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Numeric Endpoints and Adaptive Management: New York’s First Stream Nutrient TMDL. Steve Gladding, Brian Duffy, Ron Entringer , Jay Bloomfield NYSDEC Watershed Modeling: Steve Pacenka , Casey Garland, Peter Vermeulen , Tammo Steenhuis Cornell University
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Numeric Endpoints and Adaptive Management:New York’s First Stream Nutrient TMDL Steve Gladding, Brian Duffy, Ron Entringer, Jay Bloomfield NYSDEC Watershed Modeling: Steve Pacenka, Casey Garland, Peter Vermeulen, TammoSteenhuis Cornell University NYC Watershed/Tifft Science & Technical Symposium September 19, 2013
Outline • Applying Nutrient Criteria • Field Study • Results • Application • Implementation
Nutrient Criteria • 50% of U.S. streams have elevated nutrient levels* • States required to develop TMDLs for impaired waters • Can develop site specific criteria • U.S. EPA is pushing states to develop numeric nutrient criteria • Framework for State Nutrient Reductions* • Florida: Nutrient criteria imposed by U.S. EPA • Illinois: Reasonable potential analysis and nutrient limits for NPDES permits *Stoner, Nancy K. (2011) “Working in partnership with states to address phosphorus and nitrogen pollution through use of a framework for state nutrient reductions. U.S. EPA Memo.
Applicable Water Quality Standard None in amounts that will result in growths of algae, weeds and slimes that will impair the waters for their best usages (6 NYCRR Part 703.2)
Applicable Water Quality Standard None in amounts that will result in growths of algae, weeds and slimes that will impair the waters for their best usages (6 NYCRR Part 703.2) • 303(d) listing • Phosphorus • Total? SRP? • Use Impairment • Macroinvertebrates Endpoint Application • What limit is applied? • Average concentration? Maximum? • When is it applied? • Full year? Summer? Other? • How is it applied? • Daily? Weekly? Monthly? Other? • Where is it applied? • Where is assessment conducted?
Field Study Identifying an endpoint
Upper Black Creek • 46 sq. mi. • 27 mi. main stem • Bigelow Creek Tributary • Land Cover • 70% Agriculture • 20% Forest/Wetland • 10% Developed
Biomonitoring with macroinvertebrates(Determining Aquatic Life Use Impairment) • Less mobile than fish • Indicators of overall, integrated water quality • Sensitive to environmental impacts • Pollution, siltation, temperature • Differing tolerances to pollution • 5 Metric Biological Assessment Profile (BAP) Mayflies (Ephemeroptera) Mussel, Clams (Mollusca: Pelecypoda) Scuds (Amphipoda)
Use Impairment • Upper Black Creek • 303(d) listed in 2004 • Aquatic life use • Phosphorus from agriculture, municipal • Bigelow Creek • 303(d) listed in 2004 • Aquatic life use • Phosphorus from agriculture None Slight BAP5 Score Moderate Severe
Conceptual ModelNo direct toxicity effects of nutrients Paul, M. J. and L. Zheng (2007). Development of Nutrient Endpoints for the Northern Piedmont Ecoregion of Pennsylvania: TMDL Application.
Data Collection • Chemistry • DO, T, pH, Cond. • TP, SRP • Nitrogen series • Habitat Assessment • Canopy cover • Grain size analysis • Riparian buffer • Depth, Velocity • Macroinvertebrates • 6 replicates per site
Macroinvertebrate Survey Black Creek Bigelow L. Tonawanda WWTP WWTP
Statistical Analysis • Started with 80 variables • Reduced to 15 using Spearman rank-order correlation • Retained only variables that could be influenced • Discarded headwaters sites (DA < 10 mi2) • Best subset regression & multiple regression model • Total phosphorus (TP) • Soluble reactive phosphorus (SRP) • Total riparian width (TRW) • Average riparian closure (ARP) • Fraction fines in the riffle (< 16 mm) (FFR) • Total suspended solids (TSS) BAP Score = 5.68 - 16.64×TP + 0.0895×TRW - 3.43×FFR
Model Schematic TMDL Total P Load Total P Concentration Channel Regression Model Cornell Watershed Model Riparian Buffer Width Fine grained sediment in the riffle zone
Load Duration Interval Current Load TMDL Load 50th percentile flow
Phosphorus reductions at site BLAK-08 • 2012 Conditions • Total PhosphorusTP = 0.093 mg/L • Total Riparian Width TRW = 18 m • Fraction Fines in RiffleFFR = 0.30 • BAP = 4.21 • To achieve BAP Score = 5 • BAP = 5.68 – 16.64×TP + 0.0895×TRW – 3.43×FFR • Reduction target • TP = 0.046 mg/L • 50% reduction
Applicable Water Quality Standard None in amounts that will result in growths of algae, weeds and slimes that will impair the waters for their best usages (6 NYCRR Part 703.2) • 303(d) listing • Phosphorus • Total • Use Impairment • Macroinvertebrates Endpoint Application • What limit is applied? • Average concentration • When is it applied • Growing Season/Summer Permit • How is it applied • Growing season average • Where is it applied? • Critical locations at confluences and below point sources
Implementation Restoration of stream corridor Higher allowable phosphorus concentrations Less reduction from point/non-point sources Still attains aquatic life best use
Stream Restoration Approach BAP Score = 5.68 - 16.64×TP + 0.0895×TRW - 3.43×FFR
Stream Restoration Approach BAP Score = 5.68 - 16.64×TP + 0.0895×TRW - 3.43×FFR
Stream Restoration Approach BAP Score = 5.68 - 16.64×TP + 0.0895×TRW - 3.43×FFR
Stream Restoration Approach BAP Score = 5.68 - 16.64×TP + 0.0895×TRW - 3.43×FFR Riparian buffers can affect all three parameters
Adaptive Implementation • Phased implementation for point source WLA • Long compliance schedules for point source • Support for the stream restoration approach • Trees for tribs grant • Continued assessment of aquatic life • Potential TMDL revisions if aquatic life use is supported
Parting thoughts • Feasibility of stream buffers • Can municipalities directly establish? • Farmers reluctant to take land out of production • EPA reasonable assurance • Small streams have small discharges • Phosphorus limits on WWTP <0.1 MGD • Site specific study
Thank You Contact information: • Steve Gladding • 625 Broadway, 4th Floor, Albany NY 12233-3508 • smgladdi@gw.dec.state.ny.us • 518-402-8207
Multiple Regression Analysis BAP Score = 5.68 - 16.64×TP + 0.0895×TRW - 3.43×FFR BAP Score Calculated Multiple Regression – BAP Score