Boston Harbor and Massachusetts Bay
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Ambient Monitoring Plan Modifications

MWRA's Deer Island Treatment Plant has a National Pollutant Discharge Elimination System (NPDES) Permit to discharge effluent into Massachusetts Bay. Attached to this permit is an Ambient Monitoring Plan, which details monitoring goals and methods to ensure the the Harbor and Bay are protected. The NPDES permit allows MWRA to propose interim modifications to the Ambient Monitoring Plan at any time.  After interim changes are proposed, they go into effect after 30 days unless there is a written objection from the U.S. Environmental Protection Agency or Mass. Department of Environmental Protection.

  6/5/20: Interim request for modifications to permit-attached Ambient Monitoring Plan. (PDF)
  12/6/10: Modifications to the Ambient Monitoring Plan Approved (PDF)
  July 2010: Ambient monitoring plan for the Massachusetts Water Resources Authority effluent outfall, revision 2. (PDF)
  July 2010: Notice and List of changes for public comment. (PDF)
  Related Material: Maps showing the overall changes in sampling locations for water column and benthic stations for different phases of the monitoring including the Zone of Initial Dilution.

MAPS
Benthic Monitoring Design
Benthic Baseline 1992-2000
Benthic Discharge Period 2000-2003
Benthic Discharge Period 2004-2009
Benthic Station Map, all phases
Water Column Monitoring Design
Water Column Baseline 1992-2000
Water Column Discharge Period 2000-2003
Water Column Discharge Period 2004-2009
Water Column Station Map, all phases
Clostridium perfringens

Many of our reports are in PDF format, which requires Adobe Acrobat Reader®, a free program available from Adobe Systems. To request a paper copy of any report, please e-mail us at web.enquad@mwra.state.ma.us.