Chesapeake Bay Program Implementation Committee Briefing on

Water Quality Steering Committee Activities:

Introduction and Background

Bill Matuszeski

Chesapeake Bay Program Office

Annapolis, Maryland

January 24, 2001

Components

• Designated uses

• Criteria

• Standards

• Impairments

• TMDLs

Characteristics of Existing State Designated Uses

• Reflect jurisdictional boundaries, not resource habitats

• May build in low vs. high salinity waters delineation but only for determining which EPA criteria to apply (freshwater vs. saltwater)

• Use language still boils down to protection of “fishable/swimable”

Relevant EPA Criteria

• Dissolved oxygen– Only freshwater criteria were available until this winter

– EPA published saltwater criteria for the Cape Cod to Cape Hatteras region in December 2000

• Nitrogen– Criteria for nitrate, ammonia based on toxicity effect,

not eutrophication connection

Relevant EPA Criteria

• Phosphorus– Criteria based on toxicity of elemental phosphorus

• Chlorophyll a– No national criteria exist currently

• Water Clarity– Some references to turbidity, but no real criteria address

water clarity

Existing State Standards

• Dissolved oxygen– Maryland: not less than 5 mg/L

– Virginia, Delaware: 5 mg/L average, 4 mg/L minimum

• Chlorophyll a– No existing state standards

• Water Clarity– Delaware, DC: not more than 10-20 Nephelometric units

(NTUs) above natural levels, respectively

– Maryland: 50 units monthly average, never exceed 150 NTUs