total maximum daily load for zinc in nueces bay l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Total Maximum Daily Load for Zinc in Nueces Bay PowerPoint Presentation
Download Presentation
Total Maximum Daily Load for Zinc in Nueces Bay

Loading in 2 Seconds...

play fullscreen
1 / 38

Total Maximum Daily Load for Zinc in Nueces Bay - PowerPoint PPT Presentation


  • 162 Views
  • Uploaded on

Total Maximum Daily Load for Zinc in Nueces Bay. David Maidment & Lynn E. Katz & Imane Mrini Center for Research in Water Resources The University of Texas at Austin. Project Managers Sandra Alvarado - TCEQ Blake Traudt - GLO. Zinc Impairment / criteria.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Total Maximum Daily Load for Zinc in Nueces Bay' - delilah


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
total maximum daily load for zinc in nueces bay

Total Maximum Daily Load for Zinc in Nueces Bay

David Maidment & Lynn E. Katz & Imane Mrini

Center for Research in Water Resources

The University of Texas at Austin

Project Managers

Sandra Alvarado - TCEQ

Blake Traudt - GLO

slide2

Zinc Impairment / criteria

  • Texas Department of Health Guidelines :
    • Average zinc concentrations in oysters from Nueces Bay should be consistently below 700 mg Zn/kg edible tissue
  • Data Observations
    • High concentrations (~ 2,389 mg/kg) were found in oysters resulting in acute adverse health effects (TDH, 1994);
    • No threat for fish or crabs
outline
Outline
  • Review of issues
  • Study area : Nueces Bay
    • Zinc impairment
  • Study objectives
    • Study of Zinc monitoring data
    • Estimation of watershed zinc loadings
  • Next steps
water quality pollution loading model
Water Quality: Pollution Loading Model

Load [Mass/Time]=Runoff [Vol/Time]x Concentration [Mass/Vol]

Precip.

Runoff

DEM

LandUse

Accumulated

Load

EMC Table

Load

Concentration

expected mean concentration
Expected Mean Concentration

Land Use

EMC

Table derived from USGS

water quality monitoring sites

water quality analysis
Water Quality Analysis

Salinity Concentration and Mass Fluxes

in Corpus Christi Bay.

Finite Segment

Analysis

Flow of water

Transport of Constituents

Fluxes

Loads

Advection

Dispersion

observed vs expected
Observed vs. Expected

Chromium (µg/l)

Zinc (µg/l)

physicochemical reactions
Physicochemical Reactions

sunlight

Atmospheric Deposition

Photochemical Reactions

Inorganic Reactions

Flux

Flux

Organic/Biological Reactions

Sediment-Water Exchange

resuspension and deposition
Resuspension and Deposition

Deposition

Resuspension

study area nueces bay
Study Area : Nueces Bay
  • Nueces bay TMDL segment 2482
  • Average area of 74.87 Km2 Mean depth : 0.68 to 0.92m
  • Relatively small average residence time (V/Q) = 30 days
  • Uses : Aquatic life, contact recreation, fishing, production of edible oysters, clams and mussels, and shellfish harvesting (oyster water use )
  • TMDL for zinc in oyster tissue
study objectives
Study Objectives
  • Acquire existing data and information necessary to support modeling and assessment activities
  • Determine current allowable loadings of the constituent (zinc)
  • Allocate the total loadings to appropriate pollutant sources
zinc monitoring data zinc in sediments
Zinc Monitoring dataZinc in sediments

Zn conc. ( ppm)

71 - 140

140.1 - 430

430.1 - 864

864.1 - 2100

slide16

Zinc Monitoring dataZinc in sediments

C

B

Inner Harbor

A

Industries:

A Centex Cement Corp.

B Central Power and Light

C PPG Industries

zinc monitoring data zinc in water
Zinc Monitoring dataZinc in water

Zinc conc. ( g/L)

15 - 21

21.1 - 40

40.1 - 53.4

53.5 - 73.3

73.31 - 546

hydrodynamic circulation
Hydrodynamic Circulation

Simulation by Dr Junji Matsumoto, TWDB

Animation

slide21

Sediment Data for the Inner Harbor

Average Zinc Conc. = 440 ppm

zinc monitoring data zinc partitioning in sediment water oyster tissue

Zinc in water

0.042 ppm

Zinc in sediment

100 ppm

Zinc in Oyster tissue

2400 ppm

Zinc Monitoring dataZinc partitioning in sediment/water/oyster tissue

Ratio = 2300

Ratio = 55,000

Ratio = 24

watershed delineation procedure

DEM

Flow_dir

Watershed

Watershed delineation Procedure

procedure developed for delineating watersheds in coastal and low-lying regions with little to no slope.

watershed source loadings of zinc

Precipitation

Runoff

Land use

Total Zinc Loadings = 772.9 g/day

concentrations

loadings

EMC Table

Watershed source loadings of zinc
current watershed sources of zinc
Current watershed sources of zinc
  • Total annual loadings of zinc from non point source pollution : 282 kg
  • Volume of the bay : 62.26 Mm3
  • Annual concentration of Zinc from NPS :4.53 g/L
  • Mean Measured concentration of zinc in water in Nueces bay : 42.1 g/L

Watershed sources are not the whole picture

estimation of mass of zinc in sediments in nueces bay
Estimation of Mass of Zinc in Sediments in Nueces Bay
  • 10 cm sediment bed depth and surface area of 74.9 km2V = 7,490,000 m3
  • Mass of sediments = 1.984 x1010 kg
  • Average concentration of zinc in sediments = 440 ppm (mg/kg)
  • Total mass of zinc in sediments = 8,730 metric tons
pollution sources in nueces bay
Pollution Sources in Nueces Bay
  • Total mass of zinc in sediments = 8,730 metric tons
  • Based on 1 kg/day watershed loading it will take 24,000 years to accumulate this mass
  • We must have point sources or legacy sources !!
next steps
Next Steps
  • Estimate background levels of zinc in sediments
  • Evaluate point sources
  • Consider hydraulics between inner harbor and Nueces Bay
  • Suggestions …
zinc monitoring data zinc in sediments at station 12960 nueces river north of viola basin
Zinc Monitoring data Zinc in sediments at station 12960Nueces river North of Viola Basin

126.7 mg/kg