Water Quality- based Effluent Limits WQBELs Karen Holligan May 6, 2015
Transcript
Slide 1
WQBELs Karen Holligan May 6, 2015
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WQBELs A Four-Piece Puzzle Numerical criteria (toxic
pollutants) Water body quality Effluent fraction Bioavailable
fraction WQBELs A Four-Piece Puzzle Numerical criteria (toxic
pollutants) Water body quality Effluent fraction Bioavailable
fraction
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Numerical Criteria for Toxic Pollutants Found in 30 TAC Chapter
307 the Texas Surface Water Quality Standards Table 1 aquatic life
Table 2 human health Criteria revisited every three years Numerical
Criteria for Toxic Pollutants Found in 30 TAC Chapter 307 the Texas
Surface Water Quality Standards Table 1 aquatic life Table 2 human
health Criteria revisited every three years
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Numerical Criteria for Toxic Pollutants Aquatic Life Table 1 in
the Standards Freshwater acute chronic Saltwater acute chronic
Note: Acute toxicity exposures of 4 days. Chronic toxicity
exposures of 7 days. Numerical Criteria for Toxic Pollutants
Aquatic Life Table 1 in the Standards Freshwater acute chronic
Saltwater acute Chronic Note: Acute toxicityexposures of 4 days.
Chronic toxicityexposures of 7 days.
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Most criteria are for total concentrations. Some criteria are
for dissolved concentrations: aluminum arsenic cadmium chromium
(tri and hex) copper lead nickel silver (free ion) zinc Numerical
Criteria for Toxic Pollutants Aquatic Life But wait! Permit limits
are written for total concentrations. Numerical Criteria for Toxic
Pollutants Aquatic Life Most criteria are for total concentrations.
Some criteria are for dissolved concentrations: aluminum arsenic
cadmium chromium (tri and hex) copper lead nickel silver (free ion)
zinc But wait! Permit limits are written for total
concentrations.
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Numerical Criteria for Toxic Pollutants Aquatic Life Conversion
from dissolved criteria to total limits uses ambient total
suspended solids (TSS) of nearest downstream classified segment. H
INT : Dissolved fraction = bioavailable fraction. Numerical
Criteria for Toxic Pollutants Aquatic Life Conversion from
dissolved criteria to total limits uses ambient total suspended
solids (TSS) of nearest downstream classified segment. H INT :
Dissolved fraction = bioavailable fraction.
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Numerical Criteria for Toxic Pollutants Aquatic Life Freshwater
criteria for pentachlorophenol depend on pH of receiving water
body. Pentachlorophenol more toxic at lower pH values. Numerical
Criteria for Toxic Pollutants Aquatic Life
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Some freshwater criteria depend on hardness of receiving water
body: cadmium chromium (trivalent) copper lead nickel zinc Example:
copper Numerical Criteria for Toxic Pollutants Aquatic Life
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These metals are more toxic in soft water, so freshwater
criteria are lower at smaller hardness values. Example: copper
Segment Number Water Body Name Hardness (mg/L of CaCO 3 ) Acute
Criterion (g/L) Chronic Criterion (g/L) 0505 Sabine River Above
Toledo Bend Reservoir 426.274.51 1412 Colorado River Below Lake J.
B. Thomas 31041.224.8 Numerical Criteria for Toxic Pollutants
Aquatic Life These metals are more toxic in soft water, so
freshwater criteria are lower at smaller hardness values. Example:
copper Segment Number 0505, Sabine River Above Toledo Bend
Reservoir: Hardness = 42 milligrams per liter, Acute Criterion =
6.27 micrograms per liter, Chronic Criterion = 4.51 micrograms per
liter Segment Number 1412, Colorado River Below Lake J. B. Thomas:
Hardness = 310 milligrams per liter, Acute Criterion = 41.2
micrograms per liter, Chronic Criterion = 24.8 micrograms per
liter
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Numerical Criteria for Toxic Pollutants Human Health Table 2
(2014) Water and Fish Fish Only Water columnbased criteria Note:
Human health criteria based on - Childhood exposure
(non-carcinogens) Lifetime exposure (carcinogens). Numerical
Criteria for Toxic Pollutants Human Health Table 2 (2014) Water and
Fish Fish Only Water columnbased criteria Note: Human health
criteria based on - Childhood exposure (non-carcinogens) Lifetime
exposure (carcinogens).
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Water quality data for each classified segment in Procedures to
Implement the Texas Surface Water Quality Standards (IP). TSS pH
Total hardness Total dissolved solids (TDS) Chloride Sulfate Water
Body Quality Water quality data for each classified segment in
Procedures to Implement the Texas Surface Water Quality Standards
(IP). TSS pH Total hardness Total dissolved solids (TDS) Chloride
Sulfate
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Water Body Quality TSS used to calculate bioavailable fraction
of metals pH used to calculate freshwater aquatic life criteria for
pentachlorophenol Total hardness used to calculate freshwater
aquatic life criteria for most metals Chloride used in calculating
bioavailable fraction of silver (freshwater only) Water Body
Quality TSS used to calculate bioavailable fraction of metals pH
used to calculate freshwater aquatic life criteria for
pentachlorophenol Total hardness used to calculate freshwater
aquatic life criteria for most metals Chloride used in calculating
bioavailable fraction of silver (freshwater only)
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Water Body Quality Critical values of ambient water quality
data: TSS 15 th percentile pH 15 th percentile Total hardness 15 th
percentile Chloride 50 th percentile Water Body Quality Critical
values of ambient water quality data: TSS 15 th percentile pH 15 th
percentile Total hardness 15 th percentile Chloride 50 th
percentile
Effluent Fraction Numerical criteria apply at the edge of each
zone: Name of ZoneAcronym Applicable Criteria Zone of Initial
Dilution ZID Acute Aquatic Life Aquatic Life Mixing Zone MZ Chronic
Aquatic Life Human Health Mixing Zone HHMZHuman Health Effluent
Fraction Numerical criteria apply at the edge of each zone: Zone of
Initial Dilution (ZID) - Acute Aquatic Life Aquatic Life Mixing
Zone (MZ) - Chronic Aquatic Life Human Health Mixing Zone (HHMZ) -
Human Health
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Effluent Fraction Regulatory zones and critical effluent
percentages for bays, estuaries, and wide tidal rivers If receiving
water at discharge point 400 feet wide: ZID = 50 feet (30%) MZ =
200 feet (8%) HHMZ = 400 feet (4%) Effluent Fraction Regulatory
zones and critical effluent percentages for bays, estuaries, and
wide tidal rivers If receiving water at discharge point 400 feet
wide: ZID = 50 feet (30%) MZ = 200 feet (8%) HHMZ = 400 feet
(4%)
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Effluent Fraction Regulatory zones and critical effluent
percentages for lakes If receiving water at discharge point 200
feet wide: ZID = 25 feet (60%) MZ = 100 feet (15%) HHMZ = 200 feet
(8%) Effluent Fraction Regulatory zones and critical effluent
percentages for lakes If receiving water at discharge point 200
feet wide: ZID = 25 feet (60%) MZ = 100 feet (15%) HHMZ = 200 feet
(8%)
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Effluent Fraction Regulatory zones and critical flows for
streams and rivers MZ 300' downstream, 100' upstream 7-day, 2-year
low flow (7Q2) ZID 60' downstream, 20' upstream 25% of 7Q2 HHMZ
300' downstream, 100' upstream Harmonic mean flow (HM) Effluent
Fraction Regulatory zones and critical flows for streams and rivers
MZ 300' downstream, 100' upstream 7-day, 2-year low flow (7Q2) ZID
60' downstream, 20' upstream 25% of 7Q2 HHMZ 300' downstream, 100'
upstream Harmonic mean flow (HM)
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Effluent Fraction Streams and Rivers What is Q E ? Effluent
Fraction Streams and Rivers
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Q E = Effluent flow Aquatic life Domestic final average
permitted flow Industrial new or amendment to increase flow
permitted average flow requested renewal - highest daily average
flow reported in last two years Effluent Fraction Streams and
Rivers Q E = Effluent flow Aquatic life Domestic final average
permitted flow Industrial new or amendment to increase flow
permitted average flow requested renewal - highest daily average
flow reported in last two years
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Effluent Fraction Streams and Rivers Q E = Effluent flow Human
health Domestic final average permitted flow Industrial new or
amendment to increase flow permitted average flow requested renewal
- average daily average flow reported in last two years Effluent
Fraction Streams and Rivers Q E = Effluent flow Human health
Domestic final average permitted flow Industrial new or amendment
to increase flow permitted average flow requested renewal - average
daily average flow reported in last two years
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Bioavailable Fraction For most metals, numerical criteria for
aquatic life are dissolved concentrations, but effluent limits are
expressed as total concentrations. The bioavailable fraction, which
is a function of TSS, is used to make this translation.
Bioavailable Fraction For most metals, numerical criteria for
aquatic life are dissolved concentrations, but effluent limits are
expressed as total concentrations. The bioavailable fraction, which
is a function of TSS, is used to make this translation.
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Bioavailable Fraction The bioavailable fraction equals: C d C T
where: C d = dissolved concentration C T = total concentration This
fraction depends on TSS : Bioavailable Fraction
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The term K P, the partition coefficient, also depends on TSS:
where b and m are values found in Table 6 in the 2010 IP(p. 160).
Bioavailable Fraction
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Putting All the Pieces Together Numerical CriteriaWater Body
Quality Effluent Fraction Bioavailable Fraction Putting All the
Pieces Together Numerical Criteria Water Body Quality Effluent
Fraction Bioavailable
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Putting All the Pieces Together Three easy steps to calculate
WQBELs for aquatic life and human health! Calculate waste load
allocation WLA Calculate long-term average LTA Calculate effluent
limits: daily average (DLY AVG) daily maximum (DLY MAX) Putting All
the Pieces Together Three easy steps to calculate WQBELs for
aquatic life and human health! Calculate waste load allocation WLA
Calculate long-term average LTA Calculate effluent limits: daily
average (DLY AVG) daily maximum (DLY MAX)
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Putting All the Pieces Together Aquatic Life Calculate WLAs for
both acute and chronic aquatic life protection: Putting All the
Pieces Together Aquatic Life
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Compare acute and chronic LTAs Use the smaller LTA to calculate
daily average and daily maximum effluent limits based on aquatic
life criteria: Putting All the Pieces Together Aquatic Life
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Putting All the Pieces Together Human Health Calculate WLA for
human health protection: Calculate LTA for human health protection:
Putting All the Pieces Together Human Health
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Calculate daily average and daily maximum effluent limits based
on human health criteria: Putting All the Pieces Together Human
Health
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Putting All the Pieces Together Compare Aquatic Life and Human
Health Limits Some pollutants have both aquatic life and human
health criteria. Compare limits based on aquatic life with limits
based on human health Include the lower concentrations in the
permit Putting All the Pieces Together Compare Aquatic Life and
Human Health Limits Some pollutants have both aquatic life and
human health criteria. Compare limits based on aquatic life with
limits based on human health Include the lower concentrations in
the permit
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Help! My draft permit includes a new or more stringent WQBEL
what can I do? Call your permit writer! Help! My draft permit
includes a new or more stringent WQBEL what can I do? Call your
permit writer!
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Why did I get this limit? Big Picture: New limit Average
concentration from application is 85% of calculated daily average
WQBEL More stringent limit Calculated WQBELs are more stringent
than existing limits Down in the weeds: numerical criteria, water
body quality, effluent fraction, bioavailable fraction Why did I
get this limit? Big Picture: New limit: Average concentration from
application is 85% of calculated daily average WQBEL More stringent
limit: Calculated WQBELs are more stringent than existing limits
Down in the weeds: numerical criteria, water body quality, effluent
fraction, bioavailable fraction
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All Pollutants Effluent fraction river or stream: Critical
flows Stream type which criteria apply? intermittent acute (no
dilution) perennial chronic, acute, HH intermittent with perennial
pools chronic (no dilution), acute (no dilution), HH Stream flows
7Q2, HM All Pollutants Effluent fraction river or stream: Critical
flows Stream type which criteria apply? intermittent acute (no
dilution) perennial chronic, acute, HH intermittent with perennial
pools chronic (no dilution), acute (no dilution), HH Stream flows
7Q2, HM
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All Pollutants Effluent fraction lake or bay: Critical mixing
conditions Relocate outfall narrow arm smaller mixing zones =
larger effluent fractions = lower permit limits wider area larger
mixing zones = smaller effluent fractions = higher permit limits
All Pollutants Effluent fraction lake or bay: Critical mixing
conditions Relocate outfall narrow arm = smaller mixing zones =
larger effluent fractions = lower permit limits wider area = larger
mixing zones = smaller effluent fractions = higher permit
limits
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All Pollutants Numerical Criteria: Site-specific standard
adopted in Appendix E of the Standards Temporary variance allows
time for permittee to develop comprehensive information to support
site- specific standard. Permittee must request variance Permit
must show that existing standard may not be appropriate Request
included in public notices All Pollutants Numerical Criteria:
Site-specific standard adopted in Appendix E of the Standards
Temporary variance allows time for permittee to develop
comprehensive information to support site- specific standard.
Permittee must request variance Permit must show that existing
standard may not be appropriate Request included in public
notices
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All Pollutants Numerical Criteria: Site-specific standard
(cont.) Temporary variance (cont.) Must be approved by EPA
Three-year permit term Permit language requires a study Variance
may be extended Coordinate with TCEQ staff All Pollutants Numerical
Criteria: Site-specific standard (cont.) Temporary variance (cont.)
Must be approved by EPA Three-year permit term Permit language
requires a study Variance may be extended Coordinate with TCEQ
staff
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All Pollutants Numerical Criteria: Site-specific standard
(cont.) Review EPA criteria development document Remove non-native
species data Add native species data Caution: reducing total number
of species may make criteria more stringent Coordinate with TCEQ
staff All Pollutants Numerical Criteria: Site-specific standard
(cont.) Review EPA criteria development document Remove non-native
species data Add native species data Caution: reducing total number
of species may make criteria more stringent Coordinate with TCEQ
staff
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Metals (except mercury or selenium) Numerical criteria:
Site-specific standard (cont.) Water-effect ratio (WER): Use whole
effluent toxicity testing to account for difference in toxicity in
receiving water. This is w or m factor in Table 1 of Standards
Saltwater: ~2; freshwater: ~3.5-8.5 Streamlined procedure for
copper (freshwater) Coordinate with TCEQ staff Metals (except
mercury or selenium) Numerical criteria: Site-specific standard
(cont.) Water-effect ratio (WER): Use whole effluent toxicity
testing to account for difference in toxicity in receiving water.
This is w or m factor in Table 1 of Standards Saltwater: ~2;
freshwater: ~3.5-8.5 Streamlined procedure for copper (freshwater)
Coordinate with TCEQ staff
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Metals Numerical criteria, water body quality Site-specific
hardness: affects criteria for cadmium, trivalent chromium, copper,
lead, nickel, and zinc 30 samples from receiving water upstream of
discharge and outside of MZ 1 week between successive samples
Coordinate study design with TCEQ staff Metals Numerical criteria,
water body quality Site-specific hardness: affects criteria for
cadmium, trivalent chromium, copper, lead, nickel, and zinc 30
samples from receiving water upstream of discharge and outside of
MZ 1 week between successive samples Coordinate study design with
TCEQ staff
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Metals Water body quality, bioavailable fraction Site-specific
TSS: affects bioavailable fraction 30 samples from receiving water
upstream of discharge and outside of MZ 1 week between successive
samples Coordinate study design with TCEQ staff Metals Water body
quality, bioavailable fraction Site-specific TSS: affects
bioavailable fraction 30 samples from receiving water upstream of
discharge and outside of MZ 1 week between successive samples
Coordinate study design with TCEQ staff
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Metals Bioavailable fraction Site-specific ratio of dissolved
to total metal concentration 30 samples from receiving water
upstream of discharge and outside of MZ 1 week between successive
samples Mix samples with effluent to equal critical dilution If no
water upstream, critical dilution is 100% effluent Metals
Bioavailable fraction Site-specific ratio of dissolved to total
metal concentration 30 samples from receiving water upstream of
discharge and outside of MZ 1 week between successive samples Mix
samples with effluent to equal critical dilution If no water
upstream, critical dilution is 100% effluent
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Metals Bioavailable fraction Site-specific ratio of dissolved
to total metal concentration (cont.) Measure total and dissolved
metal concentrations Measure TSS of receiving water and effluent
each time a sample is collected and mixed with effluent (unless
critical dilution is 100%) Coordinate study design with TCEQ staff
Metals Bioavailable fraction Site-specific ratio of dissolved to
total metal concentration (cont.) Measure total and dissolved metal
concentrations Measure TSS of receiving water and effluent each
time a sample is collected and mixed with effluent (unless critical
dilution is 100%) Coordinate study design with TCEQ staff
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Metals - Aluminum Bioavailable fraction Although aluminum is
assumed to be 100% bioavailable, permittees may: Conduct a study to
develop a site-specific ratio of dissolved to total aluminum
concentration Perform whole effluent toxicity testing to determine
the mean no observed effect concentration (NOEC) for total aluminum
Metals - Aluminum Bioavailable fraction Although aluminum is
assumed to be 100% bioavailable, permittees may: Conduct a study to
develop a site-specific ratio of dissolved to total aluminum
concentration Perform whole effluent toxicity testing to determine
the mean no observed effect concentration (NOEC) for total
aluminum
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Metals Aluminum (cont.) Bioavailable fraction TCEQ will:
Compare NOEC to aluminum limit calculated using the site-specific
ratio of dissolved to total aluminum Use revised limit if NOEC is
significantly greater than proposed effluent limit Metals Aluminum
(cont.) Bioavailable fraction TCEQ will: Compare NOEC to aluminum
limit calculated using the site-specific ratio of dissolved to
total aluminum Use revised limit if NOEC is significantly greater
than proposed effluent limit