Alabama’s Nutrient Criteria Development

2012 Annual Meeting of the SWPBANovember 16, 2012

Overview

• Goals of Nutrient Program• Alabama Implementation Schedule and Timelines• Tallapoosa River Basin Numeric Nutrient Criteria Study• Weeks Bay Numeric Nutrient Criteria Study• Gulf of Mexico Alliance Update

Goals of Nutrient Program

• ADEM’s goals are consistent with the Clean Water Act and EPA’s National Nutrient Strategy1. Develop and adopt nutrient criteria that support the beneficial uses designated for each

waterbody and that protect these waters from potential adverse effects associated with nutrient over-enrichment

2. Restore and maintain the chemical, physical, and biological integrity of each waterbody3. Maintain the diversity and uniqueness of Alabama’s waterbodies

• Department’s rationale: establish nutrient criteria consistent with the “fishable/swimmable” goal of the Clean Water Act

Nutrient Criteria Implementation Schedule for the Waters of Alabama

Task/Description Date

Present proposed nutrient criteria for Frank Jackson, Bear Creek, Upper Bear Creek, and Woodruff Reservoirs to the AEMC

2013

Propose nutrient criteria for remaining rivers and streams, where necessary

2015

Propose nutrient criteria for estuarine and coastal waters not previously addressed, where appropriate

2015

Propose nutrient criteria for selected nutrient-sensitive wetlands 2016

Nutrient Criteria Implementation Schedule for Lakes and Reservoirs

Year Number of Reservoirs Major Basin(s) Name of Reservoirs

2001 4 Chattahoochee, Coosa, Tallapoosa West Point, W.F. George, Weiss, R.L. Harris

2002 9 Tallapoosa, Tennessee Martin, Yates, Thurlow, Guntersville, Wheeler, Wilson, Pickwick, Little Bear, Cedar

2004 11 AlabamaBlack Warrior

ChattahoocheePerdido-Escambia

Claiborne, DannellyBankhead, Holt, Lewis Smith, Oliver, Tuscaloosa, WarriorHardingGantt, Point A

2005 5 Black WarriorPerdido-EscambiaLower TombigbeeUpper Tombigbee

InlandJacksonCoffeevilleDemopolis, Gainesville

2010 8 CahabaCoosaEscatawpaUpper Tombigbee

PurdyJordan, Lay, Logan Martin, Mitchell, Neely HenryBig CreekAliceville

2013 4 Alabama Perdido-EscambiaTennessee

WoodruffFrank JacksonBear Creek, Upper Bear Creek

Tallapoosa River Basin NNC Study

Stream, river and lake embayment sample sites

Tallapoosa River Basin NNC Study

• Goal: Develop numerical nutrient criteria (P & N) for wadeable streams • Data collected by ADEM and GSA; Study by AU Water Resources Center

– Data collected at 34 sites during 2010 growing season– Data statistically analyzed using CART analysis

• CART results – TP was nutrient driving changes in response variables for both

reservoir embayment and streams/rivers– Increased TP observed with decreased photic and Secchi depths,

increased Chl a, decreased fish species and Index of Biotic Integrity• Conclusion: More data will need to be collected and analyzed over several

years to better define actual causal relationships. Limit stream order and focus on sampling small streams to more clearly define nutrient/biota interactions.

Tallapoosa River Basin NNC Study

Tallapoosa River Basin NNC Study

Tallapoosa River Basin NNC Study

Weeks Bay NNC Study

Sampling sites used for the Weeks Bay SFTE nutrient criteria pilot study

Weeks Bay NNC Study

• Goal: Develop appropriate and protective nutrient criteria for estuaries.• Study by TetraTech

– Data collected at 13 stations in 2011; Weeks Bay, Bon Secour Bay, Fish River, Magnolia River, Cowpen Branch, and Polecat Creek

• Regression analyses reveal nitrogen and phosphorus associated with spectrophotometric Chl a concentration in the bay; TN is better predictor than TP

• Recommendations1. Daily minimum DO: not to be <5 mg/L, 50% of time during summer when daily mean

temperature is above 20°C 2. 25 µg/L fluorometric Chl a (EPA and NERRS long-term monitoring) recommended to

control mag and freq of hypoxia stress on aquatic life3. Spectrophotometric Chl a (ADEM) annual geometric mean Chl a <6.4 µg/L and Summer

geometric mean Chl a <9.1 µg/L4. Recommended NC: TP <0.09 mg/L & TN <1.5 mg/L

• Determined by multiple regression model when mean relationship between TN and TP is assumed and Chl a criterion = 9 µg/L

• Values should be updated following subsequent data collections in Weeks Bay system and analyses relating them to those of other G of M estuaries.

Weeks Bay NNC Study

• Conclusion: further studies necessary to explore true causal relationship between nutrient input from upstream sources, resulting algal blooms within Weeks Bay; thus enhancing scientific defensibility of NC.

Gulf of Mexico Alliance

• GOMA Conference held June 19-21, 2012 in Corpus Christi, TX• Ongoing nutrient studies (NSFTE): St. Louis Bay, MS; Weeks Bay, AL;

Galveston Bay, TX; Mission-Aransas Bay, TX• Continuing to identify environmental or biological indicators that are

sensitive to nutrients• Ongoing communication among Gulf states on nutrient criteria

development efforts• Establish technical workgroup to evaluate appropriate biological

assessment tools, endpoints, and thresholds based on NSFTE studies and other available information

• Develop Gulf-wide classification system for use in criteria development• Current and upcoming research projects to study hypoxia, reduce hypoxia,

and efforts to improve access to hypoxia data

Questions?

Lynn SiskChief of Water Quality Branch

(334) 271-7826ls@adem.state.al.us

Jennifer HaslbauerWater Quality Branch

(334) 274-4250jhaslbauer@adem.state.al.us

Daniel SalibaWater Quality Branch

(334) 271-7843djsaliba@adem.state.al.us