Nonpoint Source Pollution

1
Nonpoint Source Pollution

• Some basic principles
• Example study of total pollution loads in the
  Corpus Christi Bay System (Ann Quenzers
  research)
• rainfall-runoff relationship
• point and nonpoint source loads
• connection to bay water quality
• Example study of total pollution loads in the
  Copano Bay System (Carrie Gibson and Ernest Tos
  research)
• Combination of spatial and statistical analysis

2
References

• CRWR Online Report 06-6 Bacterial Loadings
  Watershed Model in Copano Bay, Carrie Jo Gibson,
  David R. Maidment, and Mary Jo Kirisits, May 2006
  
• CRWR Online Report 98-1 A GIS Assessment of the
  Total Loads and Water Quality in the Corpus
  Christi Bay System , Ann Marie Quenzer, and David
  R. Maidment, May 1998
• Handbook of Hydrology Sec 14.1 and 14.2 on
  nonpoint source pollution sources
• Handbook of Hydrology Sec 28.6 on design for
  water quality enhancement

http//www.crwr.utexas.edu/online.shtml
(Handbook of Hydrology on reserve in Engr Library)
3
Adapt Water to the Land System
Water Characterization (water yield, flooding,
groundwater, pollution, sediment)
Land Characterization (Land use, Soils, Climate, T
errain)
Non Point Source Pollution (mean annual flows and
pollutant loads)
4
Possible Land-Water Transform Coefficients
5
Expected Mean Concentration

• EMC Load Mass/Flow Volume either on a single
  event basis or as an annual average

L
Q
C
L(t)Q(t)C(t)
0
T
0
T
T
0
EMC M/V
Concentration
Load
Flow
6
Map-Based Surface Water Runoff
Estimating the surface water yield by using a
rainfall-runoff function
Runoff, Q (mm/yr)
Q
P
Runoff Coefficient C Q/P
Accumulated Runoff (cfs)
Precipitation, P (mm/yr)
7
Water Quality Pollution Loading Module
Load Mass/Time Runoff Vol/Time x
Concentration Mass/Vol
Precip.
Runoff
DEM
LandUse
Accumulated Load
EMC Table
Load
Concentration
8
Expected Mean Concentration
Land Use
EMC
Table derived from USGS water quality monitoring
sites
9
Water Quality Land Surface -Water Body Connection
Bay Water Quality
Total Constituent Loads
Input for Water Quality Model
10
Total Loads and Water Quality in the Corpus
Christi Bay System

Presented by
Ann Quenzer and Dr. David Maidment
Special Thanks
Corpus Christi Bay National Estuary
Program Ferdinand Hellweger Dr. Nabil Eid Dr.
George Ward Dr. Neal Armstrong
11
Purpose

• To determine the rainfall/runoff relationship
• To estimate the point and non-point source loads
  to the bay system
• To quantify the relationship between the total
  loads and the bay system water quality

12
Basic Concept
Steady-State Model
Linkage of the Two Models
Calculate Flow and Total Loads
13
Watershed Delineation
Sub-Watersheds
14
Precipitation
Merged Precipitation Files
Precipitation Trend
Oregon State University
over Bay System
Precipitation Data


15
Regression Inputs and Outputs
16
Surface Water Runoff

17
Surface Water Runoff
Land Use

Precipitation
18
Precipitation and Runoff Gradient
Precipitation and Runoff Gradient from South (A)
to North (B) along the Bay System
Precipitation and Runoff Gradient Locations in
the South (A) and North (B)
19
Runoff Into Each Bay System
North Bay System 40.5 m3/s 56 of total flow
Entire Bay System 72 m3/s
Middle Bay System 24.5 m3/s 34 of total flow
South Bay System 7 m3/s 10 of total flow
20
Bay System Water Balance
Entire Bay System
21
Bay System Water Balance
North Bay System
Middle Bay System
South Bay System
22

Purpose

• To estimate the point and non-point source loads
  to the bay system

23
Total Constituent Loading
Land Surface Load
Point Source Load
Atmospheric Load
? Sediment Load ?
24
Land Surface Constituent Loading
Load Mass/Time Runoff Vol/Time x
Concentration Mass/Vol
25
Land Use
USGS Land
Use (1970s)
Addition of
Missing
Land Use
26
Percent Land Use
Total Study Area
Legend
27
EMC Table
28
Point Sources
Texas Natural Resources Conservation Commission
(TNRCC) Water Quality Segmentation
29
Loads Routing
30
Load Routing Methodology
31
Connection of Both Models
Bay Water Quality
Total Constituent Loads
Input for Water Quality Model
32
Total Load to Bay System
33
Atmospheric Contribution
Total Nitrogen Atmospheric Load to Land Surface
2,700 Kg/d which is 35 of Land Surface Load
from agricultural land use. This calculation
is made assuming the EMC of 4.4 mg/l for
agriculture and a Nitrogen concentration of 1.1
mg/l in precipitation
34
Bay System Segmentation
Clipped Segmentation from Drs. Armstrong and Ward
Segmentation Used in the CCBNEP Project
35
Bay System Model Methodology.
36
Bay System Model Methodology.
37
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
38
Observed vs. Expected
Total Nitrogen (mg/l)
Total Phosphorus (mg/l)
39
Observed vs. Expected
Oil and Grease (mg/l)
Copper (µg/l)
40
Observed vs. Expected
Zinc (µg/l)
Chromium (µg/l)
41
Conclusions

• Strong South-North gradient in runoff from the
  land surface
• Nearly all water evaporates from bays, little
  exchange with the Gulf
• Nonpoint sources are main loading source for most
  constituents
• Nitrogen, phosphorus, oil grease loads are
  consistent with observed concentrations in the
  bays
• Metals loads from land account for only a small
  part of observed concentrations in bays it was
  concluded later that metals concentrations were
  too high because the samples had not been
  obtained using clean sampling methods.

42
Bacterial TMDL Model for Copano Bay

• Research performed by Carrie Gibson and Ernest To
  at Center for Research in Water Resources
• Schematic processor tool developed by Tim
  Whiteaker at CRWR
• Research supported by Texas Commission for
  Environmental Quality

43
Presentation Outline

• Background
• Scope of Work
• Bacterial Loading Water Quality Model
• Non-Point Source Bacterial Loading
  Calculations/Results
• Point Source Bacterial Loading Calculations/Result
  s
• Modeling Bacteria Transport Schematic Processor
• Calibration of Model
• Conclusions
• Future Work

44
Project Location

• Copano Bay watershed

Copano Bay
45
Background

• Section 303(d) of 1972 Clean Water Act (CWA)
• Texas Surface Water Quality Standards
• Fecal coliform bacteria
• Oyster water use
• Contact Recreation Use

Mission River
Aransas River
Copano Bay
46
Existing Monitoring Data
47
Scope of Work

• Identify major bacterial sources in Copano Bay
  watershed.
• Calculate total bacterial loadings, Total Maximum
  Daily Loads (TMDLs), from bacterial sources.
• Determine amount of load reductions that is
  needed to meet water quality standards.

48
Potential Bacteria Sources

• Non-point bacteria sources
• Point sources
• Concentrated Animal Feedlot Operations (CAFOs)
• Livestock (cattle, goats, horses, sheep, hen,
  hogs, and chickens)
• Wastewater Treatment Plants (WWTPs)
• Septic Systems
• Waterbirds

49
Non-Point Bacterial Loadings

• Basic Equation
• L Q C
• L Bacterial loadings (cfu/year)
• Q Runoff (m3/year)
• C Fecal coliform concentration (cfu/m3)

50
Runoff (Q) Calculations

• Rainfall-runoff equations derived by Ann Quenzer
• Based on land use and precipitation

Quenzer Equations
Runoff, Q (m3/year)
51
EMC (C) Calculations

• From Reem Jihan Zouns thesis, Estimation of
  Fecal Coliform Loadings to Galveston Bay
• Modified dbf table in order not to account for
  livestock fecal wastes twice

0
0
0
52
Creation of EMC Grid
Join based on land use code
53
Non-Point Bacterial Loading Grid
Annual Bacterial Loading per Grid Cell

54
Non-Point Loading per Watershed
Delineated Watersheds using WRAP Hydro
Annual Bacterial Loading per Watershed (cfu/year)
Zonal Statistics
Annual Bacterial Loading per grid cell (cfu/year)
55
Point Source Calculations Livestock

• Cattle, goats, horses, sheep, layers, hogs,
  chickens
• Data (annual animal count per county) from
• 2002 Census of Agriculture, National Agricultural
  Statistics Service (NASS)
• 2004 Texas Livestock Inventory and Production,
  United States Department of Agriculture (USDA),
  NASS, Texas Statistical Office

56
Livestock Loading Results

• Results
• Add cfu/year
• to non-point
• bacterial loading
• calculations

Livestock Bacterial Loadings
57
Point Source Calculations Avian

• Texas Colonial Waterbird Census (TCWC)

Breeding Pair Locations
Locations of Applied Avian Loads
58
Avian Loading Results

• Results
• Add cfu/year
• to non-point
• bacterial loading
• calculations

59
Bacterial Loading to Watersheds

• Results

60
Water Quality Model

• Created Water Quality Model using Model Builder

Cumulative Runoff per Watershed
Runoff (m3/yr)
Schematic Processor
Load (cfu/year)
Concentration (cfu/m3)
Cumulative Loading per Watershed
61
Bacterial Loading Transport using Schematic
Processor

• Creation of Schematic Network

Reference Whiteaker, T., D.R. Maidment, J. L.
Goodall, and M. Takamatsu, Integrating Arc
Hydro features with a schematic network,
Transactions in GIS, Vol. 10, No. 2, pp.
219-238, 2006
Watershed Drainage Junction Bay
Watershed to Junction Junction to
Junction Junction to Bay
62
Schematic Processor Implements DLLs

• Dynamic linked libraries, DLLs
• First-order decay
• Simulates decay of bacteria along stream segments
• loadpassed loadreceived e-kt
• k first-order decay coefficient (day-1) -
  stored as attribute in SchemaLink
• t travel time along streams, t (days) - stored
  as attribute in SchemaLink

Decay
63
Copano Bay acts as CFSTR

• CFSTR
• Assumptions
• Bay is completely mixed and acts as Continuous
  Flow, Stirred Tank Reactor (CFSTR)
• Inflow Outflow
• c L/(QkV)
• c concentration in bay (cfu/m3)
• L bacteria load entering bay (cfu/yr)
• Q total flow (m3/yr) stored as attribute in
  SchemaNode
• k first-order decay coefficient (day-1) -
  stored as attribute in SchemaNode
• V volume of bay (m3) stored as attribute in
  SchemaNode

64
Schema Links and Nodes
65
Computations along the network
66
Moving material through links and nodes
67
Processing Steps
68
DLLs have the processes in them
69
Schematic Processor Parameters

• Parameters (Inputs)
• SchemaLink (SrcTypes 1 and 2)
• Residence Time (t in days), Decay Coefficient (k
  in day-1)
• SchemaNode
• SrcType 3 Copano Bay
• Volume (V in m3), Decay Coefficient (k in day-1)
• Cumulative Runoff (Q in m3/year)
• SrcType 1 Watersheds
• Bacterial Loading per Watershed (L in cfu/year)

Determined by User Calculated from Previous Steps
in Model Builder
70
Model Calibration Aransas River

• Calibration Locations (Four)

71
Model Calibration Aransas River

• Goal Adjust upstream k and t values of each
  calibration location until median concentration
  of existing data is achieved.
• Then set k and t parameter values and work on
  the next downstream calibration location
  (bacteria monitoring station.)

Nodes/Links parameters that can be varied for
each bacteria monitoring station calibration
72
Modeled versus Existing Data
73
Modeled versus Existing Data
74
Conclusions

• Major point and non-point source bacterial
  loadings have been calculated.
• Bacterial Loadings Water Quality Model has been
  created.
• Model has been calibrated (adjusting k and t
  parameters) to existing median bacteria
  monitoring data.
• There is uncertainty in the calculations of
  bacterial loadings and in the determination of
  parameters.