Water Quality Standards in Great Bay, New Hampshire

1. GREAT BAY andNEW HAMPSHIRE WATER QUALITY STANDARDS Southeast Watershed Alliance March 9, 2011 Paul M. Currier, PE,PG Watershed Management Bureau NH Department of Environmental Services

2. WQS Essentials • Purpose: “…provide for the protection and propagation of fish, shellfish, and wildlife…” • WATER QUALITY STANDARDS are STATE law and rule • EPA reviews and approves the standards for consistency with the federal CLEAN WATER ACT • THREE COMPONENTS • Designated Uses [aquatic life / biological integrity, recreation, and others] • Criteria to support the Uses [Measurable attributes of a waterbody] • Antidegradation Little Bay October 2001 - Chris Nash

3. KINDS OF CRITERIA • NARRATIVE [“Class B waters shall contain no phosphorus or nitrogen in such concentrations that would impair any existing or designated uses, unless naturally occurring.”] • NUMERIC […“class B waters shall have a dissolved oxygen content of at least 75% of saturation, based on a daily average, and an instantaneous minimum dissolved oxygen concentration of at least 5 mg/l.”]

4. Biological Integrity Narrative “The surface waters shall support and maintain a balanced, integrated, and adaptive community of organisms having a species composition, diversity, and functional organization comparable to that of similar natural habitats of a region” [e.g. Eelgrass cover is a measure of this in the Great Bay Estuary; a macroinvertebrate Index of Biological Integrity is a measure of this in wadeable streams]

5. Important Points • NARRATIVE criteria must be TRANSLATED into quantitative terms to be used for ASSESSMENTS • ASSESSMENT means evaluating WATERBODIES to see if criteria are met for a particular designated use • Collecting data [sampling / monitoring] • Analyzing the data in a standardized way • Comparing the analysis to WQS criteria • The CALM [Consolidated Assessment and Listing Methodology]: a compendium of protocols for monitoring and analysis of data from waterbodies to produce assessments (on the DES website) • Contains TRANSLATORS for narrative criteria

6. ASSESSMENT: Application of Criteria • Statewide waterbody catalog • Assessment Units [=Waterbodies]: Homogeneous pieces of surface water that can be monitored / assessed as one unit • Statewide assessment every 2 years • “305(b) report” and “303(d) list : • FOR EACH ASSESSMENT UNIT, Assemble all relevant data, apply the CALM, and report whether or not criteria for the designated uses are met • Result can be: FULLY SUPPORTING,NOT SUPPORTING, OR INSUFFICIENT INFORMATION / NOT ASSESSED • 2010 report is on the web • Report Cards on ONESTOP for surface water AUs

7. 303(d) LIST • A list of ASSESSMENT UNITS that are IMPAIRED [= flunk one or more criteria] by POLLUTANTS • Pollutants: things like nutrients, BOD, TSS, temperature, toxics • PROCESS • Identify pollutants [sometimes need stressor analysis] • Do a TMDL [Total Maximum Daily Load] study to: • Estimate maximum pollutant load that will meet WQS • Allocate the load between point sources (Wasteload Allocation) and nonpoint sources (Load Allocation) • Prepare and carry out a TMDL implementation plan

8. NUTRIENT CRITERIA DEFINITION • Numeric nutrient criteria define levels of nutrients (i.e., nitrogen and phosphorus) protective of the designated uses of water bodies from over-enrichment • Over-enrichment of water bodies by nitrogen and phosphorus typically stimulates plant and microbial growth, and can result in biological and physical responses that adversely affect water quality and aquatic life. • The USEPA guidance recommends development of criteria for both total nitrogen (TN) and total phosphorus (TP), the primary causal constituents, and for chlorophyll aand water clarity, the primary response constituents FROM: Empirical Approaches to Establishing Numeric Nutrient Criteria for Southwest Florida Estuaries, Janiki Environmental, Inc, July 10, 2010

9. Figure 1: Assessment Zones in the Great Bay Estuary From DES’ nutrient criteria report

11. EXAMPLE: Oyster River

12. Oyster River Aquatic Life Impairments (2010 assessment) • Chlorophyll – A [annual median > 10 ug/l] • Dissolved Oxygen Saturation [daily mean < 75%] • Estuarine Bioassessments [eelgrass loss] • Light Attenuation Coeff. [Kd <0.75(depth dependent)] • Nitrogen (total) [Annual median < 0.30 mg/l] • Oxygen, dissolved [instantaneous min. < 5 mg/l] Note: although these criteria are all monitored and assessed separately, there are Significant interactions among them.

13. IMPORTANT POINT • The Great Bay estuary is not homogeneous. • Each assessment unit has an individual assessment and will need an individual TMDL and implementation plan. • NPDES permits will utilize best available information • Water Quality Standards • Translators / CALM • TMDLs [but permits won’t wait for them] • Any other pertinent information

14. CURRENT STATUS • “Nutrient Criteria” [really translators for nitrogen, chl-a, and Kd] published June, 2009 • Most Great Bay estuary AUs have been assessed for aquatic life as of 2010 assessment, and are listed as impaired for aquatic life due to nutrient criteria • N-STEPS peer review completed • Draft “Analysis of Nitrogen Loading Reductions…” published Dec, 2010 • Load Allocation study in progress • Discussions underway about additional review • Stressor analysis [sometimes called cause and effect analysis] Nannie Island, 2001 Chris Nash