Emerging Contaminants and
Impaired Waters/TMDLs
Mindy Erickson
Environmental Analysis and Outcomes Division
Minnesota Pollution Control Agency
and
Bioproducts and Biosystems Engineering
University of Minnesota
Impairments
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MPCA Guidance: “Guidance Manual for
Assessing the Quality of Minnesota Surface
Waters for the Determination of Impairment
305(b) Report and 303(d) List”
Water Quality Standards
Beneficial Use Classes for Surface Waters
„ Numeric Water Quality Standards
„ Narrative Water Quality Standards
„ Nondegradation
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Narrative Water Quality Standards
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IX.A – Lake eutrophication
IX.B – Impairment of the biological community
IX.C – Contaminants
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Introduction and fish consumption advice
Basis for assessment of fish contaminants – narrative standards
MDH thresholds for consumption advice
Selection of single fish mealmeal-perper-week impairment threshold
Mercury
Polychlorinated biphenyls
Data requirements and determination of impaired condition
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IX.C.1 – Introduction
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Two separate beneficial uses:
aquatic community healthy, diverse and successfully
reproducing
„ fish and other aquatic organisms safe for people and
wildlife to eat
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Impairment possible for one but not the other
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IX.C.2 – Basis
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MN Rules 7050.0150, subp. 6
… A water body will be considered impaired
when the recommended consumption frequency
is less than one meal per week…
… not considered impaired if the recommended
consumption frequency is one meal per week, or
any less restrictive…
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IX.C.3 – Thresholds
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Toxicity
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Reference dose: units of daily dose, is an estimate of the
daily exposure to human populations, including sensitive subsubpopulations, that is likely to be without appreciable risk of
deleterious effects over a lifetime.
Cancer potency slope: upper 95th percentile confidence
limit of the slope from a linear nonthreshold model of
incremental cancer risk, expressed in days times kilogram
body weight per milligram of toxicant.
Exposure
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Sources of toxicants to humans
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IX.C.3 – Thresholds (con’t)
Chemical Unlimited 1 meal/
week
1 meal/
month
Do not eat
Mercury
< 0.05
ppm
0.05 – 0.3
ppm
0.2 – 1.0
ppm
>1.0 ppm
PCBs
<0.05 ppm
0.05 – 0.2
ppm
0.2 – 1.0
ppm
>1.9 ppm
PFOS
<38 ng/g
38 – 160
ng/g
161 – 700 >700 ng/g
ng/g
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IX.C.4 – Impairment Threshold
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One meal per week
30 g/day Æ about ½ pound per week
„ Site-specific advice can vary
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IX.C.3 – Data Requirements
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Fish collected after 1989
Fillet
Minimum 5 fish per species
90th percentile exceeds threshold
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Fish contaminant monitoring program
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Multi-agency program
MPCA
„ MDH
„ MDNR
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MDH fish consumption advisory
MPCA site-specific study development
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Lake selection
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MDNR conducting fish population surveys
Fishing pressure high
Previous data more than ten years old
Information needed for special studies or trend
analysis
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Differences
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How does assessment based on a narrative
standard differ from…
Numeric Standards for Protection of Aquatic Life?
„ Numeric Standard for Protection of Recreation?
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Emerging Issue Example
Perfluorochemicals (PFCs)
Mindy Erickson
Laura Solem
Mark Ferrey
Paul Hoff
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PFCs
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Surfactants with unique chemical properties
Used for many years in products that resist
heat, stains, water, oil and grease
Many specialized industrial and commercial
uses
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Some Commercial Uses of PFOS
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Fabric coatings
Carpet coatings
Paper coatings
Floor polish
Alkaline cleaners
Denture cleaners
Shampoos
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Fire-fighting foam
Aviation hydraulic fluid
Mining/oil well surfactant
Acid rust suppressant
Metal plating
Electronic etching bath
Pesticides
- U.S. Environmental Protection Agency
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Background
PFCs of concern because:
„ Widely used
„ Persistent
„ Soluble
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1,000 ppm PFOA; 550 ppm PFOS
Low adsorption, readily desorb
Atmospheric transport/deposition
Exposure and health concerns
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PFOS – liver and thyroid impairments: animal studies
PFOA – liver, immune and developmental impairments:
animal studies
PFBA – longlong-term effects not yet studied. Potentially less
toxic, but more mobile
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Emerging Issues Barriers
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Laboratory methods
Toxicology research
Regulatory framework
Standards
Knowledge of sources
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Rapid evolution
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In 2005…
HBV for PFOS: 1 μg/L
„ HBV for PFOA: 7 μg/L
„ Lab detection level for PFOA: 1.0 μg/L
„ Lab detection level for PFOS: 0.5 μg/L
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In 2007…
HRL for both PFOA and PFOA: 0.3 μg/L
„ MDH lab report levels: 0.3 ppb
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„ flag and report estimated concentrations to 0.05 ppb
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Axys lab reporting levels approximately 0.01 ppb
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PFC Source Investigation Activities
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Sampling
Ground water
„ Soil
„ Sediment
„ Effluent
„ Leachate
„ Drinking water
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Literature review
Fate and transport
„ Toxicology
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Lake Calhoun Fish - 2007
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Ambient Ground Water
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No PFCs detected in 2006
Relatively high detection level
Recommended additional sampling with lower
detection level
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Some of MPCA’s current studies
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Ambient ground water monitoring, urban and agricultural areas
Ambient surface water: Mississippi River basin, urban and
agricultural areas
Air and precipitation monitoring
Data management and public access to data
Fish tissue monitoring, urban and rural areas
Food chain/wildlife/ecological risk assessment studies
Lake Calhoun PFOS Source Investigation
Literature review: fate & transport, toxicology, risk assessment,
assessment,
standardstandard-setting
Soil microcosm studies with EPA labs
Waste water treatment plant PFC assessment
Water quality criteria development for PFBA
Fire fighting foam survey
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PFCs General Form
CF3(CF2)nCF2-R
PFC Chemical Structures
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Perfluoroalkyl Sulfonic acids
PFAS
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Perfluoroalkyl Carboxylic acids
PFCA
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Fluorotelomer Alcohols
FTOH
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Perfluoroalkyl Phosphates
PAPs
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PFCs currently analyzed
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Perfluoroalkyl sulfonates
and sulfonamide:
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Perfluorobutane sulfonate
Perfluorohexane sulfonate
Perfluorooctane sulfonate
Perfluorooctane sulfonamide
Perfluoroalkyl carboxylic
acids:
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Perfluorobutanoic acid
Perfluoropentanoic acid
Perfluorohexanoic acid
Perfluoroheptanoic acid
Perfluorooctanoic acid
Perfluorononanoic acid
Perfluorodecanoic acid
Perfluoroundecanoic acid
Perfluorododecanoic acid
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PFCs of most interest in MN
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PFOS: C8F17SO3Perfluorooctane sulfonate and its salts
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PFOA: C8F15O2Perfluorooctanoic acid and its salts
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PFBA: C4F7O2Perfluorobutanoic acid and its salts
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General PFC Pathways
Inhalation
PFCs in
atmosphere
Ingestion, Dermal
Contact, Inhalation
Product Use
(fire fighting
foam, fabric
protectors,
cookware,
shampoo)
Fish Consumption
Disposal of
Products, Wastes
Manufacturing
Aquatic
Systems,
(including wastewater
treatment, landfills)
Occupational
exposure
Fish
Stormwater
runoff
Ingestion
Drinking water
ingestion
Ground water
contamination
Soil deposition/
land application
Ag Food
Products
Ingestion
Sampled Media
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Ground water
Surface water
Waste water treatment plant
Influent
„ Effluent
„ Sludge
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Fish
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Ambient ground water
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Monitoring wells because…
shallower depths to water
„ shorter screen lengths
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17 urban wells
9 in Twin Cities area
„ 8 outstate
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17 agricultural locations (MDA)
15 monitoring wells
„ 3 springs
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Surface Water
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Rivers
St. Croix River near Wild River State Park
„ Mississippi River Pool 3
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Lakes
Calhoun (Hennepin)
„ Tettegouche (Lake)
„ Dyers (Cook)
„ Long (Kandiyohi)
„ Sagatagan (Sterns)
„ Long (Itasca)
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Waste Water Treatment Plant
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Grab samples from 28 WWTPs
across Minnesota
„ variety of municipal and industrial facilities
„ influent, effluent, sludge
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Fish
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Lake selection
higher fishing pressure
„ prevalence of bluegill and bass
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Pan fish
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Game fish
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bluegill, black crappie, yellow perch
largemouth bass, northern pike, walleye
33 urban lakes
60 outstate lakes (results not yet available)
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Ground water sampling
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Peristaltic pump, polyethylene tubing, and silicone
tubing
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Field measurements
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No teflon bailers or tubing
pH, DO, temperature, conductivity, redox
Field analyses
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Alkalinity, chloride, iron, nitrate
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All sampling
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Sampler avoided personal contact with potential
PFC sources
Lab cleaned and proofed polypropylene bottles
Bottles sealed individually, stored 4º C
PFC-free blue ice for shipping
Dry ice for shipping fish
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QA/QC
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Avoid contamination from PFC-containing materials:
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Use nitrile gloves
Wear old clothing (laundered at least six times)
Avoid prepre-wrapped food and snacks (candy bars, chips)
Avoid fast food wrappers
Avoid wearing water resistant clothing
Avoid wearing insect repellant/sunscreen
New tubing for each ground water sample
Ten percent blind duplicate samples
Blind equipment blank using PFC-free water provide
by lab
Reporting Level (RL) of 25 nanograms per liter (ng/L)
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Laboratory
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AXYS Analytical Services Ltd.
AXYS Method MLA-060
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Analytical Procedure for the Analysis of
Perfluorinated Organic Compounds in Aqueous
Samples by LC-MSIMS
No EPA-approved method for PFCs at this
time
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Urban Ground Water Results
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PFC detections at 9 of the 17 sample locations
PFBA most commonly detected
7 of 17 sample locations above RL
„ Twin Cities Metro Area
„ Industrial or sewered residential land use
„ Concentrations 43.4 – 922 ng/L
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Agricultural Area Ground Water Results
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PFBA only detected PFC
PFBA detected above reporting level 25 ng/L at two
locations
„ Highest concentration 63 ng/L
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Surface Water Results
Water Body
St. Croix River
PFBA
4.57
PFOA
PFOS
ND
ND
Mississippi River, Pool 3
383.7
30.4
26.6
Calhoun (Hennepin)
25.4
19.8
108.0
Tettegouche (Lake)
Dyers (Cook)
Long Lake (Kandiyohi)
Sagatagan (Sterns)
ND
1.42
ND
ND
ND
ND
10.3
11.7
ND
ND
1.85
ND
Long Lake (Itasca)
11.3
0.988
ND
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WWTP Effluent Results
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PFOS detected in 12 of 28 effluent samples
PFOS, PFOA, PFBS and PFHxS most
commonly detected
PFOS concentration range 7 – 1,510 ng/L
Highest concentrations at Brainerd WWTP
„ Traced to a specific industrial source
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Urban Fish Tissue Results
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4 of 31 lakes with fish fillet PFOS concentration
≥160 ng/g (at least one species)
13 of 31 lakes with PFOS 38 – 160 ng/g
14 of 31 lakes with PFOS <38 ng/g
Awaiting results for fish from 2 lakes
MDH will consider results during its fish
consumption advisory update
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Discussion
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Ground water: highest ground water PFBA
concentrations in…
Twin Cities area
„ Industrial, commercial, and sewered residential
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Surface water:
Higher PFC concentrations in urban lakes
„ PFC distribution and ratios different urban vs. rural
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Fish tissue: highest PFOS in…
Lakes in the urban core (outstate lakes not yet known)
„ No specific PFOS sources identified
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Other MPCA studies
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PFCs present in…
Landfill leachate and landfill gas condensate
„ Ground water upgradient and downgradient of
landfills
„ Waste water treatment plant influent, effluent, and
sludge
„ Urban storm water runoff
„ Air
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Additional Information
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Half-life of PFOA and PFOS in humans is more
than four years
Half-life of PFBA is a few days
MDH drinking water standard for PFOS and
PFOA: 0.3 ug/L
PFBA standard is currently being developed
National biomonitoring: low concentrations of
PFCs ubiquitous in human blood
Some PFCs undergoing ‘voluntary phase-out’
Some PFC uses will be exempt from the phase-out
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Summary
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PFCs present in general consumer and industrial
waste
PFCs partition to water and air
PFOS bioaccumulates in fish
PFC sources, transport, and fate complex
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Barriers
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Laboratory methods
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Toxicology research
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Advancing, NPDES and landfill programs evaluating
Standards
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Advancing, new papers almost weekly
Regulatory framework
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Advancing, still no EPA approved method
Advancing, PFOS and PFOA WQS and HRLs, PFBA
in process
Knowledge of sources
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Advancing slowly, proprietary information barriers
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Now what?
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TMDL development for PFC-impaired waters
Conduct further monitoring and study
„ Complete pollutant load formula allocation
„ Develop restoration strategy
„ Implement restoration strategy
„ Monitor changes
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Further monitoring/study
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Food chain studies
Lake Calhoun PFOS source study
Stormwater
„ Precipitation
„ Land use
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Fire station survey
WWTP studies
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Pollutant Load Formula
LA(s) + WLA(s) + Margin of Safety + Reserve Capacity
= Total Pollution Maximum Daily Load
Where:
LA = Load allocations from nonpoint sources
WLA = Waste load allocations from point sources
Margin of Safety = to account for potential scientific error
Reserve capacity = set aside for future development
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Develop and Implement
Restoration Strategy?
Monitor Change?
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For more information
„
Mindy Erickson
Mindy.Erickson@state.mn.us or 651-297-8383
„ Laura.Solem@state.mn.us or 218-529-6254
„ Other PFC team members: http://www.mail.state.mn.us/
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http://www.pca.state.mn.us/hot/pfc.html
http://www.health.state.mn.us/divs/eh/hazardous/t
opics/pfcshealth.html
http://www.epa.gov/opptintr/pfoa/index.htm
http://www.pca.state.mn.us/water/tmdl/index.html
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Questions?
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