Compendium of State and
Regional NPDES Nutrient
Permitting Approaches
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Table of Contents
Introduction to the Compendium v
Permitting Critical Conditions 1
Critical Receiving Water Upstream Flow 1
Colorado 1
Idaho 2
Minnesota 3
Montana 3
Wisconsin 3
Critical Effluent Pollutant Concentration 4
Colorado 4
Idaho 5
Minnesota 5
Critical Receiving Water Pollutant Concentration 6
Colorado 6
Idaho 6
Minnesota 7
Wisconsin 7
Performance Based Approaches 8
Alabama 8
Colorado 8
Delaware 11
Georgia 12
Indiana 12
Iowa 14
Michigan 15
Minnesota 16
Missouri 17
New Jersey 17
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Table of Contents
New York 18
North Carolina 20
Ohio 21
Pennsylvania 22
Tennessee 23
Texas 24
Virginia 25
Wisconsin 26
Delaware River Basin Commission 27
Water Quality Trading 30
California 30
Colorado 34
Connecticut 36
Florida 39
Idaho 41
Louisiana 44
Maryland 48
Minnesota 50
Montana 52
Ohio 54
Oregon 57
Pennsylvania 60
Virginia 63
Washington 65
Wisconsin 67
Watershed-Based Permitting 71
Integrated Municipal Permits 72
Oregon 72
Multisource Watershed-Based Permits 74
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Table of Contents
California 74
Connecticut 76
Maryland 77
New Mexico 81
North Carolina 83
Virginia 89
Wisconsin 91
Coordinated Individual Permits 92
Connecticut 92
Ohio 93
Rhode Island 96
Vermont 98
Wisconsin 102
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Introduction to the Compendium
This compendium is a collection of state practices, policies, and procedures (hereafter,
"procedures") for reducing excess nutrients. Its purpose is to facilitate state-to-state sharing
about different approaches for addressing the adverse effects of excess nutrients in National
Pollutant Discharge Elimination System (NPDES) permits. This compendium will showcase
different state procedures and open dialog on the different approaches.
The compendium includes information about nutrient-specific procedures employed by
authorized NPDES state and regional permitting authorities. It is divided into the following
sections:
Permitting Critical Conditions
o Critical Receiving Water Upstream Flow
o Critical Effluent Pollutant Concentration
o Critical Receiving Water Pollutant Concentration (i.e., background)
Performance Based Approaches
Water Quality Trading
Watershed-Based Permitting
o Integrated Municipal Permits
o Multisource Watershed-Based Permits
o Coordinated Individual Permits
EPA will update the compendium as needed based on comments received and new
information. The inclusion of any particular permit example, policy, or procedure should not be
read as an Agency endorsement of the approach taken in that permit, nor should it be read as
EPA's independent determination that the permit terms meet the regulatory requirements to
satisfy the appropriate water quality requirements of the Clean Water Act and the
implementing regulations that govern the NPDES program.
This document does not contain or impose any legally binding requirements on EPA, states, or
the regulated community, and does not confer legal rights or impose legal obligations upon any
member of the public. EPA made every attempt to ensure the accuracy of the examples
included in this document; in the event of a conflict between this compendium and any statute,
regulation, or permit, the statute, regulation, or permit controls.
For more information about nutrient permitting under the NPDES program, visit
https://www.epa.gov/npdes/nutrient-permitting.
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Compendium at a Glance
Critical
Receiving
Water
Upstream
Flow
Critical
Effluent
Pollutant
Concentration
Critical
Receiving
Water
Pollutant
Concentration
Performance
Based
Approaches
Water Quality
Trading
Watershed
Based
Permitting
State
Permitting Critical Conditions
Alternate Approaches
Alabama
Page 8
California
Page 30
Page 74
Colorado
Page 1
Page 4
Page 6
Page 8
Page 34
Connecticut
Page 36
Pages 76 & 92
Delaware
Page 11
Florida
Page 39
Georgia
Page 12
Idaho
Page 2
Page 4
Page 6
Page 41
Indiana
Page 12
Iowa
Page 14
Louisiana
Page 44
Maryland
Page 48
Page 77
Michigan
Page 15
Minnesota
Page 2
Page 4
Page 6
Page 16
Page 50
Missouri
Page 17
Montana
Page 3
Page 52
New Jersey
Page 17
New Mexico
Page 81
New York
Page 18
North Carolina
Page 20
Page 83
Ohio
Page 21
Page 54
Page 93
Oregon
Page 57
Page 72
Pennsylvania
Page 22
Page 60
Rhode Island
Page 96
Tennessee
Page 23
Texas
Page 24
Vermont
Page 98
Virginia
Page 25
Page 63
Page 89
Washington
Page 65
Wisconsin
Page 3
Page 7
Page 26
Page 67
Pages 91 &
102
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PERMITTING CRITICAL CONDITION
Permit writers may use water quality models to assess the
impact a discharge(s) has on a receiving water. Where
steady-state models are used for water quality-based
permitting, an important part of characterizing the effluent
and receiving water is identifying the critical conditions
needed as inputs to the water quality model. The critical
conditions used for nutrient permitting may be different
than the critical conditions used for permitting toxic
pollutants (EPA's NPDES Permit Writers' Manual). This
compendium identifies state policies or procedures that reflect
what permit writers have considered for the following critical conditions to control excess
nutrients: flow, pollutant concentration, and receiving water pollutant concentration.
Critical Receiving Water Upstream Flow
For rivers and streams, an important critical condition is the stream flow upstream of the
discharge. This condition, generally specified in the applicable water quality standards, reflects
the duration and frequency components of the water quality criterion that is being addressed.
For most pollutants and criteria, the critical flow in rivers and streams is some measure of the
low flow. Examples of typical critical hydrologically-based low flows in water quality standards
include the 7Q10 (lowest 7-day average expected to occur once in 10 years) low flow for
chronic aquatic life criteria, the 1Q10 low flow for acute aquatic life criteria, and the harmonic
mean flow for human health criteria for toxic organic pollutants (EPA's NPDES Permit Writers'
Manual). However, a different measure could be appropriate for nutrients due to the complex
dynamics of nutrients and the receiving waters. Unlike toxic pollutants that have a direct and
often immediate effect, the impacts of nutrients may be delayed over time as the nutrients
are processed within the aquatic system. Longer flow averaging periods may be more
representative of critical receiving water flows due to these delayed and accumulated impacts.
COLORADO
The Colorado Department of Public Health and Environment's (CDPHE's) Basic Standards and
Methodologies for Surface Water (Regulation #31) define critical flow conditions of the
upstream receiving waters for the purposes of developing effluent limitations or other
lm Critical receiving water
upstream flow
2. Critical pollutant
concentration
3- Critical receiving water
pollutant
concentration
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PERMITTING CRITICAL CONDITIONS
requirements for discharge permits. For total phosphorus and total nitrogen limitations,
Regulation #31 specifies that the critical low flow is the annual median low flow with an
average l-in-5 year recurrence interval, which can be calculated from the second driest year in
a 10-year period.
IDAHO
The Idaho Department of Environmental Quality (DEQ) provides guidance for selecting critical
conditions for nutrients in Section 3.7.1 of the Idaho Pollutant Discharge Elimination System:
Effluent Limit Development Guidance. When selecting the critical receiving water upstream
flow, the guidance recommends aligning the stream flow averaging duration and the nutrient
averaging period. If the receiving waterbody's response to nutrients is best represented on a
seasonal or annual basis, the guidance recommends using a corresponding receiving water
duration (e.g., a receiving water with a seasonal nutrient load should use the corresponding
seasonal flow).
The guidance also acknowledges that the receiving waterbody's size may also affect the
selection of the appropriate average flow. For example, low-flow conditions may represent
critical receiving water flows for small waterbodies and large rivers and reservoirs. For systems
with long retention times, large flows may represent critical receiving water flows if they result
in greater nutrient response.
Idaho DEQ's approach is designed to produce effluent limits that will ensure receiving water
nutrient concentrations will not exceed the applicable criterion more than once in a 3-year
period. For a monthly average, the critical flow condition can be defined as the lowest 30-day
(i.e., monthly) average flow occurring once in 3 years (30Q3). For seasonal nutrient averaging
periods (e.g., 60 or 90 days during growing periods), the critical flow condition can be defined
using seasonal flow conditions that return with a frequency of once in 3 years. If an annual
averaging period is appropriate for the receiving water, the guidance recommends using the
harmonic mean flow.
Consistent with Idaho's mixing zone policy at IDAPA 58.01.02.060.01.h.i. the guidance specifies
that the percentage of stream flow allocated for nutrient mixing may not be expanded to be
larger than necessary and may not exceed 25 percent of the design low flow unless justification
is provided by the permittee considering siting, technological, and managerial options available
to the discharger as required in the water quality standards mixing zone policy.
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PERMITTING CRITICAL CONDITIONS
MINNESOTA
For mixing zones and compliance with river eutrophication standards. Minnesota
Administrative Rule 7053.0205 Subpart 7.C states. "Discharges of total phosphorus in sewage,
industrial waste, or other wastes must be controlled so that the eutrophication water quality
standard is maintained for the long-term summer concentration of total phosphorus, when
averaged over all flows, except where a specific flow is identified in chapter 7050.wl
Per Rule 7053.0255. for reservoirs, residence time is determined using a flow equal to the
122Q10 for June through September.
The Minnesota Pollution Control Agency (MPCA) provides guidance for choosing critical
conditions in the Procedures for Implementing River Eutrophication Standards in NPDES
Wastewater Permits in Minnesota. When a Total Maximum Daily Load (TMDL) or a detailed
water quality model exists, it is used to determine reasonable potential and WLAs related to
phosphorus limits. The procedures also describe using the 80 percent exceeds summer flow of
the river, minus the actual flows from contributing wastewater treatment facilities, as the
critical receiving water flow (Qs) for reasonable potential analysis and effluent limit calculations,
which are based on a mass-balance approach. MPCA chose the 80 percent exceeds summer
flow because it is reliable, reproducible, and simpler to derive than conventional low flow
statistics (e.g., 30Q3 or 7Q10). Flow calculations are based on summer (June to September)
flow data collected over 30 years.
MONTANA
The Administrative Rules of Montana (ARM 17.30.635(2)) specify that the seasonal 14Q5 shall
be used as the critical low flow for developing effluent limits for total nitrogen and total
phosphorus. The seasonal 14Q5 is the lowest average 14-consecutive-day low flow, occurring
from July through October, with an average recurrence frequency of once in 5 years.
WISCONSIN
Wisconsin's Administrative Code (NR 217.13) specifies the procedures for calculating effluent
limits for phosphorus using a mass-balance approach. The procedures require that the receiving
water design flow (Qs), in units of volume per unit time, be determined using one of the
following:
1 "Averaged over all flows" means that no high or low flow conditions are excluded in the calculation of the long-
term summer average flow.
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PERMITTING CRITICAL CONDITIONS
The average minimum 7-day flow that occurs once every 2 years (7-day Ch).
The average low 30-day flow that occurs once every 3 years (30-day Q3).
Other flow deemed more representative of flow conditions.
The 7-day Ch and 30-day Q3 must be based on information derived by the U.S. Geological
Survey, or another information source approved by the Wisconsin Department of Natural
Resources (DNR), using data from a representative gauging station with a period of record of at
least 10 years.
Critical Effluent Pollutant Concentration
The critical effluent pollutant concentration represents a reasonable estimate of the maximum
amount of the pollutant that would be expected to be present in the effluent. For toxics, EPA
has recommended considering a concentration that represents something close to the
maximum concentration of the pollutant that would be expected over time (e.g., the 99th or
95th percentile of a lognormal distribution of effluent concentrations) (EPA's Technical
Support Document for Water Quality-based Toxics Control). For nutrients, a different measure
could be appropriate since the impacts of excess nutrients occur primarily as a result of long-
term average exposure rather than acute exposure and the duration component of nutrient
criteria are often longer (e.g., seasonal or annual criteria) than acute and chronic aquatic life
criteria for toxic pollutants.
COLORADO
CDPHE's Nutrients Management Control Regulation (Regulation #85) requires domestic
wastewater treatment works to characterize the nutrient load in their discharge using routine
water quality monitoring programs. Major dischargers are also required to characterize the
upstream receiving water concentrations and the nutrient load below the discharge.
Sampling for total nitrogen (total Kjeldahl nitrogen plus nitrate-nitrite, or the components to
calculate total nitrogen) and total phosphorus (or the components to calculate total
phosphorus) is required in the receiving waterbody upstream of the discharge and at the
closest active gauging station with daily flow downstream of the discharge's mixing zone.
Alternatively, facilities may take part in collaborative watershed-based monitoring efforts.
Samples must be collected at least six times a year (every 2 months) for minor discharges and
monthly for major discharges.
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PERMITTING CRITICAL CONDITIONS
IDAHO
Idaho DEQ's Idaho Pollutant Discharge Elimination System: Effluent Limit Development
Guidance specifies procedures for conducting a reasonable potential analysis and calculating
water quality-based effluent limitations following a similar approach to the mass-balance
approach described in the U.S. EPA's Technical Support Document for Water Quality-Based
Toxics Control.
To conduct the reasonable potential analysis for nutrients, the guidance specifies that the
critical effluent concentration be derived using the 95th percentile of monthly daily maximum
effluent based on daily maximum data, instead of the maximum observed effluent
concentration, multiplied by a reasonable potential multiplying factor based on a 95th
percentile confidence level and 95th percentile probability basis.
When calculating water quality-based effluent limitations for nutrients, the guidance specifies
that the long-term average be derived using the 95th percentile confidence level instead of the
99th percentile confidence level, which is used for effluent limits for toxic pollutants based on
acute or chronic criteria.
MINNESOTA
M PCA's Procedures for Implementing River Eutrophication Standards in NPDES Wastewater
Permits in Minnesota use modeling and mass-balance approaches for reasonable potential
analyses and water-quality-based effluent limit calculations for discharges to rivers.
For the reasonable potential analysis, the long-term effluent concentration, existing
concentration limit, proposed concentration wasteload allocation for the downstream
resource, or concentration target of downstream mass wasteload allocation can be used as the
effluent concentration (Ce) in the mass-balance equation. The procedures note that no
multiplier should be used to transform Ce to 95th or 99th percentile concentration since the river
eutrophication standards are long-term summer averages over multiple years. The river
eutrophication standards do not specify a frequency of exceedance (e.g., not to exceed once in
10 years).
For developing effluent limits, the procedures require that the wasteload allocation be
multiplied by a default multiplier of 2.1 to derive an average monthly limit.
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PERMITTING CRITICAL CONDITIONS
Critical Receiving Water Pollutant Concentration
The critical receiving water pollutant concentration represents a reasonable estimate of the
maximum amount of the pollutant that would be expected to be present in the receiving water.
The permit writer should determine the critical background concentration of the pollutant of
concern in the receiving water before the discharge to ensure that any pollutant limitation
derived is protective of the designated uses. For toxics, the permit writer might use the
maximum measured background pollutant concentration or, perhaps, an average of measured
concentrations as the critical condition (EPA's Technical Support Document for Water Quality-
based Toxics Control). For nutrients, a different measure could be appropriate since the
impacts of excess nutrients occur primarily as a result of long-term average exposure rather
than acute exposure and the duration component of nutrient criteria are often longer (e.g.,
seasonal or annual criteria) than acute and chronic aquatic life criteria for toxic pollutants.
COLORADO
The Colorado Department of Public Health and Environment's Nutrients Management Control
Regulation (Regulation #85) requires domestic wastewater treatment works to implement
routine water quality monitoring programs to characterize the nutrient load in their discharge,
the upstream receiving water concentrations, and the nutrient load below the discharge.
Sampling for total nitrogen (total Kjeldahl nitrogen plus nitrate-nitrite, or the components to
calculate total nitrogen) and total phosphorus (or the components to calculate total
phosphorus) is required in the receiving waterbody upstream of the discharge and at the
closest active gaging station with daily flow downstream of the discharge's mixing zone.
Alternatively, facilities may take part in collaborative watershed-based monitoring efforts.
Samples must be collected at least six times a year (every 2 months) for minor discharges and
monthly for major discharges.
IDAHO
Idaho DEQ's Idaho Pollutant Discharge Elimination System: Effluent Limit Development
Guidance specifies procedures for conducting a reasonable potential analysis following a similar
approach to the mass-balance approach described in U.S. EPA's Technical Support Document for
Water Quality-Based Toxics Control.
To conduct the reasonable potential analysis for nutrients, the guidance specifies that the
critical receiving water pollutant concentration be derived using the 90th to 95th percentile of
background pollutant concentrations.
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PERMITTING CRITICAL CONDITIONS
MINNESOTA
M PCA's Procedures for Implementing River Eutrophication Standards in NPDES Wastewater
Permits in Minnesota use modeling and mass-balance approaches for reasonable potential
analysis for discharges to rivers. For these analyses, the procedures allow the following options
for estimating the upstream total phosphorus concentration:
Use river monitoring data from upstream of point sources during low flow conditions.
Assume upstream resource meets the applicable river eutrophication standard.
Estimate the concentration based on modeling or mass-balance calculations.
WISCONSIN
Wisconsin's Administrative Code (NR 217.13) specifies procedures for calculating effluent limits
for total phosphorus using a mass-balance approach. The procedures require using the
representative upstream concentration of phosphorus, derived using data from the specific
stream or from a similar location. This concentration is equal to the median of at least four
samples collected from May through October. All samples collected during a 28-day period shall
be considered as a single sample and the average of the concentrations used. If available, up to
5 years of data may be used for the calculation. Data older than 5 years may be used if they are
representative of current conditions.
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PERFOR
Some states have adopted performance standards for nutrients that apply to certain categories
or classes of facilitiesfor example, publicly owned treatment works (POTWs)or that apply to
facilities discharging to a certain waterbody or statewide. These state performance standards
are similar to, and supplement the minimum technology-based requirements of, the Clean
Water Act. They often are associated with specific waterbodies or types of waterbodies, yet
separate from state water quality standards.
ALABAMA
The Alabama Department of Environmental
Management's Admin. Code r. 335-6-10-.10(2)
requires the establishment of a monthly limit of
1.0 milligrams per liter (mg/L) for total
phosphorus for new and expanding major
continuous point source discharges to a
waterbody classified as a "Treasured Alabama
Lake." Treasured Alabama Lakes are high-
quality waters within impoundments and
natural lakes that constitute exceptional resources: for example, waters of state parks and
wildlife refuges and waters offering exceptional whole-body water-contact recreation, water
supply, or rare and extraordinary ecological significance.
The rules require existing water quality for Treasured Alabama Lakes to be maintained and
protected pursuant to the state's Antidegradation Policy and Implementation Procedures. New
and expanding discharges to Treasured Alabama Lakes are not allowed unless a thorough
evaluation of all practicable treatment and disposal alternatives demonstrates there is no
feasible alternative.
COLORADO
CDPHE seeks to control nutrients in a number of ways, primarily through its Nutrients
Management Control Regulation (Regulation #85). Basic Standards and Methodologies for
Surface Water (Regulation #31), and Colorado Nutrient Management Plan and 10-Year Water
Quality Roadmap (Clean Water Policy 8).
o
Key Characteristics of ^
the Approach
Geographic scope: Treasured lakes in
Alabama
Pollutants: Total phosphorus
Types of facilities: New and
expanding continuous point sources
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PERFORMANCE-BASED APPROACHES
CDPHE promulgated Regulation #85 in June 2012 as part of a coordinated strategy to address
excess nutrients. Regulation #85 establishes the following numerical effluent limits for domestic
wastewater treatment plants (WWTPs) and industrial wastewater dischargers that are likely to
have significant levels of nutrients in their discharges.
Type of Facility
Total Phosphorus
Total Inorganic Nitrogen as
Na
Annual
Median
Limitation*3
95th
Percentile
Limitation0
Annual
Median
Limitation*3
95th
Percentile
Limitation0
Existing domestic WWTPs
and non-domestic facilities'^
1.0 mg/L
2.5 mg/L
15 mg/L
20 mg/L
New domestic WWTPs and
non-domestic facilities'^
0.7 mg/L
1.75 mg/L
7 mg/L
14 mg/L
Existing non-domestic
facilities within Standard
Industrial Classification (SIC)
Major Group 20 (Food and
Kindred Products)
10 mg/L
25 mg/L
20 mg/L
27 mg/L
New non-domestic facilities
within SIC Major Group 20
(Food and Kindred
Products)
5 mg/L
13 mg/L
10 mg/L
20 mg/L
a Determined as the sum of nitrate as N, nitrite as N, and ammonia as N.
b Rolling annual median: The median of all samples taken in the most recent 12 calendar months.
c The 95th percentile of all samples taken in the most recent 12 months.
d Limits apply to non-domestic facilities that, without treatment for nutrients, are expected to
discharge total inorganic nitrogen or total phosphorus concentrations in excess of the listed
concentrations (excluding non-domestic facilities within SIC Major Group 20).
The numeric effluent limits do not apply to:
existing domestic WWTPs with a design capacity of less than or equal to 1.0 MGD or
existing domestic WWTPs owned by a disadvantaged community.
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PERFORMANCE-BASED APPROACHES
Additionally, the effective date of the numeric effluent limits is delayed until
December 31, 2027, for:
existing domestic WWTPs subject to watershed protection control regulations,
existing domestic WWTPs with a design capacity of less than or equal to 2 MGD, and
existing domestic WWTPs and non-domestic facilities discharging into low-priority
watersheds.
CDPHE established the effluent limits for existing facilities based on "first-level" biological
nutrient removal (BNR) that would typically consist of a three-stage process (i.e., single stages
of anaerobic, anoxic, and aerobic zones). The effluent limits for new facilities were based on
enhanced BNR that would typically consist of a four- or five-stage process (i.e., multiple stages
of anaerobic, anoxic, and/or aerobic zones).
Voluntary Incentive Program for Early Nutrient Reduction
As described in Clean Water Policy 8, in 2027, CDPHE will amend Regulation #31 to include
revised numeric water quality criteria for nitrogen and phosphorus in rivers and streams.
NPDES permits adopted thereafter will include, where necessary, new water quality-based
effluent limits based on the revised criteria that are more stringent than the technology-based
effluent limits in Regulation #85. CDPHE anticipates that facilities in Colorado will likely need
to install more treatment facilities beyond enhanced BNR to comply with such limits.
In anticipation of the new, more stringent water-quality-based effluent limitations, Section
85.5(1.5) of Regulation #85 and the Voluntary Incentive Program for Early Nutrient Reductions
(Policy 17-1) establish the requirements for a voluntary incentive program to encourage
facilities to voluntarily reduce phosphorus and/or nitrogen concentrations below the
technology-based effluent limits applicable before 2027.
Under the voluntary incentive program, permittees that achieve early reductions in nutrient
concentrations below the concentrations allowed by the Regulation #85 effluent limits will
receive an extended compliance schedule to provide additional time to meet the new water
quality-based effluent limits after 2027. This additional time is beyond that which would
otherwise be granted to a permittee not participating in the incentive program. The amount of
time granted will be based on both the levels of reduction that the facility achieves and the
timeframe in which it achieves and maintains those levels. The total duration of the compliance
schedule, including both the time allowed by participating in the incentive program and the
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PERFORMANCE-BASED APPROACHES
time the facility would receive if it had not participated (i.e., the underlying compliance
schedule), may not exceed 15 years.
Every permittee participating in the voluntary incentive program is required to submit a
nutrient reduction plan and annual nutrient monitoring reports.
CDPHE does not require wastewater treatment facilities to implement a specific treatment
technology to participate in the voluntary incentive program, but CDPHE anticipates that
nutrient reductions will be achieved through BNR or enhanced BNR (eBNR) optimization, water
quality trades, source reduction plans, watershed nutrient reductions, or other capital
improvements.
Policy 17-1 authorizes permittees participating in the voluntary incentive program to accrue
time under a compliance schedule through water quality trading. CDPHE will use the applicable
provisions of the Colorado Pollutant Trading Policy and Section 85.5(3)(d) of Regulation #85 to
determine the appropriate amount of time to be provided. For more information on Colorado's
water quality trading program, see "Water Quality Trading." Once the voluntary incentive
program period has been completed (December 31, 2027), any trading program developed to
generate an incentive will no longer be in effect. Thereafter, any permittee desiring to continue
the reduction of nutrients at the same locations will have to submit a new request for trading
credits.
DELAWARE
As a member of the Delaware River Basin Commission (DRBC), the Delaware Department of
Natural Resources and Environmental Control implements the DRBC antidegradation policy for
discharges to the Delaware River Basin within the state. See the "Delaware River Basin
Commission" section for more information.
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PERFORMANCE-BASED APPROACHES
QKey Characteristics of
the Approach
GEORGIA
Georgia DNR issued a memorandum titled
"Strategy for Addressing Phosphorus in NPDES
Permitting." The strategy specifies effluent
limits for total phosphorus for new and
expanding municipal and industrial discharges
that exhibit reasonable potential to exceed a
water quality standard, as follows:
Major dischargers will be permitted at 1.0
mg/L total phosphorus or less.
Minor dischargers will be permitted at 8.34 pounds/day total phosphorus or less.
All discharges to or close to reservoirs, lakes, impoundments, and/or estuaries will be
permitted at 0.5 mg/L total phosphorus or less.
Geographic scope: Statewide in
Georgia
Pollutants: Total phosphorus
Types of facilities: New and
expanding municipal and industrial
facilities
QKey Characteristics of
the Approach
INDIANA
The Indiana Department of Environmental
Management's (IDEM's) nonrule policy
document2 "State Total Phosphorus Treatment I
Standard for 1 MGD or Greater Sanitary
Wastewater Dischargers" (WATER-019-NPD),
under the authority of 327 IAC 5-10-2(a)(2).
states that for total phosphorus, an effluent
limit of 1.0 mg/L (expressed as an average
monthly limit) is needed for sanitary WWTPs
with average design flows greater than or equal
to 1 million gallons per day (MGD) to protect downstream water uses. The nonrule policy is
considered applicable to all major sanitary WWTPs that were scheduled to submit a permit
renewal application after January 1, 2015, or that applied for new NPDES permits after
January 1, 2015.
Geographic scope: Statewide in
Indiana
Pollutants: Total phosphorus
(calculated as elemental phosphorus)
Types of facilities: POTWs and non-
POTWs
2 IDEM's nonrule policy documents are intended to clarify IDEM's interpretation of environmental statutes or rules
for the public. They are not intended to have the effect of law.
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PERFORMANCE-BASED APPROACHES
According to Indiana's State Nutrient Reduction Strategy, IDEM will continue to implement
phosphorus removal as required by 327 IAC 5-10-2. which requires phosphorus removal or
control facilities for discharges that:
have a daily discharge, as a monthly average, that contains 10 pounds or more of total
phosphorus (calculated as elemental phosphorus) and are within the Lake Michigan or Lake
Erie Basins, discharge directly to a lake or reservoir, or enter a tributary within 40 miles
upstream of a lake or reservoir; or
are determined to need phosphorus reduction to protect downstream water uses or
achieve water quality standards.
For applicable POTWs, the treatment facility is required to achieve the following reductions in
the discharge (calculated as elemental phosphorus) or produce an effluent containing no more
than 1.0 mg/L of elemental phosphorus as a monthly average, whichever is more stringent.
Elemental Phosphorus (P) Level in Raw Sewage
Required % Removed
>4 mg/L
80%
<4 mg/L and >3 mg/L
75%
<3 mg/L and >2 mg/L
70%
<2 mg/L and >1 mg/L
65%
<1 mg/L
60%
For applicable non-POTWs, the amount of total phosphorus (calculated as elemental
phosphorus) in the discharge must be reduced by at least 90 percent unless the permittee can
demonstrate that such a reduction is technologically infeasible, and an alternate reduction is
warranted.
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PERFORMANCE-BASED APPROACHES
IOWA
Iowa DNR developed the Iowa Nutrient
Reduction Strategy to address nutrients
delivered to Iowa waterways and the Gulf of
Mexico. Section 3 of the strategy requires the
development of technology-based effluent
limitations on a case-by-case basis.
Geographic scope: Statewide in Iowa
Pollutants: Total nitrogen and total
phosphorus
Types of facilities: Municipal and
in d ustri a I facili ti es
Each major municipal, industrial, or minor
facility that treats wastewater using biological
treatment is required to develop a feasibility study to evaluate the economic and technical
feasibility of reducing nutrient discharges. The evaluation is based on the goal of achieving
annual average mass limits equivalent to 10 mg/L total nitrogen and 1 mg/L total phosphorus.
The specific effluent limitations that apply to each discharger are developed based on the
procedures in 40 CFR Part 125 Subpart A ("Criteria and Standards for Imposing Technology-
Based Treatment Requirements Under Sections 301(b) and 402 of the Act").
According to the strategy, the limitations will be based on the effect of the pollutant in the
water and the feasibility and reasonableness of treating the pollutant. Permit requirements will
vary based on the following factors.
Whether treatment is:
o Already installed.
o Not installed, with no capacity increases planned,
o Not installed, with capacity increases planned,
o Impracticable.
Whether the discharger is a new discharger.
Whether the discharge is from a power plant.
The strategy specifies that permits will not establish limits that are more stringent than 10 mg/L
total nitrogen and 1 mg/L total phosphorus where biological treatment is the primary means of
achieving the nutrient reduction goals. Facilities that cannot achieve these reductions because
of higher nutrient concentrations in the raw wastewater are expected to achieve reductions of
66 percent total nitrogen and 75 percent total phosphorus.
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PERFORMANCE-BASED APPROACHES
For a permitted discharger that installs nutrient reduction processes and whose NPDES permit
includes technology-based total nitrogen and total phosphorus limits, the strategy states, limits
will not be made more restrictive for at least 10 years after the completion of the nutrient
reduction process construction unless it is determined that more restrictive limits are necessary
to achieve water quality standards. This is consistent with Iowa Code Section 455B.173(3.b) for
municipal dischargers. For non-municipal dischargers, the strategy states that this prohibition
on establishing more restrictive limits "can be enforced through the permitting process or as
part of the adoption of any future nutrient limitation."
The strategy provides for limits to be expressed as annual average mass limits. The limit
calculation procedure is based on Appendix A of the U.S. EPA's Technical Support Document for
Water Quality-Based Toxics Control. The annual average is the sum of all measurements for a
given pollutant collected during a 12-month period (starting on the effective date of the permit)
divided by the number of measurements made.
MICHIGAN
Michigan's Water Quality Standards
(R 323.1060) include a standard for plant
nutrients. The plant nutrient standard requires
phosphorus from point source discharges to
achieve 1 mg/L of total phosphorus as a
maximum monthly average effluent
concentration unless other limits, either higher
or lower, are deemed necessary and
appropriate by Michigan DEQ. In addition, nutrients shall be limited to the extent necessary to
prevent stimulation of growths of aquatic rooted, attached, suspended, and floating plants,
fungi, or bacteria that are or may become injurious to the designated uses of the surface waters
of the state.
o
Key Characteristics of ^
the Approach
Geographic scope: Statewide in
Michigan
Pollutants: Total phosphorus
Types of facilities: All dischargers
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PERFORMANCE-BASED APPROACHES
MINNESOTA
Per Minnesota Rule Chapter 7053.0255.
Subpart 3, the discharger must provide total
phosphorus removal to 1.0 mg/L for a
discharge:
Geographic scope: Lakes, shallow
lakes, reservoirs, and certain
designated waters in Minnesota
Pollutants: Total phosphorus
Types of facilities: Dischargers to
certain waterbodies and new or
expanded facilities
directly to or affecting3 a lake, shallow lake,
or reservoir;
to certain designated waters; or
that is new4 or expanded.5
The total phosphorus limit is applied as a
calendar month arithmetic mean, unless the MPCA Commissioner finds that a different
averaging period is acceptable.
Dischargers of new or expanded discharges subject to the 1.0 mg/L limit may request an
alternative phosphorus limit if they can demonstrate that one of the following conditions is
met:
The discharge is to or upstream of an impaired waterbody and an approved TMDL
considered impacts from the discharge.
The environmental benefits to be achieved by meeting a total phosphorus limit are
outweighed or negated by the environmental harm caused by meeting a limit.
The treatment works, regardless of the type of treatment technology, uses chemical
addition to achieve compliance with the 1 mg/L limit and the discharge is to a receiving
stream in certain watersheds.
3 "Affects" means a measurable increase in the adverse effects of phosphorus loading as determined by monitoring
or modeling, including, but not limited to, an increase in chlorophyll-a concentrations, a decrease in water
transparency, or an increase in the frequency or duration of nuisance algae blooms, from an individual point
source discharge.
4 "New discharge" means a discharge that was not in existence before May 1, 2008, and discharges more than
1,800 pounds of total phosphorus per year.
5 "Expanded discharge" means a disposal system that after May 1, 2008, discharges more than 1,800 pounds of
total phosphorus per year to a surface water on an annual average basis, and increases in wastewater treatment
capacity as indicated by an increase in the design average wet weather flow for point source dischargers of sewage
or design average daily flow rate for dischargers of industrial or other wastes.
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PERFORMANCE-BASED APPROACHES
MISSOURI
Per Missouri 10 CSR 20-7.010. discharges to
Lake Taneycomo and its tributaries between
Table Rock Dam and Power Site Dam (excluding
discharges from the dams) shall not exceed
0.5 mg/L of total phosphorus as a monthly
average. This applies to discharges permitted
after May 9, 1994, and those with design flows
equal to or greater than 22,500 gallons per day
(GPD).
QKey Characteristics of
the Approach
Geographic scope: Lake Taneycomo
and Table Rock Lake watersheds in
Missouri
Pollutants: Total phosphorus
Types of facilities: Facilities with
discharges permitted after 1994 and
1999 with flows >22,500 GPD
Discharges to the Table Rock Lake watershed
shall not exceed 0.5 mg/L of total phosphorus as a monthly average, except those discharges
with design flows less than 22,500 GPD permitted before November 30,1999, unless the design
flow is increased.
NEW JERSEY
As a member of the Delaware River Basin
Commission (DRBC), the New Jersey
Department of Environmental Protection (DEP)
implements the DRBC antidegradation policy for
discharges to the Delaware River Basin within
the state. See the "Delaware River Basin
Commission" section for more information.
QKey Characteristics of
the Approach
Geographic scope: Freshwater lakes,
ponds, and reservoirs and their
tributaries in New Jersey
Pollutants: Total phosphorus
Types of facilities: All dischargers
Section 7:14A-12.7 of the New Jersey Code
establishes a phosphorus effluent standard that states, "The effluent standard for phosphorus
discharged to a freshwater lake, pond or reservoir, or tributaries to these waterbodies is that,
at a minimum, no effluent shall contain more than 1.0 mg/L total phosphorus (as P), as a
monthly average, unless the discharger(s) to such a waterbody can demonstrate that a less
stringent requirement will not result in a violation of the Surface Water Quality Standards
(N.J.A.C. 7:9B) or that the control of point sources alone, in the absence of effective nonpoint
source controls, will not result in a significant reduction of phosphorus loadings to the
waterbody."
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PERFORMANCE-BASED APPROACHES
NEWYORK
As a member of the Delaware River Basin
Commission (DRBC), the New York State
Department of Environmental Conservation
(NYSDEC) implements the DRBC antidegradation
policy for discharges to the Delaware River Basin
within the state. See the "Delaware River Basin
Commission" section for more information.
Geographic scope: Statewide and
specific requirements for Lakes Erie
and Ontario and the New York City
Watershed in New York
Additionally, NYSDEC implements performance-
based approaches for discharges of total
Pollutants: Total nitrogen and total
phosphorus
Types of facilities: POTWs
nitrogen and total phosphorus elsewhere in the
state, as described below.
Total Nitrogen
The NYSDEC Division of Water's SPDES Permit Development for POTWs (Technical and
Operation Guidance Series [TOGS] 1.3.3), requires all POTWs with a design flow of 1.0 MGD or
greater to monitor for influent and effluent ammonia and total Kjeldahl nitrogen.
Total Phosphorus
The Division of Water's Phosphorus Removal Requirements for Wastewater Discharges to Lakes
and Lake Watersheds (TOGS 1.3.6) establishes phosphorus removal requirements for
wastewater discharges to lakes and lake watersheds. The TOGS applies to discharges to ponded
waters (waters with "P"s in their index numbers, 6NYCRR Parts 800-941) and their topographic
watersheds, with the exception of Lakes Erie and Ontario if there is no intermediate ponded
water between the discharge and the Great Lakes. Implementation of TOGS 1.3.6 for existing
discharges necessitates the inclusion of total phosphorus monitoring at the time of permit
renewal to establish baseline total phosphorus loadings before flow expansion. Permits for
discharges with design flows greater than 1.0 MGD to saline waters require influent and
effluent monitoring for total phosphorus and orthophosphorus.
For POTWs that discharge within the watershed contributing surface water to the New York
City water supply, NYSDEC requires discharges to meet total phosphorus levels set forth in the
Rules and Regulations for the Protection From Contamination. Degradation, and Pollution of
the New York City Water Supply and Its Sources Chapter 18-36(a)(8), as shown in the following
table. New facilities must be constructed to meet these limitations.
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PERFORMANCE-BASED APPROACHES
Permitted Total Flow (Gallons per Day)
Total Phosphorus Limit (mg/L)
<50,000
1.0
>50,00 and <500,000
0.5
>500,000
0.2
For POTWs that discharge to Lakes Erie or Ontario or their drainage basins and are not subject
to more stringent requirements under TOGS 1.3.6, NYSDEC implements the 1987 Great Lakes
Water Quality Agreement, which requires total phosphorus control as follows:
30 Day Average
Flow (MGD)
Guidance
Design
Actual
<1.0
<1.0
No total phosphorus limitations will be imposed.
<1.0
>1.0
If the permittee cannot reduce flows to 1 MGD or less, the permit should be
modified to limit total phosphorus to 1.0 mg/L on an average 30-day basis.
>1.0
<1.0
It is not necessary to limit total phosphorus in the permit, but the design and
construction of the POTW will include provisions for achieving a 30-day average
total phosphorus limit of 1.0 mg/L at such time as the discharge exceeds 1.0
MGD on an annual average basis.
>1.0
>1.0
The effluent concentration of total phosphorus will be limited to 1.0 mg/L on an
average 30-day basis.
The permit writer may waive total phosphorus controls for POTWs discharging to tributaries of
the Great Lakes upon acceptable demonstration that the actual amount of total phosphorus
that could reach the Great Lakes is less than 8.34 pounds/day (on an average 30-day basis) due
to transport phenomena, immobilization, or other causes.
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PERFORMANCE-BASED APPROACHES
NORTH CAROLINA
The North Carolina DEQ, Division of Water
Resources, has established performance-based
approaches for establishing nutrient limits for
discharges to specific waterbodies in the Cape
Fear River Basin in the applicable basinwide
water quality plan. DEQ has also established a
performance-based approach for the Lower
Falls Watershed as part of a nutrient strategy
adopted in the NC Administrative Code.
QKey Characteristics of
the Approach
Geographic scope: Cape Fear River
Basin and Lower Falls Watershed in
North Carolina
Pollutants: Total nitrogen and total
phosphorus
Types of facilities: All dischargers
Cape Fear River Basin: Deep River Between High Point Lake and Carbonton Dam
The 2000 Cape Fear River Basinwide Water Quality Plan
recommends the following limits for new and expanding
discharges to the Deep River between High Point Lake
and the Carbonton Dam:
1 mg/L total phosphorus for facilities with a capacity
greater than or equal to 1 MGD.
2 mg/L total phosphorus for discharges less than 1
MGD.
Cape Fear River Basin: Deep River from
Randleman Reservoir to Carbonton Dam
The 2005 Cape Fear River Basinwide Water Quality Plan
recommends the following limits for new and expanding
discharges to the Deep River from Randleman Reservoir
to Carbonton Dam:
1 mg/L total phosphorus for facilities with a capacity
greater than 1 MGD.
2 mg/L total phosphorus for discharges between 0.5 MGD and 1.0 MGD.
North Carolina DEQ has
developed basinwide water
quality plans for each of the
17 major river basins in the
state on a 5-year cycle. The
basinwide plans are part of
a watershed-based
approach to restoring and
protecting water quality.
The program is being
revised to address both
water quality and water
resources (supply)
concerns. For more
information on North
Carolina's basin planning
process, see DEQ's basin
planning website.
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PERFORMANCE-BASED APPROACHES
Cape Fear River Basin: Cape Fear River from Buckhorn Dam to Lock and Dam #3
The 2005 Cape Fear River Basinwide Water Quality Plan recommends the following limits for
discharges to the Cape Fear River from Buckhorn Dam to Lock and Dam #3:
Seasonal (April-October) mass loads based on 6 mg/L total nitrogen and 2 mg/L total
phosphorus for new discharges.
Seasonal (April-October) mass loads based on the greater of the following for expanding
discharges:
o Current mass loading using actual flows and actual nutrient concentrations,
o Mass loadings based on the permitted expansion flow and concentrations of 6 mg/L
total nitrogen and 2 mg/L total phosphorus.
followed by effluent limits based on TMDL
wasteload allocations once they are developed and approved. The phased approach allows
point sources to explore water quality trading or other options for achieving compliance. The
recommended initial limits vary depending on watershed, impairment status, and facility size.
For POTWs discharging more than 1 MGD, the strategy provides the following guidelines:
If the receiving water is in the Lake Erie Basin and is not impaired, set the initial permit limit
at 1.0 mg/L total phosphorous at the design flow.
If the receiving water is in the Ohio River Basin and is not impaired, no limit should be
established, but monitoring should be required.
If the receiving water is impaired, set the initial permit limit at the lower of 1.0 mg/L total
phosphorous at the design flow or the existing permitted load and require optimization of
the existing treatment facility to minimize discharge. Where the impairment is addressed by
an approved TMDL, Ohio EPA will follow the implementation plan identified in that
document.
OHIO
The Ohio EPA developed the Ohio Nutrient
Reduction Strategy to reduce excess nutrients in
Ohio's surface waters, which includes a phased
approach for establishing limits for nutrient
dischargers. The strategy provides guidelines for
establishing initial, performance-based effluent
limits for total phosphorus for POTWs, to be
Geographic scope: Statewide in Ohio
Pollutants: Total phosphorus
Types of facilities: POTWs
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PERFORMANCE-BASED APPROACHES
For POTWs discharging 0.15 to 1.0 MGD, the strategy provides the following guidelines:
If the receiving water is not impaired, no limit should be established, but monitoring should
be required.
If the receiving water is impaired and the POTW is the predominant contributor to the
impairment, set the initial permit limit at 1.0 mg/L total phosphorous and the design flow.
If the receiving water is impaired and the POTW is one of multiple contributors to the
impairment, set the initial permit limit at 1.0 mg/L total phosphorous and the design flow if
the limit will result in a significant improvement in biological assemblages. Monitoring
should be included in the permit if no limit is included in the permit.
For POTWs discharging 0.025 to 0.15 MGD, the strategy provides the following guidelines:
If the receiving water is not impaired, no limit should be established, but monitoring should
be required.
If the receiving water is impaired and the POTW is the predominant contributor to the
impairment, set the initial permit limit at 1.0 mg/L total phosphorus and the design flow.
If the receiving water is impaired and the POTW is one of multiple contributors to the
impairment, no permit limit should be established, but monitoring should be required.
For POTWs discharging less than 0.025 MGD, for any waterbody impairment situation, the
strategy specifies that no limit should be established, but monitoring should be required.
PENNSYLVANIA
As a member of the Delaware River Basin
Commission (DRBC), the Pennsylvania DEP
implements the DRBC antidegradation policy
for discharges to the Delaware River Basin
within the state. See the "Delaware River Basin
Commission" section for more information.
Title 25, Section 96.5(c). in the Pennsylvania
Code specifies requirements for nutrient
discharges. Where total phosphorus contributes or threatens to impair existing or designated
uses, point source discharges of total phosphorus must be limited to an average monthly
concentration of 2 mg/L. More stringent controls may be imposed as a result of an applicable
TMDL.
o
Key Characteristics of ^
the Approach
Geographic scope: Statewide in
Pennsylvania
Pollutants: Total phosphorus
Types of facilities: All dischargers
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PERFORMANCE-BASED APPROACHES
TENNESSEE
The Tennessee Department of Environment and
Conservation (TDEC) developed the Tennessee
Nutrient Reduction Framework to accomplish
long-term nutrient reductions in state waters.
Under the framework, TDEC assigns a nutrient
impact level to each U.S. Geological Survey
Hydrologic Unit Code 10 (HUC-10) watershed of
Geographic scope: Statewide in
Tennessee
Pollutants: Total phosphorus
Types of facilities: All dischargers
high, medium, or low based on a combined
analysis of an enrichment factor and the percentage of WWTP contribution. The resulting
nutrient impact level indicates the appropriate level of nutrient reduction for WWTPs to
achieve the Protective Annual Watershed Load, which is the estimated post-reduction annual
nutrient load for the watershed after incorporating the expected load reductions from point
and nonpoint sources. The Protective Annual Watershed Load represents the load that is
expected to meet the narrative nutrient water quality criteria for fish and aquatic life.
In the first stage of implementation, this strategy applied to major municipal as well as
permitted industrial WWTPs. Effluent limits for total nitrogen and total phosphorus are
assigned to WWTPs according to the impact levels, as follows:
5 mg/L total nitrogen and 0.3 mg/L total phosphorus for high impact levels.
8 mg/L total nitrogen and 1 mg/L total phosphorus for medium impact levels.
Capped at current levels for low impact levels.
The effluent limits assigned to watersheds with high impact levels represent expected
performance based on additional chemical treatment for phosphorus removal. The effluent
limits assigned to watersheds with medium impact levels represent nutrient concentrations
corresponding to conventional biological nitrogen and phosphorus removal and tertiary
filtration.
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PERFORMANCE-BASED APPROACHES
TEXAS
The Texas Commission on Environmental
Quality (TCEQ) has developed nutrient screening
procedures for wastewater discharge permit
applications to determine if permit
requirements are needed to prevent violation of
numerical nutrient criteria and/or preclude
excessive growth of aquatic vegetation. These
procedures are found in TCEQ's Procedures to
Implement the Texas Surface Water Quality
Standards.
and Edwards Aquifer in Texas
Pollutants: Total phosphorus
Types of facilities: Domestic
Geographic scope: Colorado River
Basin, Benbrook Lake Watershed,
wastewater treatment facilities
In addition, Title 30 Texas Administrative Code requires performance-based limits for nutrients
for certain watersheds.
Rule §311.43 requires discharges of treated sewage into the tributaries of Segment 1428 of the
Colorado River or directly into Onion Creek and its tributaries to achieve a 1 mg/L of total
phosphorus level of effluent treatment, based on a 30-day average.
Rule §311.67 requires any domestic wastewater discharger applying for a new or expanding
discharge after January 1, 2015 (the date of the rulemaking), other than oxidation pond
systems, to meet a daily effluent limit for total phosphorus of 1 mg/L, based on a 30-day
average, if the wastewater treatment system:
has a permitted annual or daily average flow greater than or equal to 0.10 MGD and a
discharge point in the Benbrook Lake water quality area; or
has a permitted annual or daily average flow greater than or equal to 0.25 MGD and a
discharge point in the Benbrook Lake watershed, but outside the Benbrook Lake water
quality area.
Rule §213.6 requires all new or increased discharges of treated wastewater into or adjacent to
a water in the state (other than industrial wastewater discharges) within 0 to 5 miles upstream
from the Edwards Aquifer recharge zone to achieve a level of effluent treatment for total
phosphorus of 1 mg/L, based on a 30-day average.
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PERFORMANCE-BASED APPROACHES
VIRGINIA
9VAC25-40 (the Regulation for Nutrient
Enriched Waters) provides for the control of
discharges of nutrients from point sources
affecting state waters that are designated
"nutrient enriched waters" in 9VAC25-260-350
or are within the Chesapeake Bay watershed. A
1.0 mg/L total phosphorus permit limit is
imposed on applicable dischargers to nutrient
enriched waters that are listed in the water
quality standards. New or expanding dischargers
Types of facilities: All dischargers
Chickahominy Watersheds in Virginia
Pollutants: Ammonia, total Kjeldahl
nitrogen, and total phosphorus
Geographic scope: Nutrient enriched
waters, Chesapeake Bay, Occoquan,
Potomac Embayments, and
in the Chesapeake Bay watershed are subject to
effluent limitations of 1.0 mg/L total phosphorus and 8.0 mg/L total nitrogen or 0.3 mg/L total
phosphorus and 3.0 mg/L total nitrogen depending on the size and location of the discharge.
Existing dischargers in the Chesapeake Bay watershed are not required to install treatment
technology to meet the wasteload allocations required by the Chesapeake Bay TMDL. They may
choose to trade under the watershed general permit. Any facility that installs nutrient removal
technology is subject to an annual average concentration limit based on the technology
installed. For more information on Virginia's water quality trading program and watershed-
based permit for the Chesapeake Bay watershed, see "Water Quality Trading" and "Watershed-
Based Permitting."
Discharges to specific watersheds are subject to additional nutrient limitations, as described in
the sections below.
Occoquan Watershed
The Occoquan Policy sets the following treatment and discharge requirements to protect water
quality. They are stringent, particularly since the waters are an important water supply for
almost two million residents in the area.
Unoxidized nitrogen (as total Kjeldahl nitrogen) not to exceed 1.0 mg/L as a monthly
average and requirement for operation of nitrogen removal facilities when the ambient
nitrate concentration (as N) is 5.0 mg/L or higher in the Occoquan Reservoir in the vicinity of
the Fairfax County Water Authority intake point.
Total phosphorus not to exceed 0.10 mg/L as a monthly average.
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PERFORMANCE-BASED APPROACHES
Potomac Embayments
The Potomac Embayment Policy sets stringent effluent limits for carbonaceous biochemical
oxygen demand (CBOD) and total suspended solids (TSS), as well the following limits for
nutrients:
Ammonia nitrogen (April 1-October 31) not to exceed 1.0 mg/L as a monthly average.
Total phosphorus not to exceed 0.18 mg/L as a monthly average.
Chickahominy Watershed
Special effluent limits apply to wastewater treatment facilities in the entire Chickahominy
watershed (a tributary of the James River) above Walker's Dam, excluding discharges consisting
solely of stormwater. These limits are:
Ammonia nitrogen not to exceed 2.0 mg/L as a monthly average.
Total phosphorus not to exceed 0.10 mg/L as a monthly average for all discharges (except
Tyson Foods, Inc.).
Total phosphorus not to exceed 0.30 mg/L as a monthly average and 0.50 mg/L as a daily
maximum for Tysons Foods, Inc.
WISCONSIN
Wisconsin's Effluent Standards and Limitations
for Phosphorus (Chapter NR 217) require the
following point sources that discharge
phosphorus to surface waters of the state to
meet an effluent limitation of 1 mg/L total
phosphorus as a monthly average:
POTWs and privately owned domestic
sewage works subject to Chapter NR 210
that discharge wastewater containing more
than 150 pounds of total phosphorus per
month, unless an alternative limitation is provided under NR 217.04(2).
o
Key Characteristics of ^
the Approach
Geographic scope: Statewide in
Wisconsin
Pollutants: Total phosphorus
Types of facilities: POTWs, privately
owned domestic sewage works, and
other facilities discharging
>60 pounds/month
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PERFORMANCE-BASED APPROACHES
Discharge of wastewater from facilities other than those subject to Chapter NR 210 that
contain a cumulative total of more than 60 pounds of total phosphorus per month, unless
an alternative limitation is provided under NR 217.04(2). Outfalls consisting of noncontact
cooling water without phosphorus-containing additives may not be included in the
calculation of the cumulative total of total phosphorus discharged from the facility.
Compliance with the concentration limit shall be determined as a rolling 12-month average, as
determined by the total phosphorus from all outfalls subject to the effluent limitation for the
most recent 12 months divided by the total flow for all those outfalls for the same period.
(i.e., Outstanding Basin Waters6 and Significant
Resource Waters7).
The antidegradation policy requires that there be no measurable change in existing water
quality except toward natural conditions in Special Protection Waters. For Outstanding Basin
Waters, the policy requires discharges to be treated as required and then dispersed in such a
manner that complete mixing of effluent with the receiving stream is instantaneous. For
6 "Outstanding Basin Waters" are waters contained within the established boundaries of national parks; national
wild, scenic, and recreational river systems; and/or national wildlife refuges with exceptionally high scenic,
recreational, and ecological values that require special protection.
7 "Significant Resource Waters" are waters with exceptionally high scenic, recreational, ecological, and/or water
supply uses that require special protection.
DELAWARE RIVER BASIN COMMISSION
The Delaware River Basin Commission (DRBC) I
regulates water resources in the Delaware River
Basin and comprises representatives from the |
U.S. Army Corps of Engineers and the four
states with land draining to the Delaware River:
Delaware, New Jersey, New York, and
Pennsylvania. The DRBC Administrative
Manual, at Section 3.10.3, sets forth an
antidegradation policy for surface waters of the
Delaware River Basin that includes
performance-based requirements to address
excess nutrients in Special Protection Waters
Geographic scope: Delaware River
Basin in Delaware, New Jersey, New
York, and Pennsylvania
Pollutants: 5-day carbonaceous BOD,
dissolved oxygen, TSS, ammonia,
total nitrogen, total phosphorus, and
fecal coliform
Types of facilities: New and
expanding wastewater treatment
facilities
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PERFORMANCE-BASED APPROACHES
Significant Resource Waters, the policy allows for localized degradation to provide for initial
dilution within a defined mixing zone.
In addition, the antidegradation policy requires new and expanding wastewater treatment
facilities discharging directly to Special Protection Waters (i.e., Outstanding Basin Waters and
Significant Resource Waters) to meet the effluent quality of the best demonstrable technology
(BDT). Equivalent effluent criteria for industrial facilities and seasonal limits, if any, may be
developed on a case-by-case basis. BDT may be superseded by any more stringent federal,
state, or DRBC criteria. Specifically, BDT is defined by the following effluent quality:
Parameter
30 Day Average Effluent Criteria |
5-day carbonaceous BOD
10 mg/L or less
Dissolved oxygen
6 mg/L or greater
TSS
10 mg/L or less
Ammonia-nitrogen
1.5 mg/L or less
Total nitrogen
10.0 mg/L or less
Total phosphorus
2.0 mg/L or less
Fecal coliform
50/100 mL or less
The antidegradation policy specifies that, in addition to meeting BDT, new and expanding
facilities may be approved only after the applicant demonstrates that it has fully evaluated all
non-discharge/load reduction alternatives (for discharges directly to Special Protection Waters)
or all natural wastewater treatment system alternatives (for discharges within the drainage
area of Special Protection Waters) and cannot implement these alternatives because of
technical and/or financial infeasibility. When evaluating alternatives, applicants must consider
alternatives to existing and proposed loadings in excess of actual loadings at the time of Special
Protection Water designation.
For point sources originating outside the boundaries of stream reaches classified as
Outstanding Basin Waters and Significant Resource Waters, discharges must be treated and
dispersed in the receiving water so that no measurable change occurs at boundary or interstate
control points. This requirement may be satisfied through demonstration (using a DRBC-
approved model or other methodology) that the new or incremental increase in the facility's
flow or load will cause no measurable change at the relevant water quality control point for
28 | Page
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PERFORMANCE-BASED APPROACHES
ammonia, dissolved oxygen, fecal coliform, nitrate or nitrite plus nitrate, total nitrogen or total
Kjeldahl nitrogen, total phosphorus, TSS, and BOD.
Click here to return to the Table of Contents
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WATER QUALITY TRADING
Water quality trading is an exchange of water quality credits generated through pollutant
reductions. Sources with higher pollutant control costs may purchase pollutant credits from
sources with lower control costs. For more information, see EPA's water quality trading
website: https://www.epa.gov/npdes/water-quality-trading.
CALIFORNIA
California's North Coast Regional Water
Quality Control Board (Regional Water
Board) approved the Santa Rosa Nutrient
Offset Program for the City of Santa Rosa
Subregionai Water Reclamation Facilit\ in
2008. In July 2018, the Regional Water
Board adopted Resolution No. Rl-2018-
0025 approving the Water Quality Trading
Framework, which applies to both the City
of Santa Rosa and the Town of Windsor.
The Framework is based on local
stakeholder recommendations developed
through a 3-year collaboration led by the
Sonoma and Gold Ridge Resource
Conservation Districts and funded by a
Conservation Innovation Grant issued by
the U.S. Department of Agriculture.
Kelsey Cody
kelsev.cody(5) waterboards.ca.gov
North Coast Regional Water Quality
Control Board
The Framework covers the Laguna de
Santa Rosa watershed. The Laguna de
Santa Rosa is the largest tributary to the
Russian River, draining about 254 square
miles in Sonoma County, California.
Portions of the Laguna de Santa Rosa and its tributaries are listed as impaired for total
phosphorus and low dissolved oxygen.
Key Characteristics of
the Trading Program
Geographic scope: Laguna de Santa Rosa
watershed, California
Key driver(s): Impairment for total
phosphorus and low dissolved oxygen
Trading scenario: Point source-nonpoint
source and point source-point source
Poliutant(s): Total phosphorus
Status: Active
Trade ratios: 2:1 uncertainty ratio and
0.5:1 retirement ratio
Highlights: Credit project approval
process; initial and ongoing project
verification; credit certification,
registration, and tracking; project-specific
monitoring
Contact information:
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WATER QUALITY TRADING
Although a TMDL has not yet been completed for the Laguna de Santa Rosa, the Regional
Water Board concluded that reductions in total phosphorus loading are necessary to protect
beneficial uses. In the absence of numeric water quality criteria for nutrients, the Regional
Water Board issued "no net loading" effluent limitations for total phosphorus in the NPDES
permits for the City of Santa Rosa and Town of Windsor facilities. To comply with the
limitations, the permittees must ensure that the mass of phosphorus discharged is equal to or
less than the mass controlled through nutrient offset credits generated via the trading program.
The permits require the permittees to calculate and report the mass discharged and the mass
controlled to determine compliance with the no net loading limitations.
The Framework gives the City of Santa Rosa and the Town of Windsor an approved method for
complying with their "no net loading" effluent limitations through trading. The Framework
generally supports trading between NPDES permittees and regulated and unregulated nonpoint
sources; however, it also allows trading between point source dischargers or for an entity that
generates credits for its own use (e.g., the City's municipal parks department generating credits
to be used by the City's NPDES permitted wastewater treatment facility), provided all eligibility
criteria and Framework requirements are met.
Under the Framework, a project is eligible to generate credits if it is not otherwise required by
law, regulation, permit, enforcement action, or other legal agreement.
The Framework establishes a two-part process for credit generation:
1. Pre-qualified practices for credit generationgeneral, rather than site-specific methods-
are approved. The approval process includes Regional Water Board review, public notice
and comment, and Executive Officer approval. After approval, the Regional Water Board
adds the practice to a publicly accessible list. Only these pre-qualified practices may be
proposed for credit generation in a credit project plan.
2. A credit project plan is submitted. A credit project plan contains basic information; project
design and credit information; a project maintenance plan; and a project monitoring,
verification, and reporting plan. Credit project plans are subject to a review and approval
process, which includes staff review and Executive Officer approval or rejection. Once
approved, plans and approval notices are available to the public, as are the required
verification reports (see below) once they become available.
The Framework assigns a default trade ratio of 2.5:1 for all trades, which accounts for an
uncertainty ratio of 2:1 and a retirement ratio of 0.5:1. The Regional Water Board may allow
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WATER QUALITY TRADING
the retirement ratio8 and/or uncertainty ratio9 to be adjusted downward by as much as 0.5 for
a trade under certain circumstances. The Framework specifies that the life of all credits shall be
1 year (October 1 to September 30 of the following year). The Framework allows for credit
banking (i.e., generation of a water quality credit to offset a future discharge) for 3 to 5 years,
depending on the type of credit-generating project.
To ensure accountability, the Framework specifies project implementation and verification
requirements. Credit sellers must document pre- and post-project site conditions. The
Framework also requires initial verification (by an independent and qualified third party) to
confirm whether a project has been implemented in accordance with the approved credit
project plan, as well as ongoing project verification to confirm whether a project continues to
be maintained in conformance with the credit project plan, that it continues to meet
Framework requirements, and that credits have been accurately estimated. The frequency,
required elements of project review, and reporting requirements for ongoing verification will
vary by project and must be specified in the approved credit project plan.
The Regional Water Board reviews credit verification reports and certifies credits generated by
issuing official credit certificates to the credit seller, at which time the credits are officially
available for purchase, sale, or use by an NPDES permittee. A designated administrator (i.e.,
Regional Water Board staff or third party designee) maintains an official and publicly accessible
credit registry to track the status and ownership of certified credits.
The Framework seeks to provide NPDES permittees with cost-effective and environmentally
beneficial options for complying with their total phosphorus effluent limitations. To date, the
City of Santa Rosa has implemented three nutrient offset projects to generate credits under the
2008 Nutrient Offset Program: two on low-lying dairy properties and another on an upland
nature preserve. The Town of Windsor intends to use nutrient offset credits generated under
the Framework to achieve compliance with the final effluent limitation, which becomes
effective in October 2021.
8 The Framework defines a retirement ratio as a ratio that sets aside a portion of credits generated for net
environmental benefit.
9 The Framework defines an uncertainty ratio as a ratio that accounts for scientific uncertainty, including potential
inaccuracies in estimation methods and/or variability in project performance.
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WATER QUALITY TRADING
For more information about California's trading program, visit the Regional Water Board's
website at https://www.waterboards.ca.gov/northcoast/water issues/programs/
nutrient offset program.
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WATER QUALITY TRADING
COLORADO
CDPHE's Nutrients Management Control
Regulation (Regulation #85). promulgated in
June 2012, establishes numerical technology-
based effluent limits for domestic WWTPs and
industrial wastewater dischargers that are likely
to have significant levels of nutrients in their
discharges. As a way to give permittees
flexibility in reducing total phosphorus and total
inorganic nitrogen to meet these limits, Section
85.5(3)(d) authorizes nutrient trading.
Regulation #85 allows for point source-point
source and point source-nonpoint source
trading. It establishes a trading ratio of 1:1 for
point source-point source trades and 2:1 for
point source-nonpoint source trades. A lower
trade ratio may be allowed for point source-
nonpoint source trades based on site-specific
data.
In anticipation of new, more stringent water-
quality-based effluent limitations, Section
85.5(1.5) of Regulation #85 and the Voluntary
Incentive Program for Early Nutrient Reductions
(Policy 17-1) establish the requirements for a
voluntary incentive program to encourage
facilities to voluntarily reduce phosphorus and/or nitrogen concentrations below the applicable
technology-based effluent limits prior to 2027. Policy 17-1 authorizes permittees participating
in the voluntary incentive program to accrue time under a compliance schedule through water
quality trading. CDPHE will use the applicable provisions of the Colorado Pollutant Trading
Policy and Section 85.5(3)(d) of Regulation #85 to determine the appropriate duration of the
compliance schedule. Once the voluntary incentive program period has been completed
(December 31, 2027), any trading program developed to generate an incentive will no longer be
in effect. Thereafter, any permittee desiring to continue participation in a water quality trading
program will have to submit a new request for trading credits for approval. For more
Key Characteristics of
the Trading Program
Geographic scope: A stream
segment, watershed, defined TMDL
area, or other approved area in
Colorado
Key driver(s): Anticipated adoption
of new, more stringent water quality
standards
Trading scenario: Point source-
nonpoint source and point source-
point source
Pollutants: Total inorganic nitrogen
and total phosphorus
Status: Active
Trade ratios: 1:1 ratio for point
source-point source, 2:1 ratio for
point source-nonpoint source
Highlights: Allows trading to achieve
state technology-based limits;
voluntary incentive program
Contact information:
Meg Parish
meE.parish(a)state.co.us
Colorado Department of Public
Health and Environment
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WATER QUALITY TRADING
information on Colorado's water quality trading program and voluntary incentive program, see
"Performance Based Approaches."
The Colorado Trading Policy provides more guidance on implementing water quality trading. It
specifies that water quality trading should generally occur within a single stream segment, a
defined watershed, a defined area for which a TMDL is being developed or has been approved,
or another approved area. No trade may result in an exceedance of water quality standards in
localized reaches (i.e., "hot spots") as a consequence of the difference in location between the
sources.
The Colorado Trading Policy also provides guidance on establishing appropriate baselines for
point sources, agricultural nonpoint sources, and other nonpoint sources. Baselines are based
on the most protective of the following:
The actual discharge level based on the most protective of the applicable water quality-
based effluent limitation for point sources.
The pollutant-specific loading associated with existing land uses and reasonable and
appropriate best management practices (BMPs) for unpermitted nonpoint sources other
than agriculture.
The most protective of the pollutant specific loading from existing agricultural operations
for agricultural nonpoint sources.
Wasteload allocations, load allocations, or pollutant-specific caps established in a TMDL,
watershed management plan, remedial action plan, or similar document.
The Colorado Trading Policy requires credit buyers to ensure that monitoring is conducted and
controls are operated and maintained for the life of the trade. At a minimum, monitoring and
reporting must include water quality monitoring or modeling, facility discharge monitoring and
contractual compliance, certification of proper best management practice implementation and
maintenance, and overall trade assessment.
For point source-nonpoint source trades, credit buyers are required to submit annual (or more
frequent) reports certifying that nonpoint source controls have been properly operated and
maintained. If water quality monitoring is not conducted, nonpoint source pollutant loading
reductions must be determined based on data and analysis obtained from a model. The
Colorado Trading Policy requires any nonpoint source control to be inspected immediately after
installation or initial implementation by a third-party inspector to ensure it is properly sited, the
materials and plans satisfy established quality specifications, and the installation job meets
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WATER QUALITY TRADING
performance standards. Periodic onsite assessments may also be required to ensure continuing
functionality.
To ensure verification and tracking of credits, the Colorado Trading Policy requires credit
trading documents to describe the method used for credit generation (measured or calculated).
Credits must be registered with an appropriate entity (e.g., a nonprofit corporation established
for such purposes, a volunteer governmental entity, CDPHE) and the registry of credits must be
updated regularly. Information contained in the registry must be made available to the public.
established, the goal of the Nitrogen Credit
Exchange Program was to meet the TMDL cost-effectively by encouraging nitrification at
POTWs, staggering upgrades over 13 years, and efficiently using funding and resources.
Pursuant to Public Act 01-180, Connecticut DEEP issued the General Permit for Nitrogen
Discharges in 2002, which was most recently renewed in October 2018. The 2018 General
CONNECTICUT
The Connecticut Department of Energy and
Environmental Protection (DEEP) and NYSDEC
completed a TMDL for dissolved oxygen in Long
Island Sound in December 2000 to address
hypoxic conditions that occur in Long Island
Sound every summer. The TMDL established
wasteload allocations requiring a 64 percent
Geographic scope: Long Island Sound
watershed, Connecticut
Key driver(s): TMDL to address
hypoxic conditions
Trading scenario: Point source-point
source
Pollutants: Total nitrogen
Status: Active
Trade ratios: Equivalency factor
based on geographic location
Highlights: Watershed-based general
permit; Nitrogen Credit Exchange
Program; state incentives through
financial assistance and subsidies
Contact information:
lliana Raffa
iliana.raffa@ct.gov
Connecticut Department of Energy
and Environmental Protection
reduction of total nitrogen loading from point
source discharges by 2014.
Connecticut created a Nitrogen Credit Exchange
Program to provide flexibility in implementing
the TMDL. In July 2001, the Connecticut General
Assembly passed Public Act 01-180: An Act
Concerning Nitrogen Reduction in Long Island
Sound, requiring Connecticut DEEP to issue a
general NPDES permit with effluent limits for
total nitrogen and to establish a Nitrogen Credit
Advisory Board (NCAB) to assist and advise
Connecticut DEEP with administration of the
Nitrogen Credit Exchange Program. When
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WATER QUALITY TRADING
Permit covers discharges of total nitrogen from 79 POTWs. The General Permit is the primary
mechanism for implementation of the Nitrogen Credit Exchange Program. It establishes annual
mass loading limits for total nitrogen for each POTW. If a POTW cannot comply with the
effluent limitation at their facility, it can purchase equivalent total nitrogen credits through the
Nitrogen Credit Exchange Program to comply with the effluent limitation. For more information
on the General Permit, see "Watershed-Based Permitting."
A POTW generates credits to sell
through the exchange if it
undertakes a nitrogen removal
project and removed more
nitrogen than is required by its
annual mass loading limit.
Equivalent credits are calculated
by multiplying the total nitrogen
credit (i.e., the difference between
the annual limit and the annual
load discharged) by an assigned
equivalency factor, which operates
similarly to a delivery factor. The
equivalency factor accounts for
geographic location of the POTW
and its impact on dissolved oxygen
levels in the hypoxic areas of Long
Island Sound. In general, the
equivalency factors are higher for
POTWs closer to the hypoxic areas. Facilities with a relatively high equivalency factor may find it
more economical to undertake nitrogen removal projects, whereas it may be more economical
for those with lower equivalency factors to purchase credits.
Connecticut incentivized participation in the Nitrogen Credit Exchange Program by providing
financial assistance to POTWs to undertake nitrogen removal projects through Clean Water
Fund grants and loans. Additionally, the state subsidized the program by paying sellers for
credits generated in excess of demand. For more information on Connecticut's Clean Water
Fund, visit https://portal.ct.gov/DEEP/Municipal-Wastewater/Financial-Assistance-for-
Municipal-Wastewater-Projects and https://portal.ct.gov/-
/media/DEEP/water/lis water quality/nitrogen control program/lisrafspdf.pdf.
Source: Connecticut's Nitrogen Trading Program. Connecticut DEEP. 2014.
httos://oortal.ct. aov/-
/media/DEEP/water/municipal wastewater/91714DresfutureDlansntDDdf.D
df?la=en
Nitrogen Trading Zones
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WATER QUALITY TRADING
The Nitrogen Credit Exchange Program was successful in cost-effectively achieving the TMDL
wasteload allocation by 2014, saving an estimated $300-$400 million in upgrade costs. By
2019, 58 POTWs are expected to complete construction of nitrogen removal projects. However,
Connecticut DEEP and the NCAB determined that the state subsidization of the Nitrogen Credit
Exchange Program was unsustainable long-term, with projections for 2018 estimated at over
$5 million. Therefore, the Connecticut General Assembly passed Public Act 15-38 (An Act
Concerning the Sustainability of the Nitrogen Credit Exchange Program) to move the program
toward self-sufficiency by 2016 by no longer providing subsidies. As a result, POTWs generating
credits now divide the funds paid by buyers proportionally based on the seller's relative
performance, and most sellers receive reduced payments for their credits.
For more information about Connecticut's trading program, visit
www.ct.gov/deep/nitrogencontrol.
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WATER QUALITY TRADING
FLORIDA
In 2008, the Florida DEP issued a TMDL for
nutrients for the Lower St. Johns River and a
Basin Management Action Plan (BMAP) to
address impairments based on elevated
chlorophyll a and Trophic State Index levels in
the freshwater and marine portions of the river.
In 2010, Florida DEP finalized a rule establishing
a pilot water quality credit trading program for
the Lower St. Johns River Basin. The pilot
program was intended to give entities a more
effective and cost-efficient option for meeting
their required pollutant load reductions. Under
the pilot program, at least one of the trading
parties was required to have an individual
wastewater or stormwater permit, and credits
could only be generated when a source reduced
its load below its baseline allocation.
In 2010, Florida DEP amended the water quality
trading rule to expand the program to allow
trading in basins with adopted BMAPs or
Reasonable Assurance Plans (RAPs) and to
update the rule to reflect "lessons learned"
from the pilot program.
Key Characteristics of
the Trading Program
Geographic scope: Within
boundaries covered by BMAPs or
RAPs in Florida
Key driver(s): TMDLs to address
nutrient-related impairments
Trading scenario: Point source-point
source, point source-nonpoint
source, nonpoint source-nonpoint
source
Pollutants: Total nitrogen and total
phosphorus
Status: Active
Trade ratios: Location factor and
uncertainty factor
Highlights: Pilot program, pre-
approval process for credit
generation, trade tracking
Contact information:
Kevin Coyne
kevin.covne(5)dep.state.fl.us
Florida Department of Environmental
Protection
Florida's current trading rules define the geographic scope for trading as the area within the
boundaries of BMAPs or RAPs, including those that address hydrologically connected waters.
The rule authorizes trading between both point and nonpoint sources if authorized in the BMAP
or RAP.
Credits are expressed as annual loads of total nitrogen or total phosphorus and cannot be rolled
over or aggregated from year to year. Credits generated by point sources must be measured
and confirmed through effluent monitoring. Credits generated by nonpoint sources can be
measured, if feasible. Where direct measurement of nonpoint source credits is not feasible,
estimates of the long-term average expected reduction may be used.
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WATER QUALITY TRADING
Credits are defined as the amount of nutrient load reduction below baseline requirements.
Baseline is defined as the annual nutrient load from a pollutant source after all required
pollution control activities are performed. For point sources, baseline is the more stringent of:
The wasteload allocation in the BMAP or RAP.
The water-quality-based effluent limitation in the NPDES permit.
For nonpoint sources, baseline is the more stringent of:
The entity's load allocation in the BMAP or RAP.
The nutrient load expected after required best management practices (BMPs) are
implemented for agriculture sources or nutrient management plan requirements are
implemented for concentrated animal feeding operations.
Credits are adjusted using two types of trade ratio: location factors and uncertainty factors.
Location factors are used for trades in different waterbody segments to account for the relative
impacts of nutrient discharges at the two locations. Uncertainty factors account for the
uncertainty associated with estimated credits generated from nonpoint sources. Uncertainty
factors default to 2:1 for urban stormwater and 3:1 for agricultural runoff, but can be adjusted
on a site-specific basis.
The rule establishes processes for pre-approval and tracking of credit generation. To obtain DEP
approval, the credit generator must submit a form describing the activities generating the
credits and the expected nutrient load reduction below the generator's baseline. If DEP
approves, DEP then notifies the credit generator of the maximum number of credits that could
be authorized. The credit buyer must submit a form with information on the terms of trades,
number of credits traded, credit calculations, credit unit price, and amount of any state funding
used to generate credits. A trade then becomes effective when DEP authorizes the trade in the
BMAP, RAP, or individual NPDES permit. DEP tracks all credit generation pre-approvals and all
credits traded in a publicly available registry on its website.
To verify that credits are generated, credit sellers must annually certify and document that the
BMPs or other actions on which the credits are based are fully implemented and properly
operated and maintained. For measured credits, the seller must report the quantity discharged
to DEP on a monthly basis. DEP may also conduct site inspections to review records and verify
site conditions.
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WATER QUALITY TRADING
To date, active trading has only occurred in the Lower St. Johns River watershed. As of the 2015
Progress Report, point source wastewater treatment facilities in the freshwater and marine
reaches and municipal separate storm sewer systems (MS4s) in the freshwater reach of the
river had achieved their allocations due, in part, to water quality trading.
IDAHO
Idaho's water quality standards authorize the
use of water quality trading when developing
TMDLs or equivalent processes. Idaho issued
revised Water Quality Trading Guidance in
October 2016. The 2016 Guidance is based on
recommendations from the Draft Regional
Recommendgtions for the Pgcific Northwest on
Wgter Quglity Trgding, prepared by the
Willamette Partnership and The Freshwater
Trust in collaboration with state water quality
agencies from Idaho, Oregon, and Washington
and U.S. EPA Region 10.
The 2016 Guidgnce explains that watershed-
level trading programs should be documented
in trading frameworks that detail the processes
and standards for trading in a geographic area.
Once a trading framework is developed, trading
plans containing the necessary details to
support trading are incorporated into an NPDES
permit or other binding agreement.
QKey Characteristics of
the Trading Program
Geographic scope: Watersheds or
other hydrologically connected
geographic areas in Idaho, as
specified in approved trading
frameworks
Key driver(s): Desire to improve
water quality and reduce costs of
TMDL implementation
Trading scenario: Point source-point
source and point sou rce-n on point
source
Pollutants: Total nitrogen, total
phosphorus, and thermal loading
Status: Active
Trade ratios: Delivery, attenuation,
equivalency, uncertainty, reserve,
and retirement ratios
Highlights: Implementation through
trading frameworks and trading
plans
Contact information:
Graham Freeman
Eraham.freeman(5)deq.idaho.Eov
Idaho Department of Environmental
Quality
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WATER QUALITY TRADING
The 2016 Guidance sets forth a five-step process for developing and implementing trading
frameworks:
1. Develop a TMDL or similar study. TMDLs are typically a prerequisite for establishing a
trading framework; however, the 2016 Guidance includes criteria for pre-TMDL trading for
existing discharges to impaired waterbodies.
2. Confirm that there are multiple buyers within the watershed. The 2016 Guidance supports
both point source-point source trading and point source-nonpoint source trading.
3. Develop a trading framework using information from the TMDL or similar study.
4. Hold a 30-day public comment period; get Idaho DEQ approval.
5. Incorporate trading framework elements into a trading plan in the NPDES permit.
\
Step 5.
Framework/plan
referenced in a
permit
Source: Water Quality Trading Guidance. Idaho DEQ. 2016.
https://www2. deq. idaho. gov/admin/LEIA/api/document/do wnload/4839
The 2016 Guidance recommends elements to be identified in the trading framework, including
trading area, baseline, credit quantification and trade ratios, credit life, project design and
verification, and credit registration and trade tracking, among others.
The 2016 Guidance suggests that the seller should usually be upstream from the buyer, but it
acknowledges that downstream sellers can sell to upstream buyers in certain scenarios.
Including measures or monitoring in the trading frameworks can ensure hot spots do not occur
within the trading area. The 2016 Guidance does not support trading between basins.
The trading framework specifies baseline requirements for trading parties. The baseline for a
point source credit seller is the most stringent effluent limitation in their NPDES permit. For
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WATER QUALITY TRADING
nonpoint sources, baseline can be derived from the source's TMDL load allocation or from
other sources of regulatory requirements.
The trading framework must specify how credits will be quantified. For point sources, credits
should be quantified through direct measurement of the effluent. For nonpoint sources, direct
measurement is preferred, but credits can also be estimated through modeling or BMP
efficiency rates. The 2016 Guidance identifies several types of trade ratios that may be applied
in the trading framework and recommends that the overall trade ratio be greater than 1.5:1.
Credits can only be used in the time period during which they were generated (monthly,
seasonal, or annual) and must be tied to the critical period (i.e., the time period during which
the water quality benefit is needed) for a watershed.
A list of approvable BMP packages must be included in the trading framework. A BMP package
identifies the proposed BMP and supporting information, including BMP design, installation,
and operation information; procedures for verifying and quantifying credits, and monitoring
and maintenance requirements. Idaho DEQ must approve the BMP packages during review of
the trading framework. The 2016 Guidance includes a process for adding new BMPs and
quantification methods to an existing framework, including an opportunity for public comment.
Lastly, the trading
framework are to
describe the process
to generate, review,
and track credits.
Before a project can
be used to generate
credits, it may be
screened for
desirability or
feasibility at a specific site. Initial project verification may be conducted to confirm the project
is eligible, credits were quantified accurately, and necessary nonpoint source BMPs were
installed properly or that discharge monitoring reports confirm a point source is achieving the
necessary load reductions. Credits must be certified and tracked through a registry maintained
by Idaho DEQ or a designated tracking entity. Ongoing verification and credit tracking are
required to confirm that projects are maintained and function as designed.
Project
Implementation
& Credit Sale
Identify &
design project
Implement
project
Sell Maintain
credits project
Source: Water Quality Trading Guidance. Idaho DEQ. 2016.
https://www2.deq.idaho.Qov/admin/LEIA/api/document/download/4839
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WATER QUALITY TRADING
When approving a trading framework, Idaho DEQ amends the 2016 Guidance to include the
framework as an appendix. Current trading frameworks include the Upper Snake-Rock Trading
Framework and the Lower Boise Trading Framework. Water quality trading in the Upper Snake-
Rock watershed is implemented through the 2007 General Permit for Aquaculture Facilities in
Idaho Subject to Wasteload Allocations Under Selected TMDLs.
For more information about Idaho's trading program, visit https://www2.deq.idaho.gov/
admin/LEIA/api/document/download/14946.
LOUISIANA
Louisiana has developed a water quality trading
program to incentivize reduction of pollutant
discharges to waters of the state. Louisiana's
state legislature enacted legislation in June 2017
to provide for the establishment and
administration of a trading program, set certain
criteria for credit generation and use, and allow
for use of a pilot program to aid in program
development. In December 2017, Louisiana DEQ
issued draft Louisiana Water Quality Trading
Guidance for public comment.
To develop its program, Louisiana DEQ garnered
significant support from over 50 stakeholder
groups. Louisiana DEQ held a series of six
stakeholder meetings in 2018. They also worked
with stakeholders to conduct five pilot projects
covering generation of credits from coastal
wetland restoration projects, regionalization
and home inspection programs for unsewered
communities, and agricultural practices and the
use of web applications and mapping tools to
support water quality trading.
Louisiana DEQ prepared draft rulemaking based
on stakeholder input and pilot project
QKey Characteristics of
the Trading Program
Geographic scope: Upstream of a
point of concern and within the same
hydrological basin in Louisiana
Key driver(s): Desire to induce
reductions of discharges of pollutants
to waters of the state
Trading scenario: Point source-point
source and point source-nonpoint
source
Pollutants: Total nitrogen, total
phosphorus, BOD, sediment, and
temperature
Status: Active
Trade ratios: Uncertainty,
reserve/retirement, and equivalency
ratios
Highlights: Implementation through
approved water quality trading plans
or water quality trading frameworks
Contact information:
Amanda Vincent
amanda.vincent(a)la.Eov
Louisiana Department of
Environmental Quality
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WATER QUALITY TRADING
outcomes. Louisiana DEQ proposed water quality trading rulemaking in January 2019. The
rulemaking was finalized, and the guidance was revised, in October 2019.
STEP 1 - Credit Generator
etoiw
Man-jficr/Credrt
Generator Submits
Credit Application to
IDEQ
IDFfl Initial Project
Review
LDEQ Requests
More Data
1
I
Administrative
Review of Document
Submittal
Completeness &
Correctness
Technical Review olt
Quantification
Methods
Confirmation of
Project
Implementation
LDEQ Approval
Credit Certification
Serialization
Registry Entry
STEP 2 Credit Buyer
I DEQ Rfqiml)
Revision of WUT Plan
Permittee submits
WO I Plan to LDEQ
Reference to
Certified Credits
Public Notice
Comment Period
LDEQ
Review/Respond
to Comments
LDEQ Approval
Included in LPDES
Permit by Reference
LDEQ Oneoine
Review of Certified
Credits
1 Meet Performance C
1 Standards 1
i
Does Not Meet 1
Performance 1
Standards 1
¦
¦ ¦
Credits Renewed
(value may be
modified)
LDEQ Issues Notice ol
Credit Suspension to
Credit generator &
Buyer
I
LDEQ Review
Project
Manager/Credit
Generator Submits
Revised Credit
AppRcstion
LPDES Pcrmrtec
Submits Plan for
Compliance
Purchase Additional
Credits
Modify Discharge
Credit Value
Evaluated
LDEQ Issues Notice of
Credit Cancellation
Source: Louisiana Water Quality Trading Guidance. Louisiana DEQ. 2019.
httos://v
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WATER QUALITY TRADING
The water quality trading rule (LAC 33. Part IX. Chapter 26) established a basic structure for
implementing water quality trading. Specific details of trading will be specified in permittee-
specific water quality trading plans or in watershed-level watershed trading frameworks. The
water quality trading plan will include all the specific details of trading processes and
performance standards. Where a watershed trading framework exists, the water quality trading
plan will incorporate the terms of the framework. Ultimately, information from these
documents will be incorporated into a point source's Louisiana Pollutant Discharge Elimination
System (LPDES) permit, the primary mechanism for trading.
The rule identifies the scenarios in which trading may be allowed, including trading in
waterbodies with no impairment or in impaired waterbodies with and without TMDLs or TMDL
alternatives.
Water quality trading plans must specify the geographic scope, or trading area, and be
developed and documented on a case-by-case basis. The trading area shall be defined
ecologically where a pollution reduction in one part of the area can be linked to a pollutant
being traded that results in a net water quality improvement at a point of compliance. The
trading area shall be consistent with any applicable TMDL or TMDL alternative.
The rule establishes eligibility for credit buyers and sellers. Point source buyers that meet their
technology-based effluent limitations (i.e., baseline) may purchase credits to achieve water-
quality-based effluent limitations. Trades may not cause localized impacts, and water quality
trading plans must specify measures and/or monitoring requirements to ensure they do not
occur. For sellers, credit-generating projects must use appropriate BMPs, be consistent with
other laws and be in good standing, demonstrate consistency with baseline requirements, be
able to verifiably quantify pollutant reductions, and account for risk and uncertainty. The
baseline for a point source seller is the most stringent effluent limitation in the LPDES permit.
The baseline for a nonpoint source seller is determined by current federal, state, tribal, and
local requirements; existing abatement requirements from a TMDL or other water quality goal;
or a requirement in a water quality trading plan.
The calculation of credits must account for risk and uncertainty through application of trade
ratios, which must be included in a water quality trading plan. The rule indicates that trading
ratios may be used to account for variables associated with a trading project including, but not
limited to uncertainty, reserve/retirement, and equivalency ratios. Uncertainty ratios are
applied at the time of credit estimation. Reserve/retirement and equivalency ratios are applied
at the time of the trade.
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WATER QUALITY TRADING
The rule indicates that each water quality trading plan must include credit life information.
Credit life is the period from the date a credit is certified and becomes available for sale to the
date that the credit is no longer valid. It may be annual, seasonal, or monthly, or may cover a
discrete number of years. Credits cannot be used outside their approved credit life.
The guidance includes standards for project implementation and quality assurance to ensure
that projects used to generate credits are achieving water quality benefits. Every project
requires a project design and management plan approved by Louisiana DEQ. Projects also must
demonstrate that adequate legal and financial safeguards (e.g., leases, deed restrictions,
easements, contracts) are in place to provide certainty for point source buyers that credits will
be available.
The guidance establishes a standard process to confirm credit-generating project
implementation, review project performance, and track credits. Initially, a source wishing to
generate credits will submit a credit application to Louisiana DEQ. Louisiana DEQ will then
conduct an initial project review consisting of administrative review, technical review, and
confirmation of project implementation and maintenance. For each approved project, Louisiana
DEQ issues a credit certificate to the seller and tracks credits in a ledger. Projects are subject to
ongoing review to ensure credits are generated and nonpoint source projects are maintained
and functioning as planned.
For more information about Louisiana's trading program, visit https://deq.louisiana.gov/
page/water-quality-trading.
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MARYLAND
Maryland initiated a nutrient trading program in
2008 with issuance of the Maryland Policy for
Nutrient Cap Management and Trading in
Maryland's Chesapeake Bay Watershed
(referred to as Phase I), the Guidelines for the
Generation of Agricultural Nonpoint Nutrient
Credits (Phase ll-A), and the Guidelines for
Agricultural Nonpoint Credit Purchases (Phase II-
B). Phase I established principles and guidelines
for trading in Maryland and specified
procedures for point source-point source
trading between WWTPs. Phases ll-A and ll-B
addressed point source-nonpoint source
trading.
In 2015, Maryland released the Maryland Water
Quality Nutrient Trading Policy Statement.
seeking to develop a new cross-sector trading
program to achieve reductions required by the
2010 Chesapeake Bay TMDL. To that end, the
Maryland Department of the Environment
(MDE) and Department of Agriculture (MDA)
finalized regulations establishing the Maryland
Water QualityTrading Program in July 2018. The
Trading Program was developed through
consultation with the Maryland Water Quality Trading
30 stakeholders.
QKey Characteristics of
the Trading Program
Geographic scope: Potomac River
Basin, Patuxent River Basin, and
Eastern Shore and Western Shore
River Basins in the Chesapeake Bay
watershed, Maryland
Key driver(s): Chesapeake Bay TMDL
Trading scenario: Point source-point
source and point source-nonpoint
source
Pollutants: Total nitrogen, total
phosphorus, and sediment
Status: Active
Trade ratios: Uncertainty, edge of
tide, and reserve ratios
Highlights: Maryland Nutrient
Tracking Tool, central registry, and
marketplace
Contact information:
Gregorio Sandi
mde.wqtradinE(5)marvland.Eov
Maryland Department of the
Environment
Advisory Committee, comprising over
Maryland's Trading Program requires that credits traded in impaired waterbodies must be
generated within the same waterbody or upstream of the credit user's discharge to ensure
protection of local water quality. To that end, MDE requires that an NPDES permittee
discharging in a given watershed, defined as the Chesapeake Bay TMDL segment, purchase
credits from within that same watershed.
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WATER QUALITY TRADING
Trading is authorized between agricultural, stormwater (including MS4s), wastewater, and
onsite sewage disposal sectors through point source-point source and point source-nonpoint
source trading.
The Trading Program establishes sector-specific baseline requirements for nonpoint sources,
wastewater point sources, stormwater point sources, nonregulated sources, and onsite sewage
disposal systems. Generally, all baselines must be consistent with the Chesapeake Bay TMDL or
a local TMDL, if more restrictive.
The Trading Program specifies three types of trade ratio applicable to all trades. An uncertainty
ratio is applied to compensate for discrepancies in estimated pollutant reductions and provide
a margin of safety. An edge of tide ratio is applied to all credits to normalize loads based on
delivery to the mainstem of the Chesapeake Bay. A reserve ratio of at least 5 percent is applied
to each credit to create a pool of credits that the state can use to provide a margin of safety to
compensate for project failure and/or underperformance and improve overall water quality.
Credits can be generated by implementing BMPs that are approved by the Chesapeake Bay
Program. Credit life is one year, and a credit may be used only during the year in which it is
generated. Credits may be traded only after they have been certified, verified, and registered.
Certification is the process used by MDE and MDA to quantify and register credits. Credits may
be certified for more than one year but must be applied annually. MDA certifies all eligible
agricultural credit generating practices; MDE certifies credits generated by any Chesapeake Bay
Program-approved non-agricultural practice. Upon certification, MDE enters the certified
credits into a central registry.
MDA and MDE have established and maintain the following online tools to facilitate trading:
The Maryland Nutrient Tracking Tool to calculate credits for agricultural credit generators.
A central registry to document, catalogue, and track credit trades.
A marketplace to exchange information between credit generators and potential buyers.
Since 2018, MDE has certified two trades: one between a wastewater source and an industrial
source and one between a wastewater source and an MS4. MDE is certifying credits from a
number of wastewater, stormwater, and natural BMPs.
For more information about Maryland's trading program, visit
https://mde.maryland.gov/programs/Water/WQT/Pages/index.aspx.
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WATER QUALITY TRADING
http://www.mdnutrienttrading.com. and
https://mde.maryland.gov/programs/water/pages/wqtac.aspx.
MINNESOTA
MPCA has implemented water quality trading
since 1997. In 2007, MPCA convened a Water
Quality Trading Advisory Committee of 14
stakeholders and initiated development of a
water quality trading rulemaking. MPCA did not
finalize the rulemaking, deeming it unnecessary
when the Minnesota legislature enacted a 2014
law expanding MPCA's authority to implement
water quality trading.
MPCA implements trading in impaired
waterbodies where a TMDL has been
developed and where a TMDL is under
development. MPCA's initial implementation of
pre-TMDL trading was challenged, but was
upheld in the Minnesota Supreme Court in
2006. MPCA subsequently approved a Pre-
TMDL Phosphorus Trading Permitting Strategy
(PTPT Strategy) in 2008, incorporating guidance
from the court ruling. Both the MPCA rules and
specifics associated with the PTPT Strategy are
described below.
QKey Characteristics of
the Trading Program
Geographic scope: Upstream of
targeted waterbody
Key driver(s): Nutrient-related
impairments
Trading scenario: Point source-point
source and point source-nonpoint
source
Pollutants: Total nitrogen, total
phosphorus, sediment, temperature,
and carbonaceous BOD
Status: Active
Trade ratios: Location, delivery,
uncertainty, equivalence, and
retirement ratios
Highlights: Implemented through
NPDES permits, PTPT Strategy
Contact information:
WQtradinE.PCA(5)state.mn.us
Minnesota Pollution Control Agency
MPCA allows for point source-point source and point source-nonpoint source trading. The
PTPT Strategy does not address trading with nonpoint sources in pre-TMDL waterbodies, but
MPCA may consider allowance of such trades on a case-by-case basis. The PTPT Strategy only
applies to individual NPDES permits; if a permittee interested in selling total phosphorus credits
is authorized to discharge under a general permit, it must apply for an individual NPDES permit.
MPCA limits the geographic scope of trades to buyers and sellers upstream of the nearest
impaired waterbody. Trading is not allowed where a nutrient-impaired waterbody is
downstream of the buyer and upstream of the seller. The PTPT Strategy describes options for
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WATER QUALITY TRADING
determining trading partners, which include partners inside and outside the same major
watershed.
MPCA implements trading through NPDES permits. For point sources participating in trading,
Minnesota law requires that the point source have a water-quality-based effluent limit or
wasteload allocation in place prior to the trade. Mass limits for the buyer and seller are
adjusted upward and downward, respectively, in their NPDES permits in proportion to the
trade.
The PTPT Strategy specifies the procedures for calculating mass limits in NPDES permits for
discharges to pre-TMDL waters. Because a TMDL is not available to account for geography or
proximity of the buyers and sellers, the PTPT Strategy requires a pound of total phosphorus
discharged by the buyer be offset by a pound of total phosphorus removed from the seller, with
a trade ratio applied to ensure a net aggregate reduction.
MPCA may apply various trade ratios depending on the trading scenario, including location,
delivery, uncertainty, equivalence, and retirement ratios. Generally, MPCA assigns smaller trade
ratios where the pollutant load sources and pollutant fate and transport dynamics are well-
understood and higher trade ratios where less information is known about pollutant sources
and watershed dynamics. The MPCA-commissioned document A Scientifically Defensible
Process for the Exchange of Pollutant Credits Under Minnesota's Proposed Water Quality
Trading Rules includes guidance for quantifying credits and developing trade ratios accounting
for uncertainty for credits generated by nonpoint sources. Under the PTPT Strategy, uncertainty
ratios of 1.1:1 and 1.2:1 are applied to expanding and new dischargers, respectively.
Additionally, a trade ratio of 1.4:1 is applied for trades that cross a major watershed boundary
where the buyer is closer to the impairment.
Under the PTPT Strategy, an entity interested in trading in pre-TMDL waterbodies may initiate
the trading process by submitting a completed "Application to Trade Phosphorus" form to
MPCA. If approved by MPCA, the trade is incorporated into the NPDES permits for the buyer
and seller, subject to public notification identifying the trading partners, impairment of
concern, and explanation of baseline and trade calculations. The trades are effective for the life
of the NPDES permits unless they are modified to reflect wasteload allocations consistent with
an EPA-approved TMDL for the waterbody.
Since 1997, MPCA has implemented three point source-nonpoint source trades and three point
source-point source trades through individual NPDES permits. Additionally, MPCA's Minnesota
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WATER QUALITY TRADING
River Basin General Phosphorus Permit Phase I. a multisource watershed-based permit covering
discharges of total phosphorus from 40 WWTPs, allows water quality trading among some
wastewater treatment facilities in the basin as an option for compliance. Between 2008 and
2018, 121 seasonal trades occurred under the general permit between 18 credit buyers and five
credit sellers.
For more information about Minnesota's trading program, visit
https://www.pca.state.mn.us/water/water-quality-trading.
new or increased discharge, comply with
water-quality-based effluent limits for nutrients, or provide a cost-effective method for
achieving water quality standards and ancillary environmental benefits.
The policy limits the geographic scope of trades to watershed boundaries, with credits
generated upstream in the watershed in most scenarios. Montana DEQ may consider allowing
downstream credit generation in certain situations, in which case DEQ may include increased
trade ratios to ensure protection of water quality.
MONTANA
Anticipating adoption of stringent numeric
criteria for nutrients, the Montana DEQ
developed Montana's Policy for Nutrient
Trading and the Nutrient Trading Rulemaking
in December 2012. The policy provides a
framework to use water quality trading as a
cost-effective alternative to treatment
upgrades or a water quality standards
variance. Development of the policy was
informed by the Nutrient Trading
Subcommittee of the Nutrient Workgroup, an
advisory group representing point sources,
nonpoint sources, and other interested parties.
Geographic scope: Within a
watershed boundary in Montana
Key driver(s): Proposed adoption of
numeric criteria for nutrients
Trading scenario: Point source-point
source, point source-nonpoint
source, and nonpoint source-
nonpoint source
Pollutants: Total nitrogen and total
phosphorus
Status: Policy
Trade ratios: Delivery and
uncertainty ratios
Highlights: Implementation through
MPDES permits, flexible options for
generating and calculating credits,
"business case" evaluation
The policy allows point source-point source,
point source-nonpoint source, and nonpoint
source-nonpoint source trading of total
nitrogen and total phosphorus. Trading may be
used to comply with a nutrient TMDL, offset a
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WATER QUALITY TRADING
Generating pollution reduction credits must be consistent with water quality standards. The
policy defines baseline requirements as the TMDL wasteload allocation or water-quality-based
effluent limit for point sources. For nonpoint sources, baseline is defined as the loading
associated with existing land uses and management practices that comply with applicable state,
local, and tribal regulations.
Credits are expressed as pounds of total nitrogen or total phosphorus per applicable period of
time that is delivered to surface waters in the watershed. The policy does not allow for credits
to be banked for a future period except where an off-season reduction provides water quality
benefit within the applicable period of the water quality standards. Montana DEQ may apply a
delivery ratio to account for a pollutant's travel over land or in water (or both) and/or an
uncertainty ratio to account for variation in the expected reliability and efficiency of the source
or type of reduction being applied toward credit.
The policy provides flexible options for generating and calculating credits, including specific
BMPs listed in the policy, BMPs and credit calculations implemented in other states, or others
proposed on a case-by-case basis.
The policy details the procedures for getting Montana DEQ approval for nutrient trades. The
process begins with the submission of a trading application with the Montana Pollutant
Discharge Elimination System (MPDES) permit application or permit modification request. The
trade application must contain specific details of the trade, credit buyer documentation, and
credit seller documentation. The policy identifies trade details that may be required, including
the timer period, number, and source of credits to be exchanged; consistency with approved
TMDLs; and inspection and verification requirements.
Upon review and approval, Montana DEQ will include the approved trade in a draft MPDES
permit. This draft, including the trading provisions, will be subject to public comment. If specific
conditions of the trade need to be verified over time, the permit will require submission of an
annual update to Montana DEQ to verify compliance.
In 2014, Montana DEQ commissioned a study to evaluate the "business case" for developing a
more formal water quality trading program in Montana. The study report, Water Quality
Trading Business Case for Montana, concluded that the most common opportunities for trading
are point source-point source trades and provides recommendations to further prioritize,
encourage, and enhance this type of trading.
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WATER QUALITY TRADING
For more information about Montana's trading program, visit
http://deq.mt.gov/Water/Resources/nutrientworkgroup.
OHIO
Ohio EPA established administrative
requirements for development and
implementation of water quality trading
programs in Chapter 3745-5 of the Ohio
Administrative Code in 2007. Ohio EPA
established the requirements to facilitate
watershed-based approaches, improve water
quality and minimize the cost of achieving and
maintaining water quality standards, provide
economic incentives for voluntary pollutant
reductions, and achieve additional
environmental benefits.
Trading must be conducted under an Ohio EPA-
approved water quality trading management
plan. To obtain approval, a person interested in
trading must submit a water quality trading
management plan application containing a
trading area map, identification of trading
partners, list of pollutants to be traded, water
quality assessment information, justification for
trade ratios and baselines, and anticipated
BMPs, among other requirements. Once
approved, a renewal application providing an
economic evaluation and an assessment of overall environmental and economic effectiveness
of all water quality trading activities must be submitted every 5 years.
A trading area can be a watershed, a TMDL area, or any other area approved by the Ohio EPA
Director. Trading may occur in impaired waterbodies with or without TMDLs. For impaired
waterbodies without approved TMDLs, trading must achieve progress toward water quality
standards where watershed action plans, nonpoint source implementation strategies, and
other locally developed watershed plans provide the data and scientific basis for the trading.
QKey Characteristics of
the Trading Program
Geographic scope: A watershed or
TMDL area in Ohio
Key driver(s): Cost-effective
watershed-based improvements to
water quality
Trading scenario: Point source-point
source and point sou rce-n on point
source
Pollutants: Unspecified
Status: Active
Trade ratios: Uncertainty ratios
Highlights: Water quality
management plans, public
participation requirements, ambient
water quality monitoring
requirements
Contact information:
Walter Ariss
walter.ariss(a)epa.ohio.Eov
Ohio Environmental Protection
Agency
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WATER QUALITY TRADING
When an approved TMDL is available, trading must conform to its assumptions and
requirements.
The rules specify the following default uncertainty ratios:
A point source-point source trade ratio of 1:1.
A point source-nonpoint source trade ratio of 2:1 for impaired waterbodies without TMDLs.
A point source-nonpoint source trade ratio of 3:1 for impaired waterbodies with TMDLs.
Ohio EPA may specify other trade ratios to account for site-specific considerations.
The water quality baseline for point sources is the lowest of the wasteload allocation
established by an approved TMDL, an existing NPDES permit limit or technology-based
performance standard where there is no TMDL, or the current discharge level. Loading
associated with existing land uses and management practices is used to determine the baseline
for nonpoint sources. The baseline for stormwater sources subject to an NPDES permit is the
numeric effluent limit established in the NPDES permit or the loading achieved after
implementation of BMPs specified by the permit.
Ohio EPA incorporates trades into individual NPDES permits through special conditions that
authorize trading, require implementation actions from the approved water quality trading
management plan, require notification of insufficient credits for compliance, and require
annual reporting. Ohio EPA may also include additional special conditions to ensure trading
does not cause adverse local impacts. For point source-point source trading, the permit will
include effluent limits adjusted proportional to the credits used or generated. For point source-
nonpoint source trading, the permit will include the effluent limit that would apply without
trading, effluent monitoring and reporting requirements, the credit applied to the discharge,
and special conditions for compliance determination.
The rules provide several opportunities for public participation during program development.
Applicants must hold at least one public meeting for submission of the initial water quality
trading management plan and major revisions, provide a 30-day public notice before the
meeting, and provide a summary of responses to all oral and written comments. The public may
also participate during the NPDES permit renewal process.
Ohio EPA may require ambient water quality monitoring to determine whether trading has
resulted in harm or improvements to water quality. Ambient water quality monitoring plans
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WATER QUALITY TRADING
must identify the parameters to be monitored, sampling frequency, sampling locations, and
methods and procedures used to monitor each parameter.
To date, two water quality trading programs have been developed in Ohio for the Great Miami
River watershed and the Middle Fork of the Sugar Creek watershed. The trading plans for these
programs were developed before establishment of Ohio EPA's trading rules. Ohio EPA amended
the rules in 2018 to add a compliance date for submittal of a water quality trading management
plan by January 2020 for the Great Miami River watershed. A management plan has been
submitted for the Middle Fork of the Sugar Creek watershed and is currently under review for
consistency with the rules.
For more information about Ohio's trading program, visit
https://epa.ohio.gov/dsw/WQ trading/index.
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WATER QUALITY TRADING
OREGON
As authorized by Oregon Revised Statute
468B.555. the Oregon Environmental Quality
Commission issued rules in Oregon
Administrative Rules Chapter 340. Division 039.
in December 2015 establishing a water quality
trading program. The goal of the rules was to
provide transparency, enforceability, and clarity
to permittees, the public, and Oregon DEQ staff
when establishing and implementing water
quality trading programs.
To implement the rules, Oregon DEQ issued an
Internal Management Directive (IMD) titled
Water Quality Trading in March 2016. The
trading IMD provides guidance to Oregon DEQ
staff for approving water quality trading plans,
incorporating trading into NPDES permits, and
determining compliance and enforcement. The
IMD was informed by stakeholder input
provided during trading policy forums, the
rulemaking process, and IMD development.
QKey Characteristics of
the Trading Program
Geographic scope: Watersheds or
other hydrologically connected
geographic areas in Oregon, as
specified in approved trading
frameworks
Key driver(s): TMDLs to address
impairments
Trading scenario: Point source-point
source and point source-nonpoint
source
Pollutants: Temperature, ammonia,
sediment, TSS, and nutrients and
other oxygen-demanding substances,
including BOD
Status: Active
Trade ratios: Ratios for attenuation,
pollutant equivalency, uncertainty, to
incentivize trading projects in priority
areas, to address risk, to address
time lag, and for credit retirement
Highlights: Implementation through
trading plans and trading
frameworks, guidance for permit
writers
Contact information:
Wade Peerman
peerman.wade(5)deq.state.or.us
Oregon Department of
Environmental Quality
Specific details of trading will be specified in
trading frameworks and water quality trading
plans. Trading frameworks may be established
in a TMDL water quality management plan or
water pollution control plan, but are not
required for Oregon DEQ to approve a water
quality trading plan. Where established, trading
frameworks must specify pollutants eligible for
trading, the trading area, priority areas, and baseline conditions (i.e., regulations, TMDL
allocations, and/or implementation schedules).
Water quality trading plans are the crux of a trading program. They describe the design,
implementation, maintenance, monitoring, verification, and reporting elements of a water
quality trade. Where a watershed trading framework exists, the water quality trading plan will
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WATER QUALITY TRADING
incorporate the terms of the framework. For NPDES permittees, the water quality trading plan
may be submitted as part of the application for permit renewal or modification. Ultimately,
information from the trading framework and water quality trading plans will be incorporated
into an NPDES permit or a Clean Water Act Section 401 water quality certification, which
provide the regulatory mechanisms for trading. Oregon DEQ must provide an opportunity for
public comment on a plan before it is approved.
A trading area is a watershed or other hydrologically connected geographic area, as defined
within a water quality management plan adopted for a TMDL, trading framework, or water
quality trading plan. It encompasses the location of the discharge to be offset, or its
downstream point of impact, if applicable, and the trading project to be implemented. Trading
may occur in high-quality waters and impaired waterbodies with or without an approved TMDL.
The rules define baseline as pollutant load reductions, BMP requirements, or site conditions
that must be met under regulatory requirements at the time of trading project initiation.
Trading frameworks and water quality trading plans specify applicable regulatory requirements
that must be implemented to achieve baseline requirements. If no regulatory requirements
exist in the trading area, then existing conditions may be used to represent baseline in the
trading plan.
The water quality trading plan must describe at least one trade ratio and document the ratio
components and underlying assumptions. Trade ratios may be used to address issues such as
attenuation of water quality benefits between the location where credit-generating BMPs occur
and the point of use, pollutant equivalency, uncertainty of BMP performance and methods
used to measure or estimate a water quality benefit for a particular project, natural and
human-caused risks, and time lag between project implementation and realization of water
quality benefits. Trade ratios may also be used to incentivize trading projects in priority areas
(e.g., areas of ecological significance).
Water quality trading plans must specify how a credit user will verify and document that BMPs
conform to applicable quality standards and that credits are generated as planned. NPDES
permits that authorize trading must include annual reporting requirements on implementation
and performance over the year, including verification of water quality trading plan performance
and quantification of credits generated. The trading IMD suggests that verification can be
conducted in a manner where every credit-generating activity is confirmed in person and all
associated paperwork reviewed by a third party, conducted by a trained and knowledgeable
staff employed by the permittee, or through a combination of these approaches.
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The trading IMD includes detailed guidance for permit writers for translating water quality
trading plan elements into enforceable permit conditions and for documenting the rationale in
the permit fact sheet. The NPDES permit must include the following conditions related to water
quality trading:
Effluent limitations that clearly state the quantity of credits that will be used to meet the
water-quality-based effluent limitation and when they are needed (e.g., year-round,
seasonally, or for a critical period identified in a TMDL).
Monitoring and reporting conditions require identification of credits used for compliance in
monthly discharge monitoring reports and annual reporting.
Compliance schedule provisions if the permittee cannot immediately meet the water-
quality-based effluent limitation.
Special conditions based on the approved water quality trading plan elements.
Oregon DEQ anticipates that most trading in Oregon will involve temperature, but hopes to
expand the program to include nutrient and sediment trading. Oregon DEQ has authorized
trades that involve riparian shade restoration to improve stream temperatures, flow
augmentation, and trading of BOD and ammonia between WWTPs.
For more information about Oregon's trading program, visit
https://www.oregon.gov/deq/wq/wqpermits/Pages/Trading.aspx.
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PENNSYLVANIA
Pennsylvania DEP initiated a nutrient water
quality trading program in 2005 with issuance
of a nutrient trading policy. In 2010,
Pennsylvania DEP published regulations for
water quality trading in the Chesapeake Bay
watershed (25 Pa. Code § 96.8). As part of their
efforts to implement the Chesapeake Bay
TMDL, Pennsylvania DEP published additional
guidance for implementing the nutrient trading
program in the Phase 2 Watershed
Implementation Plan Nutrient Trading
Supplement (Phase 2 WIP NT Supplement) in
2015. Pennsylvania DEP's primary purpose for
the program is to provide a cost-efficient option
for NPDES permittees in the Chesapeake Bay
watershed to meet their TMDL wasteload
allocations. Pennsylvania DEP developed the
program with significant stakeholder input.
Four types of trade ratios may be used to
calculate credits. Edge of segment ratios are
applied to account for the amount of a
pollutant expected to reach the surface waters
at the boundary of a Chesapeake Bay Model segment through surface runoff and groundwater
flows. Delivery ratios are derived from the Chesapeake Bay Model and are applied to all
pollution reduction activities to account for attenuation between the location of the activity
and the Chesapeake Bay. A 10 percent reserve ratio is applied to all credits generated to set
aside for Pennsylvania DEP's credit reserve to address pollutant reduction failures and
uncertainty. For credits generated by nonpoint sources, an additional 3:1 ratio is applied to
address uncertainty associated with the practice-based credit calculation methodology.
25 Pa. Code § 96.8 defines baseline as the compliance activities and performance standards
that must be implemented to meet current environmental laws and regulations.
Baseline for point sources is the most stringent of an applicable technology-based effluent
limitation or a TMDL wasteload allocation. The Phase 2 WIP NT Supplement specifies additional
o
Key Characteristics of ^
the Trading Program
Geographic scope: Susquehanna and
Potomac Basins in the Chesapeake
Bay watershed, Pennsylvania
Key driver(s): Chesapeake Bay TMDL
Trading scenario: Point source-point
source and point sou rce-n on point
source
Pollutants: Total nitrogen and total
phosphorus
Status: Active
Trade ratios: Edge of segment,
delivery, reserve, and uncertainty
ratios
Highlights: Certification, verification,
and registration processes; nutrient
trading auctions
Contact information:
RA-EPPANutrientTrad@pa.gov
Pennsylvania Department of
Environmental Protection
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baseline requirements for point source discharges as 6.0 mg/L for total nitrogen and 0.8 mg/L
for total phosphorus.
Baseline for nonpoint sources is the set of requirements in regulations applicable to the source
at the location where the credits or offsets are generated and the pollutant load associated
with that location as of January 1, 2005. 25 Pa. Code § 96.8 also defines additional threshold
requirements that must be met by an agricultural operation at the location where the credits
are generated. The Phase 2 WIP NT Supplement specifies additional requirements for nonpoint
source discharges in the form of an additional 3:1 uncertainty ratio to be applied to the number
of credits generated once the defined baseline compliance and threshold is reached, and
additional requirements for generation of credits from hauling of poultry manure and manure
destruction and conversion technologies. The additional Phase 2 WIP NT Supplement
requirements for nonpoint sources were implemented as an interim step until Pennsylvania
DEP can develop a performance-based or other approved method-based tool for establishing
baseline eligibility for nonpoint sources.
Pennsylvania's trading program involves a three-step process to generate credits: certification,
verification, and registration. Once credits are certified, verified, and registered, they may be
used for compliance with effluent limitations in NPDES permits.
Certification means Pennsylvania DEP has approved a pollutant reduction activity to generate
credits. Pennsylvania DEP has provided a mass certification to all significant sewage point
source discharges within the Chesapeake Bay Watershed subject to annual mass load effluent
limitations (referred to as cap loads) in their NPDES permits. Potential nonpoint source
generators must submit a request for credit certification (including credit calculations and a
verification plan) to Pennsylvania DEP. All certification requests are published in the PA Bulletin
for a 30-day public comment period. If Pennsylvania DEP certifies the activity, a notice of the
certification is published in the PA Bulletin, beginning a 30-day appeal process.
Verification means that Pennsylvania DEP has confirmed a pollutant reduction activity has
generated credits during the compliance year based on the approved verification plan included
in the generator's certification application. A credit generator must submit a verification
request for each compliance year (i.e., October 1-September 30).
Registration means Pennsylvania DEP has approved the sale of credits upon review of an
agreement between a buyer and seller. Registration is Pennsylvania DEP's mechanism to track
verified credits before they are used to comply with NPDES permit effluent limitations.
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Registered credits may be applied to meet NPDES permit cap load requirements, resold, or
retired for the benefit of the Chesapeake Bay.
Trading partners implement trades through direct communication. Pennsylvania Infrastructure
Investment Authority (PENNVEST) nutrient credit auctions were available from compliance
years 2010 through 2018. The auctions were originally established to reduce risks for buyers
and sellers and to help create a stable nutrient credit trading market, but were discontinued
due to lack of use. Historical information related to PENNVEST auction trading can be found on
the PENNVEST IHS Markit Auction website.
Pennsylvania DEP's nutrient trading program is very active, with many trades each year. Trading
primarily occurs between point sources, though some point source-nonpoint source trades also
occur. A summary of nutrient trading transactions for compliance years 2013 through 2019 is
provided on Pennsylvania DEP's Nutrient Credit Reports website.
For more information about Pennsylvania's trading program, including credit generation
requirements and the trading process, visit www.dep.pa.gov/nutrient trading.
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VIRGINIA
Virginia initiated its water quality trading I
program in 2005, when the Virginia General
Assembly enacted the Chesapeake Bay
Watershed Nutrient Credit Exchange Program.
The goals of the program are to meet the
wasteload allocations for the Chesapeake Bay
cost-effectively and expeditiously,
accommodate continued growth and economic
development in the watershed, and incentivize
achievement of nonpoint source reduction
goals. To achieve these goals, the law required
the Virginia DEQ to establish a watershed-
based general permit and nutrient trading
program.
Virginia DEQ issued a General VPDES
Watershed Permit Regulation for Total
Nitrogen and Total Phosphorus Discharges and
Nutrient Trading in the Chesapeake Bay
Watershed in Virginia, covering significant
existing dischargers and new and expanding
dischargers to the Chesapeake Bay watershed,
in 2006. This General Permit has since been
reissued in 2012 and 2017. For more
information on the watershed-based permit, see
QKey Characteristics of
the Trading Program
Geographic scope: Eastern Shore
Basin, James River Basin, Potomac
River Basin, Rappahannock River
Basin, and York River Basin in the
Chesapeake Bay watershed, Virginia
Key driver(s): Chesapeake Bay TMDL
Trading scenario: Point source-point
source and point sou rce-n on point
source
Pollutants: Total nitrogen and total
phosphorus
Status: Active
Trade ratios: Delivery, uncertainty,
and Eastern Shore ratios
Highlights: Watershed-based general
permit, Virginia Nutrient Credit
Exchange Association
Contact information:
Allan Brockenbrough
allan.brockenbrouEh(5)deq.virEinia.Eov
VA Dept. of Environmental Quality
'Watershed-Based Permitting."
The General Permit allows for point source-point source trading for total nitrogen and total
phosphorus for all permittees. Point source-nonpoint source trading is allowed for new and
expanded facilities to offset any new or increased total nitrogen or total phosphorus loads.
Permittees may engage in trading independently or through the Virginia Nutrient Credit
Exchange Association. The Association was formed in 2005 and consists of 73 owners and 105
treatment facilities in the Chesapeake Bay watershed. It coordinates and facilitates
participation in a nutrient credit exchange program for its members. The Association submits
annual compliance plan updates on behalf of its members, develops standard forms of
agreement for buying and selling credits, helps permittees identify buyers and sellers, and
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WATER QUALITY TRADING
coordinates planning to ensure sufficient credits are available for permit compliance. According
to Virginia's August 2019 Chesapeake BayTMDL Phase III Watershed Implementation Plan.
Virginia became the only state to meet the original significant point source nutrient load
reductions by 2011 by implementing their innovative water quality trading program. Since
2010, point source delivered loads have decreased by 9,934,382 pounds per year of total
nitrogen (-50%) and 437,410 pounds per year of total phosphorus (-38%).
The Chesapeake Bay watershed in Virginia consists of five tributary basins. The General Permit
specifies that purchased credits must be generated within the same tributary, except owners of
permitted facilities in the Eastern Shore Basin may purchase credits from owners of permitted
facilities in the Potomac and Rappahannock tributaries, subject to an Eastern Shore trading
ratio of 1:1 if generated in the Potomac tributary and 1.3:1 if generated in the Rappahannock
tributary.
All credits are adjusted by applicable delivery factors that are determined by the geographic
location of the facility to account for attenuation during riverine transport between the facility
and tidal waters. Credits generated by nonpoint sources are subject to an uncertainty ratio of
2:1 unless the applicant can demonstrate factors that reduce uncertainty (e.g., direct
measurement, land conservation with permanent protection).
Permittees may only acquire credits if the credits are generated and applied to a compliance
obligation in the same calendar year. Permittees must annually report the mass loads of total
nitrogen and total phosphorus discharged by February 1. Based on this information, Virginia
DEQ publishes a report by April 1, annually, summarizing annual mass loads and the number of
credits generated or required for each facility for the previous calendar year. Permittees must
provide certification that they have acquired the credits necessary to achieve compliance for
the previous calendar year by June 1. Virginia DEQ then publishes notice of all credit exchanges
and purchases for the previous calendar year by July 1.
Virginia DEQ has published guidance for agricultural nonpoint source credit generators in
Trading Nutrient Reductions from Nonpoint Source Best Management Practices in the
Chesapeake Bay Watershed: Guidance for Agricultural Landowners and Your Potential Trading
Pgrtners. The guidance describes most current practices available to generate offsets. It also
includes instructions for obtaining certification of nutrient credits. A credit generator must
submit a Nutrient Reduction Certificate identifying the BMP enhancements or land conversion
and calculation of nutrient reductions achieved, assignment of reductions to the offset broker,
assignment of reductions to the VPDES permittee, and project qualification data and
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WATER QUALITY TRADING
documentation. Virginia DEQ uses the U.S. Army Corps of Engineers' Regulatory In-lieu Fee and
Bank Information Tracking System (RlBITS) database to track the generation, use, and
retirement of nonpoint source credits.
For more information about Virginia's trading program, visit
https://www.deq.virginia.gov/Programs/Water/PermittingCompliance/PollutionDischargeElimi
nation/NutrientTrading.aspx.
Ecology, with input from interested parties,
determines what types of trades are eligible. Permittees may submit a proposed trade to
Ecology for consideration. If Ecology determines the trading program has merit, it will provide
written feedback including items that must be included in the water quality trading program. At
a minimum, permittees are required to submit a program plan/study addressing all of Ecology's
WASHINGTON
Washington Administrative Code 173-201A-450
provides authorization for water quality offsets
in Washington. In April 2011, and then again in
March 2018, Washington's Department of
Ecology released a Draft Water Quality
Trading/Offset Framework that outlines the
regulatory path for water quality trading.
Ecology anticipates finalizing the Draft
Framework once an actual trading program has
been established in a Washington watershed.
Geographic scope: Watersheds in
Washington
Key driver(s): TMDLs
Trading scenario: Point source-point
source, point source-nonpoint
source, nonpoint source-nonpoint
source
Pollutants: Phosphorus, nitrogen,
other oxygen-related pollutants,
sediment, and temperature; toxics
and fecal coliform may not be traded
Status: Policy
Trade ratios: Delivery, location,
equivalency, retirement, uncertainty,
and time lag
Highlights: Implementation through
trading plans approved by Ecology
Contact information:
Ben Rau
ben.rau(a)ecv.wa.Eov
Washington Department of Ecology
The current draft framework summarizes the
elements of a water quality trading program
that must be addressed before approval:
defining a common unit of credit (i.e., pounds of
pollutant), simultaneous credit generation and
use, managing uncertainty (i.e., use of trading
ratios, monitoring, modeling, and BMP efficiency
estimates), compliance assessment (i.e., record-
keeping, certifications, inspections),
enforcement, public notice and transparency,
and regular reassessment and modification.
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WATER QUALITY TRADING
initial concerns identified during a scoping consultation, a description of practices to achieve
pollutant credits and evidence of the effectiveness of these practices, a determination
regarding the credits generated and how uncertainty and trading ratios will be applied, a
demonstration through modeling or equivalent actual situations that the pollutant reduction
will be achieved, design details (if applicable), implementation milestones, and an effective
monitoring plan to demonstrate compliance. Additionally, proponents for water quality trading
programs must develop a quality assurance project plan before collecting new data or
conducting any work on the plan/study.
Point and nonpoint source pollution controls must be secured using binding legal agreements
between all parties for the life of the project, and implementation of the credit must be
demonstrated to have occurred in advance of the proposed action. Ecology then develops
permits that allow for trading applicable portions of the wasteload-allocation-based effluent
limit. Permittees are required to report sampling results, as well as trade-adjusted results, on
their monthly discharge monitoring reports. The trade-adjusted results must meet their
effluent limits.
To ensure credits are accrued and used in the same time period, the permittee must certify
each month that offset activities are in place, that they are properly operated and maintained,
and that the necessary pollutant reduction is achieved. Trading programs must use an
accounting system to ensure that credits are accrued, used, and tracked to ensure compliance
with the NPDES permit. Ecology may conduct periodic inspections and monitoring to validate
the reported and certified information.
Credits expire if applicable BMPs are determined to be ineffective or removed, or if the
implementation is required by a permit, TMDL, or policy regulation.
No trading is currently occurring due to a lack of interested buyers. In recent years, several
groups have expressed an interest in developing trading programs in various watersheds in
Washington. Most of these ideas involved having point sources pay for nonpoint
improvements, and most of the groups proposing these programs were potential sellers.
Washington does not anticipate that a trading program will be developed until there is an
interested point source buyer. A 2009 Washington Conservation Markets Study Report,
prepared for the Washington State Conservation Commission, found that farmers, ranchers,
and foresters are concerned that after they begin providing and being compensated for
conservation, it may become a regulatory requirement or expose them to liability.
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WATER QUALITY TRADING
Despite the lack of current trading programs within the state, a 2017 report by the Washington
State Conservation Commission found that "interest in the concept of water quality trading
remains for both buyers and sellers, depending on specifics of the TMDL."
WISCONSIN
In 1997, Wisconsin passed legislation to create
three pilot areas for water quality trading: the
Fox River Basin, Rock River Basin, and Red Cedar
Basin. Successful trading was first implemented
in Wisconsin by the City of Cumberland and
agricultural nonpoint sources within the Red
Cedar Basin when the City had to comply with a
statewide total phosphorus limit for WWTPs of
1 mg/L. The trade agreement required the
removal of 4,400 pounds of total phosphorus
within the Hay River Watershed each year. The
City pays the landowners for each pound of
total phosphorus removed by converting
conventional tillage to no-till systems.
OKey Characteristics of
the Trading Program
Geographic scope: Within a
watershed in Wisconsin
Key driver(s): New water quality
standards
Trading scenario: Point source-point
source, point source-nonpoint source
Pollutants: Total phosphorus, TSS,
temperature, total nitrogen, other
pollutants (excluding toxic
bioaccumulative chemicals)
Status: Active
Trade ratios: Delivery, location,
equivalency, uncertainty, and habitat
adjustment ratios
Highlights: Implementation through
trading plans directly with credit
generators or exchanges
Contact information:
On December 1, 2010, Wisconsin adopted water
quality standards for total phosphorus in surface
waters, which resulted in restrictive permit
limits for some permittees. Wisconsin DNR
identified water quality trading as a compliance
option for facilities with restrictive total
phosphorus limits. During the same year,
Wisconsin DNR assembled a stakeholder group
of interested parties to develop a trading
framework. In 2011, Wisconsin established the statutory framework for statewide water quality
trading (283.84. Wis State Stat.). As of December 2019, 25 wastewater dischargers have
identified adequate credit generators to fulfill compliance requirements.
Matt Claucherty
matthew.clauchertv(a)wisconsin.Eov
Wisconsin Department of Natural
Resources
Municipal and industrial permittees may use trading within Wisconsin to demonstrate
compliance with water quality-based effluent limits. Trading may occur directly between point
sources and nonpoint sources, or indirectly through third-party credit exchanges/brokers.
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WATER QUALITY TRADING
In 2013, Wisconsin DNR released two guidance manuals: Guidance for Implementing Water
Quality Trading in WPDES Permits and A Water Quality Trading How To Manual. These
documents prescribe the protocols for establishing trading within permits, and for developing
successful trading strategies.
The permittee is encouraged to review compliance alternatives and determine if trading is
feasible and economical. If trading is identified as the preferred compliance option, the
permittee must submit a Notice of Intent to Wisconsin DNR. In evaluating feasibility, the
permittee determines the pollutant offset needed, identifies potential trading partners, and
evaluates the availability of credits. Upon approval of the notice, the permittee must develop a
trading strategy and is encouraged to prioritize economic benefit and ease of partnership.
Permittees are encouraged to identify significant pollution-generating sites to generate the
most cost-effective credits possible.
f ^
Delivery
L. J
Accounts forthe distance between the credit generator and the credit user, and
the impact that this distance can have on fate and transport of the pollutant.
r i
Downstream
Accounts for local water quality impacts if the credit user is upstream of the credit
generator.
Equivalency
Accounts for situations where trading partners discharge different forms of the
traded pollutant. (Example: Total Nitrogen vs. Nitrate-Nitrogen).
Uncertainty
" *
Accounts for modeling inaccuracies used to quantify load reductions. For trades
with nonpoint source credit generators only (see Appendix A).
Habitat
Adjustment
Used to capture ancillary benefits from select practices that benefit habitat in
addition to capturing the pollutant of concern. Only applies to wetland creation,
wetland restoration, and stream habitat, improvement and management
practices.
Source: A Water Quality Trading How To Manual. Wisconsin DNR. 2013.
In developing the trading strategy, the permittee must establish trade ratios that consider a
delivery factor, a downstream factor (i.e., location factor), an equivalency factor (not necessary
for total phosphorus or TSS trades), an uncertainty factor, and an aquatic habitat adjustment
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WATER QUALITY TRADING
factor (only for aquatic habitat restoration efforts). All trades must result in a net reduction in
pollutant discharged to the receiving water.
Once partnerships and a trading strategy have been identified,
the permittee must develop and implement trade
agreements, quantify credits generated, and maintain permit
compliance throughout the permit term. Trade agreements
between the credit user and generator specify the location of
trading practices, practice description and duration, amount
of credit being generated, and other pertinent details of the
trade.
To quantify available credits, the permittee must provide the
current pollution load, pollution load after trading
implementation, and a credit threshold (i.e., performance for
trading partner at which credits are generated). The methods
for quantifying this information depend on the type of trading
partner.
For point sources, the seller must accept a lower discharge
limit than would otherwise be given to them in their
WPDES permit. The difference between the revised limit
and the previously applicable limit is the amount
generated for trading. Effluent monitoring is used to
evaluate compliance.
For nonpoint sources, the current pollutant load (i.e.,
baseline load) is determined using a variety of methods,
such as modeling. In evaluating loading from agricultural
land, the baseline should consider the previous full crop
rotation and current soil nutrient levels. Once the baseline
load is known, modeling can be used to predict future
pollutant load once management practices are installed.
The reductions made by these agricultural and urban
management practices represent the credit that is
generated.
Source: A Water Quality Trading How
To Manual. Wisconsin DNR. 2013.
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WATER QUALITY TRADING
A trading plan and checklist must be submitted to Wisconsin DNR, and the requirements of the
trade must be built into the WPDES permit, before trading may be used to demonstrate
compliance with a water-quality-based effluent limit. The information in the trading plan and
checklist will serve as the basis for permitting decisions. Permit development or modification
provides an opportunity for public comment on the trading plan.
A management practice registration is required to ensure management practices identified in
the trading plan have been properly installed and are effective. This information is used to track
implementation progress, verify compliance, and perform audits.
The permittee must submit annual reports that provide the status of management practices
and the overall trading project and identify any necessary changes to the trading plan. At a
minimum, annual reports shall include a verification that site inspections have occurred, a
summary of site inspection findings, any applicable notices of termination or practice
registrations, the amount of credit used each month over the calendar year, and any other
requirements specified in the WPDES permit.
If a trade agreement or the trading plan needs to be modified or terminated during the permit
term, the permittee is required to submit a notice of termination.
According to Wisconsin's Nutrient Reduction Strategy 2017-2019 Implementation Progress
Report, over 40 permittees have formally indicated that trading will be used to comply with
their phosphorus limits. Of these, 23 permittees have submitted an approvable trading plan.
The average phosphorus reduction for each trade is approximately 800 lbs/year, and with the
average trade ratio of 2:1, the average point source credit buyer purchases approximately
400 lbs/year of credits to offset its discharge.
For more information about Wisconsin's trading program, visit
https://dnr.wi.gov/topic/Wastewater/waterQualityTrading.html.
Click here to return to the Table of Contents
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Watershed-based permitting is a process that
emphasizes addressing all point source stressors
within a hydrologically defined drainage basin, rather
than individual pollutant sources on a discharge-by-
discharge basis. It can encompass activities ranging
from synchronizing permits within a basin to
developing water-quality-based effluent limits using a
multiple discharger modeling analysis. The type of
permitting activity will vary depending on the unique
characteristics of the watershed and the sources of
pollution affecting it. The ultimate goal of this effort is to develop and issue NPDES permits that
optimally protect entire watersheds.
There are a variety of types of watershed-based permits. This compendium categorizes state
watershed-based permitting practices into three categories:
Integrated Municipal Permits.
Multisource Watershed-Based Permits.
Coordinated Individual Permits.
There is some overlap between integrated municipal permits and multisource watershed-based
permits as these terms are not intended to be mutually exclusive. For more information, see
EPA's watershed-based permitting website at https://www.epa.gov/npdes/watershed-based-
permitting.
Types of watershed-based
permits in this compendium:
1. Integrated municipal
permits
2. Multisource watershed-
based permits
3. Coordinated individual
permits
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WATERSHED-BASED PERMITTING
Integrated Municipal Permits
Integrated municipal permits may bundle a number of point source permit requirements for a
municipality or multiple municipalities (POTWs, combined sewer overflows, biosolids,
pretreatment, MS4s, and storm water from municipally owned industrial activities such as
public works and utility yards) into a single permit.
OREGON
In 2001, Oregon DEQ issued the Tualatin
Subbasin TMDL. which established temperature
temperature requirements for the Tualatin
River and its tributaries. The TMDL was
amended in 2012 to include wasteload
allocations for total phosphorus. The NPDES
permit issued to Clean Water Services in 2004
was the first example of a municpal, intergrated
watershed-based NPDES permit in the nation,
with a principal goal of meeting temperature
requirements. The current permit, issued in
2016, also includes total phosphorus
requirements.
The Clean Water Services permit covers four
wastewater treatment facilities with outfalls in
the Tualatin River: Durham Advanced
Wastewater Treatment Facility, Rock Creek
Advanced Wastewater Treatment Facility,
Hillsboro Wastewater Treatment Facility, and
Forest Grove Wastewater Treatment Facility
with Natural Treatment System. Additionally,
the permit covers existing and new stormwater
discharges from the MS4 within the stormwater
service area of Clean Water Services.
QKey Characteristics
of the Permit
NPDES Permits OR0028118,
OR0029777, OR0023345, OR0020168,
and ORS108014
Watershed: Lower Willamette Basin
(Tualatin Subbasin)
Key water quality concerns: Elevated
stream temperatures that affect
salmonids and elevated phosphorus
due to low dilution factors
Pollutants:
Temperature
Total phosphorus
Types of point source dischargers
covered by permit: POTWs and
stormwater dischargers
Highlighted approaches:
TMDL implementation
Temperature trading
Reservoirs for cooling needs
Easements and setbacks for riparian
restoration
Flexibility to move both influent and
effluent between three sewage
treatment plants
"Bubble" limit for total phosphorus
Integrated stormwater permitting
Wetland-based natural treatment
system
Struvite recovery
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WATERSHED-BASED PERMITTING
Features of the Permit
Influent and effluent may be moved between the Rock Creek, Hillsboro, and Forest Grove
facilities.
Each discharger conducts effluent monitoring for total phosphorus.
In the dry season, Clean Water Services can treat wastewater at Hillsboro and Forest Grove
and direct wastewater through a 95-acre natural treatment system before discharging into
the Tualatin River.
The permit includes the following total phosphorus limits for the three facilities based on
the wasteload allocations in the TMDL:
Facility
Monthly Median
Phosphorus Limit
Seasonal Median
Phosphorus Limit
Applicable Time Period
Durham
0.11 mg/L
Not applicable
May 1-October 15
Rock Creek
0.10 mg/L
Not applicable
May 1-September 30
Forest Grove
Monthly median load (81.6
pounds/day) minus Rock
Creek load3
Seasonal median load
(66.1 pounds/day) minus
Rock Creekloadb
May 1-September 30
a Based on the group limit specified in the TMDL The monthly median limit is calculated as follows:
(monthly median load) - [(monthly median Rock Creek discharge concentration of total P mg/L) x (actual
monthly median Rock Creek effluent volume in MGD) x (8.34 conversion factor)].
b Based on the group limit specified in the TMDL The seasonal median limit is calculated as follows:
(seasonal median load) - [(seasonal median Rock Creek discharge concentration of total P mg/L) x (actual
seasonal median Rock Creek effluent volume in MGD) x (8.34 conversion factor)].
For more information about Clean Water Services and the Tualatin River, visit
https://www.cleanwaterservices.org/about-us/one-water/.
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WATERSHED-BASED PERMITTING
Multisource Watershed-Based Permits
A multisource watershed-based permit uses a single permit for multiple sources in the same
watershed, watershed plan, or TMDL. It would allow several point sources in a watershed to
apply for and obtain permit coverage under the same permit. This type of permit might be
appropriate when a watershed plan or TMDL identifies the need to address a specific pollutant
(e.g., nitrogen and/or phosphorus). This approach allows the permitting authority to focus on
effluent limitations, monitoring requirements, trading provisions, and other special permit
conditions that are developed on a watershed basis in a single permit and clearly links the
permitted facilities in a way that simply incorporating watershed-based permit conditions into
individual permits does not accomplish.
CALIFORNIA
San Francisco Bay is not presently impaired for
nutrients; however, recent data indicate an
increase in phytoplankton biomass and a small
decline in dissolved oxygen concentrations in
many areas, suggesting that the bay may be
losing its historical resiliency to high nutrient
loadings. Nitrogen is the growth-limiting
nutrient of San Francisco Bay, and municipal
WWTPs account for about 62 percent of the
annual average total inorganic nitrogen (the
bioavailable form of nitrogen) load to San
Francisco Bay.
To address nutrient discharges to the bay, the
San Francisco Bay Regional Water Quality
Control Board first established the Waste
Discharge Requirements for Nutrients from
Municipal Wastewater Discharges to San
Francisco Bay in July 2014. The permit was
reissued in 2019.
The permit covers 41 municipal POTWs that
discharge nutrients to the bay and its
tributaries. The Bay Area Association of Clean
QKey Characteristics
of the Permit
NPDES Permit CA0038873
Watershed: San Francisco Bay
Watershed, California
Key water quality concerns: The San
Francisco Bay appears to be losing its
historical resiliency to high nutrient
loads
Pollutants:
Total nitrogen
Total phosphorus
Types of point source dischargers
covered by permit: POTWs
Highlighted approaches:
Discharger association (BACWA)
Pre-impairment, pre-TMDL
adaptive management
Effluent monitoring
Ambient monitoring and scientific
studies of the bay
Studies on plant optimization and
treatment upgrade opportunities
Studies on natural systems and
water recycling
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WATERSHED-BASED PERMITTING
Water Agencies (BACWA) represents the POTWs and helps serve as a champion and voice for
the facilities. Working with BACWA, the Water Quality Control Board developed the permit with
nutrient control activities to provide scientific support and certainty for possible future nutrient
load reductions that may be necessary.
The 2014 permit represented the first phase of an anticipated multiple-permit-term effort. The
2014 permit required permittees to evaluate potential nutrient reduction options (e.g.,
treatment plant optimization, sidestream treatment, treatment plant upgrades) and to develop
a science plan of necessary studies to support implementation of the San Francisco Bay
Nutrient Management Strategy.
The current permit represents the second phase of the effort, the purpose of which is to track
and evaluate treatment plant performance, fund nutrient monitoring programs, support load
response modeling, and evaluate nutrient removal approaches using natural systems and
wastewater recycling. The current permit contains four main requirements:
Each permittee must conduct effluent monitoring for ammonia, nitrate-nitrite, total
inorganic nitrogen, and total phosphorus.
Permittees must, either individually or through BACWA, submit an annual report that
analyzes trends in POTW flow and nutrient loadings.
Each major POTW must participate in a regional evaluation of potential nutrient discharge
reduction by natural systems (e.g., wetlands and horizontal levees) and water recycling.
The permittees must support receiving water monitoring for nutrients and update and
implement the science plan submitted under the 2014 permit.
These requirements can be viewed as a unique combination of watershed-based permitting and
adaptive management. Requiring both effluent and ambient monitoring now will produce
robust data and relative scientific certainty to support establishment of any necessary future
limits for nutrients the POTWs. Each POTW will also know, through its optimization and
treatment upgrade studies, how much future nutrient reductions may cost.
For more information about efforts to reduce nutrient discharges to the San Francisco Bay, visit
the Water Quality Control Board's website at https://www.waterboards.ca.gov/
sanfranciscobay/water issues/progra ms/pla nn ingtmd Is/a mend ments/estuarynne. html and
BACWA's website at https://bacwa.org/nutrients/.
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WATERSHED-BASED PERMITTING
Watershed: Long Island Sound,
Connecticut
Key water quality concerns:
Excessive total nitrogen leading to
low dissolved oxygen and hypoxic
conditions.
Pollutants: Total nitrogen
Types of point source dischargers
covered by permit: POTWs
Highlighted approaches:
TMDL implementation
Point source water quality trading
To implement the TMDL, Connecticut DEEP
issued the General Permit for Nitrogen
Discharges on January 2, 2002. The permit was
reissued most recently in 2018. The permit
addresses only total nitrogen discharges from
the 79 POTWs discharging to the Long Island
Sound watershed in Connecticut. The facilities
are subject to the requirements of their individual NPDES permits for other pollutants.
The permit establishes annual mass effluent loading limits for total nitrogen, expressed in
pounds per day, for each applicable POTW. These limits represent the allocated end-of-pipe
loading for each facility.
The permit gives permittees two options for achieving compliance:
Meet their annual discharge limits on site.
Purchase equivalent total nitrogen credits through the Nitrogen Credit Exchange Program.
A permittee that exceeds its annual discharge limit and does not purchase the necessary
amount of equivalent total nitrogen credits is out of compliance and subject to enforcement.
What Is the Nitrogen Credit Exchange Program?
The permit and the Nitrogen Credit Exchange Program work in tandem to provide POTWs with
alternatives for achieving permit compliance. The permit requires applicable POTWs to meet
their specified annual discharge limits. If the facilities cannot meet those limits, they must
purchase equivalent total nitrogen credits. Facilities with treatment that enables them to
produce less than their specified annual discharge load generate credits.
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WATERSHED-BASED PERMITTING
The credit exchange program has been successful over the years, and the POTWs now generate
more credits than are needed. Projections showed the state would be spending over $5 million
by 2018 to continue to subsidize the credit exchange program as it was designed in 2001. The
state became concerned that this level of continued subsidization could not be sustained. The
governor signed Public Act 15-38 on June 5, 2015 which moved to a more self-sufficient model
where the buyer's payments are shared proportionally by the sellers.
For more information on Connecticut's water quality trading program, see "Water Quality
Trading."
For more information about Connecticut's nitrogen control plan for Long Island Sound, see the
state's website:
http://www.ct.gov/deep/cwp/view.asp?a=2719&q=325572&deepl\lav GID=1635%20.
MARYLAND
Patuxent River Watershed
EPA established the TMDL for nitrogen,
phosphorus, and sediment in Chesapeake Bay in
2010 to address poor water quality, degraded
habitats, and low populations offish and
shellfish in the bay. The Chesapeake Bay TMDL
applies to five major basins in Maryland,
including the Patuxent River Basin.
In 2008, MDE issued the Patuxent River
Watershed Nutrient Permit to the Anne Arundel
County Department of Public Works, authorizing
discharges of total nitrogen and total
phosphorus from its Patuxent Water
Reclamation Facility and Maryland City Water
Reclamation Facility. Both facilities are subject
to individual permits, issued concurrently with
the watershed-based permit, for their
performance-based nutrient annual loading cap
limits (based on actual annual discharged flow
and ENR effluent criteria) as well as all other effluent parameters.
QKey Characteristics
of the Permit
NPDES permit MD0069868
Watershed: Patuxent River
Watershed, Maryland
Key water quality concerns:
Excessive nutrients leading to algae
blooms and low dissolved oxygen
levels
Pollutants:
Total nitrogen
Total phosphorus
Types of point source dischargers
covered by permit: POTWs
Highlighted approaches:
TMDL implementation
Accommodates water quality
trading
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WATERSHED-BASED PERMITTING
The permit establishes annual mass loading limits for total nitrogen and total phosphorus based
on wasteload allocations in the Chesapeake Bay TMDL. The limits in the watershed-based
permit apply in addition to concentration-based limits established in the individual permits to
address local concerns.
The individual permits for both facilities require effluent monitoring for total nitrogen and total
phosphorus. To avoid duplicate monitoring requirements, the watershed permit does not
require effluent monitoring, but instead requires the County to calculate and report the
monthly and annual loading rates based on each facility's total monthly flow and monthly
average concentration, as measured under their individual permits.
When the watershed permit was reissued in 2013, it accommodated trading with a third facility
in the watershed in accordance with MDE's 2008 Nutrient Cap Management and Trading Policy.
The traded allocations purchased from the Piney Orchard Utility Company WWTP, also located
in the Patuxent River watershed, enable the County to expand their facilities to accommodate
growth while ensuring compliance with the TMDL. For more information on Maryland's water
quality trading program, see "Water QualityTrading."
Additionally, the permit includes reopener provisions to:
Incorporate new or revised nutrient trading elements.
Modify allocations if the County ceases discharge or assumes ownership from another
facility in the watershed.
Revise nutrient limits if a TMDL for the Patuxent River is issued.
To access the permit, visit MDE's Wastewater Permits Search Portal and enter "MD0069868" in
the "NPDES Number" field.
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WATERSHED-BASED PERMITTING
Patapsco River Mesohaline Watershed
MDE issued the Baltimore Harbor TMDL in 2006
to address water quality impairments
associated with excess nutrient loadings in
Baltimore Harbor, which includes the Patapsco
River Mesohaline watershed. Subsequently, in
2010, EPA established the Chesapeake Bay
TMDL to address poor water quality, degraded
habitats, and low populations offish and
shellfish in the bay. Both TMDLs include
wasteload allocations for the Maryland Port
Administration's (MPA's) Cox Creek Dredged
Material Containment Facility (DMCF).
In 2015, MDE issued a watershed-based permit
to MPA, authorizing discharges of total nitrogen
and total phosphorus from its Cox Creek and
Masonville DMCFs to the Patapsco River
Mesohaline watershed. Both facilities are
subject to individual permits for all other
parameters; these were reissued concurrently with the watershed-based permit to reflect the
transfer of nutrient requirements (i.e., loading limits, compliance schedules, and other special
provisions) from the individual permits to the watershed-based permit.
The permit establishes annual and growing season (May 1-October 31) mass loading limits for
total nitrogen and total phosphorus, which apply to the cumulative loading from both facilities.
The nutrient limits are based on wasteload allocations for the Cox Creek DMCF established in
the Baltimore HarborTMDL and Chesapeake Bay TMDL.
The Masonville DMCF did not exist when the wasteload allocations were established, so no
allocations were assigned for it or any future MPA facilities. The permit provides a means to
share the nutrient loads assigned to the Cox Creek DMCF with the Masonville DMCF and any
future facilities. This approach gives MPA operational flexibility, allowing it to use other
facilities once a facility is filled and to use facilities closest to its dredging operations, while also
improving water quality through broader distribution of point source loadings across the
watershed.
Key Characteristics
of the Permit
NPDES Permit MDDRG3796
Watershed: Patapsco River
Mesohaline Watershed, Maryland
Key water quality concerns:
Excessive nutrients leading to algae
blooms and low dissolved oxygen
levels
Pollutants:
Total nitrogen
Total phosphorus
Types of point source dischargers
covered by permit: Dredged material
containment facilities
Highlighted approaches:
TMDL implementation
Cumulative mass loading limits
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WATERSHED-BASED PERMITTING
The permit requires MPA to calculate and report the monthly, growing season, and annual
loading rates based on loading from each of the facilities, as measured undertheir individual
permits.
Additionally, the permit includes reopener provisions to:
Implement a TMDL issued or approved for the watershed.
Authorize additional DMCFs.
Implement wasteload allocations in the individual permits and terminate the permit.
To access the permit, visit MDE's Wastewater Permits Interactive Search Portal and enter
"MDDRG3796" in the "NPDES Number" field.
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WATERSHED-BASED PERMITTING
NEW MEXICO
In December 2014, U.S. EPA Region 6 issued the
NPDES Storm Water General Permit for MS4s in
the Middle Rio Grande Watershed
(NMR04A000). The permit authorizes MS4
discharges within the Albuquerque Urbanized
Areas (as designated in the 2000 and 2010
Census) and other MS4s in the watershed.
These MS4s were previously regulated by an
individual permit (Albuquerque MS4) and Phase
I (Medium and Large MS4s) and Phase II (Small
MS4s) general permits.
U.S. EPA Region 6 developed the general permit
as part of a pilot project to evaluate watershed-
based permitting for stormwater management.
The goals of the pilot project were to better
tailor stormwater management plans and
permits to meet watershed needs and improve
efficiency in implementing certain elements of
the stormwater program (e.g., education,
outreach, and monitoring). The permit itself was
developed:
QKey Characteristics
of the Permit
NPDES Permit NMR04A000
Watershed: Middle Rio Grande
Watershed, New Mexico
Key water quality concerns:
Impairments due to bacteria, low
dissolved oxygen, and nutrients
Pollutants:
Bacteria
Dissolved oxygen
Polychlorinated biphenyls (PCBs)
Total nitrogen
Total phosphorus
Sediment
Temperature
Types of point source dischargers
covered by permit(s): MS4
dischargers
Highlighted approaches:
BMPs to control nutrients
Dissolved oxygen strategy
Wet and dry weather monitoring
Contact information:
Nelly Smith
smith.nellv(a)epa.Eov
U.S. EPA Region 6
To address impairments with a common and
minimum set of goals.
To identify and address upstream pollutant
sources through individual and cooperative
monitoring, education, and outreach requirements.
To establish cooperation among permittees, integrate and prioritize implementation, and
potentially reduce costs.
To better understand the complex hydrological and topographical features of the
watershed affecting water quality.
To ensure protection of endangered species in the watershed.
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WATERSHED-BASED PERMITTING
The general permit includes the following requirements to address impairments for dissolved
oxygen and nutrients in the watershed:
Implementation of a dissolved oxygen strategy to assess and implement source controls to
address low dissolved oxygen and prevent impacts to endangered or threatened species.
Source identification and schedule for implementing targeted BMPs to control nutrients.
Wet weather monitoring, either individually or coordinated, for dissolved oxygen indicator
parameters and nutrients.
Dry weather screening for BOD and nutrients.
Additionally, the general permit requires stringent stormwater controls to reduce the pollutants
in discharges from new or significant redevelopment sites. U.S. EPA Region 6 estimated that
implementation of these controls will reduce the discharge of pollutants of concern, including
nutrients, from new and significant redevelopment sites by an average of 70 percent.
For more information, see U.S. EPA Region 6's Fact Sheet and Supplemental Information.
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WATERSHED-BASED PERMITTING
NORTH CAROLINA
Neuse River Basin
The Neuse River Basin has experienced harmful
algal blooms, low dissolved oxygen levels, and
increased numbers of fish kills due to excessive
levels of nutrients since the 1980s. In 1994, it
was identified as an impaired waterbody due to
exceedance of the water quality standard for
chlorophyll-o.
Control of nutrient discharges in the basin is
guided by the North Carolina Environmental
Management Commission's 1997 Neuse River
Basin Nutrient Sensitive Waters Management
Strategy and a phased TMDL for total nitrogen
approved by U.S. EPA in 1999 (Phase I) and 2002
(Phase II). The Strategy required a 30 percent
reduction from of total nitrogen loads (1995
baseline) to the Neuse River Estuary,
established a wasteload allocation of 1.64
million pounds of total nitrogen per year for all
point source dischargers in the basin, and
authorized the issuance of a multisource
watershed-based NPDES permit to a group
compliance association to provide flexibility for
meeting the total nitrogen control
requirements.
QKey Characteristics
of the Permit
NPDES Permit NCC000001
Watershed: Neuse River Basin, North
Carolina
Key water quality concerns:
Impairment due to excessive nutrient
levels
Pollutants: Total nitrogen
Types of point source dischargers
covered by permit:
POTWs
Industrial dischargers
Highlighted approaches:
TMDL implementation
Discharger association
"Group cap" effluent limits
Contact information:
Mike Templeton
mike.templeton(a)ncdenr.Eov
North Carolina Department of
Environmental Quality, Division of
Water Resources
The North Carolina DEQ, Division of Water Resources, issued a multisource watershed-based
permit to the Neuse River Compliance Association and its 22 members for discharges of total
nitrogen in 2002, which was last reissued in 2018. Effective January 1, 2020, the Association has
23 members with 26 permitted facilities, which include both POTWs and industrial discharges.
The member facilities are subject to the requirements of their individual NPDES permits for
other pollutants. The watershed-based permit includes:
An effluent limit for total nitrogen for the Association as a whole (i.e., a group limit).
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WATERSHED-BASED PERMITTING
Individual limits for total nitrogen for each member.
The group limit and individual limits are applied as annual mass limits. Because members are
located throughout the basin and are subject to a variety of transport factors, limits in the
group permit are expressed as delivered loads (end of pipe load x transport factor). If the Neuse
River Compliance Association exceeds the group limit, it is deemed out of compliance; in
addition, the members' individual limits become effective, and members that exceeded their
individual limits are also deemed out of compliance. In such cases, the Association and its
members are required to make offset payments to the Wetlands Restoration Fund to mitigate
the impact of the excess nutrient load to the estuary, and they are subject to enforcement
action for their limit violations.
The permit does not require effluent or ambient monitoring requirements since all members
are required under their individual NPDES permits to monitor total nitrogen on a regular basis.
Instead, the permit requires:
A mid-year report summarizing the Neuse River Compliance Association and members'
loads and notification of any further changes in membership or allocations (waived if the
Association's total load for the year is less than 80 percent of its limit).
A year-end report that includes an accounting of discharges for the previous calendar year,
a list of transactions (e.g., regionalization, purchases, sales, trades, leases) affecting total
nitrogen allocations, assessment of progress, and planned activities.
A 5-year report at the time of the renewal application.
For more information on North Carolina's nutrient reduction strategy for the Neuse River Basin,
visit the Division's Neuse Nutrient Strategy website. To request a copy of the permit from the
Division, contact Mike Templeton at mike.templeton@ncdenr.gov.
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WATERSHED-BASED PERMITTING
Tar-Pamlico River Basin
The Tar-Pamlico River estuary was identified as
impaired due to excessive levels of nutrients in
1989, which had resulted in harmful algal
blooms, low dissolved oxygen levels, and
increased numbers offish kills. Portions of the
estuary remain impaired based on chlorophyll-o
levels in the water column.
In 1989, the North Carolina Environmental
Management Commission adopted the first
nutrient reduction strategy through an
agreement with the Tar-Pamlico Basin
Association, a consortium of 16 POTWs within
the Tar-Pamlico River Basin. The strategy has
been revised periodically since then, with the
most recent update in July 2015. In 1994, the
state finalized the Tar-Pamlico River Basinwide
Water Quality Management Plan, a TMDL. The
TMDL required a 30 percent reduction of total
nitrogen loads and no increase in total
phosphorus loads (1991 baseline) to the Tar-
Pamlico River Basin.
The nutrient reduction strategy, TMDL, and a
Memorandum of Agreement10 were previously the mechanism by which caps on point source
nutrient discharges were applied. However, in 2009, due to concerns regarding the
enforceability of the strategy, TMDL, and agreement, the Division distributed the group caps
and established individual effluent limits in individual NPDES permits for the Tar-Pamlico Basin
Association's members.
In 2015, the Division followed up by issuing a multisource watershed-based permit to the Tar-
Pamlico Basin Association and its 16 members for discharges of total nitrogen and total
phosphorus. The group permit establishes limits for total nitrogen and total phosphorus, and
10 Parties to the agreement currently include the Association, the North Carolina Department of Agriculture and
Consumer Services, the North Carolina Environmental Management Commission, and the North Carolina Divisions
of Soil and Water Conservation and Water Resources.
o
k.
Key Characteristics ^
of the Permit
NPDES Permit NCC000002
Watershed: Tar-Pamlico River Basin,
North Carolina
Key water quality concerns:
Impairment due to excessive nutrient
levels
Pollutants:
Total nitrogen
Total phosphorus
Types of point source dischargers
covered by permit: POTWs
Highlighted approaches:
TMDL implementation
Discharger association
"Group cap" effluent limits
Contact information:
Mike Templeton
mike.temDleton(a)ncdenr.Eov
North Carolina Department of
Environmental Quality, Division of
Water Resources
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WATERSHED-BASED PERMITTING
member facilities are subject to the requirements of their individual NPDES permits, which
include effluent limitations for other pollutants and monitoring requirements (including
nutrients). The watershed-based permit includes:
Effluent limits for total nitrogen and total phosphorus for the Tar-Pamlico Basin Association
as a whole (i.e., a group limit).
Individual limits for total nitrogen and total phosphorus for each member.
The group limit and individual limits are applied as annual mass limits. If the Tar-Pamlico Basin
Association exceeds a group limit, it is deemed out of compliance; in addition, the members'
individual limits become effective and members that exceeded their individual limits are also
deemed out of compliance. In such cases, the Tar-Pamlico Basin Association and its members
are required to purchase offset credits from the North Carolina Agricultural Cost-Share Program
to mitigate the impact of the excess nutrient load to the estuary.
The watershed-based permit does not include effluent or ambient monitoring requirements,
since all members are required under their individual NPDES permits to monitor total nitrogen
and total phosphorus regularly. Instead, the permit requires:
A year-end report that includes an accounting of discharges for the previous calendar year,
a list of transactions (e.g., regionalization, purchases, sales, trades, leases) affecting total
nitrogen or total phosphorus allocations, assessment of progress, and planned activities.
An annual projections report in years the Tar-Pamlico Basin Association exceeds 85 percent
of the group limit to identify a timeline for improvements to members' nutrient controls.
A 5-year report at the time of the renewal application.
For more information on North Carolina's nutrient reduction strategy for the Tar-Pamlico River
Basin, visit the Division's Tar-Pamlico Nutrient Strategy website. To request a copy of the permit
from the Division, contact Mike Templeton at mike.templeton@ncdenr.gov.
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WATERSHED-BASED PERMITTING
Haw River Subwatershed of the Jordan Lake Watershed
B. Everett Jordan Lake was impounded in 1983
and was thereafter consistently rated as
eutrophic or hyper-eutrophic. In 1992, the lake
was listed as impaired due to excessive levels of
nutrients. In 2007, EPA approved a TMDL for
each of the three Jordan Lake subwatersheds,
including the Haw River. In 2009, the North
Carolina Environmental Management
Commission finalized the Jordan Water Supply
Nutrient Strategy rulemaking. The strategy
required a total phosphorus load reduction of 5
percent by 2010 and a total nitrogen load
reduction of 8 percent by 2016 (1997-2001
baseline) for the Haw River subwatershed, with
wasteload allocations distributed in proportion
to maximum permitted flows and applied to
dischargers with permitted flows greater than
0.1 MGD.
In 2009, the Division modified the permits for
the 10 existing facilities in the Haw River
subwatershed to incorporate total phosphorus
limits based on the TMDL wasteload allocations.
The effluent limits went into effect in 2010.
QKey Characteristics
of the Permit
NPDES Permit NCC000003
Watershed: Haw River Subwatershed
of the Jordan Lake Watershed, North
Carolina
Key water quality concerns:
Impairment due to excessive nutrient
levels
Pollutants: Total phosphorus
Types of point source dischargers
covered by permit: POTWs
Highlighted approaches:
TMDL implementation
Discharger association
"Group cap" effluent limits
Contact information:
Mike Templeton
mike.templeton@ncdenr.gov
North Carolina Department of
Environmental Quality, Division of
Water Resources
Four of the affected dischargers (the municipalities of Greensboro, Mebane, Reidsville, and
Graham) elected to establish the Haw River Nutrient Compliance Association and, in June 2016,
applied for a multisource watershed-based permit as allowed under the strategy. In December
2016, the Division issued a multisource watershed-based permit to the Haw River Nutrient
Compliance Association and its four members. (The municipality of Burlington joined the
Association effective January 1, 2020.) The watershed-based permit includes:
Effluent limits for total phosphorus for the Haw River Nutrient Compliance Association as a
whole (i.e., a group limit).
Individual limits for total phosphorus for each member.
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WATERSHED-BASED PERMITTING
The group limit and individual limits are applied as annual mass limits. If the Haw River Nutrient
Compliance Association exceeds a group limit, it is deemed out of compliance; in addition, the
members' individual limits become effective and members that exceeded their individual limits
are deemed out of compliance. In such cases, the Haw River Nutrient Compliance Association
and its members are required to purchase offset credits from the NC Division of Mitigation
Services to mitigate the impact of the excess nutrient load to the lake.
The watershed-based permit does not require effluent or ambient monitoring requirements
since all members are required under their individual NPDES permits to monitor total
phosphorus on a regular basis. Instead, the permit requires:
A year-end report that includes an accounting of discharges for the previous calendar year,
a list of transactions (e.g., regionalization, purchases, sales, trades, leases) affecting total
nitrogen or total phosphorus allocations, assessment of progress, and planned activities.
An annual projections report in years the Haw River Nutrient Compliance Association
exceeds 85 percent of the group limit to identify a timeline for improvements to members'
nutrient controls.
A 5-year report at the time of the renewal application.
For more information on North Carolina's nutrient reduction strategy for the Jordan Lake
Watershed, visit the Division's Jordan Lake Nutrient Strategy website. To request a copy of the
permit from the Division, contact Mike Templeton at mike.templeton@ncdenr.gov.
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WATERSHED-BASED PERMITTING
QKey Characteristics
of the Permit
VIRGINIA
In 2005, Virginia established wasteload
allocations in the Water Quality Management
Planning (WQMP) Regulation (9VAC25-720),
which were developed from the Commonwealth
of Virginia Chesapeake Bay Nutrient and
Sediment Reduction Tributary Strategy.
Subsequently, EPA established the Chesapeake
Bay Total Maximum Daily Load for Nitrogen.
Phosphorus and Sediment in 2010 to address
poor water quality, degraded habitats, and low
populations offish and shellfish in the bay. The
Chesapeake Bay TMDL applies to five river
basins in Virginia that drain to the Chesapeake
Bay.
The Virginia State Water Control Board first
established the General VPDES Watershed
Permit Regulation for Total Nitrogen and Total
Phosphorus Discharges and Nutrient Trading in
the Chesapeake Bay Watershed in Virginia
(VAN000000) on January 1, 2007. The current
permit was most recently reissued in January
2017. The general permit addresses only total
nitrogen and total phosphorus discharges from
wastewater treatment facilities to implement the WQMP Regulation and Chesapeake Bay
TMDL. The facilities are subject to the requirements of their individual NPDES permits for other
pollutants.
The permit establishes the following requirements:
Annual effluent loading limits for total nitrogen and total phosphorus for all significant and
new or expanding dischargers in the Chesapeake Bay watershed in Virginia.
Compliance schedules and compliance plans.
Monitoring and reporting requirements.
Conditions by which credits may be exchanged.
NPDES Permit VAN000000
Watershed: Chesapeake Bay
Watershed, Virginia
Key water quality concerns: Excessive
nutrients leading to algae blooms and
low dissolved oxygen levels
Pollutants:
Total nitrogen
Total phosphorus
Types of point source dischargers
covered by permit:
POTWs
Industrial/non-process wastewater
dischargers
Highlighted approaches:
TMDL implementation
Aggregated mass loading limits for
James River dischargers
Point and nonpoint source water
quality trading
Discharger association
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WATERSHED-BASED PERMITTING
By affording covered facilities of each watershed multiple ways to achieve water quality goals,
the permit offers a more flexible and economically feasible approach than other possible
permit options. Covered dischargers can comply with their existing load limits through:
Treatment technology upgrades.
Trading among permitted facilities through the Exchange Association.
Buying nutrient credits directly from compliant facilities within their watersheds.
Joining multiple facilities to create an aggregate nutrient cap.
Purchasing nutrient reductions generated by nonpoint source BMPs (to offset new or
expanded discharges only).
Paying into the Water Quality Improvement Fund where no other options are available.
For more information on Virginia's water quality trading program, see "Water QualityTrading."
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WATERSHED-BASED PERMITTING
Wisconsin
Wisconsin DNR adopted the Lower Fox River
Basin TDML in 2012 to address impairments
caused by excessive phosphorus and sediment
loading in the Lower Fox River Basin and Lower
Green Bay.
The Green Bay and De Pere wastewater
treatment facilities (jointly the "Green Bay
Metropolitan Sewerage District") both discharge
into the mainstem of the Lower Fox River
watershed. The facilities were previously
covered under unique individual permits.
However, on April 15, 2014, Wisconsin DNR
issued a multisource watershed-based permit to
cover both facilities in light of changes to
regulations (e.g., total phosphorus water quality
standards and the Lower Fox River Basin TMDL).
The permit expires June 30, 2019. In addition to
streamlining the permit reissuing process for
Wisconsin DNR, the permit can facilitate
coordinated optimization and upgrades at the
two facilities, as well as allow for exploration
and adaptive management options.
QKey Characteristics
of the Permit
NPDES Permit WI0065251
Watershed: Lower Fox River
Watershed, Wisconsin
Key water quality concerns:
Excessive total phosphorus and
sediment loading leading to nuisance
algae growth, oxygen depletion,
reduced submerged aquatic
vegetation, water clarity problems,
and degraded habitat
Pollutants: Total phosphorus
Types of point source dischargers
covered by permit(s): POTWs
Highlighted approaches:
TMDL implementation
Adaptive management
Facility optimization
In 2014, Wisconsin DNR published
Watershed Permitting Guidance
(Guidance Number 3400-2014-01) to
inform Wisconsin DNR staff and
others about watershed permitting,
with an emphasis on the potential use
of this process to facilitate
implementation of TMDLs, water
quality trading, adaptive
management, or other large-scale
projects. The Guidance includes an
example multisource watershed-
based permit template.
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WATERSHED-BASED PERMITTING
Coordinated Individual Permits
Coordinated individual permits are the closest to traditional NPDES permitting in that each
discharger receives a permit. Water-quality-based effluent limitations and other conditions of
coordinated individual permits are developed using a holistic analysis of the watershed
conditions rather than being established to ensure attainment of water quality standards on a
permit-by-permit basis. To strengthen the coordination among individual permits, the
permitting authority could consider synchronizing their expiration and reissuance or effective
dates.
CONNECTICUT
In the absence of numeric criteria for
phosphorus, Connecticut DEEP developed the
Interim Phosphorus Reduction Strategy for
Connecticut Freshwater Non-Tidal Waste-
Receiving Rivers and Streams Technical Support
Document, which provides a methodology to
develop total phosphorus water quality targets
non-tidal freshwater based on the narrative
criteria and policy statements. The purpose of
this strategy is to meet the pressing need to
include total phosphorus limits in NPDES
permits and be protective of the environment.
These methods were approved by U.S. EPA in a
letter dated October 26, 2010, as an interim
strategy to establish water-quality-based total
phosphorus limits for industrial and municipal
water pollution control facilities (WPCFs) until
Connecticut DEEP has established numeric
nutrient criteria.
The interim strategy is based on best available
information at a statewide level using methods to identify phosphorus enrichment levels in
waste receiving rivers and streams that adequately protects aquatic life uses. This strategy
results in overall reductions up to 95 percent of the current watershed load once the strategy is
fully implemented.
Key Characteristics
of the Permit
Number of coordinated individual
permits: 45
Watershed: Varies
Key water quality concerns:
Excessive total phosphorus loadings
leading to cultural eutrophication
and its effects on the biological
condition of the stream
Pollutants: Total phosphorus
Types of point source dischargers
covered by permit(s):
Municipal WPCFs
Industrial WPCFs
Highlighted approaches:
Narrative criteria
Watershed analysis to establish
phosphorus reduction goals
Coordinated total phosphorus
limits by watershed
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WATERSHED-BASED PERMITTING
Forty-five NPDES facilities were identified as discharging total phosphorus to 20 non-tidal
freshwater systems in Connecticut with an enrichment factor at or above 84. These facilities
would need to have NPDES permit limits for total phosphorus equivalent to the load reductions
established in the strategy at the time of their next permit renewal (see table 8 of the strategy
for facilities and permit limits). Forty-three are WPCFs and two are industrial plant dischargers.
Connecticut's approach to permitting for total phosphorus is considered a watershed approach
because the phosphorus reduction strategy analyzed each sub-watershed and established
targets for permit limits based on an overarching watershed analysis. Therefore, the individual
total phosphorus limits are coordinated on a watershed basis, even though they are not
synchronized (i.e., issued on the same watershed all at the same time).
OHIO
Upper Little Miami River Watershed
In 1998, Ohio EPA conducted chemical and
biological assessments of the Upper Little
Miami River and its tributaries that showed
impairment of aquatic life uses due to nutrient
enrichment, low dissolved oxygen, and habitat
alteration. As a result, Ohio EPA issued a TMDL
for the Upper Little Miami River in April 2002
with a goal for full attainment of the aquatic life
use.
The 11 municipal point source dischargers in
the watershed accounted for a significant
percentage of the total phosphorus loading
during critical low-flow months, so the TMDL
established wasteload allocations for those
facilities. The TMDL proposed the following
iterative, adaptive management approach for
implementing the wasteload allocations in
NPDES permits:
QKey Characteristics
of the Permit
Number of coordinated individual
permits: 11
Watershed: Upper Little Miami River
Watershed\ Ohio
Key water quality concerns:
Impairment of aquatic life use due to
nutrient enrichment
Pollutants: Total phosphorus
Types of point source dischargers
covered by permit: POTWs
Highlighted approaches:
TMDL implementation
Iterative, adaptive management
approach
Compliance schedules
Contact information:
Walter Ariss
walter.ariss@epa.ohio.gov
Ohio Environmental Protection
Agency
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WATERSHED-BASED PERMITTING
An initial 3-year compliance schedule to comply with a seasonal (May-October) 30-day
average effluent limit of 1.0 mg/L total phosphorus.
An additional 7 years to comply with a more stringent seasonal effluent loading limit based
on the facility-specific wasteload allocations from the TMDL.
The initial compliance schedule provided time to evaluate treatment plant capabilities,
implement measures to maximize the ability of the existing treatment plant, and (if necessary)
develop a plan to achieve the limits. Special conditions in the permits allowed flexibility for
achieving the additional loading reductions through:
Nonpoint source reduction projects.
Projects to increase assimilative capacity in the receiving water.
Cooperative agreements to implement projects to achieve the cumulative point source
loading reductions.
Upgrading the existing treatment facilities.
Ohio EPA conducted a Biological and Water Quality Study of the Upper Little Miami River in
2011 demonstrating that all mainstem sites downstream of the facilities are no longer
impaired, largely due to the POTWS' efforts to reduce phosphorus loadings.
Ohio EPA renewed the NPDES permits for the five major POTWs within the watershed in 2019.
These permits continued the existing concentration and loading limits as a measure to ensure
continued attainment status.
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WATERSHED-BASED PERMITTING
Lower Great Miami River Watershed
The Ohio EPA assessed the Lower Great Miami
River watershed in 2010 and found that the
river is impaired due to nutrient enrichment.
Through further evaluation, Ohio EPA
determined that the City of Dayton and
Montgomery County Western Regional WWTPs
contribute to a significant increase in the total
phosphorus concentrations, dissolved oxygen
swings, and chlorophyll-a values in the river.
Ohio EPA is implementing an adaptive
management approach to address the
impairment of the Lower Great Miami River,
with coordinated issuance of NPDES permits to
the two major municipal point sources in
December 2015 as the first step. This approach
allows Ohio EPA to evaluate the effectiveness
of controls and obtain additional information to
inform the next implementation step.
The permits for the City of Dayton and
Montgomery County Western Regional WWTPs
include:
Key Characteristics
of the Permit
Number of coordinated individual
permits: 2
Watershed: Lower Great Miami River
Watershed\ Ohio
Key water quality concerns:
Impairment of aquatic life use due to
nutrient enrichment
Pollutants: Total phosphorus
Types of point source dischargers
covered by permit: POTWs
Highlighted approaches:
Pre-TMDL implementation to
address impairment
Iterative, adaptive management
approach
Compliance schedules
Contact Information:
Walter Ariss
walter.ariss(a)epa.ohio.Eov
Ohio Environmental Protection
Agency
A final seasonal (July-October) aggregate total phosphorus loading limit based on facility
flow and a total phosphorus concentration of 1 mg/L.
A 3-year schedule for complying with the final effluent limit.
Requirements to develop a proposal for meeting the final limit (e.g., treatment
improvements or demonstration that the plant can meet the limit through current
operations).
For other major WWTPs in the watershed, Ohio EPA is requiring:
Continued effluent and receiving water monitoring for total phosphorus.
Development of studies to evaluate the technical and financial capabilities of their facilities
to reduce total phosphorus below 1.0 mg/L.
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WATERSHED-BASED PERMITTING
Before the next permit renewals, Ohio EPA will evaluate whether the river has returned to full
attainment following the required load reductions. If not, Ohio EPA may modify the effluent
limits based on an approved integrated management plan and/or an approved TMDL. Ohio EPA
may allow permittees to use alternate reduction strategies (e.g., water quality trading, habitat
restoration offsets, and physical watershed alterations) to achieve future reductions.
For more information on the watershed-based permitting approach for the Lower Great Miami
River, see the NPDES permit fact sheets for the City of Dayton and Montgomery County
Western Regional WWTPs.
RHODE ISLAND
The Rhode Island Department of Environmental
Management (DEM) issued a TMDL for Belleville
Ponds and Belleville Upper Pond Inlet in
September 2010 and a TMDL for Scott Pond in
May 2014 to address phosphorus impairments
to the ponds.
The 2014 Scott Pond TMDL identifies the five
major point sources contributing total
phosphorus to Scott Pond via discharge to the
Blackstone River: four in Massachusetts
(permits issued by EPA Region 1) and the
Woonsocket Wastewater Treatment Facility in
Rhode Island. The four Massachusetts permits
include total phosphorus limits to address
eutrophication in the Blackstone River. The
Woonsocket permit, issued by Rhode Island
DEM in 2008, included more stringent total
phosphorus limits to meet the water quality
criterion in the pond. The modeling for the
TMDL demonstrated that compliance with the
existing limits at the five point sources would be
sufficient to achieve the water quality criterion
in the pond.
o
k.
Key Characteristics ^
of the Permit
Number of coordinated individual
permits: 5 (Scott Pond), 1 (Belleville
Ponds)
Watershed: Belleville Ponds
watershed and Scott Pond
watershed, Rhode Island
Key water quality concerns:
Excessive algal growth and anoxic
conditions due to excessive
phosphorus loading
Pollutants: Total phosphorus
Types of point source dischargers
covered by permit(s):
Wastewater treatment facilities
Fish hatcheries
MS4 dischargers
Highlighted approaches:
Point source and MS4
requirements
Coordinated MS4 requirements
encouraged
Contact information:
Joseph Haberek
ioseoh.haberek(5)dem.ri.Rov
Rhode Island Department of
Environmental Management
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WATERSHED-BASED PERMITTING
The 2010 Belleville Ponds TMDL identifies a point source, the Lafayette Trout Hatchery,
contributing total phosphorus to the ponds. Rhode Island DEM issued the draft permit for the
facility, which included effluent limitations for total phosphorus based on the wasteload
allocation in the TMDL, concurrent with the comment period for the TMDL.
Both TMDLs identify two small MS4s that contribute to loading to the ponds (Town of Lincoln
and Rhode Island Department of Transportation [DOT] to Scott Pond; Town North Kingstown
and Rhode Island DOT to the Belleville Ponds). The MS4s are covered under the Rhode Island
DEM's Phase II MS4 General Permit.
The TMDL requires the MS4 permittees to update their Storm Water Management Program
Plans and implement specific BMPs to achieve compliance with TMDL. Because storm sewers
and ditches associated with stormwater runoff frequently have multiple interconnections
between MS4s, the TMDLs encourage the permittees to cooperate in developing and
implementing the six minimum control measures and in constructing BMPs (e.g., through inter-
agency agreements).
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WATERSHED-BASED PERMITTING
VERMONT
Lake Champlain and Lake
Memphremegog Basins
U.S. EPA issued phosphorus TMDLs for Vermont
segments of Lake Champlain in June 2016 and
the Lake Memphremegog phosphorus TMDL in
September 2017 to address impairments of the
aquatic life and recreational uses in the lakes.
The State of Vermont detailed its strategies to
address point source pollution in the lakes in
the September 2016 Vermont Lake Champlain
Phosphorus TMDL Phase 1 Implementation Plan
and the November 2017 Lake Memphremagog
Tactical Basin Plan.
For Lake Champlain, the Phase 1
Implementation Plan specifies that the Vermont
DEC will reissue NPDES permits for the 59 direct
discharge facilities in the basin during the first
year of implementation following development
of each Phase 2 Tactical Basin Plan. For Lake
Memphremegog, the Phase 2 Tactical Basin
Plan specifies that DEC will reissue NPDES
permits for the four direct discharge facilities
based on formal wasteload allocations. Aligning
NPDES permit issuance with the tactical basin
planning process will ensure that the permits
are developed using the most up-to-date
monitoring and scientific information available.
QKey Characteristics
of the Permit
Number of coordinated individual
permits: 59 (Lake Champlain) and 4
(Lake Memphremegog)
Watershed: Lake Champlain and
Lake Memphremegog Basins,
Vermont
Key water quality concerns:
Eutrophication due to excess total
phosphorus loading
Pollutants: Total phosphorus
Types of point source dischargers
covered by permit:
POTWs
Industrial wastewater dischargers
Highlighted approaches:
TMDL implementation
Permit issuance schedule based on
watershed basin planning cycle
Annual average effluent limits for
total phosphorus
Offers flexibility through
compliance schedules, trading, and
integrated watershed planning
Contact information:
Ethan Swift
ethan.swift(a)vermont.Eov
Vermont Department of
Environmental Conservation
The implementation plans for both lakes are designed to minimize the financial impact of
reducing total phosphorus loads and provide flexibility in meeting the wasteload allocations by
implementing the following in individual NPDES permits:
Effluent total phosphorus limits expressed as total annual mass loads to provide operational
flexibility.
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WATERSHED-BASED PERMITTING
A 12-month optimization period before limits are effective.
An 80 percent loading threshold for optimizing phosphorus treatment and/or upgrading
phosphorus treatment facilities.
A phosphorus optimization plan requirement.
Compliance schedules that allow enough time for planning, budgeting, and engineering and
take advantage of cost-efficient opportunities to couple upgrades with other planned
construction projects.
Providing other forms of flexibility to achieve wasteload allocations in a cost-effective
manner (e.g., water quality trading and integrated watershed plans and permits).
For more information about Vermont's Lake Champlain and Lake Memphremegog TMDL
implementation, visit U.S. EPA's Lake Champlain TMDL website. DEC's Lake Champlain TMDL
Implementation website, and DEC's Lake Memphremegog Basin Planning website.
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WATERSHED-BASED PERMITTING
Connecticut River Basin, Long Island Sound Watershed
In 2001, U.S. EPA approved the TMDL Analysis to
Achieve Water Quality Standards for Dissolved
Oxygen in Long Island Sound to address hypoxic
conditions that occur in Long Island Sound
resulting from excessive total nitrogen. To
implement the TMDL, Vermont DEC developed
the Vermont Long Island Sound TMDL
Monitoring and Permitting Plan in July 2013. The
Plan specifies monitoring and permitting
requirements for Vermont's 34 municipal
dischargers in the Connecticut River Basin, a
tributary of Long Island Sound.
At the time of the Plan, limited effluent data
were available to develop wasteload allocations
for the municipal dischargers. To generate
sufficient data, the Plan proposed a four-
pronged monitoring plan that includes:
A DEC-led monitoring program to collect
additional influent and effluent data.
A voluntary request to initiate and continue
data collection until each facility's next
permit renewal.
Additional monitoring requirements to be
included in each permit renewal.
Participation in a low-cost retrofit study by
the New England Interstate Water Pollution Control Commission for six Vermont facilities.
The Plan establishes a 5-year permitting schedule aligned with DEC's watershed basin planning
cycle to allow for development of formal wasteload allocations using the most current data
available for the watershed involved. As an added benefit, the schedule reduces the potential
for creating a backlog of expired permits.
QKey Characteristics
of the Permit
Number of coordinated individual
permits: 34
Watershed: Connecticut River Basin,
Long Island Sound Watershed,
Vermont
Key water quality concerns:
Excessive nutrients leading to algae
blooms and low dissolved oxygen
levels
Pollutants: Total nitrogen
Types of point source dischargers
covered by permit: POTWs
Highlighted approaches:
TMDL implementation
Monitoring requirements for total
nitrogen
Permit issuance schedule based on
watershed basin planning cycle
Facility-specific total nitrogen
loading caps and triggers
Optimization study requirements
Contact information:
Ethan Swift
ethan.swift@vermont.gov
Vermont Department of
Environmental Conservation
Per the Plan, DEC includes the following in each NPDES permit:
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WATERSHED-BASED PERMITTING
Interim annual average total nitrogen loading caps, which serve as enforceable effluent
limits, for all dischargers except lagoon and rotating biological contactor facilities.
Total nitrogen loading triggers for additional monitoring for lagoon and rotating biological
contactor facilities.
Nitrogen optimization requirements for facilities that are not designed for denitrification.
The caps and triggers ensure that all facilities in the watershed do not exceed 1,727 pounds per
day on an annual basis, consistent with the TMDL. Once sufficient data are available for all
facilities, DEC will develop formal wasteload allocations and may replace the caps and triggers
with effluent limits based on the wasteload allocations, as appropriate.
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WATERSHED-BASED PERMITTING
WISCONSIN
Wisconsin DNR adopted a TMDL for total
phosphorus and TSS in the Rock River Basin.
approved by U.S. EPA in September 2011, to
address impairments caused by excessive
phosphorus and sediment loading. The TMDL
anticipated that individual permits issued to
municipal and industrial wastewater discharges
to surface water would include limits
consistent with the approved TMDL wasteload
allocations, providing the necessary reasonable
assurance that the wasteload allocations in the
TMDL will be achieved. Facilities operating
under general permits would be screened to
determine whether additional requirements
may be needed to ensure that the permitted
activity is consistent with TMDL goals, including
issuing individual permits or other measures.
QKey Characteristics
of the Permit
Number of coordinated individual
permits: 83
Watershed: Rock River Basin,
Wisconsin
Key water quality concerns: Excessive
total phosphorus and sediment loading
leading to nuisance algae growth,
oxygen depletion, reduced submerged
aquatic vegetation, water clarity
problems, and degraded habitat
Pollutants: Total phosphorus
Types of point source dischargers
covered by permit(s):
Industrial facilities
POTWs
Highlighted approaches:
TMDL implementation
Synchronized watershed-based
permitting
Adaptive management
Water quality trading
Contact information:
Kevin Kirsch
kevin.kirsch (a) wisconsin.gov
Wisconsin Department of Natural
Resources
Amy Garbe
amy.garbe@wisconson.gov
Wisconsin Department of Natural
Resources
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WATERSHED-BASED PERMITTING
Wisconsin DNR initiated synchronized individual
permit issuance in the Upper and Lower Rock River
Basins in 2012. Permits were reissued, modified, or
revoked and reissued to put all permittees on a
similar timeline to achieve compliance with
nutrient limits. The 83 industries and
municipalities holding individual permits in the
basin were grouped (based on location within the
TMDL) into groups of nine to 12 permits that could
be reissued concurrently. Wisconsin DNR reissued
each expired one with a similar set of conditions
related to TMDL-based wasteload allocations for
total phosphorus and TSS. Wisconsin DNR encouraged permittees in each group to pool
resources, where possible, and explore joint adaptive management or water quality trading
possibilities. For more information on Wisconsin's water quality trading program, see "Water
Quality Trading."
Click here to return to the Table of Contents
In 2014, Wisconsin DNR published
Watershed Permitting Guidance
(Guidance Number 3400-2014-01) to
inform Wisconsin DNR staff and
others about watershed permitting,
with an emphasis on the potential use
of this process to facilitate
implementation of TMDLs, water
quality trading, adaptive
management, or other large-scale
projects.
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