CARTERS & BURTON CREEK TMDL MONITORING CASE STUDY. Kevin Wagner, PhD

Transcription

1 CARTERS & BURTON CREEK TMDL MONITORING CASE STUDY Kevin Wagner, PhD

2 CARTERS CREEK WATERSHED Small (36,434 ac.) rapidly urbanizing watershed Ambient flow mostly made up of wastewater effluent from the seven municipal wastewater treatment facilities in the watershed Carters Creek listed in 1999 for elevated bacteria; Burton Creek listed in 2006

3 Brazos Center CARTERS CREEK University Drive Bird Pond Road W.D. Fitch

4 CARTERS CREEK TRIBUTARIES Burton Creek Hudson Creek Sewer Creek Other tribs Bee Creek Briar Creek Wolf Pen Creek

5 LAND USE

6 TMDL & TMDL-IP COMPLETED IN 2012 Utilized SWAT model to predict stream flows No continuous flow data available Developed Load Duration Curves using data from the three existing monitoring sites

7 BURTON CREEK: STATION E+15 1.E+14 1.E+13 Needed Load Reductions: Very High: 97% High: 32% Low: 79% E. coli (MPN / day) 1.E+12 1.E+11 1.E+10 1.E+09 Very High Flows High Flows Low Flows 1.E+08 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Percent of days load exceeded Allowable Load at Geomean Criterion Non-wet Weather Event Wet Weather Event Existing Geomean Load

8 CARTERS CREEK: STATION E+15 1.E+14 1.E+13 Needed Load Reductions: Very High: 93% High: 73% Low: 75% E. coli (cfu / day) 1.E+12 1.E+11 1.E+10 Very High Flows High Flows Low Flows 1.E+09 1.E+08 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Percent of days load exceeded Allowable Load at Geomean Criterion Non-wet Weather Event Wet Weather Event Existing Geomean Load

9 CARTERS CREEK: STATION E+15 1.E+14 1.E+13 Needed Load Reductions: Very High: 95% High: 79% Low: 79% E. coli (MPN / day) 1.E+12 1.E+11 1.E+10 1.E+09 Very High Flows High Flows Low Flows 1.E+08 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Percent of days load exceeded Geomean criterion of 126 MPN/100 ml Non-wet WeatherEvent Wet weather Existing Geomean Load

10 SOURCES OF POLLUTION Point Sources WWTFs 4 facilities in the watershed Combined permits of ~17.7 MGD MS4s 5 individual permits in the watershed Nonpoint Sources Failing OSSFs Feral animals Livestock Pets Wildlife

11 LOCAL SOLUTIONS TMDL I-PLAN Management Measures Coordinate and expand monitoring Evaluate tax valuation requirements for Ag Identify, inspect and provide education on OSSFs Implement SSO initiatives Voluntarily implement Ag BMPs Promote sound development practices Control Actions Implement MS4 Phase II Stormwater Management Plans Continue monitoring WWTF effluent in accordance with permits

12 LOCAL WORK GROUP NEEDS A better understanding of the current state of the waterbodies Greater understanding of spatial variability of E. coli Allowing better targeting of potential sources of local water quality impairments A clearer understanding of the temporal variability in E. coli numbers monitored throughout the watershed Establishment of a clear baseline (pre-bmp) of current E. coli loads at a sub-watershed scale Allowing quantification of implementation success

13 QUESTIONS

14 CARTERS CREEK CASE STUDY DEFINING THE PROBLEM & OBJECTIVES INVENTORYING/ACQUIRING DATA & ASSESSING GAPS SELECTING EXPERIMENTAL DESIGN

15 WATER QUALITY PROBLEM Recreation in Burton & Carters Creek impaired because of excessive E. coli Segment 1209C Impairments: bacteria Segment 1209D Impairments: bacteria Segment 1209L Impairments: bacteria

16 MONITORING OBJECTIVES 1. To identify critical areas and locate E. coli sources within watershed exhibiting greater pollution potential than other areas 2. To evaluate program effectiveness & document changes in E. coli levels and loads resulting from implementation

17 AVAILABLE DATA TCEQ SWQMIS Quarterly TCEQ & BRA data Cities of Bryan & College Station Daily/weekly WWTF results Other sources TMDL Technical Support Document 2011 LDCs & simulated flow Harclerode Masters Thesis 2009 Semi-monthly data ( ) for Carters & major tribs USGS Peak Streamflows Burton & Hudson Creeks

18 SAMPLING SITES & PERMITTED DISCHARGES

19 CARTERS & BURTON CREEK WATER QUALITY ASSESSMENT Data collected from 2001 to 2007 Station Segment Count Geometric Mean (MPN/100 ml) Burton Cr. (1209L_01) Carters Cr. (1209C_01) Carters Cr. (1209C_01)

20 HARCLERODE MONITORING SITES (JULY 2007 JULY 2008) E. coli (cfu/100 ml)

21 EXPERIMENTAL/STATISTICAL DESIGN Reconnaissance determine magnitude & extent of water quality problem & target critical areas (Objective 1) Single watershed/before-after evaluate water quality effectiveness of program (Objective 2) H o : median E. coli (period 1) = median E. coli (period 2) Above-and-below watersheds evaluate water quality effectiveness of program (Objective 2) H o : difference = 0 Trend analysis (Objective 2) Time plot, time series analysis, regression, t-test of annual means, seasonal Kendall test

22 DATA GAPS/NEEDS Continuous flow data More representative monitoring needed Flow-weighted stormflow E. coli data Currently 2 low flow grabs, 18 normal flow, 13 high flow Greater spatial coverage of watershed (more sites) Greater monitoring frequency Critical area identification Long-term data

23 QUESTIONS

24 CARTERS CREEK CASE STUDY SELECTING MONITORING DESIGN

25 STUDY SCALE & VARIABLES Scale of study Watershed Variables Primary E. coli Flow Secondary Temperature ph DO Conductivity Field observations

26 SAMPLING SITE SELECTION CONSIDERATIONS Location of existing sites (historical data) Expanding spatial coverage Accessibility Sites located at road crossings or in public parks Cost Optimal number of sites & sampling events

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28 SAMPLING FREQUENCY & DURATION First, how many samples are needed? Existing Burton Creek data Mean = 2511 S = 4989 n=31 Definitions for equations n=calculated sample size t=student s t at n-1 degrees of freedom & confidence level (p) t=2.042 (30 degrees of freedom & p=0.05) S=standard deviation Note: Stratifying data (stormflow vs baseflow) can help further refine sampling needs Linear trend detection n=12t 2 S 2 /d 2 d=min. magnitude of trend d= = 2385 n=12(2.042) 2 (4989) 2 /(2385) 2 = 219 samples needed Step trend n=2t 2 S 2 /d 2 d=difference from mean d=95% diff. from mean=2385 n=2(2.042) 2 (4989) 2 /(2385) 2 = 36 samples needed

29 p CARTERS CREEK WATERSHED MONITORING SITES g Routine Water Quality Monitoring Site # TCEQ Station # Site Name/Location Sampling Frequency CC Carters Bird Pond Road monthly CC Carters SH 6 (upstream of Burton Creek confluence) monthly CC 3 TBD Carters William D. Fitch monthly BC Burton SH 6 (downstream of WWTF) monthly Stormflow Monitoring Site # TCEQ Station # Site Name/Location Sampling Frequency CC Carters Bird Pond Road during storm events BC Burton SH 6 during storm events Reconnaissance Monitoring Site # TCEQ Station # Site Name/Location Sampling Frequency BC Burton SH 6 (downstream of WWTF) monthly BC 2 N/A Burton 29th St. (upstream of WWTF) monthly BC 3 N/A Bee Appomattox Dr. monthly BC 4 N/A Burton Villa Maria monthly BC 5 N/A Unnamed tributary of Burton Maloney Ave. monthly BRC N/A Briar Hwy 6 monthly CC 4 N/A Carters Creek below CCWWTF outfall monthly CC 5 N/A Carters Creek above CCWWTF outfall monthly HC N/A Hudson FM 60 monthly WPC N/A Wolfpen Hwy 6 monthly

30 SAMPLE & STATION TYPES Overview Routine, stormflow and reconnaissance sampling used COB & COCS wastewater treatment facilities (WWTFs) will also coordinate self-reported data collection with monitoring efforts Sample & Station Types Reconnaissance & Routine Sampling Grab samples Storm flow monitoring Flow-weighted composite samples (automated samplers) Flow (Stream discharge) Instantaneous (Routine Sampling) Continuous (Storm flow monitoring sites) Staff gages (all sites)

31 ROUTINE MONITORING Type and Frequency Frequency: monthly 4 locations Duration: 3 years Data submitted to TCEQ for future water quality assessments Data Collected Field Data Temperature ph DO Conductivity Instantaneous stream flow Other observations: Total water depth, flow severity, days since last significant rainfall, present weather, other Lab Data E. coli (1603 Method)

32 STORMWATER MONITORING Type and Frequency Automated sample collection: flow-weighted, composite samples 2 locations Frequency: Up to 10 storm events annually Data will be submitted to TCEQ but WILL NOT be used in future water quality assessments Data Collected Field Data Temperature ph DO Conductivity Continuous Flow Lab Data E. coli (1603 Method)

33 RECONNAISSANCE MONITORING Types and Frequency Volunteer data collection using the Texas Stream Team monitoring protocol Frequency: Monthly 10 locations Data submitted to Texas Stream Team database Not used in water quality assessments Data Collected Field Data Temperature Water Transparency Total Depth DO ph Conductivity Flow Velocity Other field observations: Algae cover, water color, water odor, present weather, days since last significant precipitation, other Lab Data E. coli (IDEXX Method)

34 WWTF EFFLUENT MONITORING Continue monitoring WWTFs per their permit requirements Coordinated with routine, storm water, and reconnaissance monitoring Illustrates E. coli outputs from plants Shows potential impacts on in-stream water quality

35 DATA COLLECTION OVERLAP With the three types of monitoring used, comparability becomes important Several sites purposefully overlap to allow comparison Sample collections will be coordinated to occur on the same dates and times at these locations Collection will also be paired with BRA CRP monitoring and WWTF self reported monitoring All data integrated into the Coordinated Monitoring Schedule

36 LAND USE & MANAGEMENT MONITORING Watershed Source Survey Amass existing GIS information on the watershed Wastewater Infrastructure, Stormwater Infrastructure, etc. Conduct physical stream walks & floats to ID potential sources Small discharges to waterway, bird rookeries, bat colonies, etc. Incorporate into GIS & transfer findings to local GIS coordinators Watershed Survey Assessment Combines findings from GIS survey and physical survey to identify potential problem areas

37 SAMPLE COLLECTION & ANALYSIS E. coli Volume Required: 200 ml Container: Whirlpak (grab sampling) Plastic bottle (stormwater sampling) Preservation: Cool, 4 o C Maximum holding time: 6 hours Methods: EPA Method 1603 (Routine & Stormwater) IDEXX (recon/wwtf) Labs: SAML (Routine & Stormwater) COB & COCS WWTFs (Recon. & WWTF) Field parameters (DO, temp, ph, conductivity) In-situ Multi-probe (Routine) Texas Stream Team Kits (Reconnaissance)

38 QUALITY ASSURANCE QA samples Lab duplicates Lab blanks Positive controls Quality Objectives Precision = relative % difference of lab duplicates Accuracy = blanks & positive controls Representativeness = even time intervals + storm events Comparability = data collection overlap Completeness = 90% Proper Documentation Chain of Custody Corrective Action Reports Field data sheets (flow, observations, field measurements) Field & lab logs Multi-probe calibration & maintenance

39 DATA MANAGEMENT Data acquisition Historical E. coli data from Stations 11782, & Data validation Data Review Checklist Data storage & retrieval TWRI database TCEQ SWQMIS Texas Stream Team database Data manipulation Excel, Minitab, SigmaPlot Reporting Quarterly

40 QUESTIONS

41 CARTERS CREEK CASE STUDY OVERVIEW

42 STEP 1 WATER QUALITY PROBLEM Recreation within Carters and Burton Creeks were impaired because of excessive bacteria (E. coli) levels The TMDL and TMDL-IP identified the need for additional monitoring to confirm the impairments, assess sources, and provide baseline for evaluation of implementation measures

43 STEP 2 OBJECTIVES 1. To identify critical areas and locate E. coli sources within watershed exhibiting greater pollution potential than other areas 2. To evaluate program effectiveness & document changes in E. coli levels and loads resulting from implementation

44 STEP 3 STATISTICAL DESIGN To determine magnitude & extent of water quality problem & target critical areas (Objective 1) Reconnaissance To evaluate water quality effectiveness of program (Objective 2) Single watershed/before-after Above-and-below watersheds Trend analysis

45 STEPS 4-5 STUDY SCALE & VARIABLES Scale Watershed Primary Variables E. coli Flow Secondary Variables Temperature ph DO Conductivity Field observations

46 STEP 6 SAMPLE TYPE STEP 9 STATION TYPE Reconnaissance & Routine Sampling Grab samples Storm flow monitoring Flow-weighted composite samples (automated samplers) Flow (Stream discharge) Instantaneous (Routine Sampling) Continuous (Storm flow monitoring sites) Staff gages (all sites)

47 p STEPS 7-8 SAMPLING LOCATION, FREQUENCY & DURATION g Routine Water Quality Monitoring Site # TCEQ Station # Site Name/Location Sampling Frequency CC Carters Bird Pond Road monthly CC Carters SH 6 (upstream of Burton Creek confluence) monthly CC 3 TBD Carters William D. Fitch monthly BC Burton SH 6 (downstream of WWTF) monthly Stormflow Monitoring Site # TCEQ Station # Site Name/Location Sampling Frequency CC Carters Bird Pond Road during storm events BC Burton SH 6 during storm events Reconnaissance Monitoring Site # TCEQ Station # Site Name/Location Sampling Frequency BC Burton SH 6 (downstream of WWTF) monthly BC 2 N/A Burton 29th St. (upstream of WWTF) monthly BC 3 N/A Bee Appomattox Dr. monthly BC 4 N/A Burton Villa Maria monthly BC 5 N/A Unnamed tributary of Burton Maloney Ave. monthly BRC N/A Briar Hwy 6 monthly CC 4 N/A Carters Creek below CCWWTF outfall monthly CC 5 N/A Carters Creek above CCWWTF outfall monthly HC N/A Hudson FM 60 monthly WPC N/A Wolfpen Hwy 6 monthly

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49 STEP 10 SAMPLE COLLECTION & ANALYSIS E. coli Volume Required: 200 ml Container: Whirlpak (grab sampling) Plastic bottle (stormwater sampling) Preservation: Cool, 4 o C Maximum holding time: 6 hours Method: EPA Method 1603 Lab: SAML (Routine/Stormwater) & WWTF (Recon. & WWTF) Field parameters (DO, temp, ph, conductivity) In-situ Multi-probe (Routine) Texas Stream Team Kits (Reconnaissance)

50 STEP 11 LAND USE & LAND MANAGEMENT MONITORING Watershed Source Survey Amass existing GIS information on the watershed Wastewater Infrastructure, Stormwater Infrastructure, etc. Conduct physical stream walks & floats to ID potential sources Small discharges to waterway, bird rookeries, bat colonies, etc. Incorporate into GIS & transfer findings to local GIS coordinators Watershed Survey Assessment Combines findings from GIS survey and physical survey to identify potential problem areas

51 STEP 12 DATA MANAGEMENT Data acquisition Historical E. coli data from Stations 11782, & Data validation Data Review Checklist Data storage & retrieval TWRI database TCEQ SWQMIS Texas Stream Team database Data manipulation Excel, Minitab, SigmaPlot Reporting Quarterly

52 OTHER CONSIDERATIONS Lab hours (critical for storm samples) Costs Travel time (exceeding holding time) Drought contingencies (TCEQ Guidance) Communication Maintain open communication with project manager

53 CONSIDERATIONS: LAB HOURS & TRAVEL TIME Most labs open 8-5 Most storm events (>75%) occur during non-work hrs 40/168 = 23.8% of week M-F from 8-5 Make special arrangements with lab and field personnel to ensure holding times are met Especially important for E. coli Consider lab location/hrs, holding times & travel times when selecting sites, # teams needed & lab

54 CONSIDERATIONS: COSTS Use composite stormwater samples (flow-weighted) Produces event mean concentrations & loadings Site maintenance (for automated samplers) Budget for personnel and travel time Optimize parameters selected Evaluate correlation among parameters Note: greatest expense is generally travel & personnel time getting to the field to collect samples Utilize volunteer monitoring and/or reconnaissance monitoring to expand spatial coverage

55 DROUGHT CONTINGENCY TCEQ GUIDANCE, 11/03/11 Schedule & travel to monitoring sites as normal At monitoring site, photo document flow conditions If water present within 400 m of established site, collect routine water monitoring data Determine pool characteristics Report pool characteristics If site is dry, create sample event in SWQMIS Minimum data = flow severity & days since last signif. precip. Note comments indicating drought condition & other observations Communicate with Project Manager

56 QUESTIONS