Bacteria and Dissolved OxygenBacteria and Dissolved OxygenTotal Mass Daily Load DevelopmentTotal Mass Daily Load Development

for thefor the

Atascosa RiverAtascosa RiverJessica L. WattsJessica L. Watts

TMDL OverviewTMDL OverviewA TMDL is a tool for implementing state water quality standards. It A TMDL is a tool for implementing state water quality standards. It

is based on the relationship between sources of pollutants and is based on the relationship between sources of pollutants and in-stream water quality conditions.in-stream water quality conditions.

TMDL = LC = WLA + LA + MOSTMDL = LC = WLA + LA + MOS

LA

WLA

MOS

TMDLwhere:where:

LC = LC = loading loading capacitycapacityWLA = WLA = wasteload wasteload allocationallocationLA =LA = load load allocation; andallocation; andMOS =MOS = margin of margin of safetysafety

Natural Water QualityNatural Water QualityAssessment and ControlAssessment and Control

Priority Ranking and Targeting

Assessment of Water Quality-Based Control

Actions

Identification of Water Quality-Limited Waters

Development of TMDLs

Implementation of Control Actions

Components of TMDL Development

1. Problem Identification2. Identification of water quality indicators and targets3. Source assessment4. Linkage between water quality targets and sources5. Allocations6. Follow-up monitoring and evaluation7. Assembling the TMDL

1.1. What are the What are the Designated UsesDesignated Uses and and Associated Impairments Associated Impairments of the river?of the river?

2.2. What What DataData are readily available? are readily available?

3.3. What is the What is the Geographic SettingGeographic Setting of the TMDL? of the TMDL?

4.4. What are the What are the Exacerbating CharacteristicsExacerbating Characteristics of the river and its watershed? of the river and its watershed?

5.5. What are the What are the Pollutant Sources Pollutant Sources andand Pathways Pathways??

What temporal considerations affect the TMDL?What temporal considerations affect the TMDL?

How will margin of safety be addressed in the TMDL?How will margin of safety be addressed in the TMDL?

What are some potential control options?What are some potential control options?

Key Questions Considered for Key Questions Considered for Problem IdentificationProblem Identification

The Atascosa River’sThe Atascosa River’sdesignated usesdesignated uses

Aquatic LifeAquatic Life Subcategory – HighSubcategory – High Has NO known Federally Endangered or Has NO known Federally Endangered or

Threatened Aquatic SpeciesThreatened Aquatic Species Contact RecreationContact Recreation GeneralGeneral Fish ConsumptionFish Consumption Public Water SupplyPublic Water Supply

Key Question #1: What are the Designated Uses and Associated Impairments of the River?

Associated Impairments/Associated Impairments/2004 Concerns2004 Concerns

US

28

1

25 Miles Surrounding US 281

Concerns

Contact Recreation UseContact Recreation Use

BacteriaBacteria

Nutrient Enrichment ConcernNutrient Enrichment Concern

AmmoniaAmmonia

Algal Growth ConcernAlgal Growth Concern

Excessive Algal GrowthExcessive Algal Growth

Public Water SupplyPublic Water Supply

Total Dissolved Solids

Lower 25 Miles

Concerns

Public Water SupplyPublic Water Supply

Total Dissolved Solids

Remainder of Segment

Concerns

Public Water SupplyPublic Water Supply

Total Dissolved Solids

Readily Available InformationReadily Available InformationInformation was downloaded from the web, including:Information was downloaded from the web, including:

EPA Basins:EPA Basins: River ReachesRiver Reaches Soil Information (STATSGO)Soil Information (STATSGO) Major RoadsMajor Roads HUC BoundaryHUC Boundary Dam SitesDam Sites CountiesCounties EcoregionsEcoregions Water Quality Monitoring Station SummariesWater Quality Monitoring Station Summaries Bacteria Monitoring Station SummariesBacteria Monitoring Station Summaries Weather Station SitesWeather Station Sites USGS Gaging StationsUSGS Gaging Stations Clean Water Needs SurveyClean Water Needs Survey Industrial Facilities Discharge SitesIndustrial Facilities Discharge Sites Permit Compliance System Sites and LoadingsPermit Compliance System Sites and Loadings CERCLIS – Superfund National Priority ListCERCLIS – Superfund National Priority List RCRIS – Resource Conservation and Recovery RCRIS – Resource Conservation and Recovery

Information SystemsInformation Systems Mineral Industry LocationsMineral Industry Locations

USGS Seamless:USGS Seamless: AquifersAquifers National Elevation DatasetNational Elevation Dataset 1992 Land Use1992 Land Use

USGS – NHD:USGS – NHD: PointsPoints WellsWells Gaging StationsGaging Stations FlowlinesFlowlines WaterbodiesWaterbodies

PRISMPRISM PrecipitationPrecipitation

Key Question #2: What Data are readily Available?

Geographic SettingGeographic Settingof theof the

Atascosa RiverAtascosa River

Key Question #3: What is the Geographic Setting of the TMDL?

Land UseLand Use Key Question #4: What are the Exacerbating Characteristics of the river and its watershed?

Point Source Pollutant SourcesPoint Source Pollutant Sources

Legend

1 CERCLIS - Superfund

6 NPDES

11 Industrial Facilities Discharge

40 Mineral Industry

Key Question #5: What are the Pollutant Sources and Pathways?

Pollutant PathwaysPollutant Pathways

Use of GIS in Pollutant Transport ModelingUse of GIS in Pollutant Transport Modeling

How GIS Fits Into How GIS Fits Into BASINSBASINS& the TMDL Process& the TMDL Process

MeteorologicalData

GIS

Landuse and pollutantspecific Data

HSPFHSPF

LanduseDistribution

StreamData

Point Sources

Core Model

Post Processing

Windows interface

Landscape dataAB

D

E

F

C

CH2MHILL

Atascosa DEM Terrain ProcessingAtascosa DEM Terrain Processing

Atascosa Subwatershed CreationAtascosa Subwatershed Creation

33 Catchments 2 Gaging Stations and

1 Outlet

_____________________

36 Subwatersheds

Used a Threshold of 60 to create

What’s NextWhat’s NextBASINS Predefined Delineation ProcessBASINS Predefined Delineation Process

Shapefiles and TablesShapefiles and Tables• SubbasinsSubbasins• StreamsStreams• OutletOutlet

Questions?

Picture by: James Hindes

http://www.pbase.com/jhindes/the_river

Acknowledgements

Dr. David Maidment

Nate Johnson

Carrie Gibson