62 15  
South Bay 3.6 2.77 12 Historical Station BA30 included
Central Bay 2.2 1.51 12 Historical Station BC10 included
San Pablo Bay 3 2.08 9  
Suisun Bay 2.8 2.22 9