Metals
Turbidity
Unknown CausePercent of Waters
Listed
Prioritize TMDL
Development
0.0 5.0 10.0 15.0 20.0 25.0
Pathogens
Nutrients
Noxious Aquatic Plants
Organic Enrichment, Low DO
60%
Development
1.Nutrients
2.Bacteria
� A “pollution budget” designed to restore the
health of a waterbody
� Includes relative contributions from all pollutant
sources (e.g., point and nonpoint)sources (e.g., point and nonpoint)
� Defines reductions necessary to meet Water
Quality Standards and designated uses
http://www.mass.gov/eea/agencies/massdep/water/watersheds/massachusetts-nutrient-management-report-2013.html
� Where:
� TMDL = Loading Capacity of Receiving Water
� WLAs = Portions Allotted to Point sources
LA’s = Portion allotted to Nonpoint sources� LA’s = Portion allotted to Nonpoint sources
� MOS = Margin of Safety (account for uncertainty)
� Consideration also given for background,
seasonal variability and future growth
WWTPs (66% reduction)
• Majors/Minors–� 0.1 mg/L TP summer
� 0.3 mg/L TP winter
Stormwater (51% reduction)
� Open/agriculture (35%)
� Low density residential (45%)
� Medium density residential (65%)
� High density residential (65%)High density residential (65%)
� Commercial/industrial 65%)
� Transportation (65%)
Margin of Safety – 6 %
Kimberly Groff, Ph.D.Director Watershed Planning Program
Massachusetts Department of Massachusetts Department of Environmental Protection627 Main Street, 2nd FloorWorcester, MA 01608