Willamette Basin Mercury TMDL
Responses to Public Comments Report
February 4, 2021
Prepared by:
USEPA Region 10
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Table of Contents
Introduction 1
Author Name Ray Kinney 2
Author Name Tom Quintal 4
Author Name Tom Quintal 5
Author Name Tom Quintal 6
Author Name Tom Quintal 8
Author Name Tom Quintal 10
Author Name Tom Quintal 19
Author Name Gerald Fisher, PE 22
Author Name Carolyn A. Wesolek, MS 24
Author Name Nina Bell, J.D 25
Author Name Tom Pepiot 26
Author Name Mary Anne Cooper 28
Author Name Mary Anne Cooper 34
Author Name Thomas E. Whittington 51
Author Name Lauren Haney 66
Author Name Sharla Moffett 69
Author Name Mike Brown 80
Author Name Dennis Hebard 82
Author Name Dennis Hebard 84
Author Name Dennis Hebard 85
Author Name Dennis Hebard 87
Author Name Dennis Hebard 88
Author Name Dennis Hebard 90
Author Name Salina N. Hart, P.E 93
Author Name Bill Moore 94
Author Name Kathryn VanNatta 105
Author Name Brent Stevenson 113
Author Name Joy Archuleta 124
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Introduction
The Response to Comments document addresses comments received during the January 6, 2020
through February 4, 2020 public comment period on EPA's Willamette Basin Mercury TMDL (EPA's 2019
TMDL). EPA's 2019 TMDL was established following EPA's disapproval of the Oregon Department
Environmental Quality's Final Revised Willamette Basin Mercury TMDL (ODEQ's 2019 TMDL). Twenty-
nine comment letters were submitted by different individuals and organizations and over 170 sub-
comments were addressed by EPA. Table 1 presents the list of individuals and organizations who
provided comments, along with the corresponding letter ID. Following Table 1 are the individual
comment letters, subdivided by issues raised and EPA's response to each issue.
Table 1. Summary of Commenters
Letter ID
Author Name
Organization
L1
Ray Kinney
Siuslaw Soil and Water Conservation District
L2
Tom Quintal
Private Citizen
L3
Tom Quintal
Private Citizen
L4
Tom Quintal
Private Citizen
L5
Tom Quintal
Private Citizen
L6
Tom Quintal
Private Citizen
L7
Tom Quintal
Private Citizen
L8
Gerald Fisher, PE
City of Molalla
L9
Carolyn A Wesolek, MS
Private Citizen
L10
Matt W. Knudsen
Marion County Public Works
L11
Nina Bell, J.D.
Northwest Environmental Advocates
L12
Tom Pepiot
Private Citizen
L13
Mary Anne Cooper
Oregon Farm Bureau
L14
Mary Anne Cooper
Oregon Farm Bureau
L15
Thomas E. Whittington
Oregon Department of Forestry
L16
Lauren Haney
Clackamas County Water Environment Services
L17
Sharla Moffett
Oregon Business & Industry
L18
Mike Brown
Bureau of Land Management
L19
Dennis Hebard
Private Citizen
L20
Dennis Hebard
Private Citizen
L21
Dennis Hebard
Private Citizen
L22
Dennis Hebard
Private Citizen
L23
Dennis Hebard
Private Citizen
L24
Dennis Hebard
Private Citizen
L25
Salina N. Hart, P.E.
U.S. Army Corps of Engineers Portland District
L26
Bill Moore
Oregon Department of Environmental Quality
L27
Kathryn VanNatta
Northwest Pulp and Paper Association
L28
Brent Stevenson
Santiam Water Control District
L29
Joy Archuleta
U.S. Forest Service
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Author Name Ray Kinney
Organization Name
Letter ID
Comment ID
Comment Category
Siuslaw Soil and Water Conservation District
LI
Ll-1
Industrial
Comment Text
Reviewing the TMDL information for the Willamette, I did not get enough clarification of the mercury
sourcing that presumably comes from crematoria smokestacks. How many exist in the Willamette
valley? How much mercury from dental amalgam gets vaporized and exits these smokestacks? Is this a
point source? Does this air pollution send mercury out on the winds, to scatter across the landscape to
migrate into aquatic environments to become methylated to much higher toxicity? How is this sourcing
quantified? How long has this sourcing been happening? How much risk of inhalation is present, and is
there increased retention in the lung route compared with the ingestion route? Mercury comes from
many sources, and enters a multi toxicant environment with additive and synergistic adverse effects of
mixtures. Many neurotoxic metal pollutants have overlapping harm on many physiologic pathways in
organisms.
Response Text
Mercury that is emitted to the atmosphere through smokestacks contributes to global atmospheric
mercury cycling and, ultimately, to wet and dry deposition to the landscape and waterbodies. A
discussion of sources, atmospheric cycling, and deposition processes is included in the Technical Support
Document (TSD; included as Appendix B to the EPA TMDL) in Section 5.3.1. Major stationary source air
emissions in the Willamette River Basin (WRB) are listed in Table 5-4. As discussed in Section 6.1.4.1 of
Oregon DEQ's TMDL, most atmospheric sources of mercury deposited in the Willamette Basin originate
from sources outside the Basin.
As noted in the TSD, the Oregon Department of Environmental Quality (ODEQ) Air Quality Division
provided estimates of additional nonpoint THg releases for the 2014 National Emissions Inventory (NEI,
https://www.epa.gov/air-emissions-inventories/national-emissions inventory-nei), which is the most
recent complete estimate for Oregon, including for the ten counties that intersect the WRB (Benton,
Clackamas, Columbia, Lane, Linn, Marion, Multnomah, Polk, Washington, and Yamhill). Because portions
of some of these counties lie outside the WRB, the estimates are greater than the emissions occurring
within the WRB. The NEI is the only known estimate of the net mercury releases to the atmosphere from
small crematoria in Oregon. The NEI estimates that the net atmospheric emissions of crematoria within
the ten counties amount to 43.7 pounds of mercury per year, which is equivalent to 33 percent of the
NEI's total atmospheric emissions estimate of 131.4 pounds per year for the ten counties. The comment
is thus correct that crematoria are a significant proportion of the current atmospheric emissions of
mercury within or near the Willamette basin; however, the amount of the mercury released to the air by
crematoria that deposits within the basin is not known, and local air emissions likely constitute only a
small fraction of the total atmospheric deposition of mercury within the Willamette basin (estimated to
be less than 5% - see Section 14.2 of the ODEQTMDL).
The EPA TMDL assigns a reduction target to atmospheric deposition of mercury (in general) and does
not provide targets for individual air emission sources. Because these emissions are to the atmosphere
and not to water, they are not directly regulated under the Clean Water Act or the TMDL program. Air
emissions are discussed in the ODEQ Water Quality Management Plan (WQMP) in Section 13.3.3.1 of
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the ODEQ November 2019 TMDL (incorporated as Appendix A to the EPA TMDL). ODEQ anticipates
achieving mercury reductions from air emissions through implementation of federal Title V permits,
state Air Contaminant Discharge permits and the newly adopted state Cleaner Air Oregon program. The
WQMP does not explicitly discuss mercury emissions from crematoria; however, the WQMP is also
being developed in an adaptive management framework that will continue to be refined over time. The
commenter may wish to work with DEQto evaluate whether additional minimization efforts should be
developed for crematoria as the WQMP evolves.
Factors that affect the methylation process and bioaccumulation in the food chain are discussed in
Section 1.1 of the Technical Support Document as are the three models that were used to quantify
sources of mercury in the basin, which include the Food Web Model (Section 3), Mercury Translator
Model (Section 4) and the Mass Balance Model (Section 5).
Comment Text
Lead is a prominent pollutant that has adverse effects on many pathways that methyl mercury also
harms. Lead, in the aquatic environment, is often not evaluated accurately for water quality criteria
because appropriate water hardness dependency calculations that are required are often not applied
accurately. Are there hardness dependency issues that increase mercury toxic effects in very low
hardness"hate" bodies?
Response Text
Aquatic life criteria for many metals, including lead, are hardness-dependent. However, the relevant
aquatic life water quality criteria for total mercury are not hardness-dependent (Oregon Administrative
Rules; OAR 340-041-8033, Table 30). Further, impairments in the Willamette River Basin are based on
elevated fish tissue concentrations of methylmercury and not on excursions of the aquatic life water
quality criteria for total mercury. Fish tissue bioaccumulation of mercury is not expected to be affected
by hardness because methylmercury is a non-polar organic compound.
Comment ID
Ll-2
Applicable numeric criteria
Comment Category
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Author Name Tom Quintal
Organization Name
Letter ID
Comment ID
Comment Category
Private Citizen
12
L2-1
Mining
Comment Text
Please accept this email attachment #1 Rare earth metals for your EPA Willamette Basin Mercury TMDL
This article is very informative if EPA really cares about the United States of America. I will be sending a
few other documents individually with both emails. Sometimes when I send large documents together
your servers are not able to except over a certain Meg size.
Response Text
The attachment was successfully received. Thank you for supplying the document. The document
expresses concerns about the lack of domestic supplies of Rare Earth metals and the implications this
may have on international politics. The document also raises general concerns about the impact of
environmental regulations on mining. The connection to the Willamette Basin Mercury TMDL is not
explicitly stated. It is important to note that gold and mercury are not Rare Earth elements (as stated on
the final page of the document) and unlike Rare Earth elements, there are several operating gold mines
within the U.S. However, within the article there is a reference to an Oregon-based suction dredge
miner and a summary of their displeasure of the regulatory environment surrounding all types of mining
operations, including suction dredging. The article states that: "...instream mining, by suction dredge,
adds no pollutants." While it is correct that suction dredgers do not add mercury during the mining
process, it has been documented in several studies that suction dredging can result in the mobilization
of mercury that occurs in the stream sediments. The content of the article did not result in a change to
the TMDL.
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Author Name Tom Quintal
Organization Name
Letter ID
Comment ID
Comment Category
Private Citizen
L3
L3-1
Suction Dredging
Comment Text
Please accept this email attachment #2 (May 3, 2011 Letter from Wise and Greene to CA Department of
Fish and Game Re: "Comments regarding SEIR and Proposed Regulations for suction dredge mining in
California in Favor of Maintaining Current 1994") for your EPA Willamette Basin Mercury TMDL. Joe
Greene and Claudia Wise have important information to consider before listing Bohemia Mining district
as a 303d Willamette basin. This article is very informative if EPA really cares about the United States of
America. I will be sending a few other documents individually with my emails. Sometimes when I send
large documents together your servers are not able to except over a certain Meg size.
Response Text
The attachment was successfully received. Thank you for supplying the document.
The document consists of a letter by two retired EPA scientists (Claudia Wise and Joseph Greene)
expressing their concerns about proposed suction dredge mining regulations in California. Specifically,
the letter provides a critique of existing studies on mercury mobilization from suction dredge mining
that were performed by Fleck et al., 2011 and Humphreys 2005. In general, we concur that quantifying
the impacts of suction dredge mining is complex and the results can be impacted by many
environmental variables as well as the specific method/equipment used during the mining process. We
also concur that extrapolating results performed under one set of conditions may not be fully
representative of all suction dredge operations. However, despite these challenges, the United States
Geological Survey (USGS) studies summarized by Fleck et al., 2011 and the Humphreys 2005 study
remain the primary scientific literature available on the impacts of suction dredging on mercury
mobilization. The letter mentions the EPA/Royer et al., 1999 study from Alaska, to support the
conclusion that suction dredging does not result in an increase in mercury concentrations. However, the
EPA/Royer et al., 1999 study was not performed using standard low-level mercury methods (e.g. EPA
1631) and had a detection limit of 200 ng/L, which is several orders of magnitude above environmentally
relevant concentrations. Therefore, the analytical methods used in that study preclude the detection of
impacts to mercury concentrations.
In addition, the letter argues that selenium provides protection against methylmercury toxicity and
needs to be taken into consideration when determining the impacts of mercury pollution. The TMDL fish
tissue criteria concentration of 0.04 mg/kg methylmercury does not vary depending on the molar ratio
of selenium. The toxicological assessment that was used to derive the fish tissue criteria that forms of
the basis the TMDL was performed at the national level and was based on a very extensive scientific
assessment of the impacts of methylmercury toxicity on fish consumers (and their feti). The levels of
selenium in fish in the Willamette River are not unique, and excess levels of selenium relative to
mercury are commonly encountered throughout freshwater and saltwater fisheries in the western US as
well as globally. Therefore, we use this information to guide our understanding of the potential impacts
to the Willamette River, and the critiques presented in the attached article did not result in a change to
the TMDL.
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Author Name Tom Quintal
Organization Name
Letter ID
Comment ID
Comment Category
Private Citizen
L4
L4-1
Selenium Interaction
Comment Text
Please except this email attachment #3 for your EPA Willamette Basin Mercury TMDL. Selenium stream
benefit attachment to mercury. This power point is very informative if EPA really cares about the United
States of America. I will be sending a few other documents individually with my emails. Sometimes when
I send large documents together your servers are not able to except over a certain Meg size.
Response Text
The attached power point presentation contains information on suction dredging and on selenium.
These two topics will be discussed separately below.
The relationship between mercury and selenium is complex and has been the subject of numerous
scientific studies. Selenium has the potential to impact several aspects of mercury cycling and toxicity.
For example, 1) some studies suggest that selenium may decrease the potential for mercury methylation
(Dang et al., 2019); 2) other studies suggest that selenium protects aquatic organisms against the
impacts of mercury (S0rmo et al., 2011); and 3) some studies suggest that selenium in fish consumed by
humans protects the consumer (and its fetus) against the adverse effects of mercury exposure (Ralston
and Raymond, 2018).
1. Regarding the impact of selenium on methylmercury production, if this were occurring in the
Willamette River Basin this impact would be captured in our mercury translator model. The mercury
translator model takes the ambient total-mercury and methylmercury concentrations measured in the
basin to allow the conversion of the fish tissue-based methylmercury criteria back to a water column
total-mercury concentration. If selenium is having any impact on methylmercury production our model
is accounting for this process. However, there is detectable methylmercury throughout the Willamette
River in water and fish and therefore, any inhibitory impact of selenium on this process is not significant
enough to reduce fish-tissue methylmercury concentration below the water quality criteria.
2. The potential protective impacts of selenium on the health of aquatic organisms are beyond the
scope of this TMDL which is focused on human health. That selenium (Se) can sequester mercury (Hg) in
the body and reduce toxic effects appears to be well established (e.g., Rahman et al., "Selenium and zinc
protections against metal-(loids)-induced toxicity and disease manifestations: A review", Ecotoxicol
Environ Saf. 2019 Jan 30;168:146-163. Doi: 10.1016/j.ecoenv.2018.10.054). However, regardless of
whether this protective effect is significant, it is not germane to the TMDL because the TMDL must be
developed to attain water quality criteria adopted into state regulations. The Willamette mercury TMDL
is therefore based on attaining the fish tissue concentration criterion for methymercury (MeHg) and this
regulatory criterion does not vary based on the Hg:Se ratio.
3. The protective effects of selenium on fish consumers against methylmercury toxicity is relevant
to the TMDL in that fish tissue criteria concentration of 0.04 mg/kg methylmercury does not vary
depending on the molar ratio of selenium. The toxicological assessment that was used to derive the fish
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Selenium:
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tissue criteria that forms the basis of the TMDL was performed at the national level and was based on a
very extensive scientific assessment of the impacts of methylmercury toxicity on fish consumers (and
their feti) (National Research Council, 2000). The levels of selenium in fish in the Willamette River are
not unique and excess levels of selenium relative to mercury are commonly encountered throughout
freshwater and saltwater fisheries in the western U.S. as well as globally (Peterson et al., 2009). It is
important to note that the conclusion from Peterson et al. 2009 that selenium is often in excess of
mercury in fish is an interesting finding; however, this study did not assess the human health impacts on
fish consumers. In contrast, the derivation of the EPA reference dose for methylmercury which forms
the basis of the TMDL is based on epidemiological studies on the impacts of methylmercury in fish on
human health outcomes. More recent studies on this topic have supported the EPA's assessment of
methylmercury toxicity with the conclusion: "Overall, no evidence was found that Se was an important
protective factor against MeHg neurotoxicity." (Choi et al., 2008).
Suction Dredging:
The presentation refers to the three main papers/reports that have been written on this topic by
Humphreys, Fleck and Marvin-DiPasquale. Despite the specific concerns expressed in the presentation,
to our knowledge there are not any other scientific studies that have been completed on this topic.
While the presentation offers a critique of these studies, alternative studies/findings are not provided.
Currently, the reports led by these three authors remain the best source of information available on the
impacts of suction dredge mining on mercury mobilization. These three papers found that the sediments
containing pockets of elemental mercury from historical mining operations are typically deeply buried
and would otherwise be inaccessible to natural erosion remobilization processes except during extreme
hydrologic conditions (Fleck, 2011; Marvin-DiPasquale, 2011). While suction dredging can remove
mercury buried in stream sediments, the overall impact is that there is an increase in the mobility of
mercury in the stream environment which can increase the availability of mercury for methylation and
bioaccumulation in fish.
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Author Name Tom Quintal
Organization Name
Letter ID
Comment ID
Comment Category
Private Citizen
L5
L5-1
Selenium Interaction
Comment Text
Please except this email attachment #4 Selenium Update for your EPA Willamette Basin Mercury TMDL
Item attachment #4 Selenium Moderates Mercury Toxicity in Free-Ranging Freshwater Fish. I will be
sending a few other documents individually with my emails. Sometimes when I send large documents
together your servers are not able to except over a certain Meg size.
Response Text
The relationship between mercury and selenium is complex and has been the subject of numerous
scientific studies. Selenium has the potential to impact several aspects of mercury cycling and toxicity.
For example, 1) some studies suggest that selenium may decrease the potential for mercury methylation
(Dang et al., 2019); 2) other studies suggest that selenium protects aquatic organisms against the
impacts of mercury (S0rmo et al., 2011); and 3) some studies suggest that selenium in fish consumed by
humans protects the consumer (and its fetus) against the adverse effects of mercury exposure (Ralston
and Raymond, 2018).
1. Regarding the impact of selenium on methylmercury production, if this were occurring in the
Willamette River Basin this impact would be captured in our mercury translator model. The mercury
translator model takes the ambient total-mercury and methylmercury concentrations measured in the
basin to allow the conversion of the fish tissue-based methylmercury criteria back to a water column
total-mercury concentration. If selenium is having any impact on methylmercury production our model
is accounting for this process. However, there is detectable methylmercury throughout the Willamette
River in water and fish and therefore, any inhibitory impact of selenium on this process is not significant
enough to reduce fish-tissue methylmercury concentration below the water quality criteria.
2. The potential protective impacts of selenium on the health of aquatic organisms are beyond the
scope of this TMDL which is focused on human health.
3. The protective effects of selenium on fish consumers against methylmercury toxicity is relevant
to the TMDL in that fish tissue criteria concentration of 0.04 mg/kg methylmercury does not vary
depending on the molar ratio of selenium. The toxicological assessment that was used to derive the fish
tissue criteria that forms of the basis the TMDL was performed at the national level and was based on a
very extensive scientific assessment of the impacts of methylmercury toxicity on fish consumers (and
their feti) (National Research Council, 2000). The levels of selenium in fish in the Willamette River are
not unique and excess levels of selenium relative to mercury are commonly encountered throughout
freshwater and saltwater fisheries in the western US as well as globally (Peterson et al., 2009). It is
important to note that the conclusion from Peterson et al., 2009 that selenium is often in excess of
mercury in fish is an interesting finding; however, this study did not assess the human health impacts on
fish consumers. In contrast, the derivation of the EPA reference dose for methylmercury which forms
the basis of the TMDL is based on epidemiological studies on the impacts of methylmercury in fish on
human health outcomes. More recent studies on this topic have supported EPA's assessment of
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methylmercury toxicity with the conclusion: "Overall, no evidence was found that Se was an important
protective factor against MeHg neurotoxicity." (Choi et al., 2008).
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Author Name Tom Quintal
Organization Name
Letter ID
Comment ID
Comment Category
Private Citizen
L6
L6-1
Mass Balance Model/HSPF
Comment Text
A watershed model, which uses the Hydrological Simulation Program - FORTRAN, will simulate
movement of mercury via flow and sediment routing. Some of the many industries that will be affected
by the NEW mercury TMDL have serious concerns with the Fortran Simulation Program. Oregon miners
do not trust this program either?
Response Text
This comment expresses an unspecified concern with the Hydrological Simulation Program - FORTRAN
or HSPF model. HSPF is a comprehensive watershed model that is in the public domain with open-source
code that is recommended by EPA as an appropriate choice for the development of TMDLs (e.g., EPA
841-B-97-006, Compendium of Tools for Watershed Assessment and TMDL Development). HSPF has
been used to develop many TMDLs including those for sediment and sediment bound chemicals
throughout the U.S. EPA considers HSPF to be an appropriate tool to estimate the movement of water
and sediment in the Willamette River Basin. Because there are no specific questions raised in the
comment about the simulation of flow and sediment routing, EPA can only respond in general to this
comment.
Comment ID L6-2
Comment Category Other
Comment Text
Oregon has a mineral trespass law, ORS 517.130 and most all studies indicate the people doing stream
sampling for studies DEQ is using to list streams in the Bohemia mining district as 303d have committed
mineral trespass. Miners with Federal mining claims were not notified or gave permission for valuable
minerals to be disturbed or removed from their claims when stream studies were done. Mercury is
considered a valuable mineral. ORS 517.130 A person commits mineral trespass if a person intentionally
and without permission of the claim holder: (a) Enters a mining claim posted as required in ORS 517.010
(Locations of mining claims on veins or lodes or ORS 517.044 (Location of claims upon placer deposits)
and disturbs, or removes or attempts to remove any mineral from the claim site. Most likely legal action
will be taken against folks who are responsible for this mineral trespass. A good example of mineral
trespass is the study Tracing the source of mercury contamination in the Dorena Lake watershed,
Western Oregon. See chart reference page 856 chart (a), (b), (c) and (d) where minerals were removed
and reference page 857 table #1 for mineral elements removed for testing without claim owner's
permission.
Response Text
This comment was previously submitted on the ODEQ Public Review Draft of the TMDL (July 2019) and
the following response was provided in ODEQ's November 2019 Response to Comments: "This comment
is outside the scope of DEQ's authority. DEQ does not have the authority to determine whether or not
mineral trespass was committed. The determination as to whether or not mineral trespass occurred
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would not change the utility of the studies for determining the presence of mercury in the subject
streams, which is the basis for DEQ's prohibition of suction mining, since multiple other studies show
the potential for existing mercury to be disturbed, mobilized and methylated in the reservoir
downstream and there are no demonstrated methods to prevent the mobilization during suction dredge
mining and subsequent methylation of mercury." This comment is outside the scope of EPA's TMDL No
further response is needed.
Comment ID L6-3
Comment Category Suction Dredging
Comment Text
Miners are only allowed to suction dredge using ODF&W in water work schedule for 2 or 3 months when
low water flows carry minimal sediment flows. 700 NPDES permits only allow 300 feet turbidity and DEQ
has the ability to know where the stream locations are from GPS information when a person applies for
the permit. Most miners are lucky to work a few weeks in streams during the in water work schedule.
So what is the big issue with suction dredges causing heavy TMDL mercury in streams?
Response Text
The concern with suction dredge mining is that it can mobilize pockets of elemental mercury stored
within the sediment. Information on where elemental mercury is located within a specific watershed
remains unknown. However, it is known that historical gold and silver mining activities utilized mercury
as part of the mining process. There have been several scientific studies designed to understand the
impacts of suction dredge mining on the mobilization and bioavailability of mercury. These studies have
found that the sediments containing mercury from historical mining operations are typically deeply
buried and would otherwise be inaccessible to natural erosion remobilization processes except during
extreme hydrologic conditions (Fleck, 2011; Marvin-DiPasquale, 2011). The process of suction dredging
can capture a high percentage of elemental mercury in the sediment. However, this process can also
mobilize some smaller fraction of the mercury into the water where it can be transported downstream
to where conditions are more conducive to methylmercury production and accumulation in aquatic
organisms can occur (Fleck, 2011; Humphreys, 2005; Marvin-DiPasquale, 2011). While suction dredging
can remove mercury buried in stream sediments, the overall impact is that there is an increase in the
mobility of mercury in the stream environment which can increase the availability of mercury for
methylation and bioaccumulation in fish.
Comment ID L6-4
Comment Category Miners will require financial reimbursement
Comment Text
Oregon miners with Federal mining claims will require financial reimbursement for the loss of their
Federal Mining Mineral Estate and this mineral is considered personal property. The 9th Circuit Court
USA v. Shumway. Case 96-16480: Date file 12/28/99. Now BLM will use the Prudent Man Rule to
invalidate a claim if the claim is not able to show a profit. This rule determines value based on whether a
person will consider investing time and money to develop a potentially viable mineral deposit. The U.S.
Supreme Court concurred with this definition in 1968. The claimant is required to show a reasonable
prospect of making a profit from the sale of minerals from a claim or a group of contiguous claims. It is
not possible to retain a valid BLM claim using hand operated mining equipment with the listing of the
streams in the paragraph below as 303d; because it will not allow DEQ to issue 700 NPDES permits for a
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miner to move enough stream material. Oregon will be responsible to reimburse about 30 plus claim
owners for their personal property loss in the Bohemia mining district for thousands of dollars?
Response Text
The issue of financial reimbursement to miners under federal mining rules stemming from 303(d) and
NPDES actions by the State of Oregon is outside the scope of matters which EPA is able to address in this
TMDL and under the CWA in general.
Comment ID L6-5
Comment Category 303(d) Listings
Comment Text
Sharps Cr. is a secondary transport pathway stream for mercury according to page reference 858 figure
5 for the Dorena lake watershed study. This stream should never require a 303d listing?
Response Text
This question was previously submitted in regard to the ODEQ Public Review Draft of the TMDL (July
2019) and answered in DEQ's November 2019 Response to Comments:
"DEQ is not currently proposing to add Sharps Creek or other tributaries to Dorena Reservoir to the
303(d) list of waterbodies impaired by mercury. The studies referenced in the [DEQ] TMDL indicate that
disturbance by suction dredging increases the potential for mercury that is currently present in the
sediment of streams to be uncovered, oxygenated, transformed to dissolved and suspended states,
transported downstream to Dorena Reservoir and methylated. Sediment analyzed from Sharps Creek
was found to have a mean concentration of 0.20 mg/kg mercury (Hygelund et al 2001). Because Sharps
Creek is tributary to Dorena Reservoir and Dorena Reservoir is 303(d) listed as impaired for mercury as a
known area of mercury methylation, and has fish consumption advisories in place for mercury, and
there are no demonstrated methods to prevent the mobilization during suction dredge mining and
subsequent methylation of mercury, DEQ's TMDL prohibits suction dredge mining in tributaries to the
reservoir to reduce permitted discharges of mercury and reduce methylation potential of existing
mercury contamination in stream sediments."
Comment ID L6-6
Comment Category Mining
Comment Text
The streams listed below in the Bohemia mining district will require the state of Oregon to financial
reimburse claim owners if DEQ list these streams 303d. Mining according to the studies DEQ is using
only shows 1% of the Mercury load for the Willamette basin streams. Please justify how mining is a
mercury issue?
Response Text
This comment was previously submitted on ODEQ's July 2019 Public Draft of the TMDL and was
answered in ODEQ's November 2019 Response to Comments, as follows:
"DEQ clarifies that the TMDL modeling indicates that all permitted wastewater point source discharges
contribute approximately one percent of the mercury load within the Willamette Basin. Suction dredge
mining discharges regulated by the 700-PM permit contribute an unquantified amount of this one
percent. The TMDL modeling also estimated that the tributaries to Dorena Reservoir contribute about
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0.12 kg/yr of mercury, which is about 7% of the contribution from all permitted discharges in the entire
basin. The studies referenced in the TMDL indicate that disturbance by suction dredging increases the
potential for mercury that is currently present in the sediment of streams to be uncovered, oxygenated,
transformed to dissolved and suspended states, transported downstream to Dorena Reservoir and
methylated. Because mercury has been measured in the sediment of tributaries to Dorena Reservoir
ranging from 0.08 mg/kg to 8.78 mg/kg (Hygelund et al, 2001 & Tobias and Wasley, 2013) and Dorena
Reservoir is a known area of mercury methylation, is listed for mercury on the 303(d) list of impaired
waterways and has fish consumption advisories in place for mercury, and there are no demonstrated
methods to prevent the mobilization during suction dredge mining and subsequent methylation of
mercury, DEQ's TMDL prohibits suction dredge mining in tributaries to the reservoir to reduce permitted
discharges of mercury and reduce methylation potential of existing mercury contamination in stream
sediments. Finally, DEQ's TMDL also requires reduction of mercury by 95% from legacy mine-related
sources, with the federal agencies as designated management agencies responsible for
implementation."
EPA agrees with ODEQ's conclusion that suction dredging can be a significant source of mercury loading
in areas where stream sediments are contaminated with mercury, including their analysis of tributaries
to the Dorena Reservoir. The EPA TMDL (section 7.2.4) says that "EPA's TMDL reflects ODEQ's intent to
prohibit suction dredge mining at locations described in the ODEQ's 2019 TMDL" and includes a zero
Waste Load Allocation (WLA) for suction dredging in the Coast Fork subbasin.
Comment ID L6-7
Comment Category Suction Dredging
Comment Text
Miners for free using a suction dredge removes mercury so why would DEQ list Bohemia mining stream
tributaries with 303d listing when the state has no other way to remove mercury from this
environment?
Response Text
This comment was previously submitted on ODEQ's July 2019 Public Draft of the TMDL. Listed below is
ODEQs response from their November 2019 Response to Comments document.
"DEQ clarifies that streams in the Bohemia Mining District are not currently proposed for inclusion on
the 303(d) list of waters impaired by mercury. DEQ agrees that miners sometimes find and remove
elemental mercury during suction dredge mining and that mercury currently in tributaries to Dorena
Reservoir could migrate downstream to areas where methylation can occur. As noted in section 9.2.3 of
the draft TMDL, the streams and upland areas within the Bohemia Mining District that are known to be
contaminated with mercury due to historical mining activities are on the list of Abandoned Mine Lands
sites being tracked, investigated and remediated by state and federal agencies. In the meantime, the
TMDL prohibits suction dredge mining within mercury contaminated tributaries to Dorena Reservoir
because the studies referenced in the TMDL show that suction dredge mining can uncover, transform,
transport and increase methylation potential of mercury in stream sediment and there are no
demonstrated methods to prevent the mobilization during suction dredge mining and subsequent
methylation of mercury."
In addition to ODEQ's response, we would like to point out that suction dredging does not reduce the
potential for mercury to be mobilized downstream and converted to methylmercury. The few studies on
this topic have shown the opposite, that pockets of elemental mercury are typically stored deep in the
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sediment with limited mobility (Fleck, 2011; Marvin-DiPasquale, 2011). However, the process of suction
dredging has been shown to mobilize this mercury and increase its movement downstream where it can
become methylated (Marvin-DiPasquale, 2011). While suction dredging may result in increased
oxygenation of sediments at a particular location, the mobilization of mercury into the water can result
in methylation occurring further downstream. Streams that have been subject to suction dredging have
been shown to have increased levels of mercury in downstream biota relative to areas where suction
dredging has not occurred (Fleck, 2011).
Comment ID L6-8
Comment Category Suction Dredging
Comment Text
As miners remove sediments, sands, and gravel from streams and former mine sites to separate out the
gold, they are also removing mercury. That is a benefit to the state? A 4-inch gold suction dredge
captures 98% of the mercury it sucks from a stream and is a great benefit to streams? Explain why this is
not the best way to recover mercury?
Response Text
This comment was previously submitted on ODEQ's July 2019 Public Draft of the TMDL and was
answered in ODEQ's November 2019 Response to Comments as follows:
"DEQ clarifies that streams in the Bohemia Mining District are not currently proposed for inclusion on
the 303(d) list of waters impaired by mercury. DEQ agrees that miners sometimes find and remove
elemental mercury during suction dredge mining and that mercury currently in tributaries to Dorena
Reservoir could migrate downstream to areas where methylation can occur. As noted in section 9.2.3 of
the draft TMDL, the streams and upland areas within the Bohemia Mining District that are known to be
contaminated with mercury due to historical mining activities are on the list of Abandoned Mine Lands
sites being tracked, investigated and remediated by state and federal agencies. In the meantime, the
TMDL prohibits suction dredge mining within mercury contaminated tributaries to Dorena Reservoir
because the studies referenced in the TMDL show that suction dredge mining can uncover, transform,
transport and increase methylation potential of mercury in stream sediment and there are no
demonstrated methods to prevent the mobilization during suction dredge mining and subsequent
methylation of mercury."
There have been several scientific studies designed to understand the impacts of suction dredge mining
on the mobilization and bioavailability of mercury. These studies have found that the sediments
containing pockets of elemental mercury from historical mining operations are typically deeply buried
and would otherwise be inaccessible to natural erosion remobilization processes except during extreme
hydrologic conditions (Fleck, 2011; Marvin-DiPasquale, 2011). The process of suction dredging can
capture elemental mercury in the sediment. However, this process can also mobilize some smaller
fraction of the mercury into the water where it can be transported downstream to where conditions are
more conducive to methylmercury production and accumulation in aquatic organisms can occur (Fleck,
2011; Humphreys, 2005; Marvin-DiPasquale, 2011). Without the activity of suction dredging, this
fraction of mercury would have remained deeply buried in the sediment and would not have been
available for uptake into the food web. While suction dredging can remove mercury buried in stream
sediments, the overall impact is that there is an increase in the mobility of mercury in the stream
environment which can increase the availability of mercury for methylation and bioaccumulation in fish.
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Comment ID
Comment Category
L6-9
Little data is available to show mercury in tributaries to Dorena
Reservoir
Comment Text
The suggestion floured mercury, regardless of the source, would remain suspended for miles below the
dredging site is not supported by any evidence from studies I have found?
Response Text
Once mercury has been mobilized from the sediment into the water column it is capable of being
transported downstream in flowing water. While this may not have been measured very far
downstream in the few studies that focus on suction dredge mining, other studies on mercury
mobilization in rivers and streams downstream of contaminated sites indicate that mercury can remain
in suspension in the water for over 100 km downstream of the initial release (Eckley et al., 2020). There
have been several scientific studies designed to understand the impacts of suction dredge mining on the
mobilization and bioavailability of mercury. These studies have found that the sediments containing
mercury from historical mining operations are typically deeply buried and would otherwise be
inaccessible to natural erosion remobilization processes except during extreme hydrologic conditions
(Fleck, 2011; Marvin-DiPasquale, 2011). The process of suction dredging can capture elemental mercury
in the sediment. However, this process can also mobilize some smaller fraction of the mercury into the
water where it can be transported downstream to where conditions are more conducive to
methylmercury production and accumulation in aquatic organisms can occur (Fleck, 2011; Humphreys,
2005; Marvin-DiPasquale, 2011). Without the activity of suction dredging, this fraction of mercury would
have remained deeply buried in the sediment and would not have been available for uptake into the
food web. While suction dredging can remove mercury buried in stream sediments, the overall impact is
that there is an increase in the mobility of mercury in the stream environment which can increase the
availability of mercury for methylation and bioaccumulation in fish.
Comment Text
Mercury is one of the heavier elements and the physical/chemical facts would indicate that suspended
mercury would not travel farther than a measured dredge plume currently limited by DEQ's 700 NPDES
permit to 300 feet. That short distance to settle mercury out would not cause significant harm to
streams?
The density of mercury is 13.534 g/cm3. Therefore, all other things being equal, the greater density
(weight) of mercury would insure that it would fall out of suspension before the end of a dredge plume.
Another reason to use a suction dredge and DEQto not discriminate against small scale mining?
Suction dredges provide a net environmental benefit by removing nearly all mercury they encounter.
Who else in government will provide this service for free?
Response Text
This comment was previously submitted on ODEQ's July 2019 Public Draft of the TMDL and was
answered in ODEQ's November 2019 Response to Comments, as follows.
Comment ID
Comment Category
L6-10
Suction Dredging
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"DEQ acknowledges that stream dynamics are complex and that mercury mobilization, methylation and
settling of the many forms of mercury that could be present have not been quantified. DEQ agrees that
the density of elemental mercury may assist in it settling out within the 300 feet allowable for visible
turbidity under the 700-PM permit. Once elemental mercury has been disturbed in stream sediments, it
can become semi-dissolved in microscopic beads that can be held in suspension within flowing waters.
Some of this mercury may settle out of suspension prior to reaching Dorena Reservoir during low-flow
periods. However, because it is not deeply buried, it can be easily resuspended into the water during
periods of higher flow which occur every year during the fall and winter. The studies referenced in the
TMDL show that the process of suction dredging increases the mobility of mercury within streams,
which increases its transport to downstream waterbodies such as Dorena Reservoir. DEQ regulates
permitted point source discharges, including suction dredge mining, and determined that a 10%
cumulative decrease in mercury from permitted point sources is needed in the basin to reach reduced
in-stream targets over time and eventually safer fish consumption levels. Because mercury
contamination exists in stream sediment in tributaries to Dorena Reservoir and there are no
demonstrated methods to prevent the mobilization during suction dredge mining and subsequent
methylation of mercury, stopping suction dredge mining is needed to reduce mercury in the water and
fish in the Dorena Reservoir and its tributaries."
EPA generally agrees with ODEQs response but would also like to point out that while mercury is a heavy
metal, it is not heavy enough to settle out of suspension in streams and rivers. Even in lakes mercury is
found dissolved in the water and does not settle to the bottom unless it is attached to heavier particles.
In waterbodies mercury is encountered in the dissolved phase—often bound to dissolved organic
carbon—or bound to particles. Mercury in the dissolved phase does not settle out of suspension in
rivers or streams—even during periods of low flow. When mercury is bound to particles, which increases
its mass by orders of magnitude, it typically stays suspended in the water column during moderate to
high flow periods. During periods of low-flow, there can be some settling of particulate-bound mercury.
However, this mercury is easily re-entrained during periods of higher flow. In a recent review of mercury
contaminated sites, the downstream impacts of mercury released into waterbodies can occur for over a
hundred kilometers downstream (Eckley et al., 2020).
There have been several scientific studies designed to understand the impacts of suction dredge mining
on the mobilization and bioavailability of mercury. These studies have found that the sediments
containing mercury from historical mining operations are typically deeply buried and would otherwise
be inaccessible to natural erosion remobilization processes except during extreme hydrologic conditions
(Fleck, 2011; Marvin-DiPasquale, 2011). The process of suction dredging can capture a high percentage
of the elemental mercury in the sediment. However, this process can also mobilize some smaller
fraction of the mercury into the water where it can be transported downstream to where conditions are
more conducive to methylmercury production and accumulation in aquatic organisms can occur (Fleck,
2011; Humphreys, 2005; Marvin DiPasquale, 2011). Without the activity of suction dredging, this
fraction of mercury would have remained deeply buried in the sediment and would not have been
available for uptake into the food web. While suction dredging can remove mercury buried in stream
sediments, the overall impact is that there is an increase in the mobility of mercury in the stream
environment which can increase the availability of mercury for methylation and bioaccumulation in fish.
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Comment ID
Comment Category
L6-11
Suction Dredging
Comment Text
If not removed, mercury will eventually migrate downstream to areas where it is more likely to be
converted into methylmercury. Isn't another benefit to the state that miners using suction dredges?
Mercury methylation happens under anaerobic conditions not found in running streams and rivers.
Suction dredging even adds more oxygenation that benefits streams. Removal of elemental mercury
before it can be converted, by bacteria, to methylmercury is an important component of environmental
and human health protection and is provided as a secondary benefit of suction dredging.
DEQ regulates a suction dredge as a point source discharge with the 700 NPDES permit, so a dredge
point source would contribute significantly less mercury to streams than nonpoint sources. Why would
DEQ discriminate against one of the best tools available by using a suction dredge that removes mercury
from streams at no cost? Miners are doing this work for free for the state of Oregon.
Response Text
This comment was previously submitted on ODEQ's July 2019 Public Draft of the TMDL and was
answered in ODEQ's November 2019 Response to Comments as follows:
"DEQ agrees that mercury cycling within the environment occurs through many complex and
interrelated processes. The studies referenced in the TMDL indicate that disturbance by suction
dredging increases the potential for mercury that is currently present in the sediment of streams to be
uncovered, oxygenated, transformed to dissolved and suspended states, transported downstream to
Dorena Reservoir and methylated. Because mercury has been measured in the sediment of tributaries
to Dorena Reservoir ranging from 0.08 mg/kg to 8.78 mg/kg (Hygelund et al, 2001 & Tobias and Wasley,
2013) and Dorena Reservoir is a known area of mercury methylation, is listed for mercury on the 303(d)
list of impaired waterways and has fish consumption advisories in place for mercury, DEQ's TMDL
prohibits suction dredge mining in tributaries to the reservoir to reduce permitted discharges of mercury
and reduce methylation potential of existing mercury contamination in stream sediments."
In addition to ODEQ's response, we would like to point out that suction dredging does not reduce the
potential for mercury to be mobilized downstream and converted to methylmercury. The few studies on
this topic have shown the opposite, that pockets of elemental mercury are typically stored deep in the
sediment with limited mobility (Fleck, 2011; Marvin-DiPasquale, 2011). However, the process of suction
dredging has been shown to mobilize this mercury and increase its movement downstream where it can
become methylated (Marvin-DiPasquale, 2011). While suction dredging may result in increased
oxygenation of sediments at a particular location, the mobilization of mercury into the water can result
in methylation occurring further downstream. Stream that have been subject to suction dredging have
been shown to have increased levels of mercury in downstream biota relative to areas where suction
dredging has not occurred (Fleck, 2011).
Comment Text
After the order is signed, DEQ will provide a response to all comments received during the public
comment period. DEQ will then submit the documents to EPA for action. Why not issue it as an
administrative rule instead of an Order?
Comment ID
Comment Category
L6-12
DEQ's authority/responsibility to implement
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Response Text
This comment was originally submitted on ODEQ's Public Review Draft TMDL of July 2019 and answered
in ODEQ's November Response to Comments. ODEQ noted: Oregon Administrative Rule 340-042-0060
titled Issuing a Total Maximum Daily Load states "(1) The Director will issue a TMDL as an order." The
comment is not directly relevant to EPA's revised TMDL.
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Author Name Tom Quintal
Organization Name
Letter ID
Comment ID
Comment Category
Private Citizen
L7
L7-1
Other
Comment Text
It is important to understand Federal mining claim owners have private property rights for locatable
minerals on their mining claims. When a government agency passes a rule or law that deprives a claim
owner they can only use part of their property right to recover a valuable mineral by limiting how or
what tools that can be used; suction dredges, it deprives the profitability or value of their property. If
you owned a three or four bedroom home and the government made up a law that you could only use
part of your home for your personal life style you would have a hard time obeying such a law. EPA and
DEQ using 303d laws limiting how minerals can be recovered profitably has the same effect on a private
property federal claim owner. Because I am a private property mineral owner of a 40 acre federal
mining claim it is financially important for me to preserve the value of the minerals now and in the
future. Miners want to believe EPA will understand why 90 federal mineral claim owners in the Bohemia
mining district expect to receive fair EPA ruling for 303d waters that will allow us to preserve our private
property minerals.
Response Text
Neither EPA nor ODEQ has any direct jurisdiction over Federal mining claims and the TMDL does not
abrogate mineral ownership rights under such claims. However, EPA, under the Clean Water Act, and
ODEQ, by delegation from EPA, do have permitting jurisdiction over discharges of pollutants to waters of
the U.S., including discharges from suction dredges. EPA does not contest the validity of such Federal
mining claims; however, the Clean Water Act does authorize EPA and its designees to set permit effluent
limits on mining activities consistent with the assumptions and requirements of waste load allocations in
a TMDL. In the case of suction dredging in waterbodies where elevated mercury concentrations in
stream sediment and banks have been identified and present a potential threat to non-attainment of
water quality standards, EPA and ODEQ may set effluent limitations consistent with the TMDL target.
In the ODEQ 2019 TMDL, ODEQ determined that effluent discharges from suction dredging in certain
areas of documented mercury contamination are not consistent with obligations to achieve water
quality standards under the Clean Water Act and, upon renewal of the 700 PM permit, ODEQ will be
prohibiting mercury in discharges from suction dredging. EPA finds ODEQ's approach to suction dredge
mining to be consistent with the Clean Water Act.
Comment Text
EPA spent thousands of taxpayer dollars for their Tetra Tech study and EPA orTetra Tech never did
contact one suction dredge miner in the Bohemia Mining District to take a suction dredge water
discharge sample or any other study being used to list this basin for 303d waters. If EPA did not require a
scientific suction dredge water discharge sample then none of the sediment stream samples are valid for
listing Sharps Cr. Brice Cr. Champion Cr. or any other stream tributaries 303d. DEQ never included one
Oregon small scale miner to be part of their study commission for the Willamette Basin TMDL. This is
USEPA Region 10 19
Comment ID
Comment Category
L7-2
Inadequate data used
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another slam dunk 303d water listing against Oregon small scale mining industry. How fair is that when
you consider 303d listings?
Response Text
ODEQ in response to comments on their draft 2019 TMDL clarified that streams in the Bohemia mining
district, including Sharps, Brice and Champion, are not currently proposed for 303(d) listing, but that
there is information documenting mercury contamination in these streams and that suction dredge
mining has the potential to increase the conversion of mercury to methylmercury in downstream
ecosystems, hence ODEQ's eventual prohibition of suction dredge mining in these areas. Excerpts from
ODEQ's responses follow:
"DEQ clarifies that streams in the Bohemia Mining District are not currently proposed for inclusion on
the 303(d) list of waters impaired by mercury. DEQ agrees that miners sometimes find and remove
elemental mercury during suction dredge mining and that mercury currently in tributaries to Dorena
Reservoir could migrate downstream to areas where methylation can occur. As noted in section 9.2.3 of
the draft TMDL, the streams and upland areas within the Bohemia Mining District that are known to be
contaminated with mercury due to historical mining activities are on the list of Abandoned Mine Lands
sites being tracked, investigated and remediated by state and federal agencies. In the meantime, the
TMDL prohibits suction dredge mining within mercury contaminated tributaries to Dorena Reservoir
because the studies referenced in the TMDL show that suction dredge mining can uncover, transform,
transport and increase methylation potential of mercury in stream sediment and there are no
demonstrated methods to prevent the mobilization during suction dredge mining and subsequent
methylation of mercury."
"Because mercury has been measured in the sediment of tributaries to Dorena Reservoir ranging from
0.08 mg/kg to 8.78 mg/kg (Hygelund et al, 2001 & Tobias and Wasley, 2013) and Dorena Reservoir is a
known area of mercury methylation, is listed for mercury on the 303(d) list of impaired waterways and
has fish consumption advisories in place for mercury, DEQ's TMDL prohibits suction dredge mining in
tributaries to the reservoir to reduce permitted discharges of mercury and reduce methylation potential
of existing mercury contamination in stream sediments."
EPA cannot comment on the involvement of suction dredge miners in the TMDL Advisory Committee,
because it was a process established and implemented by ODEQ for development of its TMDL. We do
note though that ODEQ (as well as EPA) held a public comment period for its draft TMDL during which
suction dredgers and any other interested parties could provide comments regarding the TMDL. EPA
encourages suction dredge miners to work with ODEQ as they develop their TMDL implementation
monitoring strategy to fill any perceived gaps in information regarding suction dredging.
Comment ID L7-3
Comment Category Other
Comment Text
It is criminal for EPA to deprive approximately 90 federal mining claim owners who represent
approximately 220 family members to lose some of their financial worth by not allowing them to
recover enough valuable strategic minerals with the only tools available to recover minerals profitably
using a suction dredge? No DEQ suction dredge permits available for 303d streams.
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Response Text
EPA is not depriving any owners of mining claims. Neither EPA nor ODEQ have any direct jurisdiction
over Federal mining claims and the TMDL does not abrogate mineral ownership rights under such
claims. However, EPA, under the Clean Water Act, and ODEQ, by delegation from EPA, do have
permitting jurisdiction over discharges of pollutants to waters of the U.S., including discharges from
suction dredges. EPA does not contest the validity of such Federal mining claims; however, the Clean
Water Act does authorize EPA and its designees to set permit effluent limits on mining activities that
may be necessary to achieve compliance with a TMDL. In the case of suction dredging in waterbodies
where elevated mercury concentrations in stream sediment and banks have been identified and present
a potential threat to non-attainment of water quality standards, EPA and ODEQ may set effluent
limitations consistent with the TMDL target. The EPA TMDL accepts the ODEQ determination that
effluent discharges from suction dredging in certain areas of documented mercury contamination are
not consistent with obligations to achieve water quality standards under the Clean Water Act.
Comment ID L7-4
Comment Category Inadequate data used
Comment Text
If mercury concentration for fish consumption is the real reason to shut down suction dredge mining in
the streams listed above; then why did Tetra Tech use non consumable trash fish like Carp and Northern
Pike Minnow also known as Squaw Fish. Oregon Fish and Wildlife pay people to catch these fish to rid
them from our Oregon streams. Suction dredge miners for free are the only citizens using suction
dredges that are able to remove fishermen's lead, monofilament line, car parts, lead acid batteries and
other related junk from Oregon streams. Who will do this job in the future if you keep allowing streams
to be listed 303d?
Response Text
The Northern Pikeminnow was used to establish the water column THg target for the TMDL. Use of the
Northern Pikeminnow provides a margin of safety for the TMDL because this is a higher trophic level fish
species that is the most efficient mercury bioaccumulator among the species evaluated. Therefore, the
target inherently ensures that mercury tissue concentrations in lower trophic level fish species meet
human health criteria. In addition, in response to case no. 3:12-cv-01751-AC, the court required the
2006 TMDL to be updated. The earlier version also applied the Northern Pikeminnow for TMDL target
development.
While not a popular sport fish, EPA disagrees that the Northern Pikeminnow is "non consumable" as
consumption has been documented.
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Author Name Gerald Fisher, PE
Organization Name
Letter ID
Comment ID
Comment Category
City of Mo!alia
L8
L8-1
Non-point Source Load Allocations
Comment Text
I attended a webinar held by DEQ in March 2019, which included discussion regarding targeting
reductions in mercury through additional regulation on small cities with a population of 5,000. My issue
with DEQ's approach at that time was that it will have a negative financial impact on smaller agencies
without having a real measurable impact on reducing Mercury. Molalla will reach a population of 10,000
in a very short period of time and we have most of DEQ's stormwater requirements for larger cities
already in place. The issue I had with DEQ's approach was that they focused only on their permit holders
and agencies they regulate to fix an issue that is much larger in scope. If a majority of the mercury is
from atmospheric deposits and erosion then the focus should not be on making things harder on cities.
If you look at the total footprint of cities compared to agriculture, forest lands, and mining operations,
our impact is very small. We control erosion from construction activities, manage our roadways to the
best of our financial capabilities, and manage storm systems in the same manner.
My opinion is that instead of focusing on cities, DEQ and the EPA should refocus its efforts with the
Oregon and US Department of Agriculture to limit runoff from agricultural sites, the Oregon and US
Department of Forestry for timber lands, and federal and state agencies with oversight over all mining
operations including grass turf production and agricultural lands. We've all seen ag lands tilled up and
clear cutting right before it rains and then watched the topsoil wash away into roadside ditches and
streams. I don't think that cities are the problem and believe that the EPA and DEQ should instead focus
on the land uses that have a larger impact on water quality in rivers and streams. Once all uses are held
to the same standard as cities are then we can talk about whether or not we need to do more. Cities
have had increasing regulation applied to them since the Clean Water Act was passed and I challenge
DEQ and EPA to demonstrate the same level of regulation and enforcement on agricultural, forestry,
and mining operations.
I've contacted the Oregon Ag Department in the past about the release of mercury and sediment
through erosion for ag lands and have been told that their hands are tied because their rules have no
enforcement teeth and the Ag lobby is a powerful force at the state legislature. If the branches of the
state and federal government really do want measurable reductions in mercury then their focus on this
TMDL and future TMDL's should be comprehensive across all land use types and hold everyone to the
same standards. Erosion and sediment control required on all agriculture, timber, and mining operations
similar to what we have to endure for construction within city limits would go a long way to controlling
mercury, sediment, and other transport of materials into our rivers and streams. My recommendation is
that this TMDL focus on bringing those lands up to standard before applying more regulation on local
communities.
I hope that the EPA and DEQ take the lead on bringing agriculture, timber, and mining interests into the
same regulatory umbrella as is applied to our community. Thanks for your time.
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Response Text
The TMDL analysis indicates that large reductions in existing mercury loads will be needed to achieve
the fish tissue methylmercury goal of 0.040 mg/kg. Because such large reductions are needed it will be
important for all source sectors to participate in controlling the transport and delivery of mercury from
the land surface to the waterbodies of the Willamette River Basin. The comment notes that larger
sediment loads are likely to be generated from agricultural lands than from urban lands; however,
impervious surfaces associated with urban areas tend to generate more direct surface runoff that can
carry mercury loads deposited from the atmosphere to the stream network. EPA agrees with ODEQ's
decision to apply the six minimum stormwater requirements to small cities with populations between
5,000 and 10,000, including Molalla, as shown in Table 13-11 of the ODEQTMDL and Water Quality
Management Plan.
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Author Name Carolyn A. Wesolek, MS
Organization Name Private Citizen
Letter ID L9
Comment ID L9-1
Comment Category Point Source Wasteload Allocations
Comment Text
I am not in support of the EPAs proposed changes to the mercury TMDL
It is too strict and since much of the mercury issues in the state are due to environmental deposition,
regulating industry water flows so strictly is foolish, unprofessional, and unwarranted. It is going to
cause financial problems for industry & private businesses in an already environmentally expensive and
nonproductive 'business' environment in Oregon. The water rules in this state are already extremely
challenging to live by and take many, many hours of time (and money) to manage. If this was for a
pollutant that we would actually be able to impact, I would support it. But, since there is no control over
depositional mercury it seems foolish and a waste of time and money.
We already have many rules that we abide by. The proposed Mercury TMDL is too strict and onerous.
We need to be able to encourage industry and business enterprise in this country. These types of
regulations do just the opposite. This is why I am not in favor of them.
Response Text
The focus of the TMDL is to control in-basin transport of mercury into waterbodies, such as reducing
erosion on the landscape and using the best available management practices and treatment measures.
In some subbasins point sources are relatively small contributors. In other subbasins stormwater and
wastewater point sources are more important contributors. For example, about 11% of the THg load in
the Lower Willamette catchment is attributed to NPDES permitted Publicly Owned Treatment Works
(POTWs) and industrial wastewater dischargers and about 21% originates from permitted urban
stormwater sources. Additionally, Section 13 of ODEQ's TMDL provides examples of proven techniques
for point source controls that have reduced mercury concentrations. Monitoring also shows that a
combination of point and non-point source control activities have reduced mercury concentrations.
Reductions from point sources are necessary to achieve water column and fish tissue standards in the
waterbodies in the Willamette River Basin.
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Author Name Nina Bell, J.D.
Organization Name
Letter ID
Comment ID
Comment Category
Northwest Environmental Advocates
Lll
Lll-1
Reasonable Assurance
Comment Text
The commenter disagrees with the conclusion in EPA's TMDL that ODEQ's approach for addressing
"reasonable assurance" is "technically reasonable and legally sufficient" and suggests that the 2019
ODEQ Water Quality Management Plan will not be sufficient to achieve TMDL targets. The commenter
also suggests that the vast majority of non-point source loading in the Willamette Basin comes from
logging and farming lands. Some of the attachments submitted by the commenter present information
about inadequacies in programs such as Oregon's Coastal Non-Point Pollution Control Program and
Oregon Department of Forestry's Riparian Rules, inadequacies which EPA has identified in the past.
Response Text
ODEQ's Water Quality Management Plan (WQMP) is designed to address all the nonpoint source
mechanisms of mercury transport and goes beyond simply controlling sediment from agriculture and
forestry. The WQMP requires all designated management agencies (DMAs) and responsible persons to
establish individual TMDL implementation plans. Implementation plans will include measures specific to
each DMA/responsible person and will include components to assess the effectiveness of management
measures, an adaptive management provision, and five-year review milestones. Other elements of the
WQMP include but are not limited to education, outreach, technical and financial assistance, permit
administration, permit enforcement, and DEQ's enforcement of the TMDL implementation plans. EPA
recognizes that control of mercury will take significant time. Implementation of specific actions called
for in the WQMP with revisions over time based on continued monitoring and information gathering is a
reasonable approach to address a complicated environmental pollutant. EPA has concluded that the
detailed WQMP developed by DEQ and its partner agencies and stakeholders provides reasonable
assurance that the nonpoint source control measures, implemented over time, will achieve expected
load reductions.
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Author Name Tom Pepiot
Organization Name
Letter ID
Comment ID
Comment Category
Name Private Citizen
L12
L12-1
Suction Dredging
Comment Text
I am writing you to ask for a variance for suction dredging in the Bohemia Mining District. I have been
suction dredging in the BMD for 30 years as a way to supplement my income and pay for college
education for my 2 boys, they also work with me to find gold and other minerals on our private mining
claim. I have seen the studies done and have been to the meetings at ODEQ and have a lot of issues on
how and where this information was obtained. We have had a Superfund site that was done by the USFS
at the Champion mill site and water and sediment samples taken through the years since completion
has no mercury found in any samples all the way into Brice creek. The creeks in the BMD is pretty cold,
water samples in July into August 2019 ranged from 51- 56 degrees from what I understand from EPA
scientist is methyl-mercury occurs in higher temperatures with low oxygenated waters, we dredge in
moving streams that have plenty of oxygenated waters, Dorena lake on the other hand is warm waters
with stagnated waters due to being a containment source . I personally have not found mercury in
Sharps Creek, I have found it in California and the new modern fine gold recovery suction dredges
collect a lot of it, the older dredges collected 98% of mercury just think what our fine gold recovery does
maybe 100%, the main thing is that if our dredges catch any mercury its better for the environment and
proper disposal is essential. We mine the gravels below the water and the only profitable, economically
and environmentally sound way to extract minerals is a suction dredge. In the Bohemia Mining District
there are hundreds of mining claims that this will affect with thousands of dollars worth of property that
will be become worthless if suction dredging is no longer a method we can use, safety and injuries are
going to accompany with a much harder and physical methods that will have to be used and I hate to
see that. The 700 NPDES permit has become excessively restrictive with more and more restrictions put
in place to make it impossible to comply, the cost for these permits have became so expensive that
those on limited incomes can no longer afford anymore. Now in the new permit, fines have become
ridiculously high seemingly to intimidate miners into getting a permit, we got these permits to keep in
accordance with clean water act not be attacked with a permit and threatened with violations, felony's
and fines. We ask you not to make streams in the Bohemia Mining District a 303d for mercury and not to
shut down our industry. I feel as do many miners that studies need to be done with suction dredges in
the BMD with miners, we need to get any mercury out of the sediments if it's there, because winter and
spring floods will move it down if we don't get it first.
Ultimately, we know you have a job to do and so do we. We spend a lot of time and money improving
and mining our federal mining claims, I have approximately 20k of mining equipment alone that is for
suction dredging. I would like to say leave us alone but we can't do that. These waters are our waters
and we don't add nothing to the waters we take material, heavy metals and trash away and reinstate all
the material within the stream. I hope you can see my problems with listing these waters for mercury, I
hope we can find a solution that does not involve eliminating suction dredging.
Response Text
We appreciate the interest in removing mercury from and otherwise cleaning up streams in the
Bohemia mining district. A similar comment regarding 303(d) listing and suction dredging in the
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Bohemia mining district was submitted to ODEQ during the public comment period on the ODEQ 2019
TMDL Oregon provided the following response:
"DEQ clarifies that streams in the Bohemia Mining District are not currently proposed for inclusion on
the 303(d) list of waters impaired by mercury. DEQ agrees that miners sometimes find and remove
elemental mercury during suction dredge mining and that mercury currently in tributaries to Dorena
Reservoir could migrate downstream to areas where methylation can occur. As noted in section 9.2.3 of
the draft TMDL, the streams and upland areas within the Bohemia Mining District that are known to be
contaminated with mercury due to historical mining activities are on the list of Abandoned Mine Lands
sites being tracked, investigated and remediated by state and federal agencies. In the meantime, the
TMDL prohibits suction dredge mining within mercury contaminated tributaries to Dorena Reservoir
because the studies referenced in the TMDL show that suction dredge mining can uncover, transform,
transport and increase methylation potential of mercury in stream sediment and there are no
demonstrated methods to prevent the mobilization during suction dredge mining and subsequent
methylation of mercury."
EPA agrees with the State's response. With regard to the request for a variance for suction dredge
mining in the Bohemia mining district, variances for point sources are outside the scope of the EPA
TMDL and are normally issued by ODEQ for point sources in Oregon.
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Author Name Mary Anne Cooper
Organization Name
Letter ID
Comment ID
Comment Category
L13
L13-1
Other
Oregon Farm Bureau
Comment Text
The Oregon Farm Bureau (OFB), Oregon Forest & Industries Council (OFIC), and Oregon Association of
Nurseries (OAN) submit this letter jointly to convey our comments pertaining to the Environmental
Protection Agency's Willamette Basin Mercury Total Maximum Daily Load (TMDL). Our comments are
based on our review of the revised, final TMDL document, our participation as members of the Advisory
Committee for this TMDL, our previous comments to the Oregon Department of Environmental Quality
(ODEQ) and the very real impact this TMDL could have on our memberships.
By way of background, OFB is a nonprofit organization that has been a voice for Oregon's family farmers
and ranchers for 100 years. The OFB has nearly 7,000 members statewide. Over 3,000 of those members
are located within the Willamette Valley. In the Willamette Valley, OFB members raise nearly 225 types
of crops and livestock. OFIC is a nonprofit organization that represents over 50 Oregon forestland
owners and forest products manufacturers who manage over 5 million acres of Oregon forestlands and
employ nearly 60,000 Oregonians. The OAN is a nonprofit organization that provides a voice for over
700 nursery stock producers, retailers, landscapers, and other companies across the state.
Since the inception of our nonpoint source water quality programs, and for years before, our members
have worked to protect, maintain and enhance water quality throughout the Willamette Valley.
Response Text
We thank OFB, OFIC, and OAN for submitting these comments on the TMDL and their work to protect,
maintain and enhance water quality throughout the Willamette River Basin.
Comment Text
Agriculture and Forestry are not the Source of Mercury Exceedances
The agricultural and forestry sectors have always been proactive about protecting, maintaining and
enhancing water quality on agricultural and forestry lands, which combined represent by far the largest
land use in the Willamette Valley. Indeed, our industries were proactive in developing the Agricultural
Water Quality Management Program and Forest Practices Act years before most states had thought of
developing their nonpoint source programs. Since that time, we have invested millions in studies, on-
the-ground work, and compliance with our respective programs. We will continue to be proactive into
the future, as evidenced by the millions invested by each of our sectors each year in proactive water
quality improvements.
Section 4.1 of EPA's TMDL document states clearly that atmospheric deposition of mercury is the
dominant source of mercury reaching Willamette Basin streams. All land in Oregon receives mercury
from far away sources; because of the large land area occupied by farms, forests, and nurseries, these
nonpoint sources are the largest land use types on which foreign mercury deposits. Additionally, air
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Comment ID
Comment Category
Nonpoint Source
L13-2
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emissions from Oregon are small relative to global sources. The fact that Oregonians are not the source
of mercury exceedances has made writing this TMDL exceedingly challenging, and we do not envy ODEQ
or EPA's work to address a source of pollutant outside its control. Although the mercury entering the
Willamette River system from our land originated from the atmosphere, and not from our activities, we
will continue to invest in water quality on our lands and meet the rigorous requirements under our
respective programs. However, without addressing the real cause of the mercury exceedances, this
TMDL may request reductions that are larger than any basin stakeholder can manage.
Response Text
EPA concurs that atmospheric deposition of mercury is the dominant source of mercury reaching
waterbodies in the Willamette River Basin. EPA acknowledges that the agriculture and forestry
industries are generally not responsible for creating atmospheric deposition loads of mercury. However,
agriculture and forestry management practices do have an important impact on the delivery of mercury
from the land surface to streams. As noted in Section 14.2 of the ODEQ November 2019 TMDL, "...the
greatest potential for reductions of mercury delivered to streams is through enhancing controls on
nonpoint source land use activities that have the potential to result in erosion and surface runoff."
As noted in the comment, the agricultural and forestry sectors "...represent by far the largest land use in
the Willamette Valley." It is for that very reason that it will be essential to reduce the runoff of dissolved
and sediment-sorbed mercury from agricultural and forestry land. EPA also acknowledges that the
agricultural and forestry industries have generally made large strides in reducing sediment erosion over
the last few decades, yet additional reductions are still needed to achieve the mercury targets. The
TMDL sets forth general reduction targets by sector and large (HUC8) watersheds. Details of how this
will be implemented on the landscape are the responsibility of ODEQ and the DMAs. Initial
implementation strategies are laid out in the Water Quality Management Plan section of the ODEQ
TMDL (included as Appendix A to the EPA TMDL). In the WQMP, DEQ has committed to an adaptive
management approach that can adjust source control strategies as more information is obtained. EPA
encourages the commenter to work with DEQ to ensure that adaptive management will facilitate a cost-
effective approach to the implementation of the TMDL with an emphasis on controlling the most
significant sources of nonpoint source loading (e.g., activities on highly erodible land or producers with
substandard management practices).
Comment Text
Neither ODEQ nor EPA Adequately Addressed our Technical Concerns with the Model
Oregon's farmers and foresters are doing an exceptional job investing in water quality improvements,
studying water quality on our lands, and meeting the requirements of our programs, and we will
continue to do so after this TMDL is adopted. That said, we continue to have concerns about the
modeling as set forth in our previous comment letter to ODEQ, and those concerns were not addressed
by EPA. We have attached this comment letter for your reference.
The myriad of significant issues with the modeling underlying the TMDL, combined with the fact that our
sectors are not responsible for the mercury emissions causing the mercury exceedances, has resulted in
the agriculture and forestry sectors being unable to support the load allocations and reductions
requested through the TMDL. As always, we will continue to work with our designated management
agencies (DMAs) to continue to invest in and improve water quality across Oregon. We continue to have
Comment ID
Comment Category
L13-3
General Modeling Issues - Examples
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significant concerns with ODEQ and EPA's modeling, as set forth in our previous comment letter. These
include many concerns about specific dimensions of the modeling that underlies the TMDL allocations,
and related concerns about the loading capacity and the ensuing load allocations.
Response Text
EPA acknowledges that the farm and forestry sectors have made significant progress in addressing water
quality improvements over the last several decades. However, the TMDL analysis establishes that
additional actions will be needed from these and other sectors to mitigate mercury impairments within
the Willamette River Basin. The mercury loads associated with farms and forests are indeed due
primarily to atmospheric deposition (both historic and ongoing); however, the ways in which farm and
forest lands are managed determine the fraction of the mercury derived from atmospheric deposition
that is transported into the stream network.
This comment summarizes previous comments from the Oregon Farm Bureau on the July 2019 Public
Review Draft of the ODEQ TMDL. Those comments were addressed point by point in Section 58 in
ODEQ's November 2019 TMDL, Final Revised Willamette Basin Mercury TMDL and Water Quality
Management Plan, Response to Public Comments. EPA disagrees with the characterization that these
concerns about modeling were not addressed.
Comment Text
Consequently, we disagree with EPA's acceptance of both ODEQ's target concentration for water
column mercury and the unquantified margin of safety that results from developing this target
concentration from the Northern Pikeminnow.
Response Text
The commenter has concerns about ODEQ's development of the TMDL and EPA's decision to revise the
TMDL. The Water Quality Standard is highly conservative and designed to be protective of health and
aquatic life uses. Federal regulations require EPA to establish the TMDL at a level sufficient to achieve
the loading capacity, defined as the amount of a pollutant or pollutants that a waterbody can receive
and still meet water quality standards (40 CFR 130.2(f)). While EPA acknowledges that there is
uncertainty in the modeling analyses, the presence of such uncertainty does not remove EPA's
obligation to establish the TMDL at levels sufficient to meet water quality standards. As noted in 40 CFR
130.2(g), load allocations for nonpoint sources "...are best estimates of the loading, which may range
from reasonably accurate estimates to gross allotments, depending on the availability of data and
appropriate techniques for predicting the loading." The Clean Water Act and 40 CFR130.7(c)(1) also
require that TMDLs include a margin of safety (MOS) "...which takes into account any lack of knowledge
concerning the relationship between effluent limitations and water quality." See the response to
comment L14-3 regarding the unquantified MOS. EPA determined that the target concentration for
water column mercury is appropriately based on the Food Web Model analysis of tissue concentrations
in the Northern Pikeminnow as this species is the most efficient bioaccumulator of mercury evaluated.
Comment ID L13-5
Comment Category Non-point Source Load Allocations
Comment Text
EPA's Additional Load Reduction Targets Compound Existing Issues with the Model
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Comment ID
Comment Category
L13-4
Applicable Water Quality Standards
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Given the significant issues with the model, we are very disappointed to find that EPA's revised TMDL is
seeking even larger reductions from agriculture and forestry in the five basins where EPA believes that
ODEQ's reductions were insufficient. EPA is increasing proposed reductions from nonpoint sources in
these basins to 97%. These basins include several keys to agriculture and forestry in Oregon: Coast Fork
Willamette, Upper Willamette, Middle Willamette, and the Tualatin. While the Lower Willamette is not
as agriculture or forestry dominant, both industries will still be impacted.
Given the significant issues with the modelling associated with this work, increasing from a basin wide
88% reduction to 97% reduction in several key basins is not supported by the technical work completed
by the agencies. The shortcomings suggested in our previous comment letter suggest that the 97%
reduction may be higher than needed to protect human health in the Willamette Basin. This larger
reduction will put our industries in an increasingly difficult position of being held responsible for
astronomical reductions in a pollutant that we are not responsible for, and where we do not think ODEQ
or EPA has support for its determination that such reductions are necessary or even possible.
Response Text
The regulations require EPA to establish the TMDL at a level sufficient to achieve the loading capacity,
defined as the amount of a pollutant or pollutants that a waterbody can receive and still meet water
quality standards (40 CFR 130.2(f)). EPA found that the reductions proposed in the ODEQ November
2019 TMDL were not sufficient to achieve water quality standards in several of the impaired HUC8
watersheds within the Willamette River Basin.
While EPA acknowledges that there is uncertainty in any modeling analyses, the presence of such
uncertainty does not remove EPA's obligation to establish the TMDL at levels sufficient to meet water
quality standards. As noted at 40 CFR 130.2(g), load allocations for nonpoint sources "...are best
estimates of the loading, which may range from reasonably accurate estimates to gross allotments,
depending on the availability of data and appropriate techniques for predicting the loading."
The rationale for assigning 97% reductions in erosion-associated mercury loads in some HUC8 subbasins
is explained on pages 8-9 of EPA's TMDL. The reduction of 88% proposed in the ODEQ TMDL was not
sufficient to attain the TMDL fish tissue targets in five HUC8 watersheds. The EPA analysis suggested
that reductions in nonpoint source erosion-associated mercury loads ranging from 89% to 97% would be
needed to achieve targets in these watersheds. EPA established a 97% reduction for all five HUC8
watersheds where targets were not met "...for consistency purposes across land management
categories." Having a consistent allocation goal can simplify implementation planning, and development
of specific Best Management Practices (BMPs), where land uses cross multiple watersheds, such as in
forested landscapes. It can also establish an even playing field, so to speak, where there are different
landowners in different watersheds, for a particular industry. We note that the ODEQ TMDL allocations
applied a consistent nonpoint source allocation across all subbasins. We have attempted to continue
that approach in the EPA TMDL, though it is challenging to do so given the varying land uses in each
subbasin, and varying subbasin mercury concentrations. Applying a 97% reduction to these five
subbasins we feel provides a consistent allocation and is protective for all.
Atmospheric deposition of mercury is the dominant source of mercury reaching waterbodies in the
Willamette River Basin. EPA acknowledges that the agriculture and forestry industries are generally not
responsible for creating atmospheric deposition loads of mercury. However, agriculture and forestry
management practices do have an important impact on the delivery of mercury from the land surface to
streams. As noted in Section 14.2 of the ODEQ November 2019 TMDL, "...the greatest potential for
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reductions of mercury delivered to streams is through enhancing controls on nonpoint source land use
activities that have the potential to result in erosion and surface runoff."
Comment ID L13-6
Comment Category General Comments
Comment Text
Conclusion
Our organizations and the foresters, farmers, and growers of Oregon have done much in recent decades
to protect surface water quality. From new stream buffers to wet weather haul rules to strategic
implementation areas, we have worked with ODEQ and our DMAs to protect the waters of our state.
We commit to continuing this close engagement on water quality issues into the future. However, we
have significant concerns about ODEQ's development of this TMDL and the compounded uncertainties
created by EPA's decisions to revise the TMDL. Given that this pollution is largely outside of Oregon's
control, the concern with the TMDL outlined above will make it hard to create buy in on this TMDL from
our members.
Response Text
EPA acknowledges that there are stakeholders from multiple sectors, representing varied land uses and
sources of mercury, that have already been implementing strategies and actions that are protective of
water quality. EPA anticipates that continued, as well as increased efforts to protect water quality will
help the basin reach water quality goals for mercury and other TMDL pollutants. Much of the mercury in
the Willamette River Basin arises from sources outside of Oregon and outside of the U.S. via
atmospheric deposition, however, this does not change the need for a TMDL. Load allocations are
needed for nonpoint sources, whether or not they are original sources of mercury, because land
management of those nonpoint sources strongly affects the fraction of mercury (whether newly
deposited from the atmosphere or already present on site) transported from such lands into the stream
network of the Willamette River and its tributaries.
Comment ID L13-7
Comment Category Applicable Water Quality Standards
Comment Text
The uncertainty in this model at every stage creates the very real risk that Oregon will require very
expensive measures with no change relative to the actual water quality standard. This problem is due in
part to the highly conservative water quality standard upon which this TMDL is based.
Response Text
ODEQ developed a revised fish tissue consumption criterion for methylmercury of 0.040 mg/kg wet
weight that was subject to a full public review and comment process and was approved by EPA in 2011.
This criterion is much lower than the previous criterion of 0.35 mg/kg wet weight that was applicable to
the 2006 TMDL. The revision to the fish tissue criterion inevitably results in lower mercury ambient
concentration and loading targets. However, the revised criterion is incorporated into Oregon
regulations (OAR 340-041-8033, Table 40) and is explicitly required to be used for the TMDL revisions in
the findings set forth by Magistrate Judge Acosta in Northwest Environmental Advocates vs. USEPA
(2017).
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EPA does not agree that management measures to be undertaken in the implementation of this TMDL
will provide "...no change relative to the actual water quality standard." The available evidence suggests
that reductions in mercury loads will result in lower fish tissue concentrations, and thus movement
toward achieving the regulatory criterion. EPA does encourage ODEQto continue to collect additional
data and information that could be used in an adaptive management approach to maximize the
reductions in fish tissue concentrations relative to the implementation cost (see Section 14.1.4 Evaluate
implementation plans and progress, pp. 137 - 140, ODEQTMDL, November 2019).
Comment Text
When compounded by additional, unquantified, and conservative assumptions in the TMDL modeling,
the margin of safety implicit in the load reductions specified by this TMDL are exceedingly cautious and
divorced from reality.
Oregon farmers and foresters should not be asked to bear the risk of this uncertainty. We encourage
EPA to address our concerns, and not move forward with its proposed changes to the Willamette
Mercury TMDL.
Response Text
The Clean Water Act and 40 CFR130.7(c)(1) require that TMDLs include a margin of safety (MOS)
"...which takes into account any lack of knowledge concerning the relationship between effluent
limitations and water quality." The MOS in the TMDL is not unduly conservative given the many sources
of uncertainty identified in the TMDL linkage analysis identified by this commenter and others.
The majority of the mercury load in the Willamette River Basin is ultimately derived from atmospheric
deposition and is transported to the stream network in runoff and erosion from the land surface.
Because atmospheric deposition occurs over the entire watershed, it will be important for all land
managers, including farmers and foresters to work together to reduce mercury transport. The proposed
TMDL allocations attempt to provide an equitable division of responsibility for achieving the TMDL. The
details of how this will be achieved will be further refined in the implementation plans for relevant
DMAs described in Section 14 of the ODEQTMDL. It is expected that these implementation plans will be
refined and adjusted over time as part of an adaptive management strategy that will help reduce
uncertainty and target management actions to the most effective strategies for achieving the needed
total load reduction.
Comment ID
Comment Category
L13-8
Margin of Safety
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Author Name Mary Anne Cooper
Organization Name
Letter ID
Comment ID
Comment Category
Oregon Farm Bureau
L14
L14-1
General Comments
Comment Text
The agricultural and forestry sectors have always been proactive about protecting, maintaining and
enhancing water quality on agricultural and forestry lands, which combined represent by far the largest
land use in the Willamette Valley. Indeed, our industries were proactive in developing the Agricultural
Water Quality Management Program and Forest Practices Act years before most states had thought of
developing their nonpoint source programs. Since that time, we have invested millions in studies, on-
the-ground work, and compliance with our respective programs. We will continue to be proactive into
the future, as evidenced by the millions invested by each of our sectors each year in proactive water
quality improvements.
Response Text
EPA acknowledges that there are stakeholders from multiple sectors, representing varied land uses and
sources of mercury, that have already been implementing strategies and actions that are protective of
water quality. EPA anticipates that continued, as well as increased efforts to protect water quality will
help the basin reach water quality goals for mercury and other TMDL pollutants.
Comment Text
Appendix A of the TMDL document, the Technical Support Document, describes no sensitivity analyses
of the model output to reasonable variations in model input data sets or parameters. For example, no
sensitivity analyses have been performed to determine how the values of the biomagnification factor of
the Food Web Model (FWM) might vary given other modeling decisions or how its variation might affect
the calibration of the FWM. This implies that other reasonable values for this and other important
modeling input parameters might also lead to satisfactory model calibrations. However, these different
values would also lead to different outcomes for the target mercury concentration that drives the load
and wasteload allocations.
Response Text
EPA disagrees with the statement that no sensitivity analysis was performed. EPA's TMDL includes
Attachment A which is ODEQ's November 2019 TMDL. ODEQ's TMDL included an 'Appendix A' named
the 'Technical Support Document'. In the Technical Support Document, the Food Web Model analysis
established values of the biomagnification factor for the different fish species. The modeling process to
get values of the biomagnification factor for the different fish species explicitly incorporated the
variation model parameters by using the probabilistic approach in the Monte Carlo simulation. The
model parameters and how they were simulated in the Monte Carlo application are listed in Table 3-2 in
the Technical Support Document. Also, the response of the model to these variations is discussed in
Section 3.6 of the Technical Support Document. Some key insights about how some model parameters
are provided in this discussion, such as specification of the distribution of exposure concentrations is a
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Comment ID
Comment Category
L14-2
Lacks sensitivity analysis
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primary factor controlling the tails of the cumulative distribution functions used in the simulations or
future to refine predator-prey interaction probabilities in the Food Web Model. This is the information
that DEQ used to "...determine how the values of the biomagnification factor of the Food Web Model
(FWM) might vary given other modeling decisions or how its variation might affect the calibration of the
FWM".
Comment ID L14-3
Comment Category Margin of Safety
Comment Text
The Margin of Safety (MOS) provided by the modeling has not been quantified. Section 11 of the draft
TMDL document describes an implicit MOS due to the use of the northern pikeminnow as the fish
species whose bioaccumulation determines the target concentration of mercury in the river system, the
use of the median concentration from the FWM as the TMDL target concentration, and the use of total
mercury concentration in fish tissue. These are conservative assumptions that provide a MOS, but the
degree of conservativism achieved by these assumptions has not been described quantitatively. It is
therefore possible that the TMDL study may have produced an overly conservative target THg
concentration for the Willamette River that has led to unnecessarily low load and wasteload allocations
in the TMDL.
Response Text
The Clean Water Act and 40 CFR130.7(c)(1) require that TMDLs include a margin of safety (MOS)
"...which takes into account any lack of knowledge concerning the relationship between effluent
limitations and water quality." The MOS can be either explicit, through allocation of a portion of the
loading capacity, or implicit, through use of conservative assumptions in the TMDL analysis or in
developing a TMDL target, or both.
EPA reviewed the MOS discussion provided by ODEQ and accepted only the first and third of the
proposed three components of the ODEQ MOS. EPA rejected the component of the MOS regarding the
method of calculating the Food Web Model. However, EPA also added an additional MOS component, as
described in Section 9 of the EPA TMDL:
"3. Needed reductions in loads are based on comparing water column mercury targets to ambient
monitoring data. Those monitoring data are available through 2011 in only 9 of the 12 HUC8 watersheds
and thus do not incorporate any reductions in mercury loading that have occurred since 2011. Data
presented in ODEQ's 2019 TMDL (p. 37) indicate that mercury concentrations have been declining in
more recent years (2012 - 2019) in the Tualatin and Lower Willamette subbasins."
With these modifications, EPA found that the components of the implicit MOS account for any lack of
knowledge or uncertainties concerning the relationship between pollutant loading and receiving water
quality and that the MOS is thus approvable. There is no requirement that TMDLs include a quantitative
MOS. It is EPA's opinion that the MOS is not unduly conservative given the many sources of uncertainty
identified in the TMDL linkage analysis by the commenter and others.
Comment Text
The FWM links methylmercury exposure of fish to fish tissue concentrations based on an understanding
of the Willamette River food web and the bioaccumulation and biomagnification within it. This model is
Comment ID
Comment Category
Food Web Model
L14-4
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calibrated so the concentrations of mercury in fish tissue match the concentrations measured in fish
tissue samples collected from the Willamette River and its tributaries. However, once calibrated, its
main utility is to provide one of its parameters, the biomagnification factor, to the mercury translator
model (discussed below). This approach introduces significant and compounded uncertainty to the
target Thg concentration in the Willamette River.
Response Text
This comment was originally submitted in response to ODEQ's Public Review Draft of the TMDL (July
2019) and was partially answered in ODEQ's November 2019 Response to Comments.
The use of a Food Web Model to develop biomagnification parameters is a standard approach for
developing TMDLs and Superfund cleanup targets based on fish tissue concentrations. The
biomagnification factors are not "parameters" of the Food Web Model, but rather depict the output of
the process-based model by summarizing the relationship between environmental exposure
concentrations and the central tendency of contaminant levels in the tissue of each fish species. This
allows the fish tissue target to be converted to an environmental concentration target.
EPA considers the median biomagnification factors from the Food Web Model to be sufficiently accurate
based comparison to national values. The median biomagnification factors from the calibrated Food
Web Model are compared to national values from EPA in Figure 6-2 of the ODEQ's final TMDL issued in
November 2019 (Appendix A to the EPA TMDL) and discussed at greater length in the Technical Support
Document (Appendix B to the EPA TMDL). The median of the biomagnification factor Northern
Pikeminnow falls within the ranges of the national values given by EPA, confirming that the
biomagnification factor is reasonable and appropriate for estimation of the water column target.
Comment Text
The FWM calibration is marginal for the northern pikeminnow. This is the only fish whose
parameterization is used in the determination of the target concentration of THg in the river system.
Although no statistical evaluation of the quality of the calibration was provided in the contractor's
modeling report, inspection of Figure 3-4 in the Technical Support Document (i.e., TMDL Appendix A)
reveals that the cumulative distribution function of modeled fish tissue mercury concentrations in the
northern pikeminnow agrees with the distribution of observed data only around the 60th percentile
concentration. Most of the rest of the modeled distribution is outside the 95% confidence interval of the
distribution based on observed data. With this marginal and unquantified model calibration (and the
lack of sensitivity analyses described above), we cannot be confident in the target THg concentration.
Response Text
EPA calibrated the Food Web Model for eight species. Results for Northern Pikeminnow (NPM) are used
to develop the water column targets because the NPM is the most efficient mercury bioaccumulator of
the species considered.
EPA acknowledges that, like any model, the FWM is an approximation of observed conditions. The Food
Web Model was calibrated by attempting to match the cumulative distribution functions generated by
the Food Web Model to the cumulative distribution functions for observed data (Technical Support
Document [TSD] Figure 3-4) and the TSD notes that "...the fit for NPM is not perfect but is reasonable."
TSD Figure 3-4 shows that the match between model and data remains within 95% confidence limits
Comment ID
Comment Category
Food Web Model
L14-5
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from the 50th to 70th percentile and is thus acceptable for estimating the median of the distribution
(50th percentile), which is the basis for estimating the THg target, while discrepancies are associated
with the tails of the distribution. TSD Figure 3-6 shows that the relationship between fish length and
mercury tissue concentration is reasonably well reproduced by the model. Finally, the bioaccumulation
factor (BAF) simulated for NPM in the FWM is well within the 95% confidence limits of reported BAF
values for Trophic Level 4 fish species. EPA believes that the discrepancies between the model and
observed fish tissue data in the tails of the distribution - which are not used to set the water column
target - are attributable to use of a steady-state bioaccumulation model to approximate the results of a
dynamic relationship between exposure concentration and body burden, along with other simplifying
assumptions regarding mercury uptake and depuration. These issues are discussed at length in the TSD.
Please also note that the November 2019 ODEQ TMDL contains incorrectly pasted values of the species
biomagnification factor estimates in Table 6-2. The cumulative BMFs shown in ODEQ's Figure 6-2 are
correct.
Comment Text
We understand that the model input parameters pertaining to three main processes were used to
calibrate the FWM: the fish ingestion rate of mercury, the fish assimilation rate of mercury, and the fish
elimination rate of mercury. From this approach, the necessary biomagnification factor is determined
for the model to match observed fish tissue concentrations as closely as possible. We are concerned
that there may be other reasonable values for these model input parameters that produce a decent
match between the model output and observed fish tissue concentrations. If so, these would require
different biomagnification factors for model output to match data. We acknowledge that this
probabilistic model does not use single values for its model input parameters but instead expresses
them as distributions. However, the median value of the distribution of biomagnification factor, not a
range resulting from the distribution, is used in the calculation of the target THg concentration in the
river. Therefore, there may be other reasonable distributions for the biomagnification factor (and,
consequently, other median values) that can lead to an acceptable model calibration. This implies that
the model could produce the "right" answer for the wrong reason. Consequently, we lack confidence in
the target THg concentration that is calculated, in part, from the median biomagnification factor
determined by the EPA contractor.
Response Text
The Food Web Model processed 10,000 Monte Carlo iterations. During each iteration, values of each
model input parameter are sampled from a range or distribution of inputs, as explained in Section 3 and
summarized in Table 3-2 of the Technical Support Document (Appendix B to the EPA TMDL). Thus, the
analysis already accounts for uncertainty and variability in key parameters. The range of potential
resulting biomagnification factors is summarized in Table 3-3 of the Technical Support Document.
(Please note that the November 2019 ODEQTMDL contains incorrectly pasted values of the species
biomagnification factor estimates in Table 6-2).
EPA does agree that there can be multiple combinations of ingestion, assimilation, and elimination rates
that could lead to similar predictions offish tissue concentrations; however, these would of necessity
converge toward the same central tendency of the bioaccumulation factor to achieve calibration that
reproduces the relationship between observed fish tissue concentrations and exposure concentrations,
which constitutes the biomagnification factor (BMF). The values of these parameters are also
Comment ID
Comment Category
Food Web Model
L14-6
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constrained to be reasonable based on information in the literature. EPA and ODEQ selected the median
estimate of the BMF for each species as a robust estimator of central tendency and to avoid concerns
derived from relatively poorer fit to the upper and lower tails of cumulative distribution function in
many species. The resulting cumulative BMF (an estimate of the bioaccumulation factor or BAF) is within
the 95% confidence interval of EPA's information on BAFs for trophic level 4 fish (Figure 6-2 in the final
ODEQTMDL), confirming that the median-based BMF is appropriate to use in the calculation of the
exposure concentration target.
Comment Text
The Mercury Translator Model uses the biomagnification factor from the FWM and a mercury translator
value to calculate a target concentration of THg in the water column from the concentration of dissolved
methylmercury used as an input variable to the FWM. In this model, the slope of the regression line
calculated from the aggregation of individual pairs of measured THg and methylmercury concentrations
in the water column is heavily influenced by three pairs of observations. The remaining pairs of
observations in Figure 6-3 do not fall in a line. We question whether linear regression is an appropriate
statistical method for calculating the translator value. It may be more appropriate to present the
translator value for each HUC8 basin and then average the 12 values while expressing the uncertainty of
that mean. The use of linear regression on a data set that is neither linear nor normally distributed leads
us to question the validity of the target THg concentration.
Response Text
The comment was resubmitted for the EPA TMDL, although clarification had already been provided in
ODEQ's Response to Comments and wording changes had been included in the final ODEQ November
2019 TMDL, which is Appendix A to the EPA TMDL.
"Regarding the statement, 'The use of linear regression on a data set that is neither linear nor normally
distributed leads us to question the validity of the target THg concentration', please refer to Section 4.2
in the Technical Support Document for a more thorough discussion of the mercury translator approach.
Median dissolved methylmercury and median total mercury do exhibit an approximately linear
relationship and there is no strong evidence of heteroscedasticity. Perfect linear correlation is neither
expected nor required for linear regression. Regarding normality, it is common for environmental data
to deviate from an assumption that regression residuals are normally distributed. However, a linear
regression remains the best linear, unbiased estimator (BLUE) of the coefficients regardless of whether
the residuals are normally distributed; the normal distribution assumption is relevant primarily to the
interpretation of statistical tests on the regression parameters. The actual requirements for linear
regression to be BLUE under the Gauss-Markov theorem are less restrictive: The residuals should be
uncorrelated, have approximately equal variances and have an expectation of zero. Further, the linear
model assumptions are generally robust to small deviations from these assumptions. See for example
Peter Kennedy's A Guide to Econometrics (1979) for discussion of these issues. Because we are working
with medians of data from different geographic areas, we do not expect correlation among the
residuals. If the expected value of the residuals was non-zero, the primary result would be a bias in the
intercept term of the linear regression; however, we are imposing a zero- intercept model here. Visual
examination does not suggest any strong difference in residual variances between sites, although a
rigorous parametric test is not possible due to the presence of many non-detects. Note that simply
averaging the ratios across HUCs would give approximately the same answer for most points
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Comment ID
Comment Category
L14-7
Mercury Translator
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(dMeHg:THg approximately equal to 0.016), but without a correction for sample size or meeting BLUE
criteria, because the relationship is essentially linear." DEQ concluded that the translator analysis is
appropriate for use in the TMDL and no changes have been made to the document or analysis. EPA
agrees with ODEQ's conclusion. No further response is needed.
Comment Text
Description: Modeling - MBM - Acknowledge uncertainty in models, perform additional model
simulations
Comment: Summary of suggested change: acknowledge model uncertainties in the calculation of
existing loads in the TMDL, perform additional model simulations with reasonable upper and lower
bounds of, for example, atmospheric deposition or soil mercury concentrations. The Mass Balance
Model (MBM) exists separately from the FWM and the Translator Model. Whereas the FWM and
Translator Model are used together to determine the target THg concentration in the water column, the
MBM determines the present-day contributions of THg to the Willamette River system from a variety of
sources. These values are compared to the THg loading capacity (discussed below) when developing the
load allocations of the TMDL. The representation of nonpoint sources in the MBM raises the following
concerns: -Results of three other models serve as important inputs or points of comparison for the
contributions of nonpoint sources to the Willamette River system. These models are: -the hydrology
model of the Willamette Basin created by the EPA contractor several years ago using the software
package HSPF, -the model of dry atmospheric deposition of mercury used by Domagalski et al. (2016),
and -the USGS LOADEST model from which the EPA contractor calculated THg concentrations in the
Willamette River that were then used as a calibration target for the MBM. For this reason, the TMDL will
be based on six models, not the three commonly described by your team, the EPA, and its contractor.
Using the output of two models as inputs of the MBM compounds uncertainty. Calibrating to the results
of a separate model implies that the MBM is calibrated to match a number with its own, presently
unquantified, uncertainty. While this may be unavoidable, we do not find an acknowledgement of these
uncertainties in the calculation of existing loads in the TMDL. It would be appropriate to perform
additional model simulations with reasonable upper and lower bounds of, for example, atmospheric
deposition or soil mercury concentrations. No such calculations are described in the TMDL document (or
the Technical Support Document), which reports single numbers (i.e., values with no associated
uncertainties) in Table 6-7. The lack of an acknowledgement of the uncertainty in the MBM decreases
our confidence in the existing loads and the subsequent calculations that use them.
Response Text
Requirements for the revised TMDL were set forth in the court findings of Magistrate Judge Acosta and
include "...an analysis of factors affecting mercury pollution, including potential multiple sources,
bioaccumulation patterns, and changes in the types of mercury being released and transformed in the
entire complex river system." In addition, modeling to support the TMDL update "must be revised and
incorporate all the new data related to mercury that has been gathered since the first TMDL..." These
requirements were met because the modeling and technical assessments for the TMDL revision
incorporated new mercury monitoring data (e.g., water column, sediment, fish tissue, point source
effluent, etc.), as well as relevant information from recent research and modeling efforts.
The use of simulation modeling to describe the relationship between pollutant sources and
environmental impacts that cause waterbody impairment is standard practice in the development of
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Comment ID
Comment Category
L14-8
Mass Balance Model/HSPF
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TMDLs and is essential to fill in gaps in available observations and to predict the likely impacts of
changes in pollutant sources.
All the separate models could be combined into a single modeling code, but this would not change the
level of uncertainty in the model outputs. EPA acknowledges that there is uncertainty related to the
modeling and analysis that was completed for the Willamette Mercury TMDL. However, EPA and ODEQ
find that the modeling and analysis is suitable for TMDL development and is sufficient for implementing
the TMDL and meeting water quality criteria. The modeling and analysis is consistent with EPA's
understanding of the processes that control the loading, transport, transformation, and bioaccumulation
of mercury and methylmercury in the basin. Potential uncertainties and how they were addressed are
discussed in the following sections of the ODEQ TMDL report: 6. Explanation of Models; 7.2 Excess Load;
and 11. Margin of Safety. The Technical Support Document (Appendix B to the EPA TMDL) provides
further information on model uncertainty along with a detailed discussion of the data sources used in
the TMDL analysis. The data used for development of the Food Web Model and mercury translator are
discussed in Section 2 of the Technical Support Document. The data sources and methods used to
estimate the sources for the Mass Balance Model are discussed in section 5.3 of the Technical Support
Document.
The Mass Balance Model results summarized in Table 6-7 of the ODEQ TMDL represent EPA's best
estimates of conditional existing data. EPA acknowledges that there is uncertainty associated with these
estimates. Their primary use is to develop load allocations for nonpoint sources of mercury in the
Willamette River Basin. This is consistent with regulatory requirements at 40 CFR 130.2(g): "Load
allocations are best estimates of the loading, which may range from reasonably accurate estimates to
gross allotments, depending on the availability of data and appropriate techniques for predicting the
loading." Uncertainty in the analysis is addressed through the Margin of Safety and Reasonable
Assurances (Sections 9 and 10 in the EPA TMDL and Sections 11 and 14 in the November 2019 ODEQ
TMDL).
ODEQ has indicated that it intends to use additional monitoring and modeling during implementation of
the TMDL to improve upon the representation of mercury/methylmercury system in the Willamette
River Basin. ODEQ is working with watershed partners to develop an Assessment and Monitoring
Strategy that will help to reduce uncertainty in the representation of mercury in the Willamette River
Basin, as well as support more robust decision-making regarding implementation of the Mercury TMDL.
As discussed in Sections 13, 13.6 and 14 of the ODEQTMDL/WQMP, data collection will continue and
expand to allow for further analysis to better represent mercury sources and transport and
transformation mechanisms - such as methylation in reservoirs, bioaccumulation, and groundwater
mercury concentrations. It is expected that the implementation of the TMDL will be further refined over
time as part of an adaptive management process.
Comment Text
The HSPF model raises some additional concerns: -Our experience suggests the model's representation
of agricultural land may be poor. We are unsure of the impact of any inaccuracies on the final modeling
results. We have not seen an explanation of the justification of infiltration rates in this model. This is
critical for the distinction used by your team between mercury attributable to atmospheric sources and
to groundwater. -The soil mercury concentrations interpolated from a 2013 USGS study appear to be
Comment ID
Comment Category
L14-9
Mass Balance Model/HSPF
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highly uncertain due to a low spatial resolution of the observed data and a lack of detail in the
interpolation (TetraTech, 2018a).
Response Text
ODEQ and EPA used an existing Hydrological Simulation Program - FORTRAN (HSPF) model of the
Willamette Basin. The HSPF model provides a very good tool for source characterization and more
robustly simulates the generation and transport of total mercury within the Willamette Basin. EPA
acknowledges that there is uncertainty related to the modeling and analysis that was completed for the
Willamette Mercury TMDL. However, EPA and ODEQfind the modeling and analysis is suitable for TMDL
development and is sufficient for implementing the TMDL and meeting water quality criteria.
As described in the Technical Support Document (Appendix B to the EPA TMDL), the existing HSPF model
was updated to incorporate the most recent available land use but was not recalibrated. The existing
model used State Soil Geographic database (STATSGO) soil survey information on hydrologic soil group
(HSG) to assign initial values of the HSPF index to soil infiltration rate (INFILT) for each of the four HSG
classes (A, B, C, and D). Initial values for INFILT were set at the middle of the ranges for each HSG as
recommended in EPA's BASINS Technical Note 6, "Estimating Hydrology and Hydraulic Parameters for
HSPF." These ranges are HSG A: 0.4-1.0 in/hr, HSG B: 0.1-0.4 in/hr, HSG C: 0.05-0.1 in/hr, and HSG D:
0.01-0.05 in/hr. Note that in HSPF INFILT is an index to the mean soil infiltration rate that controls
division of water between surface runoff and infiltration. INFILT is not equivalent to a maximum rate or
measured rate or measured soil infiltration capacity, and its values for a given soil are generally
substantially less than published infiltration rates or measured soil percolation rates. During calibration
of the existing model to gaged flows, the modelers reported that "Infiltration was generally decreased
from the initial values to increase storm peaks and reduce low flows..."; however, the values remained
within the recommended ranges for each HSG class.
HSPF predictions for the partitioning of precipitation into evapotranspiration, surface runoff, and
groundwater, along with HSPF predictions of soil erosion and transport, are used to estimate the total
mercury loads associated with surface runoff, erosion, and groundwater baseflow loading. ODEQ and
EPA concluded that the existing results for hydrology and associated flow pathways are reasonable and
provide a sufficient basis for the development of TMDL allocations. As with all environmental simulation
models, there are uncertainties in the predicted results that could potentially be reduced by additional
efforts at model calibration and adjustment of the model to a finer spatial scale. ODEQ has indicated
that it plans to identify key sources of uncertainty in the Mass Balance Modeling as part of the
monitoring program being developed for the WQMP and may refine the HSPF model in future if needed.
EPA also acknowledges that the soil mercury concentrations derived from the 2013 USGS study are
uncertain due to a low spatial resolution of the observed data (there were only three samples from
agricultural land, so simple averaging was used: there were not a sufficient number of samples for
spatial interpolation). This is the best information currently available. The resulting soil concentrations
for agriculture and forest are consistent with the general trends among land uses summarized in D.
Obrist et al., 2016, Science of the Total Environment 568:522-535. Further refinement of surface soil
mercury concentrations in agricultural land areas would require additional sampling. If such data are
obtained, the results and could potentially be stratified based on tillage, harvest, and residue
management practices, as well as adjusted to reflect spatial patterns across the basin, and could be used
to further refine estimates of total mercury loads.
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Comment ID
Comment Category
L14-10
Loading Capacity
Comment Text
The calculation of the daily loading capacity of THg in the Willamette River system is presented in
Section 7.2. The load determined is 42.17 g/day. This value is critical for developing the load and
wasteload allocations in Section 10. However, this calculation is unclear. Below Table 7-1, the text states
that the quantity Lcurrent is "estimated to be 361 g/day", a value consistent with Table 6-7. However, in
the ensuing equations that calculate the quantities Lexcess and Load Capacity, the value 351.42 g/day is
used for Lcurrent. Using the value of 361 g/day leads to a slightly higher load capacity. If this is an error,
please correct it. If 351.42 g/day is the correct value for Lcurrent, please alter this passage to resolve the
confusion we express here.
Response Text
This comment was submitted to Oregon DEQ during the public comment period for the State issued
TMDL. The following is Oregon DEQ's response to the comment:
The value "351.42 g/day" for the current load was an error. DEQ recalculated the TMDL equation and
components using a current load of 361 g/day and made associated changes in the TMDL report.
EPA agrees with ODEQ's response, and that the current load of 361 g/day was incorporated in the
State's TMDL, as well as the final EPA TMDL, for the development of wasteload and load allocations.
Comment Text
ODEQ evaluated the use of the concentration of TSS as a surrogate for the concentration of THg in
water. If the relationship between the concentrations of TSS and THg is statistically robust, then TSS
could be measured in place of THg, thus reducing the costs of assessment and monitoring related to this
TMDL. As presently drafted, the analysis presented in Section 10.3 and Appendix H raises several
concerns about whether the concentration of TSS can defensibly be adopted as a surrogate for the
concentration THg in this system.
In a memo from the EPA contractor that was provided to the Willamette Basin TMDL Advisory
Committee in an e-mail from Priscilla Woolverton on 14 June 2019, TSS is ranked as the least preferable
of four surrogates analyzed, behind suspended sediment concentration and two separate turbidity
measurements (Tetra Tech 2018b). This analysis was not mentioned in the TMDL document or Appendix
H. Please explain why TSS has been chosen by ODEQ as a surrogate rather than other options that have
been judged as preferable.
The use of TSS as a surrogate is justified with a citation in Section 1.1 of Appendix H to a paper about
urban stormwater runoff. Please justify this use of TSS as a surrogate by providing and explaining in
detail the findings of any papers that show a relationship between TSS and THg in a river system that
resembles to the Willamette River and its tributaries.
The statistical relationship described in Appendix H (known as a Linear Mixed Effects, or "LME"
statistical model), shows that measurements of TSS and the specification of the location of that
measurement can explain 81% of the variation in the THg data set. Thus, estimating THg concentrations
with a surrogate introduces uncertainty into measurements of THg. This is especially true because of the
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Comment ID
Comment Category
TSS as surrogate
L14-11
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low concentrations of THg, which imply that even small absolute uncertainty can have a large relative
importance. Please describe how this uncertainty will be addressed if TSS is to be used as a surrogate
during allocation, compliance, or field monitoring.
Response Text
This comment was originally submitted in response to ODEQ's Public Review Draft of the TMDL (July
2019) and refers to ODEQ's Appendix H in the Public Review Draft, which is now Appendix G in ODEQ's
November 2019 TMDL.
EPA's 2019 TMDL document does not discuss use of (Total Suspended Solids) TSS as a surrogate. Indeed,
the EPA TMDL document mentions TSS only once, in the context of Reasonable Assurances, where it is
noted that "ODEQ's review focuses on water quality trends in TSS loading which ODEQ intends to
associate with mercury loading." The TSS surrogate is thus properly seen as part of the TMDL
implementation strategy, which is determined by ODEQ.
Tetra Tech did produce a draft memorandum to EPA dated July 27, 2018 that recommended use of
turbidity as a surrogate measure. EPA shared this memorandum with ODEQ for informational purposes
only, as the implementation strategy is determined by ODEQ. ODEQ decided that TSS was a more
appropriate surrogate for detecting large erosion events that are likely to be associated with elevated
loading of mercury stored in sediment.
Comment ID L14-12
Comment Category TSS as surrogate
Comment Text
Please demonstrate that the data used for the LME model are: -Sufficient: Why does ODEQ believe that
63 paired observations are enough for this analysis? How many samples are generally used to develop
strong LME models? -Adequate: Please show the results of statistical tests that evaluate the normality of
the TSS and THg data sets following the logarithmic transformation that was performed.
Response Text
This comment was originally submitted in response to ODEQ's Public Review Draft of the TMDL (July
2019) and refers to ODEQ's Appendix H in the Public Review Draft, which is now Appendix G in ODEQ's
November 2019 TMDL.
EPA's 2019 TMDL document does not discuss use of TSS as a surrogate. Indeed, the EPA TMDL
document mentions TSS only once, in the context of Reasonable Assurances, where it is noted that
"ODEQ's review focuses on water quality trends in TSS loading which ODEQ intends to associate with
mercury loading." ODEQ's TMDL, which is attached to the EPA TMDL as Appendix A, does incorporate a
discussion of instream surrogate targets, in Section 10.3, and proposes TSS as a surrogate "...to
supplement but not supplant the allocations and TMDL water column target for evaluating TMDL
implementation strategy, which is determined by ODEQ.
There is not a specific minimum criterion for sample size in linear mixed effects regression (LMER)
models. Instead, the performance of the models is evaluated through their ability to explain the
observed variance in THg concentrations, which appears reasonable (RA2=0.81 for the final LMER
model). It is the case that LMER, like ordinary least squares, assumes normally distributed residuals,
although small deviations from normality do not cause problems. As shown in the revised Appendix G to
the ODEQ TMDL, ODEQ used Box-Cox transformation to demonstrate that a loglO transformation of
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both THg and TSS was appropriate and provided Normal Q-Q plots to demonstrate that approximate
normality was achieved.
Comment ID L14-13
Comment Category TSS as surrogate
Comment Text
The LME model is complicated. Please justify the use of the LME model by explaining: -why a simpler
model (such as a multivariate model using TSS and sampling location) cannot be used here, -why it is
valid to assume that observations from the same sampling site are not independent (this is implied by
the choice of "sites" as a random effect in the LME model), and -how the "sites" variable was
represented in the LME model. Is it categorical or continuous?
Response Text
This comment was originally submitted in response to ODEQ's Public Review Draft of the TMDL (July
2019) and refers to ODEQ's Appendix H in the Public Review Draft, which is now Appendix G in ODEQ's
November 2019 TMDL.
EPA's 2019 TMDL document does not discuss use of TSS as a surrogate. Indeed, the EPA TMDL
document mentions TSS only once, in the context of Reasonable Assurances, where it is noted that
"ODEQ's review focuses on water quality trends in TSS loading which ODEQ intends to associate with
mercury loading." ODEQ's TMDL, which is attached to the EPA TMDL as Appendix A, does incorporate a
discussion of instream surrogate targets, in Section 10.3, and proposes TSS as a surrogate "...to
supplement but not supplant the allocations and TMDL water column target for evaluating TMDL
implementation effectiveness." The TSS surrogate is thus properly seen as a part of the TMDL
implementation strategy which is determined by ODEQ.
Comment ID L14-14
Comment Category TSS as surrogate
Comment Text
The results of this analysis are unclear. Please clarify by: -Stating the intercepts for the fixed and random
effects separately in Equation 3 of Appendix H. This will make the random effects due to the variable
"sites" clearer. -Showing both the adjusted R2 and conditional R2 in Table 9 and discussing each
separately. -Providing examples in which "sites", which you have identified as a random predictor
variable, are used along with TSS to predict concentrations of THg.
Response Text
This comment was originally submitted in response to ODEQ's Public Review Draft of the TMDL (July
2019) and refers to ODEQ's Appendix H in the Public Review Draft, which is now Appendix G in ODEQ's
November 2019 TMDL.
ODEQ revised Appendix H in response to this and other comments. DEQ included the full model
summaries for the LME models, including conditional and adjusted R2 values. The random effects are
adjustments to the model intercept (one for each of the site groups) and are traditionally not directly
shown in the equations for LME models. Instead, these values are now shown in Table G-10.
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Comment ID
Comment Category
TSS as surrogate
L14-15
Comment Text
Please resolve concerns about the quality of this analysis, specifically those related to: -Example 1 in
Section 1.5 uses the LME model to indicate that a THg concentration of 0.14 ng/L is predicted by a TSS
concentration of 4.272 x 10-14 mg/L. The former is a low but plausible concentration for THg in a river,
but the latter is many orders of magnitude lower than the lowest TSS concentration one could ever hope
to measure in a large river like the Willamette River. -Example 2 in Section 1.5 uses the LME model to
relate a TSS concentration of 100 mg/L, which is high yet reasonable for a large river, to a concentration
of THg of 8.38 mg/L, which is implausibly high relative to all observations presented in Table 1 of
Appendix H.
Response Text
This comment was originally submitted in response to ODEQ's Public Review Draft of the TMDL (July
2019) and refers to ODEQ's Appendix H in the Public Review Draft, which is now Appendix G in the
ODEQ November 2019 TMDL. The error noted in the comment had already been fixed in the final ODEQ
TMDL of November 22, 2019, which is attached as Appendix A to the EPA TMDL.
Appendix H in the ODEQ July 2019 Public Review Draft contained units errors in the example
calculations. The error in the units of TSS given in Example 1 in the ODEQ Public Review Draft was
corrected in response to this and other related comments. The units error in total mercury was also
present in Example 2: at a TSS concentration of 100 mg/L, the predicted total mercury concentration
should be 8.38 ng/L, not mg/L. Likewise, at a TSS concentration of 80 mg/L the predicted total mercury
concentration should be 7.48 ng/L, not mg/L. This units error does not affect the percent reduction
calculation, but it was corrected in the revised ODEQ TMDL.
Comment ID L14-16
Comment Category TSS as surrogate
Comment Text
Finally, if the above concerns can be resolved, we request that ODEQ clarify how a complicated LME
model can guide mercury management by ODEQ or Designated Management Agencies. Does including
"sites" as a random effect imply that each surrogate relationship will need to be site-specific? How can a
surrogate relationship be used in practice to monitor THg concentrations (via measuring TSS
concentration) when the relationship includes random effects?
Response Text
This comment was originally submitted in response to ODEQ's Public Review Draft of the TMDL (July
2019). In response to this comment, clarification had already been provided in ODEQ's Response to
Comments on the Public Review Draft and wording changes had been included in the final ODEQTMDL
of November 22, 2019, which was attached as Appendix A to the EPA TMDL.
In response to the original submission of this comment, ODEQ revised Section 10.3 and Appendix G
(formerly Appendix H) of their TMDL with clarifications on the intention that TSS surrogate targets will
be used as one tool for evaluating TMDL implementation effectiveness. Based on the relationship found
between TSS and total mercury, surrogate instream targets were set for reductions in high TSS
concentrations to reduce total mercury in waterbodies and evaluate progress towards achieving the
allocations and total mercury TMDL water column target. These reductions of TSS are expected to
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reduce total mercury loads that occur during high precipitation events and high flows. In addition, the
use of TSS surrogate targets and other tools is described in the Assessment and Monitoring Strategy
overview, which is provided in Sections 13.6 and 14.1.6 of the ODEQTMDL.
A "random effect" is a statistical term for describing a site-specific effect on the value of a variable. The
term "fixed" effect refers to how the value of a variable changes according to changes in the value of
another variable. In the case of the TSS surrogate analysis, the "random effect" is the sampling site for
total mercury and TSS, which controls the starting values for the two constituents. The "fixed effect" is
TSS, which means the change in total mercury in response to a change in TSS is expected to be the same
regardless of the site sampled. In other words, the site sets the starting value for total mercury, but the
response of total mercury to change in TSS is the same regardless of the site sampled.
Comment Text
The present surrogate analysis leads us to three main concerns: 1. This surrogate analysis creates
opacity for our members because it does not incorporate available background information, adds
uncertainty, and adds complexity without justification. It could easily lead to in-stream TSS requirements
that seem arbitrary to our members. 2. The apparent flaws in the statistical model cause concern that its
use by ODEQ or our Designated Management Agencies will require our members to do much more than
necessary to control erosion and sediment runoff. One of the examples in Appendix H implies that the
water must have unmeasurably low concentrations of suspended sediment to meet the target
concentration of THg. 3. This surrogate analysis will be confusing to our members because we do not
understand how a statistical model with random effects will be used in practice.
Response Text
This comment is a copy of a comment that was submitted on the July 2019 Public Review Draft of the
ODEQTMDL and does not correctly reflect the contents of either the November 2019 final ODEQTMDL
or the December 2019 EPA TMDL.
The Clean Water Act and 40 CFR130.7(c)(1) require that TMDLs include a margin of safety (MOS)
"...which takes into account any lack of knowledge concerning the relationship between effluent
limitations and water quality." The MOS can be either explicit, through allocation of a portion of the
loading capacity, or implicit, through use of conservative assumptions in the TMDL analysis or in
developing a TMDL target, or both.
EPA reviewed the MOS discussion provided in ODEQ's November 2019 TMDL and accepted only the first
and third of the proposed three components of the ODEQ MOS. EPA rejected the component of the
MOS regarding the method of calculating the Food Web Model. However, EPA also added an additional
MOS component, as described in Section 9 of the EPA TMDL:
"Needed reductions in loads are based on comparing water column mercury targets to ambient
monitoring data. Those monitoring data are available through 2011 in only 9 of the 12 HUC8 watersheds
and thus do not incorporate any reductions in mercury loading that have occurred since 2011. Data
presented in ODEQ's 2019 November TMDL (Figure 7-3, p. 37) indicate that mercury concentrations
have been declining in more recent years (2012 - 2019) in the Tualatin and Lower Willamette
subbasins."
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Comment ID
Comment Category
TSS as surrogate
L14-17
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With these modifications, EPA found that the components of the implicit MOS account for any lack of
knowledge or uncertainties concerning the relationship between pollutant loading and receiving water
quality and that the MOS is thus approvable. The MOS is not unduly conservative given the many
sources of uncertainty identified in the TMDL linkage analysis by this commenter and others.
Comment Text
Further, Section 10.3 of the TMDL document justifies the use of a surrogate by citing Oregon
Administrative Rule (OAR) 340-042-0040(5)(b), which permits the use of a surrogate "to estimate
allocations for pollutants addressed in the TMDL". However, Section 10.3 of the TMDL document
presents a statistical relationship between TSS and THg and uses it to determine allocations of TSS that
would correspond to the allocations of THg already developed. The TMDL document then states that
these TSS allocations will be "used for evaluating effectiveness of the TMDL" because monitoring of
"total mercury can be difficult and cost-prohibitive". This indicates that ODEQ seeks to use TSS as a
surrogate to facilitate monitoring following the allocations of mercury in Section 10.1, not to create the
allocations themselves. This contradicts the allowed use of a surrogate in OAR 340-042-0040(5)(b).
Section 10.3 of the TMDL document and Section 1.1 of Appendix H state in general terms that
monitoring for THg can be difficult and cost-prohibitive. However, monitoring of THg must have
occurred to include Willamette River reaches and tributary reaches on the 303(d) list in the first place. If
a surrogate will be used, what will be the appropriate mix of surrogate measurements and THg
measurements? Will any THg measurements be made if a surrogate is used? What would be the cost
savings gained from using TSS as a surrogate for THg, and why is this enough to justify the development
of this statistical relationship and the uncertainties that will come with the use of a surrogate?
Response Text
This comment was originally submitted in response to ODEQ's Public Review Draft of the TMDL (July
2019) and refers to ODEQ's Section 10.3 and Appendix G (formerly Appendix H). The issues noted in the
comment had already been addressed in the final ODEQ TMDL of November 22, 2019, which was
attached as Appendix A to the EPA TMDL.
As noted in ODEQ's previous response, "Surrogate Measures" are defined in OAR 340-42-0030(14) as
"...substitute methods or parameters used in a TMDL to represent pollutants." In addition, OAR 340-
042-0040(5)(b) states that "DEQ may use surrogate measures to estimate allocations for pollutants
addressed in the TMDL." This statement does not preclude use of surrogate measures in other TMDL
components. In using surrogate measures, DEQfollowed OAR 340-042-0040(5)(b) in that the TMDL
establishes the relationship between the surrogate measure (TSS) and pollutant (mercury; mercury is
difficult to measure and TSS is closely related to mercury and is easier to monitor and track.)
In response to this comment, ODEQ revised Section 10.3 and Appendix H with clarifications on the TSS
surrogate targets. Based on the relationship found between TSS and total mercury, surrogate instream
targets were set for reductions in high levels of TSS concentrations to reduce total mercury in stream
and evaluate progress towards achieving the allocations and total mercury TMDL water column target
described in Section 10. These reductions of TSS are expected to reduce total mercury loads that occur
during high precipitation events and high flows.
DEQ also noted that the TSS surrogate targets will apply to the mainstem Willamette and HUC8 outlets.
The TSS surrogate targets will be used for reducing total mercury in waterbodies and as one tool for
Comment ID
Comment Category
TSS as surrogate
L14-18
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evaluating progress towards achieving allocations and the total mercury TMDL water column target
described in Section 10. In addition, because TSS is a cost-effective surrogate it will be used to
supplement, but not supplant, the allocations and total mercury water column target for evaluating
TMDL implementation effectiveness. The Assessment and Monitoring Strategy that DEQ is developing
will include information on monitoring for THg in addition to other parameters, which will be discussed
with DMAs during implementation planning. The TSS surrogate is thus properly seen as a part of the
TMDL implementation strategy which is determined by ODEQ.
Comment Text
Finally, the structure of Appendix H, Table 12 makes this surrogate analysis start to look like a TSS
reduction program rather than a THg reduction program. It would be more appropriate to write about
the THg reductions ODEQ seeks and correlate that to TSS rather than discuss the TSS reductions ODEQ
needs to see.
Response Text
The comment was resubmitted for the EPA TMDL, although clarification had already been provided in
ODEQ's Response to Comments and wording changes had been included in the final ODEQ November
2019 TMDL, which is Appendix A to the EPA TMDL. In their response, ODEQ agreed with the comment
and added content to the ODEQ TMDL clarifying how the TSS surrogate will be used. See Appendix G of
ODEQ's November 2019 TMDL. ODEQ's November 2019 TMDL is Appendix A of EPA's December 2019
TMDL. EPA has no further response to this comment.
Comment ID L14-20
Comment Category General Comments
Comment Text
Our organizations and the foresters, farmers, and growers of Oregon have done much in recent decades
to protect surface water quality. From new stream buffers to wet weather haul rules to strategic
implementation areas, we have worked with DEQ and our DMAs to protect the waters of our state. We
commit to continuing this close engagement on water quality issues into the future.
However, we have significant concerns about ODEQ's development of this TMDL and the compounded
uncertainties discussed above. Given that this pollution is largely outside of Oregon's control, the
concern with the TMDL outlined above will make it hard to create buy in on this TMDL from our
members. Why should Oregon's farmers and foresters be required to mitigate pollution they did not
introduce? Likewise, the TMDL proposes to regulate Total Suspended Solids as a means of driving
reductions in fish tissue methylmercury concentrations. The relationship between these two parameters
is extremely remote, and requires the agency model several water quality parameter relationships with
compounding uncertainty. This creates the very real risk that Oregon will require very expensive
measures with no change relative to the actual water quality standard. This problem is due in part to the
highly conservative water quality standard upon which this TMDL is based. When compounded by
additional, unquantified, and conservative assumptions in the TMDL modeling, the margin of safety
implicit in the load reductions specified by this TMDL are exceedingly cautious and divorced from reality.
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Comment ID
Comment Category
L14-19
TSS as surrogate
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Oregon farmers and foresters should not be asked to bear the risk of this uncertainty. We encourage
ODEQto address our concerns, and to work closely with the Designated Management Agencies (DMAs)
on implementation to assess what is truly possible and necessary within localized areas.
Response Text
The comment was resubmitted for the EPA TMDL, although clarification had already been provided in
ODEQ's Response to Comments and wording changes had been included in the final ODEQ November
2019 TMDL, which is Appendix A to the EPA TMDL.
As noted in ODEQ's previous response, "DEQ acknowledges that there are stakeholders from multiple
sectors, representing varied land uses and sources of mercury, that have already been implementing
strategies and actions that are protective of water quality. DEQ anticipates that continued, as well as
increased efforts to protect water quality will help the basin reach water quality goals for mercury and
other TMDL pollutants."
"Based on the relationship found between total suspended solids and total mercury, surrogate instream
targets were set for reductions in high levels of TSS concentrations to reduce total mercury in stream
and evaluate progress towards achieving the allocations and total mercury TMDL water column target
described in the TMDL. These reductions of TSS are expected to reduce total mercury loads that could
occur during high precipitation events and high flows."
EPA agrees that significant improvements have occurred in the management practices used by farmers
and foresters over the last several decades. To the extent that loadings have been reduced by recent
actions relative to the baseline period used to estimate current THg concentrations in any HUC8, it
would be reasonable to account for improvements since that time period as progress towards meeting
the percent reductions set forth in the TMDL. Also see responses to comment L14-01 through L14-19
and L14-21.
Comment Text
The role of atmospheric deposition is unclear. The TMDL allocations depend on the categorization of
different sources (Table 10-1). In this categorization, atmospheric deposition is double counted as part
of both the "General Non-point Source and Background" and as its own separate category. Additionally,
the TMDL lacks clarity on atmospheric deposition of mercury and the impact that foreign sources of
mercury are having on our waterways. Section 14.2 of the TMDL document states clearly that
atmospheric deposition of mercury is the dominant source of mercury reaching Willamette Basin
streams and that air emissions from Oregon are small relative to global sources. Atmospheric deposition
is entered twice in table 10-1 - under "General Nonpoint Source and Background" and under
Atmospheric Deposition. What is the difference? Is it double counted?
Response Text
This comment was originally submitted in regard to ODEQ's July 2019 Public Review Draft of the TMDL
and was addressed in ODEQ's Response to Comments document. This response clarified ODEQ's choice
of terminology and resulted in changes that were incorporated into ODEQ's November 2019 final TMDL
draft. EPA believes that atmospheric deposition is not double-counted and agrees with ODEQ's response
to this comment, which is reproduced below:
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Comment ID
Comment Category
L14-21
Atmospheric deposition
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"DEQ acknowledges that accounting for atmospheric deposition in the TMDL is complex and the
simplification of all sources into Table 10-1 can be confusing. The second paragraph of Section 10
acknowledges that the analysis of the available information did not allow for quantification and
distinctions between the various components of atmospheric deposition. The closing sentence of the
paragraph clarifies that the broad category of "atmospheric deposition/' as it appears in Table 10-1,
captures the source categories modeled and described in the TMDL Technical Support Document as
"sediment erosion," "surface runoff" and "atmospheric deposition direct to streams." For clarity,
particularly with regard to implementation, DEQ used different terminology in the TMDL and WQMP
than was used in the TMDL Technical Support Document. DEQ acknowledges that the categories in
Table 10-1 are confusing, even with the footnotes which were intended to add clarity. DEQ revised the
presentation of category labels in Table 10-1 and added an additional footnote to explain that modeled
estimates from the TMDL Technical Support Document for the categories of General Nonpoint Source,
Non-Permitted Urban Stormwater and Atmospheric Deposition are combined, although allocations for
the three source categories are assigned separately. While atmospheric deposition affects all source
categories, it is not double-counted in the allocations, as summarized in the revised Table 10-1 of the
November 2019 ODEQTMDL."
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Author Name Thomas E. Whittington
Organization Name
Letter ID
Comment ID
Comment Category
Oregon Department of Forestry
LIS
L15-1
Forestry
Comment Text
To whom it may concern, The Oregon Department of Forestry would like to refer the EPA to our
previously submitted comments concerning the Revised Willamette Basin Mercury TMDL to the Oregon
DEQ. The submitted comments can be found at response #54, page 112 by Kyle Abraham, Oregon
Department of Forestry in the PDF link:
https://www.oregon.gov/deq/wq/Documents/willHgRevPubComments.pdf.
2.2. "Of the many different types of land use that exist within the Willamette Basin, forestry, agriculture,
and urban uses dominate across the basin." (pg. 11) ODF Comment: Please revise this by stating that
land-uses that contribute to non-point sources dominate (X%) the total land area of the Willamette
Basin. Also, please define non-point sources here.
Response Text
This comment was previously submitted during the response to comment period for ODEQ's September
2019 TMDL. ODEQ revised their TMDL based on this comment as discussed in the response to public
comments report under A_K#2: Suggested Change ID #270 (page 232). EPA concurs with ODEQ's
response which is reflected in ODEQ's November 2019 TMDL. EPA adopted ODEQ's November 2019
TMDL as Appendix A in EPA's December 2019 TMDL.
In the Executive Summary of ODEQ's November 2019 TMDL, DEQ changed the sentence: "Of the many
different types of land use that exist within the Willamette Basin, forestry, agriculture and urban uses
dominate across the basin..." to: "Of the many different types of land use that exist within the
Willamette Basin, forestry, agriculture and urban uses comprise most of the area within the basin.
Management actions on these land uses influence the amount of mercury from these sources that reach
streams and rivers in the basin." Point and non-point sources are defined in the Executive Summary of
Oregon DEQ's TMDL as well. EPA concurs with ODEQs response, and no further response is needed.
Comment Text
2.3. "...for the eventual attainment of the mercury criterion and, ultimately, full restoration of the
beneficial use of fish consumption and protection of aquatic life and wildlife throughout the Willamette
Basin." (pgs. 11-12)
ODF Comment: It is ODFs opinion that full restoration of the beneficial use will never be achieved if the
issue of the atmospheric deposition of mercury on our state from outside national and international
sources is not addressed. At least, an attempt should be made to identify contamination sources within
and outside of DEQs sphere of influence to help set reasonable goals for reductions by Designated
Management Agencies (DMAs) here in Oregon.
Comment ID
Comment Category
Nonpoint Source
L15-2
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Response Text
EPA acknowledges that it will be challenging to achieve fish tissue concentration targets while mercury
continues to be supplied by atmospheric deposition. EPA does believe that reductions in atmospheric
deposition will occur over time, as discussed in Section 7.1.1 of the EPA TMDL; however, these
reductions may be slow, due in part to the re-emission of previously deposited mercury back to the
atmosphere. Unfortunately, much of the atmospheric mercury pool that results in mercury deposition in
Oregon arises from global sources that are outside the regulatory purview of either EPA or ODEQ.
Nonetheless, Federal regulations implementing the Clean Water Act, as well as Magistrate Judge
Acosta's directions for revising the TMDL, require that a TMDL be developed that is consistent with
achieving water quality standards to protect designated uses (along with an additional Margin of Safety).
Comment ID L15-3
Comment Category Nonpoint Source
Comment Text
3. STREAM FLOW [Sec. 1.2.4]
ODF Comment: We appreciate the recognition that streamflow is highly modified due to dams and
reservoirs with "...unintended consequences that influence water quality." We recommend that this be
included in a monitoring program to better understand how this facet influences the mercury cycle in
the Willamette basin.
Response Text
This comment was previously submitted on ODEQ's July 2019 Public Review Draft of the TMDL. In the
November 2019 Response to Comments, ODEQ explained that "The DMAs and responsible persons who
own the largest reservoirs in the basin will conduct initial assessments and monitoring to evaluate
factors that are affecting methylation rates, and then develop a plan to reduce those methylation rates.
A monitoring program such as the one proposed by the commenter is a reasonable assessment
approach but should not postpone taking action to reduce the methylation rate. As discussed in Sections
13, 13.6 and 14 of the TMDL/WQMP, data collection will continue and expanded to allow for further
analysis to better represent mercury sources, transport and transformation mechanisms - such as
methylation in reservoirs, bioaccumulation, and groundwater mercury concentrations. It is expected
that the implementation of the TMDL will be further refined over time as part of an adaptive
management process." EPA concurs with ODEQs response, and no further response is needed.
Comment ID L15-4
Comment Category Nonpoint Source
Comment Text
4. EXCESS LOAD [Sec. 7.2]
4.1. "DEQ decided to pool all of the HUC8 data together and calculate a single median for the existing
surface water total mercury concentration for the entire Willamette Basin." (pg. 44)
ODF Comment: This is an understandable approach if you tested for and did not find differences
between sample sites. If there are particular HUC 8's that are driving the mercury contamination levels
in the Willamette Basin it would be important to identify those and focus recovery efforts there. The
exclusion of the Coast Fork is an example. Still, it begs the question of whether mercury is a universal
issue across the Willamette Basin or is driven by particular HUC 8's deserving a more site-specific
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approach. ODF recommends that the core assumption of equal contributions across watersheds be
checked as part of implementation monitoring plans.
Response Text
This comment was previously submitted on ODEQ's July 2019 Public Review Draft of the TMDL. The
"single median" approach was a primary reason for EPA's disapproval of the ODEQTMDL because it did
not result in predicted achievement of water quality standards in all listed waterbody segments. EPA's
TMDL, therefore, revised the allocations to ensure that water quality standards are predicted to be met
in all HUC8 watersheds of the Willamette River Basin. In the November 2019 Response to Comments,
ODEQ explained that "Estimation of the particular contribution among the HUC8s will be one of the
objectives in the Monitoring and Assessment Strategy." EPA concurs that it would be appropriate to
focus efforts on hotspots that drive mercury contamination in the Willamette River Basin and believes
that ODEQ's proposed WQMP and commitment to adaptive management will help to facilitate this
focus.
Comment Text
5. BENEFICIAL USES [Sec. 2]
5.1. "The revised TMDL for mercury is designed to restore the beneficial use of fishing to the Willamette
River and its tributaries." (pg. 23)
ODF Comment: See Executive Summary comments, part 2.3.
Response Text
This comment was submitted by ODF on ODEQ's November 2019 TMDL and it is addressed in the
responses to ODF's Executive Summary comments.
Comment ID L15-6
Comment Category Insufficient data and uncertainty in the process
Comment Text
6. SUMMARY OF MERCURY TMDL DEVELOPMENT ANDAPPROACH [Sec. 5]
6.1. Mercury TMDL Approach [Sec. 5.2]: "Within a watershed, wetlands or areas with saturated soils can
often provide important locations for methylmercury production. The relative importance of internally
produced (within the waterbodies and their sediments) or externally produced (within soils and
groundwater prior to reaching waterbodies) sources of methylmercury has not been assessed for the
Willamette Basin." (pg. 28)
ODF Comment: Some clarification as to whether the model accounted for this uncertainty, or any way to
quantify this uncertainty, would be helpful. ODF recommends this as a monitoring opportunity for DEQ's
implementation plan. Further, better understanding the potential linkages between carbon sources in
water (dissolved organic carbon and particulate organic carbon) might be one approach to improve
understanding of mercury cycling and export, particularly in the forest environment.
Comment ID
Comment Category
Nonpoint Source
L15-5
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Response Text
The uncertainty in the models and how it was accounted for is discussed in Sections 5, 6, 7 and 11 of the
ODEQTMDL and Sections 2, 3, 4 and 5 of the TMDL Technical Support Document. This comment was
initially submitted in regard to the July 2019 Public Review Draft. ODEQ added clarifying language to the
noted sections of the November 2019 final ODEQTMDL regarding the conservative assumptions
throughout the TMDL evaluations to address uncertainty. ODEQ intends to use monitoring and modeling
during implementation, including a better evaluation of reservoir methylation processes, to improve
ODEQ's representation of mercury/methylmercury system in the Willamette Basin. In addition, ODEQ's
forthcoming Assessment and Monitoring Strategy will identify approaches for continuing to improve
understanding of mercury in the Willamette Basin. EPA agrees that a better understanding of organic
carbon sources and cycling in water may be useful to improve understanding of mercury cycling and
export in the forest environment and encourages ODF to participate in the development of the
assessment and monitoring strategy.
Comment ID L15-7
Comment Category General Modeling Issues - Examples
Comment Text
7. EXPLANATION OF MODELS AND CURRENT MERCURY LOAD [Sec. 6]
7.1. Nonpoint source input data development (Sec. 6.1.4.).
ODF Comment: It isn't clear by this description of how non-point sources vs. point sources were
distinguished by land-use and how non-point and point sources were teased apart in Table 6-7. Some
discussion (here or elsewhere) on the connection between Table 6-7 and Table 1-3 would be beneficial
for the reader.
Response Text
The comment was previously submitted on ODEQ's July 2019 Public Review Draft of the TMDL. In the
November 2019 Response to Comments, ODEQ explained that "Point sources are permitted and the
information associated with the permit and facility characteristics was used to calculate the point source
contribution. The land use was not used to distinguish point sources from nonpoint sources." EPA notes
that the land use information shown in Table 1-3 of ODEQ's November 2019 TMDL was used in the
process of generating the nonpoint loading rates in Table 6-7. Specifically, the spatial coverage of land
use that is summarized in Table 1-3 was used to update the HSPF watershed model, which was then
used to estimate average annual surface runoff rates, groundwater discharge, and sediment erosion
delivery for each land use type. The process of assigning mercury concentrations to these different
loading pathways is described at length in Section 5 of the Technical Support Document (Appendix B to
the EPA TMDL).
Comment ID L15-8
Comment Category Nonpoint Source
Comment Text
7.2. Groundwater [Sec. 6.1.4.3], "As such, this resulted in large loads of total mercury (approximately 17
percent of the total source load to the stream network) estimated from groundwater contributions."
(Pg-41)
ODF Comment: ODF recommends that groundwater as a mercury source be included as a key
monitoring opportunity in the implementation plan.
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Response Text
This comment was previously submitted on ODEQ's July 2019 Public Review Draft of the TMDL In the
November 2019 Response to Comments, ODEQ explained that "DEQ agrees that groundwater source
need to be better characterized and intends to use monitoring and modeling during implementation to
improve our representation of mercury/methylmercury system in the Willamette Basin." EPA concurs
with this response and no further response is needed.
Comment Text
7.3. Current total mercury load estimation [Sec. 6.2]: "The great majority of the load (greater than 95%)
is from nonpoint sources point sources accounting for less than five percent." ODF Comment: Please
be specific: 'Based on the model output, nonpoint sources contributed 95.7% of the total load and point
sources contributed 4.3%.'
Response Text
This comment was previously submitted on ODEQ's July 2019 Public Review Draft of the TMDL. In the
November 2019 Response to Comments, ODEQ explained that they "...did not make this change.
Specificity can imply certainty and DEQ's language comports with the acknowledged uncertainty of the
modeled load estimates in a statement conflating the source categories into just two bins - nonpoint
and point sources. Table 6-7, directly below the text in the comment, provides the estimated loads from
all source categories modeled." EPA concurs with ODEQ's response to this comment and no further
response is needed.
Comment ID L15-10
Comment Category Nonpoint Source
Comment Text
8. NONPOINT SOURCES [Sec. 9.2]
8.1. "As noted in Figures 5-17 and 5-18 of the TMDL Technical Support Document, modeling indicates
that the source categories of surface runoff and sediment erosion together, contribute approximately 76
percent of the total mercury load to basin streams. These two source categories are implicated in
nonpoint source load contributions due to land use management activities (agriculture, forestry,
impoundments, water conveyances, background and nonMS4-permitted urban areas), as well as
stormwater point source contributions. Figure 5-19 of the TMDL Technical Support Document indicates
that 86 percent of surface runoff and 91 percent of sediment erosion may be affected by the natural and
anthropogenic activities within the forestry, agriculture and urban development land use areas."
ODF Comment: ODF looks forward to addressing these concerns as part of the implementation plan
under the FPA, both with describing its approach to sediment control and with identifying priority areas
to clarify areas of uncertainty through monitoring.
Response Text
The comment was resubmitted for the EPA TMDL, although clarification had already been provided in
ODEQ's Response to Comments and wording changes had been included in the final ODEQ November
2019 TMDL, which is Appendix A to the EPA TMDL.
Comment ID
Comment Category
Nonpoint Source
L15-9
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"DEQ agrees that identifying priority areas for mercury and sediment movement is an important
element of adaptive management and will help nonpoint source DMAs focus efforts and resources." EPA
concurs with ODEQ's response and no further response is needed.
Comment ID L15-11
Comment Category Nonpoint Source
Comment Text
9. ALLOCATIONS [Sec. 10]
9.1. "Furthermore, the mercury reduction potential from these sources is high because some activities
in the category have not implemented mercury minimization measures and the large aggregated load
means that even relatively small percentage reductions would achieve larger quantitative declines in
loading. As a result, a large reduction requirement was applied for nonpoint sources generally."
ODF Comment: ODF is curious about which activities in this category have not implemented mercury
minimization measures that initiated this comment in the draft TMDL, especially given the linkage to
sediment reduction practices. Regardless, ODF under its Forest Practices Act (FPA) administration,
Oregon Plan Voluntary measures promotion, and incentive programs has engaged in a robust program
to reduce and minimize sediment delivery to waters of the state for decades. We look forward to
working with DEQ to report on this program in the implementation plan.
Response Text
This comment was previously submitted on ODEQ's July 2019 Public Review Draft of the TMDL and was
answered in ODEQ's November 2019 Response to Comments: "DEQ acknowledges that many DMAs
have already been implementing programs and best management practices that reduce mercury and
sediment movement in the Willamette Basin. DEQ anticipates there are different or additional measures
that can be taken in order to achieve further reductions. Examples of measures that nonpoint sources
can focus on include but are not limited to increased monitoring and analysis of BMP effectiveness in
reducing sediment movement, increased efforts to protect and enhance riparian areas, increased efforts
to reduce erosion and sediment movement from road networks. DEQ also anticipates that the
Assessment and Monitoring Strategy DEQ and EPA are developing for the Willamette Basin will help to
reduce uncertainty in DEQ's representation of mercury in the basin, as well as support more robust
decision-making regarding implementation of the Mercury TMDL." EPA concurs with ODEQ's response,
and no further response is needed.
Comment ID L15-12
Comment Category Non-point Source Load Allocations
Comment Text
9.2. Instream surrogate allocations [Section 10.3] and [Appendix H]
9.2.1. ODF Comment: These comments also cover Section 14.1.4. DEQ has already described the great
level of uncertainty in determining anthropogenic versus natural sediment sources in the Willamette
Basin, and the uncertainty in understanding the same for THg and MeHg. While we appreciate the level
of detail provided on the THg and TSS analysis at the end of this document (Appendix H), moving to a
surrogate of an already highly uncertain metric creates an unacceptable level of compounded
uncertainty. The R2 values and scatter plots of log-transformed data suggest a weak correlation
between THg and TSS. While adding a random effect (i.e., site) does increase the R2 value, the
ecological/biochemical significance of including site as a factor in the model is unclear. Furthermore,
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DEQ decided to exclude non-detect data (65% of the samples) from the surrogate analysis, while similar
analyses in other studies (Eckley et al. 2018) included non-detect data. For these reasons, ODF does not
support the use of TSS as a surrogate for mercury concentrations at this time given our current
uncertainty of this relationship. We recommend further exploration of this proposed surrogate as part
of the monitoring in the implementation plan. We look forward to supporting you in this endeavor.
Response Text
This comment was originally submitted on the July 2019 Public Review Draft of the ODEQTMDL;
however, the answer in ODEQ's Response to Comments document addressed only the final sentences of
the full comment.
EPA's 2019 TMDL document does not address use of TSS as a surrogate and the EPA TMDL document
only refers to TSS in the context of Reasonable Assurances, where it is noted that "ODEQ's review
focuses on water quality trends in TSS loading which ODEQ intends to associate with mercury loading."
ODEQ's TMDL, which is attached to the EPA TMDL as Appendix A, does incorporate a discussion of
instream surrogate targets, in Section 10.3, and proposes TSS as a surrogate "...to supplement but not
supplant the allocations and TMDL water column target for evaluating TMDL implementation
effectiveness." The TSS surrogate is thus properly seen as part of the TMDL implementation strategy,
which is determined by ODEQ.
In response to this comment, ODEQ revised Section 10.3 and Appendix G (formerly Appendix H) of their
November 2019 TMDL with clarifications on the strong relationship ODEQ's analysis found between TSS
and total mercury measurements in the Willamette River Basin. ODEQ also describes the intended use
of TSS surrogate targets in Section 10.3 as one tool for evaluating TMDL implementation effectiveness.
Comment Text
10. WATER QUALITY MANAGEMENT PLAN [SECTION 13]
10.1. Implementation plans [Section 13.1.1]
10.1.1. "Implementation plans must be posted to a publicly accessible website, unless the DMA does not
have a website."
ODF Comment: For one-stop shopping for users of information related to a TMDL, it would be more
efficient for implementation plans to be posted on DEQs webpage under the relevant TMDL. It is not
intuitive to look to a multitude of other agency and DMA websites for implementation plan information.
Response Text
This comment was previously submitted on ODEQ's July 2019 Public Review Draft of the TMDL. In the
November 2019 Response to Comments (A_K#12: Suggested Change ID #280), ODEQ agreed "...that
providing copies or links to DMA plans on DEQ's website would be an improvement and will consider
moving forward with this recommendation outside of the Mercury TMDL process. DEQ also concludes
that it is important for DMAs to make their plans available on their own websites as they may incur
traffic from online users that may not access DEQ's website." Implementation planning is outside the
scope of EPA's TMDL.
Comment ID
Comment Category
L15-13
Water Quality Management Plan
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Comment ID
Comment Category
L15-14
Water Quality Management Plan
Comment Text
10.1.2. Proposed management strategies [Section 13.3]
10.1.2.1. "For some of the DMAs, DEQ included a list of management measures as an implementation or
"good practice" baseline. The list is not intended to be comprehensive or prescriptive and DMAs and
responsible persons may propose alternative approaches or management strategies."
ODF Comment: If the purpose of the Implementation Plan is to describe what the final implementation
measures are, it is unclear what the purpose of this section is and could be confusing for readers. For
example, if a reader sees a proposed practice for a DMA identified in this section but does not see it in
the final implementation plan, the reader may perceive that the implementation plan is missing this
element even if the DEQ agrees with the DMA that different management practice(s) will best achieve
the outcome.
Response Text
This comment was originally submitted on ODEQ's July 2019 Public Review Draft of the TMDL and
changes were made in the ODEQ November 2019 TMDL in response. (A_K#13: Suggested Change ID
#281). ODEQ agreed with the comment and revised language in the introductory paragraph of Section
13.3 of the ODEQ 2019 TMDL to provide more clarity about the management measures described in this
section. Section 13 of the ODEQ November 2019 TMDL focuses on the WQMP which is outside the
scope of EPA's TMDL.
Comment Text
10.1.3. Oregon Department of Forestry [Section 13.3.1.5]
10.1.3.1. ODF Rules Related to Water Quality and Erosion Control [Table 13- 4],
ODF Comment: Recommend including Reforestation (OAR 629-610- 0000 through 629-610-0090) and
Afforestation rules (OAR 629-611- 0000 through 629-611-0020). ODF is also considering where and how
to address fire prevention, managed fire, and wildfire as an aspect of this TMDL and is looking forward
to having these discussions with DEQ.
Response Text
The comment was resubmitted for the EPA TMDL, although clarification had already been provided in
ODEQ's Response to Comments and wording changes had been included in the final ODEQ November
2019 TMDL, which is Appendix A to the EPA TMDL.
In response, ODEQ included references to the cited rules in Table 13-4, of ODEQ's November 2019 TMDL
which is identified as Appendix A in EPA' December 2019 TMDL.
EPA encourages ODF to work with ODEQ to incorporate aspects of fire prevention, managed fire, and
wildfire in ODEQ's Water Quality Management Plan. No additional response is needed by EPA.
USEPA Region 10 58
Comment ID
Comment Category
Other
L15-15
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Comment ID
Comment Category
Other
L15-16
Comment Text
10.1.3.2. Table Pollutant sources and example management strategies to address sediment and mercury
and supporting section language [Table 13-5],
ODF Comment: The ODF section and this table provide a good summary of our strategies, thank you.
Some additional recommendations:
10.1.3.2.1. Change references to "Prescriptive rules for forest operations" to "Prescriptive and outcome-
based rules for forest operations" (row 1) to better reflect the different approaches used in the FPA.
Some rules are indeed prescriptive but others describe an outcome that landowners and operators can
use a variety of means to achieve.
Response Text
This comment was previously submitted on the ODEQ Public Review Draft of the TMDL (July 2019). In
response, ODEQ made the suggested changes. DEQ addressed the question in its response to the
commenter during its Response to Comments (RTC) process. The comment focuses on TMDL
implementation which is not a component of EPA's TMDL. No additional response is needed by EPA.
Comment Text
10.1.3.2.3. Change reference to "Partnership for Forestry Education (last row)".
10.1.3.2.4. Reference to ODF Compliance Audits (rows 1 and 11). Thank you for including this important
ODF program.
Response Text
This comment was previously submitted on the ODEQ Public Review Draft of the TMDL (July 2019). In
response, ODEQ made the suggested change. DEQ addressed the question in its response to the
commenter during its RTC process. The comment focuses on TMDL implementation which is not a
component of EPA's TMDL. No additional response is needed by EPA.
Comment ID L15-18
Comment Category Other
Comment Text
10.1.3.2.2. Please add a bullet to row 4 (roads) with text: "Cease active road use during wet weather
when roads have deep ruts or covered by a layer of mud that results in visible increases in stream
turbidity (OAR 629-625-0700).
10.1.3.2.5. Hydrologically-connected roads, potentially unstable road prisms, and metrics informing at-
risk stream crossings are already included in the compliance audit protocol. Road inventories are also
included as an Oregon Plan voluntary measure. We look forward to discussions with DEQ about how
existing programs can address these concerns as part of the implementation plan.
USEPA Region 10 59
Comment ID
Comment Category
Other
L15-17
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Response Text
This comment was previously submitted on the ODEQ Public Review Draft of the TMDL (July 2019). In
response, ODEQ made the suggested changes. DEQ addressed the question in its response to the
commenter during its RTC process. The comment focuses on TMDL implementation details which is not
a component of EPA's TMDL. No additional response is needed by EPA.
Comment ID L15-19
Comment Category Other
Comment Text
10.1.3.2.6. For tethered logging, ODF has already created guidance for landowners and operators for the
information required to support a Plan for Alternate Practice (PFAP) to operate this new cutting, and
sometimes yarding, system on steep slopes. We look forward to discussing with DEQ the information
provided in the PFAP and how this existing business process can address any concerns.
Response Text
This comment was previously submitted on the ODEQ Public Review Draft of the TMDL (July 2019) and
the following response was provided in ODEQ's November 2019 Response to Comments: "DEQ agrees
that existing programs may be able to facilitate and support implementation of this TMDL. DEQ also
looks forward to continued collaboration between agencies." DEQ addressed the question in its
response to the commenter during its RTC process. The comment focuses on TMDL implementation
which is not a component of EPA's TMDL. No additional response is needed by EPA.
Comment Text
10.1.3.2.7. "Reports or other documents used for ODF TMDL reporting should be made available on a
publicly accessible website."
ODF comment: We respectfully recommend that it would be less confusing to the public consuming
information about TMDLs that all supporting information be posted in a single location on the DEQ
website rather than multiple agency websites.
Response Text
This comment was previously submitted on the ODEQ Public Review Draft of the TMDL (July 2019) and
the following response was provided in ODEQ's November 2019 Response to Comments: "DEQ agrees
that providing copies or links to DMA plans on DEQ's website would be an improvement and will
consider moving forward with this recommendation outside of the Mercury TMDL process. DEQ also
concludes that it is important for DMAs to make their plans available on their own websites as they may
incur traffic from online users that may not access DEQ's website."
DEQ addressed the question in its response to the commenter during its RTC process. The comment
focuses on TMDL implementation which is not a component of EPA's TMDL. No additional response is
needed by EPA.
Comment ID
Comment Category
Other
L15-20
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Comment ID
Comment Category
Other
L15-21
Comment Text
10.1.4. Reservoir management [Section 13.3.1.22] 10.1.4.1. ODF Comment: ODF is interested in the
recommended monitoring and calibration efforts in this section as a model for what monitoring would
be of highest interest for DEQ in the non-federal forest environment. We look forward to having this
discussion with DEQ.
Response Text
This comment was previously submitted on the ODEQ Public Review Draft of the TMDL (July 2019) and
the following response was provided in ODEQ's November 2019 Response to Comments: "This is one of
the topics that DEQ will work to better understand during implementation through monitoring,
assessment and updates to the analysis, which includes modeling. DEQ is working with EPA to develop a
draft Assessment and Monitoring Strategy. DEQ will work with the DMAs, including ODF, to refine this
Strategy and for identifying priorities for better understanding methylmercury and total mercury in the
basin that can then be used for adaptive management of the TMDL." DEQ addressed the comment
during the RTC process for its November 2019 TMDL. The specific comment pertains to details in the
WQMP which is not a component of EPA's TMDL. No additional response is needed by EPA.
Comment ID L15-22
Comment Category Other
Comment Text
10.1.5. Nonpoint Source DMAs and responsible persons [Section 13.4.1]
10.1.5.1. ODF Comment: ODF recognizes the 18 month timeline but also appreciates the expressed
flexibility for setting specific timelines in the plan. ODF business reporting processes are currently
focused on statewide or FPA administrative regions and districts: we do not currently have a mechanism
to report on watershed basins. We look forward to discussions with DEQ on the most efficient and
effective way to create reports that meet TMDL needs. ODF also appreciates the specific mention of
adaptive management. Many of the items in the 2016 ODF Monitoring Strategy relate to issues that are
likely significant for this TMDL. We look forward to discussing monitoring and adaptive management
processes with DEQfor inclusion in the implementation plan. We see this same idea mentioned in the
draft TMDL section "14.1.4 Evaluate implementation plans and progress".
Response Text
This comment was previously submitted on the ODEQ Public Review Draft of the TMDL (July 2019) and
the following response was provided in ODEQ's November 2019 Response to Comments: "DEQ
appreciates ODF's participation and engagement during the TMDL development process and looks
forward to collaborating with ODF after TMDL issuance to develop and refine monitoring and reporting
approaches." The comment focuses on TMDL implementation which is not a component of EPA's TMDL.
DEQ addressed the question in its response to the commenter during its RTC process. The comment is
on DEQ's WQMP which is not a component of EPA's TMDL. No additional response is needed by EPA.
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Comment ID L15-23
Comment Category Other
Comment Text
10.1.6. Timeline for attainment of water quality standards [Section 13.5]
10.1.6.1. ODF Comment: ODF appreciates the recognition of global mercury emissions and air deposition
as the primary mercury source in Oregon. While we recognize the limited regulatory sphere that DEQ
has for this issue, Oregon has an opportunity to create messaging and take action on a state, regional,
and national level messaging about how mercury contamination is affecting our state, our citizens, its
business sectors, and its environment. We are currently taking these steps with climate change, another
global issue, and mercury contamination is strongly linked with climate change in many ways (e.g., coal
emissions). ODF is looking forward to discussing with DEQ about messaging and other strategies to
influence state, regional, national, and global actions to reduce mercury contamination over time.
Response Text
This comment was previously submitted on the ODEQ Public Review Draft of the TMDL (July 2019) and
the ODEQ's November 2019 Response to Comments noted that ODEQ agreed with the statement. DEQ
addressed the question in its response to the commenter during its RTC process. The comment is the
WQMP which is not a component of EPA's TMDL. No additional response is needed by EPA.
Comment ID L15-24
Comment Category Other
Comment Text
10.1.6.2. ODF Comment: ODF also appreciates DEQs recognition that "...continued air emissions from
global sources may offset these efforts". ODF recommends that DEQ engage in monitoring to track and
distinguish, by monitoring and modeling, in- versus out-of-state air contamination rates in order to
understand what is driving mercury contamination rates in our state. If nonpoint implementation plans
are conducted in a timely fashion, the failure of recovery may not be due to these sources but due to
natural runoff and erosion from unavoidable air deposition.
Response Text
This comment was previously submitted on the ODEQ Public Review Draft of the TMDL (July 2019) and
the following response was provided in ODEQ's November 2019 Response to Comments: "This is one of
the topics that DEQ will work to better understand during implementation through monitoring,
assessment and updates to the analysis, which includes modeling. DEQ is working with EPA to develop a
draft Assessment and Monitoring Strategy to better understand the methylmercury and total mercury in
the basin. The information from this Strategy will be used for adaptive management." DEQ addressed
the question in its response to the commenter during its RTC process. No additional response is needed
by EPA since the comment is on the WQMP.
Comment ID L15-25
Comment Category Other
Comment Text
10.1.6.3. ODF Comment: An ODF and DEQ collaborative approach to setting reasonable and attainable
expectations for forest practices is the best way to avoid an adversarial approach. Developing a full
accounting of the State of Oregon Department of Environmental Quality 118 mercury cycle in Oregon
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will provide the best available information for responding to this issue. In the absence of information, an
adaptive management approach based on monitoring is an effective way to set reasonable expectations.
Response Text
This comment was previously submitted on the ODEQ Public Review Draft of the TMDL (July 2019) and
the following response was provided in ODEQ's November 2019 Response to Comments: "DEQ agrees
and anticipates that the draft Assessment and Monitoring Strategy DEQ and EPA are developing for the
Willamette Basin will help to reduce uncertainty in DEQ's representation of mercury in the basin, as well
as support more robust decision-making regarding implementation of the Mercury TMDL. DEQ plans to
use adaptive management during implementation of the TMDL. Use of adaptive management is briefly
described in section 13.1.2 of the WQMP." The comment focuses on TMDL implementation and
adaptive management, elements of DEQ's WQMP that are not part of EPA's review. DEQ addressed the
question in its response to the commenter during its RTC process. No additional response is needed by
EPA since the comment is on the WQMP.
Comment Text
10.1.6.4. ODF Comment: We recommend that references to the sphere of the FPA relating to "private"
forestlands be changed to "non-federal" forestlands to account for its jurisdiction over other public
lands such as those owned by the state or counties.
Response Text
This comment was previously submitted on the ODEQ Public Review Draft of the TMDL (July 2019). In
response, ODEQ made the suggested revision. DEQ addressed the question in its response to the
commenter during its RTC process. The comment is on the WQMP which is not a component of EPA's
TMDL. No additional response is needed by EPA.
Comment ID L15-27
Comment Category Other
Comment Text
10.1.7. Monitoring and evaluation [Section 13.6]
10.1.7.1. ODF Comment: ODF is curious about the "Assessment and Monitoring Strategy to Support
Implementation of Mercury Total Maximum Daily Loads for the Willamette Basin" that DEQ is building
with EPA. If this assessment will include expectations for non-federal forestlands, we look forward to
being included in this conversation.
Response Text
This comment was previously submitted on the ODEQ Public Review Draft of the TMDL (July 2019) and
the following response was provided in ODEQ's November 2019 Response to Comments: "Yes, DEQ will
work with DMAs where possible to collect information, including monitoring data, to improve our
representation of mercury/methylmercury system in the Willamette Basin. In addition, DEQ is working
with EPA to develop the draft Assessment and Monitoring Strategy and will seek DMA input on this
Strategy. DEQ expects the Strategy to help guide efforts on better understanding mercury in the basin."
DEQ addressed the question in its response to the commenter during its RTC process. No additional
response is needed by EPA since the comment is on the WQMP.
Comment ID
Comment Category
Other
L15-26
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Comment ID
Comment Category
Other
L15-28
Comment Text
10.1.8. Costs and funding [Section 13.7]
10.1.8.1. Partial list of funding programs available in the Willamette Basin that may be used to support
planning and implementation activities that benefit water quality. [Table 13-22]
ODF Comments:
10.1.8.1.1. Please add ODF to the list of agencies involved in the EQIP Program.
Response Text
This comment was previously submitted on the ODEQ Public Review Draft of the TMDL (July 2019). In
response, ODEQ made the suggested revision. The comment is on the WQMP (specific TMDL
implementation activities) which is not a component of EPA's TMDL. No additional response is needed
by EPA.
Comment ID L15-29
Comment Category Other
Comment Text
10.1.8.1.2. Please add the Emergency Forest Restoration Program (EFRP). The EFRP helps the owners of
non-industrial private forests restore forest health damaged by natural disasters. The EFRP does this by
authorizing payments to owners of private forests to restore disaster damaged forests. This program is
implemented by the local Farm Services Agency County Committee, along with ODF and likely others,
for all disasters with the exceptions of drought and insect infestations. In the case of drought or an
insect infestation, the national FSA office authorizes EFRP implementation.
Response Text
This comment was previously submitted on the ODEQ Public Review Draft of the TMDL (July 2019). In
response, ODEQ made the suggested revision. The comment is on the WQMP which is not a component
of EPA's TMDL. No additional response is needed by EPA.
Comment ID L15-30
Comment Category Other
Comment Text
10.1.9. Evaluate implementation plans and progress [Section 14.1.4]
10.1.9.1. "DEQ is proposing TSS as a surrogate measure for evaluating implementation of the allocations
for the mainstem Willamette River and its tributaries. TSS will be used for evaluating the effectiveness of
implementation plans." ODF Comment: See ODF Comments on Section 10.3.
Response Text
This comment was previously submitted on the ODEQ Public Review Draft of the TMDL (July 2019) and
the following response was provided in ODEQ's November 2019 Response to Comments: "DEQ revised
Section 10.3 and Appendix H with clarifications on the strong relationship DEQ's analysis found between
Willamette Basin TSS and total mercury measurements. In Section 10.3 DEQ established TSS surrogate
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targets and their use, which will be used as one tool for evaluating TMDL implementation effectiveness.
The use of TSS surrogate targets and other tools will also be described in the Assessment and
Monitoring Strategy that is being jointly developed by DEQ and EPA, an overview of which is provided in
Sections 13.6 and 14.1.6." DEQ's use of TSS as a surrogate measure is a component of implementation
monitoring, a component that is not part of EPA's TMDL. DEQ addressed the question in its response to
the commenter during its RTC process. No additional response is needed by EPA.
Comment Text
10.2. Dominance of atmospheric deposition of mercury [Section 14.2]
10.2.1. "...DEQ opted to allocate aggregated nonpoint source loads and point source wasteloads using
the proportionality approach." ODF Comment: In the absence of better information, we can understand
this approach. It is recommended, however, that validation monitoring of this core assumption be
incorporated into monitoring plans. ODF looks forward to discussing how this may be achieved.
Response Text
EPA thanks ODF for the comment. ODEQ has indicated that it will develop a monitoring plan as part of
its Water Quality Management Plan. EPA encourages ODF to participate in the stakeholder discussions
leading to the development of the monitoring plan.
USEPA Region 10 65
Comment ID
Comment Category
L15-31
General non-point sources
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Author Name Lauren Haney
Organization Name
Letter ID
Comment ID
Comment Category
Clackamas County Water Environment Services
L16
L16-1
TMDL Implementation
Comment Text
As holders of several NPDES permits, which continue to tightly regulate any discharges that contain
mercury, we want to remind EPA that the vast majority of the mercury discharged into the Willamette
River and tributaries is coming from non-point sources, such as erosion of soil. According to the Oregon
DEQ, all of the wastewater treatment plants combined in the entire watershed only discharge about
0.8% of the mercury in the watershed. We urge the EPA and state agencies to focus their TMDL
implementation efforts on reducing these much larger sources of mercury. Even if smaller sources of
mercury, like municipal storm systems, factories, and wastewater treatment plants, were to somehow
eliminate their discharges of mercury, this would only yield a tiny reduction in concentration of
methylmercury in the tissue offish which live in the river and its tributaries. The amount of mercury in
resident fish tissue in the Willamette River watershed will not be substantially reduced until after the
largest sources of mercury have been controlled.
Response Text
EPA agrees that non-point sources, including surface runoff of atmospherically deposited mercury,
sediment erosion, and resurfacing groundwater are higher contributors of mercury to waterbodies in
the Willamette River Basin. Allocations established in the TMDL reflect this distribution because higher
reductions are generally required for non-point sources compared to point sources. The relative
contributions of point versus non-point source mercury loading, however, vary for different catchments
in the Willamette River Basin. For example, NPDES permitted POTWs and industrial wastewater
dischargers in the Lower Willamette contribute about 11% and NPDES permitted stormwater sources
contribute about 21% of the THg load in that catchment. The TMDL is developed to attain standards in
waterbodies in the Willamette River Basin. Reductions from point sources are necessary to achieve
water column and fish tissue standards.
Comment Text
Regarding the EPA's analytical approach, the DEQ's draft 2019 TMDL established the TMDL load capacity
by calculating an existing Willamette basin-wide median instream total mercury concentration (1.2 ng/L)
and determining that 88% reduction was needed to achieve the new TMDL's instream target of 0.14
ng/L. EPA's December 2019 draft TMDL rejected the basin-wide approach and proposed additional
mercury reductions in five of the Willamette River watersheds twelve HUC 8 sub-basins (examples of
HUC 8 sub-basins include the Tualatin River and the Clackamas River). The amount of flow which is
generated within these twelve HUC 8 sub-basins varies greatly; in any given year, the Clackamas River
generates far more acre-feet of water compared to the Tualatin River, due to the fact that the
Clackamas River drains a large section of the west side of the Cascade mountains. A discharger in a HUC
8 sub-basin which possesses more clean flow from mountainous areas such as the Clackamas River will
have more dilution to assist with attaining the new TMDL's instream target of 0.14 ng/L. Dischargers in
USEPA Region 10 66
Comment ID
Comment Category
Point Source Wasteload Allocations
L16-2
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other HUC 8 sub-basins, such as the Kellogg WRRF in the "Lower Willamette", which generates much
less flow that some other HUC 8 sub-basins, are penalized with very high and potentially unattainable
mercury reductions. Furthermore, dischargers in some places, such as the Kellogg WRRF in the "Lower
Willamette", depend on a river which already has an elevated level of instream mercury due to
numerous upstream sources, and as a result, EPA proposes to apply tighter restrictions to sources who
are located on the lower Willamette River. Discriminating against dischargers based on their location,
such as those who are downstream in the Portland metro area, in this TMDL is unfair. The EPA should
employ mercury reduction allocations that are fair and reasonable, by allocating the benefits of the total
river's capacity to all dischargers equally, rather than frontloading the ability to discharge to upriver
points and overburdening lower river dischargers.
Response Text
The EPA 2019 TMDL is developed to achieve the 0.14 ng/l target within each subbasin, based on
reductions of existing concentrations and sources in each subbasin. It is therefore assumed in the TMDL
model that the TMDL target is met at the upstream boundary of the Lower Willamette subbasin. Source
reductions in the Lower Willamette, both point and nonpoint, are established to reduce sources within
the Lower Willamette such that the target will be met there as well. There is no bias towards greater
reduction of sources in the lower portion of the Basin, as reductions by subbasin are set to meet the
TMDL target given the sources within each subbasin. All subbasins require significant reductions.
Greater reductions for both point and nonpoint sources are called for where concentrations are higher,
and where sector loading is higher. Point source reductions are higher in the Lower Willamette and
Middle Willamette subbasins because greater overall reductions are needed throughout these
subbasins, and the point source contributions are greater in these subbasins than in others. The point
source relative contribution in the Lower Willamette subbasin is the highest of any subbasins, and
accounts for 11% of the overall load in the catchment. Point source reductions in the Lower Willamette
(65%), are less than reductions established for the nonpoint source and stormwater categories (97%).
Comment Text
In addition, EPA's Willamette River Mercury TMDL says NPDES Permitted Major Wastewater Discharges
in the Lower Willamette sub-section of the watershed shall reduce their total mercury concentration by
65%. Most of the other sources of mercury in this portion of the watershed - such as NPDES Permitted
Stormwater Point Source Discharges - were also notified in the TMDL of EPA's intent to require a
greater percentage reduction compared to Oregon DEQ's Nov. 22, 2019 Mercury TMDL. But EPA's TMDL
notifies NPDES Permitted Industrial Dischargers that they will only need to reduce their discharges of
mercury by 10% in this same HUC 8 watershed. This approach seems arbitrary in that it treats
dischargers within the same sub-basin differently. The Oregon DEQ's approach was more predictable,
consistent, and fair.
Response Text
Allocations in the ODEQ 2019 TMDL would not achieve the mercury target in all subbasins with mercury
impaired waterbodies, therefore greater reductions were needed in order to achieve the target and
meet water quality standards. In many cases the point sources are relatively small contributors, though
municipal stormwater generally contributes greater loading. In some subbasins for which the TMDL
target would not be achieved in the ODEQ TMDL, stormwater and other point sources are more
important contributors. Given the need for an overall significant reduction in mercury loading from all
Comment ID
Comment Category
Point Source Wasteload Allocations
L16-3
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watersheds, in places where point sources were greater contributors, it was necessary to establish
greater reductions from these facilities in order to meet the TMDL load capacity.
In revising the Willamette River Basin (WRB) TMDL, EPA only made changes to allocations necessary to
achieve the TMDL target in each subbasin. In doing so, EPA considered both the load and discharge
concentration of point sources, focusing reductions on those sources which have higher loading and/or
discharge concentration. The industrial dischargers currently account for <1 % of the load in the Lower
Willamette subbasin. Consequently, requiring greater reductions from this sub-sector will have very
small impact on mercury loading, and EPA therefore determined to retain ODEQs Wasteload Allocation
(WLA) of 10% for this sector. The POTWs on the other hand, accounted for 11% of the subbasin mercury
load. Consequently, EPA increased the reduction from this sector from 10% to 65%. The nonpoint source
category accounted for 68% of the load, and their reduction percent was increased from 88% to 97%.
Comment Text
Regarding the required reductions of mercury in stormwater and wastewater discharges, it appears that
the TMDL was developed based on information gathered from 2000-2006 through various sources. That
data set was used to establish the baseline targets for mercury reduction that have been pursued by
DEQ and regulated entities. The additional information gathered since then has been used to enhance,
but not replace, that baseline set. Therefore, the rulemaking process necessarily requires that the 2006
baseline set of data be the starting point for measuring compliance with the TMDL (the "2006
Baseline"). This is not clearly stated in the TMDL. The EPA in the "Reasonable Assurances" section of the
TMDL should clarify this assumption when discussing progress already made by Oregon DEQ and
regulated entities in reducing mercury discharges to the river. This would more clearly support EPA's
assertion that water quality goals will be met by the actions proposed in the Oregon DEQ Water Quality
Management Plan for the Willamette Mercury TMDL.
Response Text
The TMDL did include data collected between 2002-2006; however, newer data through 2019 were
incorporated as shown in Figure 2-2 of the Technical Support Document. The years with the most water
column THg samples were 2007, 2008, and 2014, and the year with the most fish tissue records was
2011. Recent records were also applied to quantify loads from stormwater and wastewater dischargers.
For example, wet atmospheric deposition of mercury grids from 2000 to 2013 were applied in the Mass
Balance Model to determine loads associated with surface runoff as discussed in Section 5.3.1 of the
Technical Support Document. Records available or provided by Municipal Separate Storm Sewer
Systems (MS4s), POTWs, industrial dischargers, and mines from 2002 to 2019 were used to quantify
loads from those sources. Thus, data from 2002-2019 were combined to determine source loads and
required reductions for both ODEQ's TMDL and EPA's TMDL, and this period will serve as the baseline
for measuring compliance.
Comment ID
Comment Category
Reasonable Assurance
L16-4
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Author Name Sharla Moffett
Organization Name
Letter ID
Comment ID
Comment Category
Oregon Business & Industry
L17
L17-1
Lacks sensitivity analysis
Comment Text
OBI had significant reservations with the underlying technical analysis and the layering of conservative
assumptions made by DEQ in its original TMDL and adopted by EPA in its TMDL. EPA has failed to
address the numerous technical flaws with DEQ's underlying analysis, which has been the focus of
substantial technical review. Oregon Farm Bureau, Oregon Forest & Industries Council and Oregon
Association of Nurseries carried out considerable analyses of the modeling in the Technical Support
Document, and we refer you to the complete technical comments submitted in September 2019
(attached). We would, however, like to highlight a few of the concerns:
• No sensitivity analyses were completed. This could produce a variance in the Food Web Model's
(FWM) biomagnification factor resulting in unnecessarily stringent load and wasteload allocations.
Response Text
The introductory statement of this comment implies that comments contained in Oregon Farm Bureau,
Oregon Forest & Industries Council and Oregon Association of Nurseries prior technical comments were
not considered. Those comments summarized earlier comments from OBI, which were addressed in the
ODEQ November 2019 Response to Comments document.
EPA disagrees with the statement that no sensitivity analysis was performed. The Food Web Model
approach to get values of the biomagnification factor for the different fish species explicitly
incorporated the variation model parameters by using the probabilistic approach in the Monte Carlo
simulation, which is itself a sensitivity analysis. The model parameters and how they were simulated in
the Monte Carlo application are listed in Table 3-2 in the Technical Support Document. Also, the
response of the model to these variations is discussed in Section 3.6 of the Technical Support Document.
Some key insights about model parameters are provided in the discussion. For example, specification of
the distribution of exposure concentrations is a primary factor controlling the tails of the cumulative
distribution functions used in the Food Web Model simulations.
Comment Text
The modeled fish tissue mercury concentrations do not appear to fully support the FWM calibration for
the Northern Pikeminnow making target concentrations of Total Mercury (THg) questionable.
Response Text
This comment refers to the Technical Support Document (TSD), attached to the EPA TMDL as Appendix
B.
The comment does not provide any specific detail to support the contention that the modeled
concentrations "...do not appear to fully support the Food Web Model (FWM) calibration for the
Comment ID
Comment Category
Food Web Model
L17-2
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Northern Pikeminnow". However, EPA acknowledges that, like any model, the FWM is an approximation
of observed conditions. The FWM was calibrated by attempting to match the cumulative distribution
functions generated by the FWM to those in observed data (TSD Figure 3-4) and the TSD notes that
"...the fit for Northern Pikeminnow (NPM) is not perfect but is reasonable." TSD Figure 3-4 shows that
the match between model and data remains within 95% confidence limits from the 50th to 70th
percentile and is, thus, acceptable for the median of the distribution (50th percentile), which is the basis
for estimating the THg target. TSD Figure 3-6 shows that the relationship between fish length and
mercury tissue concentration is reasonably well reproduced by the model. Finally, the Bioaccumulation
factor (BAF) simulated for NPM in the FWM is well within the 95% confidence limits of reported BAF
values for Trophic Level 4 fish species. EPA believes that the discrepancies between the model and
observed fish tissue data in the tails of the distribution are attributable to use of a steady-state
bioaccumulation model to approximate the results of a dynamic relationship between exposure
concentration and body burden, along with other simplifying assumptions regarding mercury uptake
and depuration. These issues are discussed at length in the TSD.
EPA acknowledges that there is uncertainty in the estimated relationship between NPM tissue
concentrations of mercury and exposure concentrations, but not significant bias. EPA concludes that the
FWM model provides a reasonable and best-available relationship between exposure concentrations
and fish tissue mercury concentrations and thus provides a reasonable basis for developing the THg
targets.
Comment Text
The THg concentration appears to lack certainty, as alternative approaches could be employed for
determining input parameters and result in a different target THg concentration.
Response Text
EPA acknowledges that the linkage analysis for the TMDL includes uncertainty, as is the case with all
modeling analyses. Federal regulations require that the TMDL be developed despite uncertainty in the
analysis and the presence of such uncertainty does not remove EPA's obligation to establish the TMDL at
levels sufficient to meet water quality standards. As noted at 40 CFR 130.2(g), load allocations for
nonpoint sources "...are best estimates of the loading, which may range from reasonably accurate
estimates to gross allotments, depending on the availability of data and appropriate techniques for
predicting the loading." The Clean Water Act and 40 CFR 130.7(c)(1) also require that TMDLs include a
margin of safety (MOS) "...which takes into account any lack of knowledge concerning the relationship
between effluent limitations and water quality." Different parameter values would indeed result in
different target THg concentrations. This is directly addressed in Tables 3-3, 3-4, and 4-4 of the Technical
Support Document, in which Monte Carlo analysis is used to present the distribution of biomagnification
factors, fish tissue concentrations, and corresponding water column concentrations.
Comment Text
The Mercury Translator Model introduces further uncertainty as its methodology determined a target
concentration of THg in the water column from the dissolved methylmercury input parameter.
Comment ID
Comment Category
L17-3
Applicable numeric criteria
Comment ID
Comment Category
L17-4
Mercury Translator
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Response Text
EPA acknowledges that the translation between total mercury (THg) and dissolved methylmercury is a
source of uncertainty in the TMDL calculations. The pollutant addressed by this TMDL is total mercury.
However, food chain bioaccumulation, which results in elevated fish tissue concentrations of mercury, is
driven primarily by dissolved methylmercury, most of which is derived from bacterial transformation of
ionic mercury in the environment. It is, therefore, necessary to develop a translation between total
mercury and methylmercury concentrations to establish a causal linkage between total mercury loads in
the watershed and impairment based on fish tissue concentrations of mercury.
Comment Text
The Mass Balance Model (MBM) employs an additional three models to provide input values and data
comparisons for calculating present-day mercury contributions. Using modeling outputs as subsequent
model inputs further compounds the magnitude of unreliability in the estimates.
Response Text
Developing a TMDL requires establishing a linkage between the impairment and the pollutant load
sources causing the impairment. The linkage analysis is needed to estimate the amount of reduction in
loads that would be required to achieve water quality standards. For the Willamette Mercury TMDL, the
linkage between sources of total mercury load and elevated fish tissue concentrations of mercury is
complex, including the release of mercury loads to waterbodies, fate and transport in the hydrologic
network, transformations between total and methylmercury, entry of methylmercury into the food
chain, and bioaccumulation within the food chain to higher trophic levels. EPA acknowledges that
representing this complex causal chain increases uncertainty in the estimates. However, it is also
necessary to represent all the links in the causal chain (to the best of current ability) to establish the
TMDL. The statement that the MBM's use of "...an additional three models to provide input values..."
and that this "...compounds the magnitude of unreliability in the estimates..." is misleading. Rather than
using multiple linked models, EPA could have chosen to combine all of the steps in the linkage analysis in
a single, unified model - which would have no impact on the total uncertainty in the estimates.
Comment ID L17-6
Comment Category Margin of Safety
Comment Text
EPA also adopted, without question, DEQ's "margin of safety." DEQ employs three distinct elements in
its calculation for a margin of safety:
• The use of the Northern Pikeminnow as an efficient bioaccumulator of mercury;
• The method of calculating the Food Web Model which results in a lower value than the average
concentration; and
• The use of total mercury concentrations in fish tissue rather than methylmercury in the water quality
criterion.
Pursuant to 33 U.S.C. § 1313(d)(c), the margin of safety takes into account any lack of knowledge
concerning the relationship between effluent limitations and water quality. It is OBI's position that
DEQ's analysis is flawed and the load and wasteload allocations are far more stringent than necessary. If
Comment ID
Comment Category
L17-5
Mass Balance Model/HSPF
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EPA is going to issue its own TMDL, EPA cannot simply adopt DEQ's flawed analysis. EPA must undertake
its own analysis, fully explain the rationale behind its approach and assess the likely impact that each
element would have, as well as the cumulative impacts.
Response Text
The Clean Water Act and 40 CFR 130.7(c)(1) require that TMDLs include a margin of safety (MOS)
"...which takes into account any lack of knowledge concerning the relationship between effluent
limitations and water quality." The MOS can be either explicit, through allocation of a portion of the
loading capacity, or implicit, through use of conservative assumptions in the TMDL analysis or in
developing a TMDL target, or both.
The claim that "EPA also adopted, without question, DEQ's 'margin of safety'" is incorrect. EPA reviewed
the MOS discussion provided in ODEQ's November 2019 TMDL and accepted only the first and third of
the three components of the ODEQ MOS. EPA rejected the component of the MOS regarding the
method of calculating the Food Web Model. However, EPA also added an additional MOS component, as
described in Section 9 of the EPA TMDL:
"3. Needed reductions in loads are based on comparing water column mercury targets to ambient
monitoring data. Those monitoring data are available through 2011 in only 9 of the 12 HUC8 watersheds
and thus do not incorporate any reductions in mercury loading that have occurred since 2011. Data
presented in ODEQ's 2019 TMDL (p. 37) indicate that mercury concentrations have been declining in
more recent years (2012 - 2019) in the Tualatin and Lower Willamette subbasins."
With these modifications, EPA found that the components of the implicit MOS account for any lack of
knowledge or uncertainties concerning the relationship between pollutant loading and receiving water
quality and that the MOS is thus approvable.
Comment Text
EPA also adopted DEQ's use of TSS as a surrogate. The TMDL does not sufficiently explain whether TSS is
the best and most accurate surrogate that could be utilized and whether other surrogate options exist.
The TMDL must explain EPA's rationale for the selection of TSS as the preferred surrogate for THg.
Response Text
EPA's 2019 TMDL document does not discuss use of TSS as a surrogate. Indeed, the EPA TMDL
document mentions TSS only once, in the context of Reasonable Assurances, where it is noted that
"ODEQ's review focuses on water quality trends in TSS loading which ODEQ intends to associate with
mercury loading."
ODEQ's TMDL, which is attached to the EPA TMDL as Appendix A, does incorporate a discussion of
instream surrogate targets, in Section 10.3, and proposes TSS as a surrogate "...to supplement but not
supplant the allocations and TMDL water column target for evaluating TMDL implementation
effectiveness." The TSS surrogate is thus properly seen as part of the TMDL implementation strategy, as
determined by ODEQ.
EPA does concur that TSS is an appropriate surrogate for mercury load during high TSS, high flow
conditions because a large portion of the total mercury load to the waterbodies of the Willamette River
basin is derived from mercury stored in the soil matrix that is delivered to the waterbodies via sediment
Comment ID
Comment Category
TSS as surrogate
L17-7
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erosion. The empirical analysis conducted by ODEQ (Appendix G of ODEQ's November 2019 TMDL)
confirms a strong correlation between TSS and total mercury concentrations. It is thus reasonable to
choose TSS as a surrogate for mercury loading.
The primary reason for choosing TSS as the recommended surrogate is that it can be analyzed quickly
and at low relative cost compared to the high expense and stringent analytical requirements for
mercury analyses. Use of TSS as a surrogate can thus provide a cost-effective way to track progress in
reducing sediment-associated mercury loads as well as to indicate potential problem areas where more
expensive mercury analyses may be needed.
EPA acknowledges that surrogates other than TSS could be used in the implementation plan for the
TMDL. ODEQ also evaluated use of turbidity and suspended sediment concentration (SSC) as surrogates,
but reportedly selected TSS as the best surrogate choice because it combines a proven correlation to
THg concentration with low cost and ease of analysis.
Comment ID L17-8
Comment Category Point Source Wasteload Allocations
Comment Text
EPA's proposed TMDL takes DEQ's already very conservative load and wasteload allocations and makes
them even more stringent in several of the subbasins without any rational basis. EPA concedes that the
dominant source of mercury stems from wet deposition of mercury from global anthropogenic sources.
EPA and DEQ acknowledge that even the complete elimination of the estimated 4% of mercury
contributed to the Willamette River and its tributaries from wastewater and municipal stormwater is
unlikely to result in a measurable reduction of mercury. Nevertheless, EPA's TMDL imposes reductions
on these sources that will be all but impossible to achieve. EPA's decision to impose these reductions is
arbitrary and capricious and without sufficient basis to support the TMDL.
Response Text
Allocations in the ODEQ 2019 TMDL would not achieve the mercury target in all subbasins with mercury
impaired waterbodies, therefore greater reductions were needed in order to achieve the target and
meet water quality standards. In many cases the point sources are relatively small contributors, though
municipal stormwater generally contributes greater loading. In some subbasins for which the TMDL
target would not be achieved in the ODEQ TMDL, stormwater and other point sources are more
important contributors. Given the need for an overall significant reduction in mercury loading from all
watersheds, in places were point sources were greater contributors, it was necessary to establish
greater reductions from these facilities in order to meet the TMDL load capacity.
Comment ID L17-9
Comment Category TMDL Implementation
Comment Text
OBI recognizes the significant work and staff hours that have gone into preparing the TMDL as well as
DEQ's mission to protect water quality in Oregon. We remain concerned, however, that implementation
of this TMDL will require businesses to dedicate valuable time, money and attention attempting to
address a problem that is largely beyond their control. DEQ acknowledges that the accumulation of
mercury in the Willamette Basin originates from historical anthropogenic emissions deposited into our
landscape or background sources that are beyond the regulated community's control. Further, DEQ
states that even the complete elimination of the estimated 4% of mercury contributed to the Willamette
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River and its tributaries from wastewater and municipal stormwater is unlikely to result in measurable
reduction of mercury. These factors make implementation of this TMDL quite different from those
previously issued for other pollutants and other waterbodies.
Response Text
EPA appreciates the commenter's perspective and recognizes the challenges of controlling mercury as a
pollutant. Global sources emit mercury that is atmospherically deposited in the Willamette River Basin;
therefore, the focus of the TMDL is to control in-basin transport of mercury into waterbodies, such as
reducing erosion on the landscape and using the best available management practices and treatment
measures. In some subbasins point sources are relatively small contributors. In other subbasins
stormwater and wastewater point sources are more important contributors. For example, about 11% of
the THg load in the Lower Willamette catchment is attributed to NPDES permitted POTWs and industrial
wastewater dischargers and about 21% originates from permitted urban stormwater sources.
Additionally, Section 13 of ODEQ's TMDL provides examples of proven techniques for point source
controls that have reduced mercury concentrations. Monitoring also shows that a combination of point
and non-point source control activities have reduced mercury concentrations. Reductions from point
sources are necessary to achieve water column and fish tissue standards in the waterbodies in the
Willamette River Basin.
Comment Text
In this TMDL, DEQ assigned wasteload allocations of 10% for wastewater dischargers and 75% for
stormwater dischargers, and a load allocation of 88% for nonpoint sources. It is difficult to fathom how
these sources will achieve these massive reductions. Existing regulations already require point sources
to implement practices that limit mercury transport into waterways, typically by reducing total
suspended solids (TSS). Similarly, nonpoint sources also have already been implementing many, if not
all, of the best practices described including protecting riparian buffers, maintaining roads and culverts,
stabilizing and re-vegetating streambanks, protecting wetlands, crop rotation and grazing management.
Response Text
This comment was submitted during the public comment period for ODEQ's TMDL but was not
responded to in DEQ's responses to comments. Reductions assigned as wasteload and load allocations
have been revised in EPA's TMDL to ensure attainment of water quality and human health standards in
the Willamette River Basin. The focus of the TMDL is to control in-basin transport of mercury into
waterbodies. EPA recognizes that best management practices, such as maintaining or restoring riparian
buffers along waterways, are being implemented in some areas. However, additional treatment
technologies and control measures that reduce mercury loading to waterbodies will be necessary to
achieve water column and fish tissue standards throughout the basin. Through DEQ's implementation of
its Water Quality Management Plan (WQMP), more specifically through monitoring and adaptive
management, it will become evident where greater control measures will be needed to achieve the
goals of the TMDL.
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Comment Category
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Comment ID
Comment Category
L17-11
TMDL Implementation
Comment Text
We appreciate the inclusion of the adaptive management provisions. We expect these provisions to
allow for flexibility as the TMDL is implemented and as future monitoring and research yield better data
sets. An adaptive management approach is especially prudent given the size and complexity of the
TMDL, and the lack of certainty with respect to data and modeling outputs.
Response Text
This comment was originally submitted during the public comment period for ODEQ's TMDL. As
described in ODEQ's response to public comments, ODEQ plans to use adaptive management during the
implementation of the TMDL as described in Section 13.1.2 of the WQMP. EPA's supports ODEQ's use of
adaptive management for implementing the TMDL.
Comment ID L17-12
Comment Category Lacks sensitivity analysis
Comment Text
No sensitivity analyses were completed. This could produce a variance in the Food Web Model's (FWM)
biomagnification factor resulting in unnecessarily stringent load and wasteload allocations.
Response Text
EPA disagrees with the statement that no sensitivity analysis was performed. The Food Web Modeling
approach to get values of the biomagnification factor for the different fish species explicitly
incorporated the variation model parameters by using the probabilistic approach in the Monte Carlo
simulation, which is itself a sensitivity analysis. The model parameters and how they were simulated in
the Monte Carlo application are listed in Table 3-2 in the Technical Support Document. Also, the
response of the model to these variations is discussed in Section 3.6 of the Technical Support Document.
Some key insights about model parameters are provided in this discussion. For example, specification of
the distribution of exposure concentrations is a primary factor controlling the tails of the cumulative
distribution functions used in the simulations. This is the information that ODEQ used to "...determine
how the values of the biomagnification factor of the Food Web Model (FWM) might vary given other
modeling decisions or how its variation might affect the calibration of the FWM..."
Comment Text
The modeled fish tissue mercury concentrations do not appear to fully support the FWM calibration for
the Northern Pikeminnow making target concentrations of Total Mercury (THg) questionable.
Response Text
EPA acknowledges that, like any model, the Food Web Model (FWM) is an approximation of observed
conditions. The FWM was calibrated by attempting to match the cumulative distribution functions
generated by the FWM to the cumulative distribution functions for observed data (Technical Support
Document [TSD] Figure 3-4) and the TSD notes that "...the fit for NPM is not perfect but is reasonable."
TSD Figure 3-4 shows that the match between model and data remains within 95% confidence limits
Comment ID
Comment Category
L17-13
Food Web Model - uncertainty regarding the target THg
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from the 50th to 70th percentile and is thus acceptable for the median of the distribution (50th
percentile), which is the basis for estimating the THg target, while discrepancies are associated with the
tails of the distribution. TSD Figure 3-6 shows that the relationship between fish length and mercury
tissue concentration is reasonably well reproduced by the model. Finally, the bioaccumulation factor
(BAF) simulated for NPM in the FWM is well within the 95% confidence limits of reported BAF values for
Trophic Level 4 fish species. EPA believes that the discrepancies between the model and observed fish
tissue data in the tails of the distribution - which are not used to set the water column target - are
attributable to use of a steady-state bioaccumulation model to approximate the results of a dynamic
relationship between exposure concentration and body burden, along with other simplifying
assumptions regarding mercury uptake and depuration. These issues are discussed at length in the TSD.
Comment Text
The THg concentration required by DEQ appears to lack certainty, as alternative approaches could be
employed for determining input parameters and result in a different target THg concentration.
Response Text
This is the same comment as L17 Comment 3. EPA acknowledges that the linkage analysis for the TMDL
includes uncertainty, as the case with all modeling analyses. Federal regulations require that the TMDL
be developed despite uncertainty in the analysis, and the presence of such uncertainty does not remove
EPA's obligation to establish the TMDL at levels sufficient to meet water quality standards. As noted at
40 CFR 130.2(g), load allocations for nonpoint sources "...are best estimates of the loading, which may
range from reasonably accurate estimates to gross allotments, depending on the availability of data and
appropriate techniques for predicting the loading." The Clean Water Act and 40 CFR 130.7(c)(1) also
require that TMDLs include a margin of safety "...which takes into account any lack of knowledge
concerning the relationship between effluent limitations and water quality."
Different parameter values would indeed result in different target THg concentrations. This is directly
addressed in Tables 3-3, 3-4, and 4-4 of the Technical Support Document, in which Monte Carlo analysis
is used to present the distribution of biomagnification factors, fish tissue concentrations, and
corresponding water column concentration targets.
Comment Text
The Mercury Translator Model introduces further uncertainty as its methodology determined a target
concentration of THg in the water column from the dissolved methylmercury input parameter.
Response Text
EPA acknowledges that the translation between total mercury (THg) and dissolved methylmercury is a
source of uncertainty in the TMDL calculations. The pollutant addressed by this TMDL is total mercury.
However, food chain bioaccumulation, which results in elevated fish tissue concentrations of mercury, is
driven primarily by dissolved methylmercury, most of which is derived from bacterial transformation of
ionic mercury in the environment. It is, therefore, necessary to develop a translation between total
mercury and methylmercury concentrations to establish a causal linkage between total mercury loads in
the Basin and impairment based on fish tissue concentrations of mercury.
Comment ID
Comment Category
L17-14
Applicable Water Quality Standards
Comment ID
Comment Category
L17-15
Mercury Translator
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Comment ID
Comment Category
L17-16
Mass Balance Model/HSPF
Comment Text
The Mass Balance Model (MBM) employs an additional three models to provide input values and data
comparisons for calculating present-day mercury contributions. Using modeling outputs as subsequent
model inputs further compounds the magnitude of unreliability in the estimates.
Response Text
This is the same comment as Comment ID 5 from the same comment letter (L17). Please see that
response.
Comment Text
Beyond concerns with the modeling, we find the way in which DEQ has incorporated a margin of safety
into the TMDL problematic. The margin of safety, as required by OAQ 340-042-0040, is intended to
account for uncertainty in the data, as well as uncertainties with estimating pollutant loads, modeling
water quality, and monitoring water quality.
DEQ employs three distinct elements in its calculation of a margin of safety:
• The use of the Northern Pikeminnow as an efficient bioaccumulator of mercury;
• The method of calculating the Food Web Model which results in a lower value than the average
concentration; and
• The use of total mercury concentrations in fish tissue rather than methylmercury in the water quality
criterion.
By layering so many conservative assumptions, DEQ has far exceeded regulatory expectations for
ensuring a reasonable margin of safety. While we understand DEQ's interest in ensuring a cautious
approach in the face of imperfect knowledge, we believe it is possible that the load and wasteload
allocations are far more stringent than necessary and that this highly conservative approach has
resulted in a significant compliance burden for regulated entities. DEQ should more fully explain the
rationale behind their approach and assess the likely impact that each element would have, as well as
the cumulative impacts.
Response Text
This comment is the same comment submitted on ODEQ's July 2019 Public Review Draft TMDL and does
not correctly reflect the contents of either ODEQ's November 2019 TMDL or the EPA TMDL. The Clean
Water Act and 40 CFR 130.7(c)(1) require that TMDLs include a margin of safety (MOS) "...which takes
into account any lack of knowledge concerning the relationship between effluent limitations and water
quality." The MOS can be either explicit, through allocation of a portion of the loading capacity, or
implicit, through use of conservative assumptions in the TMDL analysis or in developing a TMDL target,
or both.
EPA reviewed the MOS discussion provided in ODEQ's November 2019 TMDL and accepted only the first
and third of the proposed three components of the ODEQ MOS. EPA rejected the component of the
Comment ID
Comment Category
L17-17
Margin of Safety
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MOS regarding the method of calculating the Food Web Model. However, EPA also added an additional
MOS component, as described in Section 9 of the EPA TMDL:
"Needed reductions in loads are based on comparing water column mercury targets to ambient
monitoring data. Those monitoring data are available through 2011 in only 9 of the 12 HUC8 watersheds
and thus do not incorporate any reductions in mercury loading that have occurred since 2011. Data
presented in ODEQ's 2019 TMDL (p. 37) indicate that mercury concentrations have been declining in
more recent years (2012 - 2019) in the Tualatin and Lower Willamette subbasins."
With these modifications, EPA found that the components of the implicit MOS account for any lack of
knowledge or uncertainties concerning the relationship between pollutant loading and receiving water
quality and that the MOS is thus approvable. The MOS is not unduly conservative given the many
sources of uncertainty identified in the TMDL linkage analysis by this commenter and others.
Comment ID L17-18
Comment Category T SS as surrogate
Comment Text
Given the cost and complexity associated with direct monitoring of methylmercury levels in fish tissue,
OBI acknowledges the practicality of employing a surrogate. While using TSS as a surrogate for assessing
and monitoring THg may be effective, we question whether TSS is the best and most accurate surrogate
that could be utilized when other surrogate options exist. We request that DEQ explain the selection of
TSS as the preferred surrogate for THg.
Response Text
This comment summarizes an earlier comment from OBI that was originally submitted in response to
ODEQ's Public Review Draft of the TMDL (July 2019). For the November 2019 TMDL, ODEQ revised
Section 10.3 and Appendix G (formerly Appendix H in the Public Review Draft) in response to this and
other related comments.
ODEQ's November 2019 Response to Comments document (Section 72) provided the following response
to the earlier OBI comment: "Based on the analysis presented in Section 10 of the TMDL and Appendix H
[now G], DEQ considers there to be a strong relationship between THg and TSS. Therefore, based on the
relationship found between total suspended solids and total mercury, surrogate instream targets were
set for reductions in high levels of TSS concentrations to reduce total mercury in stream and evaluate
progress towards achieving the allocations and total mercury TMDL water column target described in
the TMDL. ODEQ revised Section 10.3 and Appendix H [G] with clarifications on the intention that TSS
surrogate targets will be used. The use of TSS surrogate targets and other tools will be described in the
Assessment and Monitoring Strategy that is being developed, an overview of which is provided in
Sections 13.6 and 14.1.6 of the ODEQ November 2019 final TMDL." The use of TSS as a surrogate for THg
is a component of ODEQ's implementation strategy, which is determined by DEQ.
Comment Text
Finally, we have noted that DEQ is entrusting significant authority to a great variety of Designated
Management Agencies (DMA), which will assume the bulk of the responsibility for preparing
implementation plans for the TMDL and Water Quality Management Plan (WQMP). While we believe
this strategy could be beneficial in arriving at sector-specific plans addressing unique factors and
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Comment ID
Comment Category
L17-19
Water Quality Management Plan
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challenges associated with each sector, we are concerned about uneven implementation. With so many
DMAs involved, we fear that some implementation plans might impose more burdensome requirements
than others. Because the upside outweighs the potential pitfalls, we do not suggest that this provision
be modified. However, we would like DEQto remain cognizant of the risk as the DMAs develop TMDL
implementation plans.
Response Text
EPA reviewed ODEQ's Water Quality Management Plan and found it was sufficient to support
Reasonable Assurances relative to nonpoint source control to meet the scope of EPA's TMDL. Section 13
of ODEQ's 2019 TMDL provides examples of required measures for the DMAs to address mercury
loading from nonpoint sources of pollution. For example, within 18 months after issuance of the TMDL,
DMAs must develop and submit to ODEQTMDL implementation plans to address mercury loading
through controlling erosion and runoff from their respective sector activities. However, EPA does agree
with OBI that there is a risk of uneven implementation and other potential pitfalls in what, of necessity,
will be a complex implementation process. In this regard, ODEQ's commitment to a 5-year review
process and adaptive management in the TMDL (Section 13.4 of the DEQTMDL, which is attachment A
to the EPA TMDL) will be a key mechanism for identifying and resolving problems of uneven
implementation.
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Author Name Mike Brown
Organization Name
Letter ID
Comment ID
Comment Category
Bureau of Land Management
L18
L18-1
Background
Comment Text
The Bureau of Land Management (BLM) would like to thank the Environmental Protection Agency for
the opportunity to comment on the Willamette Basin Mercury Total Maximum Daily Load (TMDL). The
BLM's participation on the Willamette Basin Mercury TMDL Advisory Committee over the past two years
has provided our agency with the information and context to help inform the development of this
document and to continue our work with the Oregon Department of Environmental Quality (ODEQ) to
maintain and improve water quality in the Willamette Basin. The BLM administers public lands in the
Willamette Basin for multiple uses, including timber production, recreation, mining, and habitat
management. The Resource Management Plans for Western Oregon (2016) incorporated new science,
policies, and technology to protect water resources. Our rigorous environmental planning process
incorporates into the design of every action measures that avoid or mitigate pollutants from entering
the waters of the State of Oregon. The BLM implements a suite of site-specific and action-specific best
management practices with each action to protect water resources. The BLM follows established
processes to monitor project implementation and the efficacy of our protections to ensure all actions
are implemented to the designed standards. The measures that the BLM takes for actions planned
under the Resource Management Plans for Western Oregon (2016) greatly reduces the probability of
sediment delivery to streams.
Response Text
EPA agrees that the planned water quality protection strategies are important components of the
mercury TMDL Implementation, and appreciates the work done by BLM towards this effort.
Comment Text
The BLM supports actions that improve water quality and reduce mercury in fish tissue. In general, the
BLM supports this TMDL, however we have concerns about the additive assumptions used in the
analyses and the subsequent uncertainty from which conclusions are drawn. Mercury methylation is a
product of complex processes that move and transform mercury in the environment. Most of the
mercury in the Willamette Basin's forested landscape is derived from air deposition. Tetra-tech's mass
balance, mercury translator, and food web models do little to characterize exactly how and where
inorganic mercury is methylated and the pathways for bioaccumulation. The connection between BLM
management actions and methylmercury fish tissue concentrations is not clear from the modeling effort
that serves as the foundation for the load allocations in this document.
Response Text
EPA acknowledges that there are multiple sources of uncertainty in the TMDL and that mercury
methylation is a complex process. However, the combination of the state of the science for modeling
mercury methylation and the lack of data on methylation hotspots did not allow for a process-based
Comment ID
Comment Category
L18-2
Analytical Framework
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representation of mercury methylation in this TMDL This issue is discussed in Section 1.1 of the
Technical Support Document (Appendix B to the EPA TMDL): "Determining the TMDL linkage between
the ultimate stressor (THg loads) and the management objective (attaining acceptable fish tissue
concentrations of MeHgto protect human health) is complicated because of the many intervening
kinetic and transport processes. MeHg is produced under anoxic conditions, which can occur within a
river or within its watershed. Within a river, MeHg production mostly occurs within the sediment, with
the quiescent water of backwater channels potentially having higher rates of methylation. Within a
watershed, wetlands or areas with saturated soils can often provide important locations for MeHg
production. The relative importance of internally produced (within the waterbodies and their
sediments) or externally produced (within soils and groundwater prior to reaching waterbodies) sources
of MeHg has not been assessed for the WRB. MeHg monitoring data are available primarily from the
water column. The simplified conceptual framework used in this TMDL is that the long- term average
MeHg concentration in the water column depends on THg concentrations in the sediment, which in turn
depend on rates of THg loading from upstream. The complex transformations between different forms
of mercury are not explicitly simulated; rather, they are approximated by an empirical relationship
between observed MeHg and THg in the water column..."
As stated in Section 13.6 of the November 2019 ODEQ TMDL and Water Quality Management Plan, DEQ
has committed to developing an Assessment and Monitoring Strategy to Support Implementation of
Mercury Total Maximum Daily Loads for the Willamette Basin. In general, this strategy will evaluate
effectiveness of implementation actions and determine progress toward meeting the total mercury
loading capacity of 0.14 ng/L and methylmercury fish tissue criterion of 0.040 mg/kg. Data collected as
part of this strategy could potentially be used to refine the characterization of how and where inorganic
mercury is methylated and the pathways for bioaccumulation, which in turn may support adaptive
management to improve the effectiveness of implementation strategies over time. EPA encourages the
commenter and other interested stakeholders to participate in the development of this monitoring
strategy.
Comment Text
The BLM, along with all other Designated Management Agencies (DMAs) worked together with ODEQ to
help inform the parameters of a successful Water Quality Management Plan. We are encouraged that
the EPA determined that this Water Quality Management Plan demonstrated a reasonable assurance
that our proposed actions move towards the targets described in the TMDL. The BLM also looks forward
to continuing our collaborative water monitoring program with ODEQ and will continue to invest
resources as staffing and funding allows.
The BLM is committed to designing actions consistent with the Resource Management Plans for
Western Oregon (2016) while working with the ODEQ and the partner agencies of the Willamette Basin
to maintain and improve water quality. We understand how difficult this process was for all involved,
and we look forward to working with the ODEQ in the coming months on the Water Quality Restoration
Plan for the Willamette Basin Mercury TMDL.
Response Text
EPA appreciates the BLM's support for the TMDL and their contributions to the Water Quality
Management Plan developed under ODEQ's leadership.
Comment ID
Comment Category
L18-3
DEQ's authority/responsibility to implement
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Author Name Dennis Hebard
Organization Name
Letter ID
Comment ID
Comment Category
Private Citizen
L19
L19-1
Suction Dredging
Comment Text
My name is Dennis Hebard, please accept my comments on the Willamette Basin Mercury TMDL I object
to excluding small suction dredge mining in waters that are not impaired. You cannot establish a 0 WLA
for streams that may or may not be covered in the future. Oregon says that they will extend the TMDL
to streams if they are determined to be impaired and added to 303d listings in the future, saving having
to write a new TMDL they can just be applied. The stated source is the Bohemia Mining District, while
small suction dredging disturbs in-place sediments, there will be no increase in supply of sediment to
the stream if the activity is conducted according to the permit. Each stream in the Upper Row River
Watershed should be evaluated independent of the others as the BMD is the source and only comes
down Champion Creek and into Brice creek and yet the Sharps creek watershed is not contaminated and
should not be included in the dredge ban. Sharps creek and Marten creek sampling ranges from 0.04 to
0.18 mg/kg and averages O.llmg/kg (l.Omg/kg = 1 part per million) again this is within rock and mineral
we don't have elemental mercury, the actual amount of material moved in a day from a small suction
dredge is less than 1 cubic yard as this does not include the rock and boulders that have to be moved by
hand, we do not crush or grind, use a flare to feed the sluice box, most of the gold is small mixed with
black iron sands so our concentrates are taken away from the stream to process in camp or at home. It's
generally accepted by agencies from peer review (Humphreys 2005) that a small suction dredge
captures 98% of mercury. Using the Sharps creek mean concentration of < 0.2 mg/kg (Hygelund et al
2001) the 2% not captured by the sluice for Sharps creek this would be less than 0.004 mg/kg.
Calculating the 50 cubic yards maximum per season the amount would be less than 0.14 mg/kg lost by
the dredge for the most we are allowed to move. If it was just sediment, what percentage are rocks and
pebbles? Freshwater Level 2 screenings for sediment is 0.2 mg/kg, concentrations do not exceed limits
(https://www.oregon.gov/deq/FilterDocs/GuidanceEcologicalRisk.pdf) From DEQ guidance "If the
maximum detected concentration is less than the default value that metal is not present in site soil
above background levels then that metal is not a chemical of potential concern or potential ecological
concern." Background mercury levels for soil 0.24 mg/kg (https://www.oregon.gov/deq/FilterDocs/cu-
bkgrmetals.pdf) The transport and fate of mercury not removed from a stream that is Not impaired has
not been studied in much detail if any.
Response Text
DEQ is not currently proposing to add Sharps Creek, Marten Creek, or other tributaries to Dorena
Reservoir to the 303(d) list of waterbodies impaired by mercury. EPA does not contend that ecological
risks from mercury are present within these creeks (consistent with the screening level cited in
https://www.oregon.gov/deq/FilterDocs/GuidanceEcologicalRisk.pdf); however, mercury loads
generated from these creeks are of concern for downstream waters.
The studies referenced in the ODEQTMDL indicate that disturbance by suction dredging increases the
potential for mercury that is currently present in the sediment of streams to be uncovered, oxygenated,
transformed to dissolved and suspended states, transported downstream to Dorena Reservoir and
methylated. Sediment analyzed from Sharps Creek was found to have a mean concentration of 0.20
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mg/kg mercury (Hygelund et al 2001). Sharps Creek is a tributary to Dorena Reservoir and Dorena
Reservoir is a known area of mercury methylation, is listed for mercury on the 303(d) list of impaired
waterways and has fish consumption advisories in place for mercury. There are no demonstrated
methods to prevent the mobilization during suction dredge mining and subsequent methylation of
mercury.
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Author Name Dennis Hebard
Organization Name
Letter ID
Comment ID
Comment Category
Private Citizen
120
L20-1
Suction Dredging
Comment Text
I object to removing the NPDES 700pm small suction dredge permit in waters that are not impaired,
while small suction dredging disturbs in-place sediments, there will be no increase in supply of sediment
to the stream, the NPDES does Not regulate movement of stream bed material in Oregon that is
regulated by removal/fill the streams of the URRW are not ESH no permit is required for moving less
than 50cy, in the NPDES the discharge is assigned a mixing zone at no time is this above the limits for
mercury, turbidity or any of the defined pollutants within the permit. The stated source is the Bohemia
Mining District, while small suction dredging disturbs in-place sediments, there will be no increase in
supply of sediment to the stream if the activity is conducted according to the permit. Each stream in the
Upper Row River Watershed should be evaluated independent of the others as the BMD is the source
and only comes down Champion Creek and into Brice creek and yet the Sharps Creek watershed is not
contaminated and should not be included in the dredge ban.
Response Text
ODEQ is not currently proposing to add Sharps Creek or other tributaries to Dorena Reservoir to the
303(d) list of waterbodies impaired by mercury. The studies referenced in the ODEQTMDL indicate that
disturbance by suction dredging increases the potential for mercury that is currently present in the
sediment of streams to be uncovered, oxygenated, transformed to dissolved and suspended states,
transported downstream to Dorena Reservoir and methylated. Sediment analyzed from Sharps Creek
was found to have a mean concentration of 0.20 mg/kg mercury (Hygelund et al 2001). Sharps Creek is a
tributary to Dorena Reservoir and Dorena Reservoir is a known area of mercury methylation, is listed for
mercury on the 303(d) list of impaired waterways and has fish consumption advisories in place for
mercury. There are no demonstrated methods to prevent the mobilization during suction dredge mining
and subsequent methylation of mercury.
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Author Name Dennis Hebard
Organization Name
Letter ID
Comment ID
Comment Category
Private Citizen
121
L21-1
Suction Dredging
Comment Text
We tried to tell DEQthe form of Mercury is rock and mineral-bound, samples had to be ground, a small
suction dredge does not do that, little to No elemental mercury is present. "Speciation testing showed
strong-complexed species (mercurous chloride) and cinnabar (HgS) both species comprised up to 96% of
the mercury detected in samples" HgS made up to 64% in stream sediment, HgS is generally resistant to
chemical and physical weathering at nominal pH (Gray et al. 2003) and therefore, not expected to be a
primary source of dissolved Hg (II) ions in the aqueous stream and lake environment. If this type of
mercury is transformed to dissolved and suspended states in our streams it would be in the water
column after 50+ years of suction dredging, it is not. if activities, transport/fate from small suction
dredge mining it would be detectable in the water column My comments about winter flooding moving
mercury were misrepresented and rewritten. I wrote that in the Humphries 2005 Yuba dredge study the
liquid mercury hot spots and sticking to clay that were actually describing mine slickens from historic
mining in the Sacramento valley, but that normal bench run gravels or from a river bar in the study they
conclude "it would take 1,000,000 hours using an 8" dredge to compare to the natural particulate
transport during an average dry year to affect the reservoir downstream".
Response Text
There are several papers by John Gray in 2003 that focus on mercury associated with mine waste and it
is unclear which one is specifically being referred to here. Regardless, in a review of the Gray et al., 2003
publications, none of them focused on mercury speciation associated with suction dredge mining. To
our knowledge, the primary scientific studies on this topic are Humphreys et al., 2005, Marvin-
DiPasquale et al., 2011 and Fleck et al., 2011. These studies focus on the specific impacts of suction
dredge mining and the mobilization of elemental mercury. While mercury is found in many different
forms in the environment, the form of mercury that is of concern at suction dredge sites is elemental
mercury. Elemental mercury is often present in areas targeted by suction dredge miners because
elemental mercury was used as part of historical gold and silver mining activities. The elemental
mercury from historical mining operations is typically deeply buried and would otherwise be inaccessible
to natural erosion remobilization processes except during extreme hydrologic conditions (Fleck, 2011;
Marvin-DiPasquale, 2011). The process of suction dredging can capture a high percentage of elemental
mercury in the sediment. However, this process can also mobilize some smaller fraction of the mercury
into the water where it can be transported downstream to where conditions are more conducive to
methylmercury production and accumulation in aquatic organisms can occur (Fleck, 2011; Humphreys,
2005; Marvin-DiPasquale, 2011). While suction dredging can remove a large fraction of the mercury
buried in stream sediments, the overall impact is that there is an increase in the mobility of mercury in
the stream environment which can increase the availability of mercury for methylation and
bioaccumulation in fish.
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Comment ID
Comment Category
L21-2
DEQ's authority/responsibility to implement
Comment Text
DEQ claims authority under Title 33 US Code 1313(d) But under section (d) Identification of areas with
insufficient controls; maximum daily load; certain effluent limitations revision (4) Limitations on revision
of certain effluent limitations.— (B) Standard attained.— For waters identified under paragraph (1)(A)
where the quality of such waters equals or exceeds levels necessary to protect the designated use for
such waters or otherwise required by applicable water quality standards, any effluent limitation based
on a total maximum daily load or other waste load allocation established under this section, or any
water quality standard established under this section, or any other permitting standard may be revised
only if such revision is subject to and consistent with the antidegradation policy established under this
section. Streams in the upper Row river watershed were not included in the 2006 Mercury TMDL so
would be a change of the previous plan, under 33 US Code 1313(d)(4)(B) (standard attained) they can
only apply antidegradation policy to them, that would limit changes to New or increased discharges, but
not suction dredging under the 700pm because it is an existing permitted activity.
Response Text
EPA disagrees with the commenter's interpretation of the Clean Water Act and accompanying
regulations. The cited sections say that lowering of existing water quality, even if the existing water
quality exceeds levels necessary to protect the designated use, is only allowed if it is consistent with
antidegradation policy designed to protect existing instream uses. See the implementing regulations at
40 CFR 131.12. These sections do not imply that more stringent requirements cannot be imposed when
necessary to meet water quality standards.
EPA also disagrees with the contention that "...streams in the upper Row river watershed were not
included in the 2006 Mercury TMDL." While the upper Row River and its tributaries were not identified
as impaired waters in the 2006 TMDL, these are upstream of and contribute mercury load to Dorena
Reservoir, which was identified as impaired. As a result, the 2006 TMDL (pages 3-33) did apply nonpoint
source load allocations in the form of a 29.8% reduction in existing loads to all waters upstream of
Dorena Reservoir.
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Author Name Dennis Hebard
Organization Name
Letter ID
Comment ID
Comment Category
Private Citizen
122
L22-1
Suction Dredging
Comment Text
I object to excluding small suction dredge mining in waters that are not impaired. The NPDES 700pm
does not regulate movement of stream sediment, since you put small suction dredging in the EPA's
Mercury TMDL does this mean we can bring this to a federal court? Each stream in the Upper Row River
Watershed should be evaluated independent of the others as the BMD is the source and only comes
down Champion Creek and into Brice creek and the Sharps creek watershed is not contaminated and
should not be included in the dredge ban.
Response Text
ODEQ is not currently proposing to add Sharps Creek or other tributaries to Dorena Reservoir to the
303(d) list of waterbodies impaired by mercury. The studies referenced in the ODEQ TMDL indicate that
disturbance by suction dredging increases the potential for mercury that is currently present in the
sediment of streams to be uncovered, oxygenated, transformed to dissolved and suspended states,
transported downstream to Dorena Reservoir and methylated. Sediment analyzed from Sharps Creek
was found to have a mean concentration of 0.20 mg/kg mercury (Hygelund et al., 2001). Because Sharps
Creek is tributary to Dorena Reservoir and Dorena Reservoir is a known area of mercury methylation, is
listed for mercury on the 303(d) list of impaired waterways and has fish consumption advisories in place
for mercury, and there are no demonstrated methods to prevent the mobilization during suction dredge
mining and subsequent methylation of mercury, DEQ intends to prohibit suction dredge mining in
tributaries to the reservoir to reduce permitted discharges of mercury and reduce methylation potential
of existing mercury contamination in stream sediments.
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Author Name Dennis Hebard
Organization Name
Letter ID
Comment ID
Comment Category
Private Citizen
123
L23-1
General
Comment Text
Each stream in the Upper Row River Watershed should be evaluated independent of the others as the
BMD is the source and only comes down Champion Creek and into Brice creek and the Sharps creek
watershed is not contaminated and should not be included in the dredge ban.
Response Text
Sediment analyzed from Sharps Creek was found to have a mean concentration of 0.20 mg/kg mercury
(Hygelund et al., 2001). Sharps Creek is a tributary to Dorena Reservoir and Dorena Reservoir is a known
area of mercury methylation, is listed for mercury on the 303(d) list of impaired waterways and has fish
consumption advisories in place for mercury. There are no demonstrated methods to prevent the
mobilization during suction dredge mining and subsequent methylation of mercury. ODEQ's 2019 TMDL
provides that upon renewal of the 700PM permit, DEQ will prohibit suction dredge mining in tributaries
to the reservoir to reduce discharges of mercury and reduce methylation potential of existing mercury
contamination in stream sediments. EPA's TMDL is consistent with this approach by assigning a zero
WLA to the suction dredge mine industry in the Coast Fork subbasin.
Comment Text
Social and economic impacts should be looked at in any environmental regulation or rulemaking
otherwise local people will be discriminated against as they are doing now. The Bohemia Mine Owners
Association (est.1903) will be irreparably harmed. BMOA, it's not just the ones that mine, its whole
families, BMOA not only promotes and defends our common interest, but are stewards of the lands with
substantial interest invested. The reason we exist is to mine our claims and provide an opportunity for
members to mine our nine common claims; these in turn involve members and family recreational
opportunity. We have a mine patrol, like a neighborhood watch, including 2-way radio
equipment/antenna this assists travelers, other forest users, report crimes, prevent vandalism and
homeless or extended camping beyond the 14 day limit. BMOA adopted Champion Creek Road, Sharps
Creek Road, Ray Nelson Bohemia Saddle Park, and Mineral Camp Park. The BMOA assists Lane County
and the United States Forest Service and Bureau of Land Management in performing maintenance and
litter control on the Parks and Roads, with an MOU with each agency.
Response Text
The Clean Water Act requires TMDLs to be set such that pollutant loads are less than or equal to the
maximum amount that a waterbody can receive while still meeting water quality standards (through
application of the loading capacity). The regulations for establishing the loading capacity do not include
a consideration of social or economic impacts in determining its numeric value; however, such factors
could be considered in deciding how the TMDL is divided up into load allocations and wasteload
allocations for individual nonpoint and point sources of pollutant loads. The Willamette mercury TMDL
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Comment ID
L23-2
Comment Category
General Comments
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requires large reductions in all sources of mercury loading to achieve water quality standards. In
developing the revised TMDL, EPA endeavored to keep as many of the assumptions regarding
allocations made by ODEQ as were consistent with achieving the TMDL in all HUC8 watersheds of the
basin. EPA agreed with ODEQ's conclusion that suction dredging can be a significant source of mercury
loading in areas where stream sediments are contaminated with mercury as shown in the Coast Fork
Subbasin. Therefore, EPA's TMDL assigns a zero WLA to the suction dredge mine industry in the Coast
Fork subbasin.
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Author Name Dennis Hebard
Organization Name
Letter ID
Comment ID
Comment Category
Private Citizen
124
L24-1
Suction Dredging
Comment Text
Please accept attached documents in support of my objection to removing small suction dredge mining.
(Three documents were attached: Suction Dredge Gold Mining ... Cleaning Our Streams, One Rock at a
Time (power point presentation); IDEQ Water Quality Summary Report 34; Western Mining Alliance
document titled "Suction Dredging for Gold").
Response Text
We have reviewed the attached power point presentation titled: SUCTION DREDGE GOLD MINING . . .
CLEANING OUR STREAMS, ONE ROCK AT A TIME, and the IDEQ report Water Quality Summary Report
34. These documents do not address the potential for mercury mobilization during the process of
suction dredge mining, which is the specific impact of concern as it relates to this TMDL. The document
by the Western Mining Alliance titled Suction Dredging for Gold does address mercury; however, it does
not provide any information that refutes the conclusions from previous studies. These studies have
found that the sediments containing mercury from historical mining operations are typically deeply
buried and would otherwise be inaccessible to natural erosion remobilization processes except during
extreme hydrologic conditions (Fleck, 2011; Marvin-DiPasquale, 2011). The process of suction dredging
can capture a high percentage of the elemental mercury in the sediment. However, this process can also
mobilize some smaller fraction of the mercury into the water where it can be transported downstream
to where conditions are more conducive to methylmercury production and accumulation in aquatic
organisms can occur (Fleck, 2011; Humphreys, 2005; Marvin-DiPasquale, 2011). Without the activity of
suction dredging, this fraction of mercury would have remained deeply buried in the sediment and
would not have been available for uptake into the food web. While suction dredging can remove
mercury buried in stream sediments, the overall impact is that there is an increase in the mobility of
mercury in the stream environment which can increase the availability of mercury for methylation and
bioaccumulation in fish.
Comment Text
Attachment: Suction Dredge Gold Mining... Cleaning Our Streams, One Rock at a Time
Response Text
We have reviewed the attached power point presentation titled: SUCTION DREDGE GOLD MINING . . .
CLEANING OUR STREAMS, ONE ROCK AT A TIME, the Western Mining Alliance's SUCTION DREDGING
FOR GOLD, and the IDEQ report Water Quality Summary Report 34. These documents do not address
the potential for mercury mobilization during the process of suction dredge mining, which is the specific
impact of concern as it relates to this TMDL. The document by the Western Mining Alliance titled
Suction Dredging for Gold does address mercury; however, it does not provide any information that
refutes the conclusions from previous studies. These studies have found that the sediments containing
Comment ID
L24-2
Suction Dredging
Comment Category
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mercury from historical mining operations are typically deeply buried and would otherwise be
inaccessible to natural erosion remobilization processes except during extreme hydrologic conditions
(Fleck, 2011; Marvin-DiPasquale, 2011). The process of suction dredging can capture a high percentage
of the elemental mercury in the sediment. However, this process can also mobilize some smaller
fraction of the mercury into the water where it can be transported downstream to where conditions are
more conducive to methylmercury production and accumulation in aquatic organisms can occur (Fleck,
2011; Humphreys, 2005; Marvin-DiPasquale, 2011). Without the activity of suction dredging, this
fraction of mercury would have remained deeply buried in the sediment and would not have been
available for uptake into the food web. While suction dredging can remove a large fraction of the
mercury buried in stream sediments, the overall impact is that there is an increase in the mobility of
mercury in the stream environment which can increase the availability of mercury for methylation and
bioaccumulation in fish.
Comment ID L24-3
Comment Category Suction Dredging
Comment Text
Attachment: IDEQ Water Quality Summary Report: A Recreational Suction Dredge Mining Water Quality
Study on South Fork Clearwater River.
Response Text
We have reviewed the IDEQ report Water Quality Summary Report 34. This document does not address
the potential for mercury mobilization during the process of suction dredge mining, which is the specific
impact of concern as it relates to this TMDL. Previous studies have found that the sediments containing
mercury from historical mining operations are typically deeply buried and would otherwise be
inaccessible to natural erosion remobilization processes except during extreme hydrologic conditions
(Fleck, 2011; Marvin-DiPasquale, 2011). The process of suction dredging can capture elemental mercury
in the sediment. However, this process can also mobilize some smaller fraction of the mercury into the
water where it can be transported downstream to where conditions are more conducive to
methylmercury production and accumulation in aquatic organisms can occur (Fleck, 2011; Humphreys,
2005; Marvin-DiPasquale, 2011). Without the activity of suction dredging, this fraction of mercury would
have remained deeply buried in the sediment and would not have been available for uptake into the
aquatic food web. While suction dredging can remove mercury buried in stream sediments, the overall
impact is that there is an increase in the mobility of mercury in the stream environment which can
increase the availability of mercury for methylation and bioaccumulation in fish.
Comment ID L24-4
Comment Category Other
Comment Text
Attachment: Suction Dredging for Gold
Response Text
We have reviewed the attached power point presentation titled: SUCTION DREDGE GOLD MINING . . .
CLEANING OUR STREAMS, ONE ROCK AT A TIME, the Western Mining Alliance's SUCTION DREDGING
FOR GOLD, and the IDEQ report Water Quality Summary Report 34. These documents do not address
the potential for mercury mobilization during the process of suction dredge mining, which is the specific
impact of concern as it relates to this TMDL. The document by the Western Mining Alliance titled
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Suction Dredging for Gold does address mercury; however, it does not provide any information that
refutes the conclusions from previous studies. These studies have found that the sediments containing
mercury from historical mining operations are typically deeply buried and would otherwise be
inaccessible to natural erosion remobilization processes except during extreme hydrologic conditions
(Fleck, 2011; Marvin-DiPasquale, 2011). The process of suction dredging can capture a high percentage
of the elemental mercury in the sediment. However, this process can also mobilize some smaller
fraction of the mercury into the water where it can be transported downstream to where conditions are
more conducive to methylmercury production and accumulation in aquatic organisms can occur (Fleck,
2011; Humphreys, 2005; Marvin-DiPasquale, 2011). Without the activity of suction dredging, this
fraction of mercury would have remained deeply buried in the sediment and would not have been
available for uptake into the food web. While suction dredging can remove a large fraction of the
mercury buried in stream sediments, the overall impact is that there is an increase in the mobility of
mercury in the stream environment which can increase the availability of mercury for methylation and
bioaccumulation in fish.
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Author Name Salina N. Hart, P.E.
Organization Name
Letter ID
Comment ID
Comment Category
U.S. Army Corps of Engineers Portland District
125
L25-1
EPA's authority to require DEQto implement
Comment Text
The U.S. Army Corps of Engineers Portland District (Corps) appreciates the opportunity to comment on
the U.S. Environmental Protection Agency's (EPA) Willamette Basin Mercury TMDL, dated December 30,
2019. The Corps supports the overall goal of reducing mercury and improving water quality in this
important watershed; however, there are concerns with the proposed requirements for "Designated
Management Agencies" to reduce load allocations from the impoundments they operate in the sub-
basins that failed to achieve the Oregon Department of Environmental Quality's (ODEQ) 2019 TMDL
targets. The development of an implementation plan requires authority and funding, which is not at the
discretion of the agency. The Corps is congressionally mandated to operate its projects for the included
authorized purposes (flood risk management, hydropower, fish & wildlife, water supply, irrigation,
navigation, recreation). Some of the proposed actions within the TMDL would interfere with the Corps'
ability to operate for these project purposes, by mandating specific actions to reduce presumed mercury
loading at Corps' dams. These requirements are in direct conflict with the authorities cited by ODEQ as
justification for agency compliance. Therefore, the Corps is respectfully requesting the State and EPA
clarify its authority to require actions that directly interfere with the operations and traditional uses of
these congressionally authorized water development projects or revise the TMDL requirements for
DMAs. The Corps is receptive to working with the agencies in a collaborative effort on the role of DMAs.
Response Text
EPA thanks the U.S. Army Corps of Engineers (USACE) for their overall support for the TMDL and
commitment to working with the agencies. EPA is concerned that reservoirs can play a significant role in
the mobilization and methylation of mercury in the Willamette River Basin and believes that ODEQ has
correctly identified USACE as a Designated Management Agency (DMA) for operation of its reservoirs.
The determination and responsibilities of DMAs is a component of implementation under the discretion
of ODEQ, and as such is only reviewed by EPA for the purposes of reasonable assurance. EPA is not
asserting any regulatory authority to require USACE to undertake these actions. Should USACE agree to
implement measures to address methylation of mercury, those actions may require authority and
funding from Congress or the Department of Defense that is outside of EPA's control.
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Author Name Bill Moore
Organization Name
Letter ID
Comment ID
Comment Category
Oregon Department of Environmental Quality
126
L26-1
Other
Comment Text
Good afternoon, Oregon's Department of Environmental Quality appreciates the opportunity to provide
the attached letter of comment on EPA's 2019 Total Maximum daily Load for Mercury in the Willamette
Basin, Oregon.
Response Text
EPA appreciates ODEQ's comments. Responses to specific items are provided individually.
Comment ID L26-2
Comment Category General Comments
Comment Text
Oregon's Department of Environmental Quality appreciates the opportunity to provide this letter of
comment on EPA's 2019 Total Maximum Daily Load for Mercury in the Willamette Basin, Oregon. In
general, DEQ is providing comment on three overarching themes. First, EPA's TMDL should provide
adequate documentation of EPA's work, which is needed to justify the changes made to DEQ's TMDL
and for readers to understand the new requirements. The document also contains multiple errors and
inconsistencies with DEQ's TMDL, sections of which EPA's document refers to or incorporates by
reference. Finally, EPA's proposed subbasin-specific allocations are more stringent than necessary
because EPA relied on basin level assumptions and policies for development of subbasin-specific
allocations, including assumptions about more recent data at the subbasin scale.
Response Text
EPA disagrees with ODEQ's characterization of the revised 2019 EPA TMDL. EPA in large part accepted
the work and calculations completed by ODEQ. EPA rejected ODEQ's final TMDL allocations as these
were not sufficiently stringent to achieve water quality standards in five of the HUC8 watersheds of the
Willamette River Basin. Modifications to the allocations and to the margin of safety are explained in the
EPA 2019 TMDL document. ODEQ subsequently requested additional documentation in the form of the
spreadsheets that were used to calculate the final allocations, which EPA supplied.
This comment refers to unspecified "...multiple errors and inconsistencies with DEQ's TMDL...". These
are answered separately to the extent that they are identified in separate comments within this letter.
Finally, EPA disagrees with the assertion that "...allocations are more stringent than necessary..." EPA
disapproved ODEQ's 2019 TMDL on November 29, 2019 after determining that the load and wasteload
allocations based on percent reductions would not achieve the TMDL target in all the subbasins
addressed by the TMDL. In light of this decision, more stringent allocations that achieve the TMDL target
in all the subbasins addressed by the TMDL were developed by EPA and incorporated into the final
TMDL.
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Comment ID
Comment Category
L26-3
DEQ's authority/responsibility to implement
Comment Text
The cover/signature page of EPA's TMDL states that, following incorporation of any revisions arising
from public comment, EPA "intends to transmit this TMDL to the State of Oregon for incorporation into
its current water quality management plan." DEQ maintains an overall water quality management plan,
per CWA Section 303(d) and 40 CFR Section 130.7(d), of priority ranking of impaired waters needing a
TMDL. However, per OAR 340-42, DEQ develops Water Quality Management Plans specific to each
TMDL that DEQ develops that provide a framework for TMDL implementation and detailed strategies to
achieve allocations, including sector or source-specific implementation plans. The process is not the
same for TMDLs developed by EPA. Moreover, the WQMP was developed based on the TMDL written by
DEQ. DEQ will work with EPA for incorporation of EPA's TMDL for Mercury in the Willamette Basin,
Oregon into Oregon's water quality management plan under Section 303(e) of the Clean Water Act.
Response Text
EPA thanks ODEQfor noting the difference between the State's overall water quality management plan
(WQMP) and the WQMP specific to the Willamette Mercury TMDL and has revised the quoted sentence
to clarify this. We look forward to working with you to translate the provisions in this TMDL to your
waterbody specific WQMP.
Comment ID L26-4
Comment Category General Comments
Comment Text
EPA's November 29, 2019 letter disapproved DEQ's TMDL, and EPA's December 30, 2019 TMDL includes
DEQ's TMDL and Appendix A and specifically incorporates most sections by reference. DEQ found some
discrepancies, as noted specifically below. The current combined format contains conflicts, lacks clarity
as to which document is to be followed and requires the public to flip between documents. This makes it
confusing for those subject to allocations to attempt to identify the basis of the allocations, and in some
cases, the application of the allocations themselves. These conflicts should be resolved. The TMDL
would benefit from being presented as a comprehensive document. These changes would provide
clarity to the public regarding the regulatory requirements.
Response Text
EPA appreciates your comment and made appropriate changes to the revised final TMDL. Specific
discrepancies are discussed in individual comments and responses. EPA agrees that it would be less
confusing to the reader if there were a single, unified document; however, that may not be feasible, as
certain portions of ODEQ's TMDL, as required under state regulations (e.g., the Water Quality
Management Plan), are not requirements of the EPA TMDL but remain ODEQ's responsibility.
Comment Text
EPA should to make available to DEQ and the public EPA's 2019 Memo to File: Air Emission Hg
Allocations for Revised Willamette Mercury TMDL, authored by Chris Eckley, and referenced in footnote
Comment ID
L26-5
Comment Category
General Comments
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3 on page 3 of EPA's TMDL It appears this memo was relied upon in EPA's increased allocation to air
sources, and should be presented as part of EPA's documentation and justification for that allocation.
Response Text
The Eckley memorandum is part of EPA's administrative record for the TMDL and EPA sent the
document to QDEQ as requested.
Comment Text
4. Source Categories: Section 7, Tables 2 and 3, and Appendix C of EPA's TMDL present allocations using
different category names, comprised of different components and with additional categories compared
to DEQ's TMDL. As a result, it is unclear how EPA's sectors and allocations matchup with DEQ's sectors
and allocations which could affect DMA implementation. Most sections of DEQ's TMDL are incorporated
by reference into EPA's TMDL, so clarification is needed on which EPA sector labels compare with DEQ
categories. Specifically: a. EPA's TMDL contains a "Groundwater (agriculture, forest shrub, developed,
other)" category, which was not included as a separate DEQ source category. Rather DEQ captured
groundwater under "General Nonpoint Source and Background." Is EPA's 88% reduction for
"Groundwater (agriculture, forest shrub, developed, other)" in addition to the 88% and 97% subbasin-
specific "Agriculture, forest shrub, developed, other (runoff and sediment)" reductions that includes the
same land managers? b. EPA's footnote 1 indicates that water impoundments and conveyances entities
are included in both the "Groundwater ( agriculture, forest shrub, developed, other)" and "Agriculture,
forest shrub, developed, other (runoff and sediment)" categories. Whereas, DEQ captured water
impoundments and conveyances entities under "General Nonpoint Source and Background." c. Does
"Agriculture, forest shrub, developed, other (runoff and sediment)" align with DEQ's "General Nonpoint
Source" category, excluding groundwater and background? If so, where is background captured? d.
EPA's TMDL contains "Atmospheric deposition direct to water" as a distinct category. In contrast, DEQ
captured atmospheric deposition direct to streams in the "General Nonpoint Source and Background"
category. In addition, DEQ assigned an allocation to Atmospheric Deposition. DEQ's footnote 3 clarifies
that this allocation applies to precipitation deposited mercury that generates runoff, e. EPA's TMDL
assigned separate allocations to "NPDES Permitted POTW Wastewater • Discharges" and "NPDES
Permitted Industrial Wastewater Discharges," yet DEQ's basin-wide aggregate allocation applies to all
NPDES Permitted Wastewater Discharges.
Response Text
EPA's TMDL includes the same sources as ODEQ's TMDL, however, some allocation categories were
modified. EPA made changes to EPA's TMDL so that both TMDLs and DEQ's WQMP align to clarify the
differences.
Responses to sub-questions/comments A to E follow.
A. ODEQ's TMDL included a general non-point source category that included mercury associated with
surface runoff, sediment, and groundwater. Given that land managers have different opportunities to
control surface runoff and sediment compared to groundwater, the latter source was disaggregated for
EPA's TMDL. Therefore, reductions are assigned for groundwater and reductions are assigned to land
managers for surface runoff and sediment-based transport of mercury under the category titled
"Agriculture, forest, shrub, developed and other (runoff and sediment)" in Table 3 of EPA's TMDL.
Comment ID
L26-6
TMDL Implementation
Comment Category
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B. The footnote in Table 3 of EPA's TMDL is not accurate and will be updated in the revised final TMDL.
The "other" category includes runoff, sediment, and groundwater from the following land uses: barren,
grassland/herbaceous, pasture/hay, wetlands, and open water excluding the river network and lakes
explicitly represented in the HSPF watershed model.
C. The "Agriculture, forest, shrub, developed, other (runoff and sediment)" and "Groundwater
(agriculture, forest, shrub, developed, other)" categories in EPA's TMDL align with ODEQ's "General
Nonpoint Sources and Background" category as discussed above in response to A. Background sources
of mercury are implicitly represented in these categories. For example, soil mercury concentrations in
the watershed are attributed to legacy (background) and current atmospheric deposition processes, as
well as sediment erosion, fate and transport.
D. EPA's TMDL contains a category for "Atmospheric deposition direct to water", which aligns with the
"Atmospheric Deposition" category under non-point sources in ODEQ's TMDL. Both TMDLs assign
explicit allocations to atmospheric deposition direct to water. Atmospheric deposition of mercury that is
transported to streams by surface runoff is included in the "Agriculture, forest shrub, developed, other
(runoff and sediment)" category in EPA's TMDL.
E. ODEQ's TMDL included the allocations for both POTWs and industrial wastewater dischargers in the
"NPDES Wastewater Point Source Discharges" category. These are represented in separate categories
for EPA's TMDL, which include "NPDES Permitted POTW Wastewater Discharges" and "NPDES Permitted
Industrial Wastewater Discharges" because different reductions were allocated for these sources in
some catchments, such as the Middle Willamette.
Comment Text
5. Allocations: Both EPA's and DEQ's TMDLs cover 12 subbasins (by HUC08) as well as Multnomah
Channel and Columbia Slough. EPA's TMDL presents the rationale for revised allocations for:
"Atmospheric deposition direct to water" in all subbasins; "Agriculture, forest, shrub, developed, other
(runoff and sediment) in five sub basins; "NPDES Permitted Stormwater Point Source Discharges" in two
subbasins; "Non-Permitted Urban Stormwater" in two subbasins; "Legacy mining" in one subasin;
"NPDES Permitted POTW Wastewater Discharges" in two subbasins; and "NPDES Permitted Industrial
Wastewater Discharges" in one subbasin. No information is provided on the calculations presented in
each subbasin summary table. However, the subbasin-specific calculations appear to be derived from
basin-wide modeling and analysis. As explained in detail in DEQ's November 22, 2019 Response to EPA
Comment on Meeting WQC in All WRB HUC08s (see 3 attached), there are not sufficient data at a
subbasin scale to support the development of different instream targets for each subbasin in the larger
Willamette basin. While the basin-wide data, assumptions and technical decisions agreed to by DEQ,
EPA and EPA's contractor were appropriate for the basin-wide approach, subbasin scale decisions
require revisiting the modeling and analysis on a subbasin-by-subbasin basis. Some important
considerations include updating the subbasin- specific datasets with more current data; using only the
more recent data for the total mercury existing condition; devising an acceptable method for
representing the subbasins without adequate data; evaluating fish species presence and use at the
subbasin level; and accounting for water column data no longer being paired with fish tissue samples.
Comment ID
L26-7
Inadequate data used
Comment Category
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Response Text
ODEQ's November 2019 TMDL estimated TMDL allocations using a basin-wide approach. EPA reviewed
this approach and determined that the basin-wide percent reduction allocations in the ODEQTMDL
would not result in meeting the TMDL target in all subbasins in the Willamette River Basin. As a result,
EPA revised the allocations for five of the 12 HUC8 watersheds, as well as for the Multnomah Channel
and Columbia Slough watersheds using available data for these HUCs, as explained on page 6 of the EPA
TMDL.
All TMDLs must use readily available data (EPA 1991). Data collected within the subbasins are a better
representation of the subbasin condition than a summary of mercury concentrations at the much larger
basin scale. Because impaired segments are located within each of the five subbasins which EPA revised,
it is necessary to ensure that load capacities and allocations are set at the subbasin scale in order to
achieve the TMDL target using available data. Although there will always be inherent uncertainty in
estimating current concentrations, for the five subbasins for which EPA revised ODEQ's allocation
scheme, there is generally as much or more data available than there is for other HUCs, and there is
sufficient data for characterizing existing conditions. In the Tualatin subbasin, for example, there are 239
water column THg samples available for 2002-2019. Instead of including all available data for the
development of a HUC-specific loading capacity, ODEQ requested data from earlier years be removed,
which EPA did for the final TMDL.
EPA agrees that collection of additional data could be used to further refine and improve subbasin-
specific load allocations. It could also allow for future refinement of the analysis to reflect regional
differences in food web structure and bioaccumulation patterns and, when combined with paired data
on mercury exposure concentrations, enable development of subbasin-specific mercury loading targets
consistent with achieving the fish tissue criterion. Such additional data collection could be addressed in
ODEQ's proposed Assessment and Monitoring Strategy.
Comment Text
6. EPA's increased point source (wastewater and stormwater) reductions are disproportionate to source
contributions. While proportionality is only one consideration within a state's discretion that DEQ used
in assigning allocations, lack of consideration of proportionality is inconsistent with EPA's 2010
Guidance for Implementing the January 2001 Methylmercury Criterion and EPA's 2008 guidance "TMDLs
Where Hg Loadings are Predominantly from Atmospheric Deposition."
Response Text
Relative source contributions were one of the factors which EPA considered in developing revised WLAs
for wastewater and stormwater. However, there are a number of other considerations in revising
allocations as well. While some sources with relatively small loading would seem to warrant lesser
reductions, our analysis revealed that it simply was not feasible to achieve the TMDL target without
greater reductions from even small source contributions. In addition, where atmospheric deposition to
surface water was a more prominent source of loading, e.g. Lower Willamette subbasin, increased
reductions in both nonpoint and point sources were needed, due the limited ability to reduce
atmospheric loading direct to surface water. In the Lower Willamette, this coincided with the greatest
contribution from POTWs in any subbasin, resulting in the need for greater reductions from these
sources than in other subbasins. Since the relative source contributions from nonpoint and point
sources varied within each subbasin, as did the current mercury concentration, the resulting point and
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Comment ID
L26-8
Comment Category
Point Source Wasteload Allocations
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nonpoint source reductions also by necessity varied by subbasins. EPA strived to maintain consistency in
sector specific allocations, to match the approach of the ODEQTMDL.
Comment ID L26-9
Comment Category Allocations
Comment Text
7. Section 7.2.2 of EPA's TMDL assigns an allocation of 0% reduction for minor POTW and minor
industrial permitted discharges. This conflicts with DEQ's TMDL in that minor industrial facilities may
conduct activities with the potential to increase mercury in discharges. Because the TMDL data set
includes effluent data for only about 42% of industrial facilities and flow data for even fewer, DEQ
captured minor industrial facilities in the basin-wide NPDES Permitted Wastewater Discharges
wasteload allocation (10% reduction), conditional to review of effluent and flow monitoring. DEQ
disagrees with assigning minor industrial facilities a 0% reduction, because they have the potential to
increase mercury in their discharge, and some of these e sources may require mercury reductions based
on further evaluations.
Response Text
ODEQ's comments clarified a misunderstanding in EPA's review of the proposed reductions to mercury
discharges from minor POTWs and minor industrial wastewater permits in ODEQ's 2019 TMDL and
provided useful information about the limited data on these types of discharges and the potential for
future expansion. In light of this information, EPA is deleting section 7.2.2 and EPA's TMDL reflects
ODEQ's inclusion of the minor POTWs and minor industrial dischargers within the aggregate reduction
WLAs for POTWs and industrial dischargers in each subbasin. This approach is reasonable given the very
small cumulative contribution of these sources to the overall load (0.07%: p.48, Appendix A). If Minor
facilities in the WRB increase in size to become Major facilities, the permit requirements would be
expected to change to include TMDL implementation and monitoring requirements as provided in
ODEQ's 2019 TMDL. To address the possibility that some of these sources may increase their mercury
discharges over time, the EPA TMDL includes a 1% Reserve Capacity, consistent with the ODEQ 2019
TMDL, which may be granted to dischargers at ODEQ's discretion.
Comment ID L26-10
Comment Category Point Source
Comment Text
No data, information or rationale is provided in EPA's TMDL to support the proposed 97% mercury
reduction in non-permitted stormwater discharges within the Middle Willamette subbasin (aside from a
singular statement in Appendix C). The TMDL needs to include a rationale for any increased reductions.
Response Text
The loading capacities ODEQ developed were based on a basin-wide uniform reduction in THg loading of
88 percent. As discussed in EPA's TMDL this approach was not protective of water quality in HUCs that
exhibit median THg concentrations that are higher than the basin-wide median concentration, including
the Middle Willamette. Oregon DEQ established allocations that varied by source category, expressed as
required percent reductions. For example, nonpoint source reductions were generally 88%, point source
reductions were generally 10%, and regulated and unregulated stormwater reductions were 75%. EPA
retained these allocations where they would achieve the TMDL target. In other subbasins, EPA revised
the allocations. In doing so, EPA continued to vary reductions by source category as in the ODEQTMDL,
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but revisions were not identical in each subbasin due to differences in current concentration and the
mix of sources within each subbasin. In the Middle Willamette, the ODEQTMDL called for 75% reduction
in regulated and unregulated stormwater. In EPA's TMDL, nonpoint source reductions were increased to
97% (as in the other four subbasins where revisions were necessary), Wastewater Treatment Plant
(WWTP) and industrial point sources were increased to 17 - 65%, and both regulated and unregulated
stormwater were increased to 97%. The increase in stormwater reductions was chosen to be consistent
with the NPS reductions, and to have consistency for all stormwater sources, both regulated and
unregulated, since control measures would be the same between the two categories. As noted, this
allocation necessary to ensure water quality protection within each HUC in the Willamette Basin.
Comment ID L26-11
Comment Category Allocations
Comment Text
9. Section 7.2.4 of EPA's TMDL establishes a "zero WLA for the suction dredging industry in these
locations" referenced in DEQ'sTMDL. Section 10.2 of DEQ'sTMDL prohibits permitted suction dredge
mining in the tributaries to Dorena Reservoir and specifies that these reductions, though unquantifiable,
will contribute to the basin-wide 10% reduction aggregated across all permitted wastewater discharges,
a. Please clarify what a zero WLA means, which is a different expression than all other allocations which
are expressed as reduction percentages, b. Please clarify in which source category and in which subbasin
these reductions would be aggregated.
Response Text
A zero WLA means that no loading of total mercury is allowed from the source assigned the WLA. It is
equivalent to a 100% reduction. EPA's TMDL incorporates by reference page 62 of ODEQ's November
2019 TMDL document, which states that the zero WLA for suction dredging will apply to "...streams that
flow from the former Bohemia Mining District and are tributary to the Dorena Reservoir (including Row
River, Brice Creek, Sharps Creek, and Champion Creek)." There has been some confusion regarding
Sharps Creek as various commenters have contended that it does not flow from the Bohemia Mining
District. EPA believes that it is appropriate to include Sharps Creek in this list. Sediment analyzed from
Sharps Creek was found to have a mean concentration of 0.20 mg/kg mercury (Hygelund et al., 2001).
Sharps Creek is tributary to Dorena Reservoir and Dorena Reservoir is a known area of mercury
methylation, is listed for mercury on the 303(d) list of impaired waterways and has fish consumption
advisories in place for mercury. There are no demonstrated methods to prevent the mobilization during
suction dredge mining and subsequent methylation of mercury. All of the streams for which the zero
WLA is assigned are within the Coast Fork HUC8 watershed. Because the 700PM discharge permit
applies to suction dredging, reduction in THg loads from suction dredging will also be tabulated as part
of the overall reduction goal for wastewater and industrial dischargers. EPA retained a 10% reduction
goal for this category in the Coast Fork HUC8 watershed.
Comment ID L26-12
Comment Category TMDL Implementation
Comment Text
10. Implementation Uncertainty: a. Section 7.1.2 and Tables 2 and 3 of Section 7.4 of EPA's TMDL
assigns an 88% reduction of mercury in groundwater to land managers of agriculture, forest, shrub,
developed, water impoundments and water conveyance entities. The text acknowledges high
uncertainty about groundwater mercury loading, but lacks data, information and any other justification
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for establishing a new source category, which is not addressed in DEQ's TMDL or WQMP. An approach
to implementation of this reduction is uncertain, and a better understanding of groundwater mercury
and how reductions could be attained from these land managers is needed. B. Section 7.2.1 of EPA's
TMDL states EPA's intention to impose greater reductions on major POTWs and industrial dischargers
with the greatest contributions of mercury. However, increased reductions are applied in only two
subbasins, which don't include all the higher contributing POTWs, and don't affect any operating major
industrial facilities. The reductions impact five POTW s in the Middle Willamette and three POTW s in
the Lower Willamette. Only one of these is a higher load contributing POTW and it appears that six of
these will be expected to achieve mercury effluent concentrations below the range (1 ng/L to 5 ng/L)
demonstrated by all advanced treatment technologies currently feasible at the scale of major POTW
discharge. C. Section 7.2.3 of EPA's TMDL assigns a 97% reduction of mercury in permitted stormwater
discharges to approximately 16 jurisdictions within the Middle Willamette and Lower Willamette sub
basins without accompanying data, information or support. One third of these jurisdictions straddle
multiple subbasins with different reduction requirements. Many are co-permittees, but would have
different reduction requirements under the same permit, and one third have zero or very low estimated
loads of mercury. D. No justification is provided in EPA's TMDL for 97% reductions from non-permitted
stormwater discharges within the Middle Willamette sub basin, which appears to affect 10 small rural
communities out of 61 in the entire Willamette Basin. Because all these discharges were estimated
together to contribute 0.92 Kg/yr of mercury, individual contributions may be very minimal.
Response Text
EPA's TMDL specifies an 88% reduction in mercury loading from groundwater, not an 88% reduction in
groundwater concentrations.
In response to specific components of this comment:
A. Available mercury monitoring records for groundwater were used to estimate loading to streams in
the Willamette River Basin from groundwater. Groundwater mercury observations were limited;
therefore, data collection and analysis during the implementation process will guide adaptive
management strategies to protect water quality and human health. ODEQ's TMDL contained a general
non-point source category that included mercury associated with groundwater ("General Nonpoint
Source and Background"). This category also included loading from surface runoff and sediment. EPA's
TMDL separated groundwater allocations from the allocations assigned to surface runoff and sediment
because land managers have different opportunities to control surface runoff and sediment as
compared to groundwater.
B. Higher reductions to POTWs and industrial dischargers were only assigned in catchments that require
higher reductions from these sources to meet the TMDL targets based on the fish tissue criterion. This
includes the Middle Willamette and Lower Willamette. In the latter, for example, NPDES permitted
POTWs and industrial wastewater dischargers contribute about 11% of the THg load in the catchment.
Multiple major POTWs in the Middle Willamette and Lower Willamette exhibited effluent mercury
concentrations between 10 to 30 ng/L, whereas, several other major POTWs in the Basin exhibited
effluent mercury concentrations in the much lower range of 2 to 5 ng/L. Upon renewal, DEQ will
determine how to implement TMDL requirements in the effluent limits of applicable NPDES wastewater
permits.
C. As discussed in ODEQ's TMDL and EPA's TMDL, the water column THg target is 0.14 ng/L. Existing
median THg concentrations differ by HUC as shown in Table 1 of EPA's TMDL, therefore, different
percent reductions are required for different catchments in the Basin. For a given catchment, the
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allocated reduction for permitted urban stormwater is applicable to the portions of MS4s within the
catchment.
D. Non-permitted urban stormwater contributes about 4% of the total load in the Middle Willamette
catchment, which is higher than NPDES permitted POTW wastewater discharges and higher than NPDES
permitted industrial wastewater discharges in the Middle Willamette. The reductions allocated are
necessary to meet the water column concentration target of 0.14 ng/L for the TMDL that is based on the
fish tissue criterion.
Comment ID L26-13
Comment Category TMDL Implementation
Comment Text
Section 7 .1.1 of EPA's TMDL explains the rationale for assigning a 35% passive reduction of mercury
deposited from global air emissions, as opposed to DEQ's allocation of 11 %. However, Table 3 presents
EPA's reductions in at-source loads with a 35% reduction for air deposition direct to water only. This
contrasts with the text in Section 7.1.2 and footnote 6 on page 8, which assert that reductions in wet
and dry air deposition of mercury to the landscape are assumed to be 35%, which therefore, increases
the effective reduction of air deposited mercury running off the landscape. As noted in Figure 5-17 of
Tetra Tech's TMDL Technical Support Document, atmospheric deposition direct to streams accounts for
only 1 % of the mercury contributions in the basin and "most of the sediment erosion, surface runoff,
and groundwater loads (pictured as 93% collectively of the mercury contributions in the basin) originate
from past atmospheric deposition of legacy emissions." Please correct the category label in all tables or
clarify if the 35% reduction in atmospherically deposited mercury is intended to account for deposition
everywhere or only to streams.
Response Text
The existing loads and assigned reductions in Table 2 and Table 3 of EPA's TMDL, respectively, for the
category "Atmospheric deposition direct to water" are for mercury atmospherically deposited to water
surfaces in the Willamette River Basin. Atmospheric deposition of mercury to the landscape that is
transported to waterbodies is represented in the loads for the following categories: "Agriculture, forest,
shrub, developed, other (runoff and sediment)" and "Groundwater (agriculture, forest, shrub,
developed, other)". The reductions required for land managers after accounting for the 35% reduction
in atmospheric deposition to the landscape, which is equivalent to the percent reduction for
atmospheric deposition direct to waterbodies, are presented in Table 3. The footnote on page 8 of EPA's
TMDL (#6) explains that these are not additive. It describes the computation of the cumulative reduction
achieved through reductions to atmospheric deposition and land management controls.
Comment ID L26-14
Comment Category Allocations
Comment Text
12. In Section 7.2.1, EPA applied an increased subbasin-specific wasteload allocation (17% reduction)
specific to major industrial facilities in the Middle Willamette subbasin. In contrast, DEQ's wasteload
allocation is aggregated across the entire basin and captures all municipal, industrial and general
wastewater permits to achieve a cumulative reduction of 10%. Although there are three major
permitted industrial facilities in the Middle Willamette sub-basin, none of them currently operate. The
TMDL needs to include an explanation and rationale for how this increased and distinct allocation will
result in additional reductions in this subbasin.
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Response Text
We appreciate this information. At the time the EPA TMDL was established it was not known that some
of these facilities did not currently operate, but they do continue to have active NPDES discharge
permits. If these facilities resume operation, the allocations established in the TMDL will ensure that the
TMDL target will be achieved in this subbasin. If these facilities remain permanently closed and their
NPDES permits are terminated, the loading from these facilities could be counted towards attaining the
point source reductions in this subbasin, in future TMDL revisions.
Comment Text
Section 7.2.4 of EPA's TMDL references "page 62 of Appendix A in DEQ's TMDL" for specifics on "the
suction dredging industry... locations" to which a zero WLA applies. However, Appendix A of DEQ's
TMDL is the Tetra Tech TMDL Technical Support Document, which does not present DEQ's conclusions
and does not provide information on suction mining locations on page 62. Suction mining locations in
the tributaries to Dorena Reservoir are provided on page 51 of DEQ's TMDL (not in any appendix).
Please correct the reference.
Response Text
Section 7.2.4 of EPA's TMDL refers to "...suction dredge mining at locations described in the ODEQ's
2019 TMDL (p. 62, Appendix A...") This is intended to refer to Appendix A to the EPA TMDL, which
consists of the ODEQTMDL document. The list of locations is given on page 62 of the main body of
ODEQ's 2019 TMDL. EPA revised the TMDL to clarify this point.
Comment ID L26-16
Comment Category General Comments
Comment Text
Section 10 of EPA's TMDL refers to DEQ's TMDL and WQMP and finds DEQ's approach to demonstrating
reasonable assurance to be technically feasible and legally sufficient. However, EPA's text contains
inaccuracies, which should be corrected.
A. The text incorrectly refers to Section 14 of DEQ's TMDL as including elements of the WQMP, which
are in Section 13.
b. The text misstates DEQ's examples of proven techniques for reducing mercury from point sources.
i. DEQ does not rely on monitoring permitted effluent discharge as a mercury reduction technique.
Rather, monitoring is used to determine the need for minimization measures. The application of
minimization measures reduce mercury.
ii. DEQ does not state that application of advanced wastewater treatment accomplishes greater
biosolids removal. Rather, DEQ provided an example of measured reductions of mercury in biosolids at
one facility. This demonstrates that minimization measures (specifically the dental amalgam removal
program) have resulted in less mercury entering the wastewater treatment facility. Importantly, this
specific mercury minimization program has been implemented for more than a decade and most dental
facilities in the Willamette Basin have now been addressed. Additional reductions from that source
cannot be relied on to accomplish greater reductions from POTWs.
Comment ID
L26-15
Comment Category
General Comments
USEPA Region 10
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Response Text
EPA appreciates your comments and will:
Change the reference of Section 14 to Section 13; and
Clarify EPA's discussion of ODEQ's examples of proven techniques for reducing mercury from
point sources.
Comment Text
Table 3 on page 13 of EPA's TMDL indicates that reductions are "NA" for Non-Permitted Urban
Stormwater in the McKenzie subbasin. "NA" is not used for any other category or subbasin and no
explanation is offered as text or notes. This designation is not reflected for the McKenzie subbasin in the
unnumbered table on page 26 summarizing allocation revisions for seven subbasins. Please clarify the
designation, provide a rationale for its application in only one source category in one subbasin and align
the information presented in multiple tables. DEQ looks forward to EPA's response to comments and
completion of the Willamette Basin Mercury TMDL revision process.
Response Text
The 75% reduction for non-permitted urban stormwater was called for in ODEQ's 2019 TMDL. EPA
agreed with this reduction as reflected in Appendix C. Allocation Summary for the McKenzie -1709004,
p. 26 of EPA's TMDL. The "NA" reduction in Table 3 of EPA's TMDL was listed in error. As a conforming
change, EPA replaced the "NA" in Table 3 in EPA's final TMDL and assigned a 75% reduction to non-
permitted urban stormwater in the McKenzie subbasin.
Comment ID
L26-17
Comment Category
General Comments
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Author Name Kathryn VanNatta
Organization Name
Letter ID
Comment ID
Comment Category
Northwest Pulp and Paper Association
127
L27-1
Other
Comment Text
In the prior 2006 Mercury TMDL, NWPPA supported a "phased approach" with adaptive management by
the Department. NWPPA believes the phased approach and additional mercury monitoring has resulted
in a much larger data set and an improved scientific foundation for this revised TMDL.
Response Text
EPA agrees that a phased or adaptive management approach to TMDL implementation by ODEQ is
needed and appropriate.
Comment ID L27-2
Comment Category Other
Comment Text
NWPPA supports the TMDL's scientific foundation that in-stream mercury pollution comes from a
variety of sources with a majority of the mercury load contributions from air deposition sources outside
the Willamette Basin and that the science of mercury methylation is still evolving.
Response Text
EPA appreciates the commenter's support of the scientific foundation applied in development of the
Comment Text
NWPPA supports the TMDL's pollution prevention and minimization approach, similar to other mercury
TMDLs across the nation, to comply with Oregon's exceptionally stringent methyl mercury fish tissue
water quality criterion of 0.040 mg/kg (wet weight). NWPPA believes both point and non- point source
contributors should be regulated via the TMDL and Water Quality Management plan through pollution
prevention and minimization best management practices, to the extent practicable, by the Department
or designated management agency.
Response Text
EPA appreciates the comment in support of ODEQ's pollution prevention and minimization approach
proposed in the Water Quality Management Plan. EPA agrees that both nonpoint source and point
source actions are needed to collectively improve water quality in the Willamette River Basin. While the
TMDL is not regulatory, implementation of the Willamette TMDL is achieved through regulatory
programs such as the NPDES program and Oregon's non-point source program and the WQMP for the
Willamette TMDL.
TMDL.
Comment ID
Comment Category
Other
L27-3
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Comment ID
Comment Category
Other
L27-4
Comment Text
Comment 4
NWPPA believes that the TMDL's conservative policy decisions and modeling assumptions, combined
with an aggressive approach to pollutant prevention and minimization result in a TMDL that is very
highly protective of the most sensitive beneficial use of fish consumption in addition to being highly
protective of all other designated beneficial uses of waters in the Willamette Basin.
Response Text
EPA appreciates the commenter's support of the TMDL's protection of beneficial uses.
Comment Text
NWPPA supports the aggregate 10 percent reduction total mercury target for National Pollution
Discharge Elimination System (NPDES) permits with the proposed narrative waste load allocation
approach for point source total mercury reductions to the extent practicable under DEQ's wastewater
permit program.
NWPPA believes the 10 percent aggregate reduction of total mercury per day for all point source water
permit holders is appropriate given that: 1) industrial point sources in the Willamette Basin provide 0.3
percent of the total load for mercury to the Willamette; 2) all permitted point source dischargers
(NPDES and stormwater) comprise approximately 4 percent of the total mercury load; 3) the applicable
water quality criterion is a methylmercury fish tissue criterion; and, 4) scientific knowledge of the
Willamette Basin methylation processes are still evolving.
NWPPA strongly supports the Department's conclusion in the TMDL Draft for Public Comment, dated
July 3, 2019, on page 66. As discussed in the TMDL Technical Support Document, deposition of mercury
onto the Oregon landscape is the dominant source of mercury reaching Willamette Basin streams. While
these deposited air emissions originate as a mix of global, national, regional and local sources, the
largest portion is derived from historical deposition of global anthropogenic mercury emissions
(TetraTech, 2019), or background sources outside of DEQ's control, per Oregon's definition in OAR 340-
042-0030. Further, mercury loads from all permitted (wastewater and stormwater) point source
discharges combined are conservatively estimated to be approximately four percent of the total load to
Willamette Basin streams. As was found in the 2006 TMDL analysis, even total elimination of this
estimated 1.1 percent wastewater and the 3 percent estimated municipal stormwater contributions
would not result in measurable response in terms of lowered mercury in the streams, due to the far
greater proportion of contributions from atmospheric deposition and nonpoint source delivery to
streams, as well as the decades long lag time for measurable in-stream response. However, DEQ
recognizes that, as an environmentally persistent bioaccumulative toxic substance, mercury should be
eliminated from discharges to the extent practicable. Therefore, based on the Clean Water Act's
allowance for aggregate or individual allocations (40 CFR 130.2(i)); EPA's Guidance for implementing the
January 2001 Methylmercury WQ Criterion (2010) and EPA's Memo on Elements of Mercury TMDLs
Where Mercury Loadings are Predominantly from Air Deposition (2008); precedents of EPA approved
mercury TMDLs of 21 other states (dated 2001-2018); and as indicated by a rigorous scientific
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Comment ID
L27-5
Comment Category
Point Source Wasteload Allocations
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evaluation, DEQ is assigning aggregate waste load allocations for municipal and industrial wastewater
and municipal stormwater point source discharges. The waste load allocations that follow meet the
intent of individual allocations by requiring site -specific permit requirements and monitoring with
enforceable conditions, such that individual site reductions will be completed and will cumulatively add
up to the aggregate percent reduction requirements by sector set by the TMDL.
Response Text
The commenter provides support for ODEQ's basin-wide aggregate waste load allocation approach of
10% reduction for point sources as presented in the ODEQ's July 2019 TMDL. As discussed in EPA's
TMDL, this approach was not protective of water quality in HUCs that exhibit median THg
concentrations that are higher than the basin-wide median concentration, such as the Middle
Willamette. Oregon DEQ established allocations that varied by source category, expressed as required
percent reductions. EPA retained these allocations where they would achieve the TMDL target. In other
subbasins, EPA revised the allocations. In doing so, EPA continued to vary reductions by source category
as in the ODEQTMDL, but revisions were not identical in each subbasin due to differences in current
concentration and the mix of sources within each subbasin. EPA believes this approach still allows ODEQ
flexibility in determining how to implement wasteload allocations among individual permittees, within
subbasin source sectors. EPA deviated from ODEQ's 10% basin-wide reduction approach to ensure the
allocations were protective of water quality in all HUCs across the basin.
Comment Text
NWPPA has concerns with the TMDL's conservative approach in the application of the food web model
to determine an overly conservative in-stream water column target of 0.14 ng/L to meet the
exceptionally stringent fish tissue criterion of 0.040 mg/kg (wet weight) methyl mercury (OAR 340- 041-
8033, Table 40). The recalibrated and updated Food Web Model yields a highly conservative in-stream
target of 0.14 ng/L of total mercury because: 1) various non-native species are used in the model; 2) the
in-stream target is derived from the most conservative median total mercury target level of the selected
fish species—that is, for the Northern Pikeminnow, which is a non-native species known to predate
salmon and steelhead smolts; 3) and other conservative policy and modeling assumptions.
Response Text
The statement that the Northern Pikeminnow (Ptychocheilus oregonensis) is a non-native species is
incorrect as the Northern Pikeminnow is native to the Columbia River and its tributaries. (See A.M.
Garcia, 2014, Northern Pikeminnow, Ptychocheilus oregonensis, Northern Squawfish at
https://depts.washington.edu/oldenlab/wordpress/wp-
ontent/uploads/2015/09/Ptychocheilus_oregonensis_Martinez_2014.pdf and L.M. Page and B.M. Burr,
2011, A Field Guide to Freshwater Fishes of North America North of Mexico.) In any case, the TMDL
target is based on a fish tissue concentration for the protection of human health, so it would not matter
if a species was non-native as long as it was present in the Willamette River Basin and potentially subject
to consumption by anglers. Selection of the target based on the most conservative calculation from the
studied fish species is consistent with the directions from Magistrate Judge Acosta to update the 2006
TMDL, which also relied on the most conservative fish species, with new data and incorporating the new
mercury fish tissue criterion. The calculated in-stream target of 0.14 ng/L is very low primarily because
the Oregon Administrative Rules revised the fish tissue target criterion from 0.35 mg/kg to 0.040 mg/kg
(OAR 340-041-8033, Table 30).
Comment ID
L27-6
Food Web Model - uncertainty regarding the target THg
Comment Category
USEPA Region 10
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Comment ID
Comment Category
L27-7
Margin of Safety
Comment Text
NWPPA believes the implicit Margin of Safety is appropriate and the use of the Reserve Capacity for
future point source growth/expansion should be allowed without additional regulatory restrictions
because the TMDL's conservative policy choices are highly protective of beneficial uses. These highly
conservative policy choices, modeling assumptions and mercury transportation assumptions are used
throughout the Food Web Model, Mass Balance and Translator models as noted in the Tetra Tech
Technical Support Document.
NWPPA is concerned with the compounded conservatism of the policy choices and assumptions used in
the models leading to overly conservative outcomes and unduly stringent regulatory approaches.
Mercury load reduction efforts should be common sense minimization efforts similar to other TMDLs
across the nation, to the extent practicable, given that the majority of mercury loading comes from air
deposition.
Response Text
This comment was originally submitted on ODEQ's July 2019 Public Review Draft of the TMDL. EPA
agrees with the commenter that an implicit margin of safety is appropriate. However, EPA's TMDL
(Section 9) rejected one of the three components of the margin of safety proposed by ODEQ and instead
added another element "Needed reductions in loads are based on comparing water column mercury
targets to ambient monitoring data. Those monitoring data are available through 2011 in only 9 of the
12 HUC8 watersheds and thus do not incorporate any reductions in mercury loading that have occurred
since 2011. Data presented in ODEQ's 2019 November TMDL (Figure 7-3, p. 37) indicate that mercury
concentrations have been declining in more recent years (2012 - 2019) in the Tualatin and Lower
Willamette subbasins." EPA agrees that reserving an allocation for future growth or expansions is
considered good practice and retained the 1% allocation for Reserve Capacity proposed by ODEQ,
portions of which may be granted to dischargers by ODEQ at its discretion. ODEQ made changes in the
November 2019 TMDL in response to this comment, as described in the ODEQ Response to Comments
(VN#8: Suggested Change ID #350). Therein ODEQ clarified that "...additional regulatory restrictions..."
are not proposed in the TMDL for use of reserve capacity for new or expanded point sources. Rather,
Section 12 of the ODEQ TMDL states that allocation of a portion of the 1% reserve capacity requires
prior "...demonstration of effluent condition and implementation of DEQ approved mercury
minimization measures,..." which are the same requirements applied to implementation of the
wastewater and stormwater aggregated point source sector wasteload allocations. EPA understands the
commenter's concern about mercury load reduction efforts needing to be common sense minimization
efforts. As part of ODEQ's WQMP planning process, individual implementation plans will be established.
Comment Text
NWPPA believes the future implementation activities by DEQ and Designated Management Agencies
should focus on pollution prevention as regulatory agencies make policy decisions implementing the
TMDL and Water Quality Management Plan.
Discussion
Comment ID
L27-8
TMDL Implementation
Comment Category
USEPA Region 10
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Suggested Remedy
The Department and Designated Management Agencies should focus on adaptive management and
allow best management practices already in place designed to reduce anthropogenic mercury loads. The
draft TMDL on page 66 addresses that fact that additional analysis reduced the estimated amount of
total mercury contributed by point sources in the 2019 draft TMDL from the prior 2006 TMDL.
Response Text
This comment was previously submitted on DEQ's July 2019 Public Review Draft of the TMDL. In the
November 2019 Response to Comments (VN#9: Suggested Change ID #351), ODEQ provided the
following response, with which EPA concurs: "Response: As noted in Section 13.6, DEQ intends to apply
adaptive management principles toward achievement of TMDL goals, informed by the monitoring and
evaluation strategy. DEQ clarifies that the referenced statements on page 66 were not conclusions that
management actions have resulted in reduced mercury loads in the basin since the 2006 TMDL. Rather,
the revised evaluations were more robust and included more data, which allowed for more accurate
estimates of mercury loads. The current estimated loads from municipal and industrial point sources are
lower than the 2006 estimates, but this does not necessarily indicate loads from these sources were
reduced due to application of management measures since 2006. Additional analysis and information is
needed for evaluating the effects of implementation on mercury in the basin. DEQ acknowledges that
there are stakeholders from multiple sectors, representing varied land uses and sources of mercury, that
have already been implementing strategies and actions that are protective of water quality. DEQ
anticipates that continued as well as increased efforts to protect water quality will help the basin reach
water quality goals for mercury and other TMDL pollutants."
Comment Text
NWPPA believes the Department should continue to leverage new scientific findings to objectively
consider whether reducing total mercury has a linear effect on reducing methyl mercury in fish tissue in
Willamette Basin fish species and whether the very low proposed modeled target of 0.14 ng/L of
instream total mercury can be met. This information (or lack of information) should also be considered
when determining the length of time needed to comply with the water quality criterion.
Suggested Remedy
The Department's mercury reductions must be fact checked during TMDL implementation by analyzing
methylmercury in fish tissue. Measuring methyl mercury in fish tissue is the correct evaluation factor for
complying with the water quality criteria under the Clean Water Act. Without a significant breakthrough
in the mechanistic understanding of the factors controlling methylation in the ambient environment
there is no remedy to the relationship dilemma between total and methyl mercury. Significant scientific
questions remain, including what is the spatial distribution of methylation and does methylation follow
temporal (e.g., seasonal) patterns? As the science of mercury methylation processes and mercury
transport expands, the Department should use adaptive management for monitoring and adjust the
TMDLs best management practices for pollution minimization accordingly.
Response Text
This comment was received during the public comment phase for ODEQ's TMDL. ODEQ provided the
following response:
Comment ID
L27-9
TMDL Implementation
Comment Category
USEPA Region 10
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"Thank you for your comment. DEQ will conduct monitoring during implementation to not only measure
progress to improving total mercury levels in the water and methylmercury concentration in fish tissue,
but will also work with partners and DMAs to conduct studies to better represent the processes
influencing methylmercury in fish tissue in the Willamette Basin. DEQ is working with EPA to develop a
draft Assessment and Monitoring Strategy that could provide this information. DEQ will work with DMAs
for refinement of the draft Strategy and its implementation.:." In another response, ODEQ indicated that
it planned to use adaptive management during implementation of the TMDL as described in the WQMP,
which also describes proposed monitoring to fill data gaps and better characterize sources.
Comment ID L27-10
Comment Category TMDL Implementation
Comment Text
The Department uses literature values for some point source and non-point source mercury loading
values.
Suggested Remedy
As future monitoring yields additional mercury loading data, the Department must use adaptive
management and adjust accordingly the TMDLs best management practices for pollution minimization.
Response Text
Literature values were used appropriately to estimate loads from certain point and nonpoint sources
when direct monitoring data were not available. This question was submitted previously on ODEQ's July
2019 Public Review Draft of the TMDL and a response was provided in ODEQ's November 2019
Response to Comments (VN#12: Suggested Change ID #354). In that response, ODEQ indicated that it
planned to use adaptive management during implementation of the TMDL as described in the WQMP,
which also describes proposed monitoring to fill data gaps and better characterize sources.
Comment ID L27-11
Comment Category TSS as surrogate
Comment Text
NWPPA objects the use of Total Suspended Solids (TSS) as a surrogate for measuring mercury and the
possible unintended consequences of using TSS as a surrogate for mercury transportation over land into
water. NWPPA questions the level of current scientific knowledge regarding: 1) TSS transport
contributing to in-stream concentrations of total mercury; 2) the relationship of TSS to methylation
processes; and 3) whether a linear cause-and effect relationship exists between TSS and methyl mercury
concentrations in Willamette Basin fish tissue.
Discussion
NWPPA has concerns with the reliance on TSS as a surrogate for measuring compliance with methyl
mercury reductions in fish tissue. NWPPA questions the scientific relationship between TSS as a
surrogate for total mercury transport from land into the Willamette river system. NWPPA believes the
scientific relationship is unproven between TSS transport contributing to total mercury loading in the
Willamette Basin and the assumption is also unproven that reductions of TSS will result in attainment in
the near future of the methylmercury fish tissue water quality criterion. DEQ has already reduced Total
Suspended Solid (TSS) benchmarks in 1200-Z Industrial Stormwater Permits in the 2017-2018 permit
revision. While we agree TSS reduction is a regulatory tool to reduce soil transport into a river system,
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the relationship and timing between TSS load reductions resulting in reductions to methylmercury
reductions in fish tissue remains unproven.
Suggested Remedy
NWPPA asks for a written response regarding the Department's plans for future scientific study and
baseline validation of TSS as it relates to total mercury transport into river systems and the scientific
relationship of TSS reductions contributing to attainment of the 0.040 mg/kg (wet weight)
methylmercury water quality criterion.
Response Text
This comment was originally submitted in response to ODEQ's Public Review Draft of the TMDL (July
2019) and refers to ODEQ's Appendix H in the Public Review Draft, which is now Appendix G to the
revised ODEQTMDL. For the November TMDL, ODEQ revised Section 10.3 and Appendix G (formerly
Appendix H in the Public Review Draft) in response to this and other related comments.
EPA's 2019 TMDL document does not discuss use of TSS as a surrogate and mentions TSS only once, in
the context of Reasonable Assurances, where it is noted that "ODEQs review focuses on water quality
trends in TSS loading which ODEQ intends to associate with mercury loading." ODEQ's TMDL, which is
attached to the EPA TMDL as Appendix A, does incorporate a discussion of instream surrogate targets, in
Section 10.3, and proposes TSS as a surrogate "...to supplement but not supplant the allocations and
TMDL water column target for evaluating TMDL implementation effectiveness." The TSS surrogate is
thus properly seen as a part of the TMDL implementation strategy which is determined by ODEQ. Note
that ODEQ has proposed TSS as a surrogate for the loading of particle-associated total mercury and not
as a direct surrogate for methylmercury concentration in water or fish tissue. Erosion of soils is only one
of several pathways for mercury loading to waterbodies in the Willamette River Basin. No linear cause-
and-effect relationship is proposed between TSS and methylmercury concentrations in fish.
EPA does not believe there is any plausible reason to doubt the relationship between TSS loading and
mercury loading. The empirical analysis conducted by ODEQ (Appendix G of ODEQ's November 2019
TMDL) confirms a strong correlation between TSS and total mercury concentrations during times of high
TSS loading. It is thus reasonable to choose TSS as a surrogate for mercury loading. Atmospheric
deposition of mercury results in elevated concentrations of mercury in surface soils, and erosion of soils
will thus transport mercury to streams. EPA encourages NWPPA to participate in the stakeholder
process for development of ODEQ's monitoring and assessment plan, which may provide a venue to
conduct additional studies to evaluate TSS as a surrogate.
Comment Text
Comment 12
NWPPA asks that facilities with 1200-Z Industrial Stormwater permits be able to prove compliance with
the TMDL's proposed TSS surrogate for methyl mercury in fish tissue by alternative compliance methods
until the relationship between TSS and mercury has been scientifically evaluated.
Suggested Remedy
As noted in Comment 11, NWPPA is concerned and questions the level of scientific knowledge of TSS
loading contributing to exceedances of methyl mercury fish tissue criterion and asks for further scientific
Comment ID
L27-12
Comment Category
TSS as surrogate
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study to establish a surrogate relationship between TSS loading and methylmercury in Willamette Basin
fish tissue.
Response Text
This comment refers to ODEQ's proposed use of TSS as a surrogate for mercury monitoring to estimate
loading as part of the implementation plan associated with the TMDL The same comment was
submitted for the Public Review Draft of ODEQ's TMDL In response to this comment, ODEQ clarified
that the TMDL TSS surrogate is not being applied as a compliance point in NPDES permits. Rather, based
on the relationship found between TSS and total mercury, surrogate instream targets were set for
reductions in high TSS concentrations to reduce total mercury in waterbodies in the Willamette River
Basin. In addition, the TSS surrogate was to be used to evaluate progress towards achieving the
allocations and total mercury water column target for the TMDL. These reductions of TSS are expected
to reduce total mercury loads that occur during high precipitation events and high flows. ODEQ revised
Section 10.3 and Appendix H in response to this and other comments regarding the TSS surrogate. Those
changes are incorporated in Appendix A to EPA's TMDL.
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Author Name Brent Stevenson
Organization Name
Letter ID
Comment ID
Comment Category
Santiam Water Control District
128
L28-1
TMDL Implementation
Comment Text
The Santiam Water Control District ("SWCD") is an Oregon water control district operating under the
power and authority granted to water control districts by Oregon Revised Statutes, Chapter 553
("Statutory Authority"). SWCD is controlled by a board of directors comprised of local farmers. SWCD
provides irrigation water to agricultural patrons in the Willamette Basin along the North Santiam River.
SWCD holds water rights to irrigate over 17,000 acres.
The SWCD water conveyance facilities ("SWCD facilities") run approximately 118 miles and consist
primarily of open canals located on rights-of-way across the agricultural lands of district members.
SWCD does not own or control land that discharges into the SWCD Facilities. SWCD does not hold legal
control over water quality discharges into SWCD facilities.
Response Text
A similar comment was submitted on ODEQ's July 2019 Public Review Draft of the TMDL (Comment 76
in ODEQ's November 2019 Response to Comments). EPA recognizes that the SWCDs do not have
regulatory control over land that discharges into SWCD facilities. However, as noted by ODEQ in the
November Response to Comments, "The TMDL WQMP requires water conveyance entities to implement
management strategies and actions that are specific to the parts of the system that are owned and/or
operated by the water conveyance entity, for example implementation of best management practices to
reduce sediment movement when canals and ditches are cleaned or dredged. Water conveyance
entities have the legal ability to implement best management practices that pertain to maintenance
activities on their system." EPA supports ODEQ's identification of SWCD and Water Conveyance Entities
(WCEs) as DMAs or responsible persons. EPA also supports DEQ's commitment to work with DMAs and
"responsible persons" to help develop their TMDL implementation plans for achieving the goals of this
TMDL.
Comment ID L28-2
Comment Category TMDL Implementation
Comment Text
SWCD understands that development of a TMDL is a complex process and appreciates the work DEQ has
invested in preparing the Draft TMDL. Brent Stevenson, SWCD District Manager, is a member of the
TMDL Advisory Committee. SWCD has committed resources to meaningful participation in the DEQ
administrative process surrounding the Draft TMDL. During this public process, SWCD and other
agricultural water districts have consistently expressed concern over the Draft TMDL "responsible
person" designation.
III. SWCD Interest in the Draft TMDL.
The Draft TMDL designates SWCD as a "responsible person" obligated to implement management
strategies and develop sector-specific implementation plans. SWCD has several concerns with this
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designation. First, SWCD and many other water conveyance entities ("WCEs") do not perform activities
that contribute mercury to waterbodies. Instead, WCEs merely transport water. SWCD is limited by its
Statutory Authority, which does not grant SWCD regulatory authority over the water quality of third-
party discharges into SWCD Facilities. Other agencies and jurisdictions control and regulate water quality
entering SWCD Facilities. Therefore, SWCD cannot perform the obligation to implement the
management strategies required by the Draft TMDL. The unspecific and undefined "responsible person"
designation imposes a compliance obligation without extending the corresponding control over the
factors necessary to achieve compliance. Therefore, the legal disconnect of the Draft TMDL codifies
environmental decline by agency order while exposing "responsible persons" to unbound legal risk and
potentially infinite administrative burden. The Draft TMDL proposes a legal mechanism that would
assure mercury water quality standards are not attained because the regulated entities upon which it
relies cannot perform the proposed obligations. Because of this threatened harm to SWCD operations
and SWCD members, SWCD has an immediate and important interest in the draft TMDL.
Response Text
This comment was originally submitted on ODEQ's July 2019 Public Review Draft of the TMDL and minor
changes were made in the ODEQ November 2019 TMDL in response. The comment focuses on the
validity of WCEs being identified as "responsible persons" with implementation responsibilities, a
subject not within the scope of EPA's TMDL. EPA recognizes that the SWCDs do not have regulatory
control over land that discharges into SWCD facilities. However, as noted by DEQ in the November
Response to Comments, "The TMDL WQMP requires water conveyance entities to implement
management strategies and actions that are specific to the parts of the system that are owned and/or
operated by the water conveyance entity, for example implementation of best management practices to
reduce sediment movement when canals and ditches are cleaned or dredged. Water conveyance
entities have the legal ability to implement best management practices that pertain to maintenance
activities on their system."
Comment Text
The Draft TMDL fails to clearly distinguish "responsible person" obligations from DMA obligations. The
Draft TMDL states that a "responsible person" is "an entity identified in a TMDL that has responsibility to
meet assigned allocations and/or surrogate measures. DMAs and "responsible persons "are responsible
for implementing management strategies and developing and revising sector-specific or source-specific
implementation plans, unless otherwise indicated in the WQMP." DEQ's administrative rules do not
differentiate between a "responsible person" and a DMA. The rules do not define the term "responsible
person." The rules define a DMA in OAR 340-042-0030(2) as "a federal, state or local governmental
agency that has legal authority over a sector or source contributing pollutants, and is identified as such
by the Department of Environmental Quality in a TMDL". SWCD holds no such legal authority.
Obliquely, the Draft TMDL distinguishes WCEs (as a sub-group of "responsible persons") from DMAs by
acknowledging that unlike DMAs, WCEs do not have the regulatory authority to assert legal controls
over mercury in their facilities. This leads to the conclusion that "responsible persons" are entities
without regulatory authority which are nonetheless required to meet the requirements placed on DMAs
(DMAs which, unlike SWCD, have actual regulatory authority over a sector of activity.
Comment ID
L28-3
TMDL Implementation
Comment Category
USEPA Region 10
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Response Text
This comment was originally submitted on ODEQ's July 2019 Public Review Draft of the TMDL and minor
changes were made in the ODEQ November 2019 TMDL to clarify the definition of "responsible
persons". The comment focuses on the need to clarify the difference between the obligations of a
"responsible person" and a "DMA", a subject not within the scope of EPA's TMDL. EPA recognizes that
the SWCD does not have regulatory control over land that discharges into SWCD facilities. However, as
noted by DEQ in the November 2019 Response to Comments, "The TMDL WQMP requires water
conveyance entities to implement management strategies and actions that are specific to the parts of
the system that are owned and/or operated by the water conveyance entity, for example
implementation of best management practices to reduce sediment movement when canals and ditches
are cleaned or dredged. Water conveyance entities have the legal ability to implement best
management practices that pertain to maintenance activities on their system." In the ODEQ November
2019 TMDL, ODEQ provides that over the next two years ODEQ will work directly with responsible
persons to determine implementation planning and reporting requirements for each system. EPA
supports ODEQ's approach to work with WCEs as responsible persons to develop appropriate
implementation plans for achieving the goals of the TMDL.
Comment ID L28-4
Comment Category TMDL Implementation
Comment Text
The Draft TMDL fails to clearly define the role of Santiam Water Conveyance District (SWCD). SWCD is
named once in the Draft TMDL -Appendix E, under the heading "DMA Name." Appendix E also
categorizes SWCD as a "water conveyance" type of "DMA Category." The Draft TMDL notes that
"Appendix E . . . lists the WCEs that DEQ has identified as other persons." Communications from DEQ
indicate that the agency intends to designate SWCD, along with the other "water conveyance" entities,
not as a Designated Management Agency ("DMA"), but as a "responsible person." The Draft TMDL must
clearly define SWCD's role in order for SWCD to be able to comply. A failure to provide such definition
exposes SWCD to potentially open ended and arbitrary DEQ enforcement and penalties. This would
render the requirements void for vagueness.
Response Text
This comment was originally submitted on ODEQ's July 2019 Public Review Draft of the TMDL and
changes were made in the ODEQ November 2019 TMDL. In its response, DEQ did agree "...that the
column header in the table shown in Appendix E is inaccurate and the column header was revised to
reflect responsible persons as well as Designated Management Agencies. EPA concurs with DEQ's
change to its November 2019 TMDL which identifies the WCEs as responsible persons.
Comment Text
SWCD does not have regulatory authority over the water quality of discharges into SWCD Facilities.
The Draft TMDL appears to require SWCD to control mercury within SWCD Facilities as if SWCD had the
statutory authority and the regulatory control held by a DMA. SWCD holds no such legal control. Water
control districts, such as SWCD, have the authority granted by the Oregon Legislature, specifically, ORS
Chapter 553. ORS Chapter 553 does not grant SWCD the authority to regulate agricultural return flow
water quality or the water quality of other parties discharging into SWCD Facilities. The Draft TMDL
Comment ID
L28-5
TMDL Implementation
Comment Category
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acknowledges that WCEs do not have the regulatory authority to assert legal control over mercury levels
in their facilities, yet the Draft TMDL still assigns a regulatory obligation and the corresponding legal
exposure to those entities; the same requirements the Draft TMDL would impose upon DMAs holding
actual legal control.
DEQ claims WCEs have "direct control over land or water management activities affecting mercury
loading to rivers and streams." Accordingly, DEQ expects WCEs to "[m]anage upland conveyance system
infrastructure, for example, roads, pumps, etc. to prevent soil erosion, and sediment delivery to
waterbodies." SWCD does not have control over the uplands from which return flows and stormwater
originate. SWCD does not have control over the private landowner conveyances that discharge into
SWCD Facilities. SWCD does not have control over private and municipal roads that create run-off
discharged into SWCD Facilities.
Response Text
This comment was originally submitted on ODEQ's July 2019 Public Review Draft of the TMDL and
changes were made in the ODEQ November 2019 TMDL in response.
EPA recognizes that the SWCDs do not have regulatory control over land that discharges into SWCD
facilities. However, as noted by ODEQ in the November Response to Comments, "The TMDL WQMP
requires water conveyance entities to implement management strategies and actions that are specific to
the parts of the system that are owned and/or operated by the water conveyance entity, for example,
implementation of best management practices to reduce sediment movement when canals and ditches
are cleaned or dredged. Water conveyance entities have the legal ability to implement best
management practices that pertain to maintenance activities on their system." EPA concurs with
ODEQ's approach in identifying water conveyances as DMAs or responsible persons.
Comment Text
DEQ's designation of water conveyance entities as "responsible persons "in the Draft TMDL is
overbroad, has no legal basis, and improperly shifts a regulatory burden from DEQ.
DEQ lists all WCEs in the Willamette Basin as "responsible persons "in the Draft TMDL without basing
the designation on any WCE-shared mercury producing activity. DEQ also fails to identify WCEs by type
(irrigation, water control, etc.) by primary purposes, or by actual entity activities. DEQ appears to have
listed every entity that potentially falls within the undefined "water conveyance entity" term without
any developed basis for inclusion.
DEQ does not point to any specific sediment or erosion-initializing activities performed by all the listed
WCEs. The only "activity" in which all listed WCEs engage is the transport of water. For example, one
listed WCE operates a closed (piped) water conveyance system, another does not hold water rights, and
another pumps water from one end of a natural waterbody to the other without changing the
composition of the conveyed water.
WCEs should not adopt management responsibilities under the TMDL because they are not "sources" of
mercury pollution and because they cannot regulate or otherwise control any sector of mercury
pollution. DEQ has provided no other basis for which it can impose requirements on WCEs under the
TMDL. Under OAR 340-042-0030 a "Source" is defined as "any process, practice, activity or resulting
condition that causes or may cause pollution or the introduction of pollutants to a waterbody." The
Comment ID
L28-6
TMDL Implementation
Comment Category
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WCEs identified in the Draft TMDL have no common process, practice, or activity beyond the mere
transport of water. The conveyance of water does not create mercury. Instead, the pollutant is
discharged by the lands draining into conveyance facilities.
DEQ will rely upon its "Decision Tree" (not included with the Draft TMDL or in the materials for public
comment) to determine the planning and reporting requirements of WCEs. But the Decision Tree does
not accommodate or consider whether the subject WCE introduces or controls the introduction of
mercury into the waterbodies-there is no administrative step where DEQ evaluates whether a WCE
performs a sediment or erosion-initializing activity. Rather, the Decision Tree's threshold question is
whether WCE return flows enter waters of the state. Such an evaluation is at once insufficient and
unnecessary. It is insufficient to determine whether the WCE has any control over the pollutant level
and it is unnecessary if cases where the WCE operates a closed conveyance environment and in all cases
where the facilities are not the source of the pollutant.
Designation of all WCEs as responsible persons, without any basis showing they either contribute, or can
control the contribution of, the pollutant which the TMDL regulates, is overbroad and outside the lawful
scope of the TMDL. Further, DEQ is improperly shifting its own burden to show an entity is jurisdictional
to the WCEs by requiring WCEs to prove out of TMDL regulation rather than DEQ providing evidence
that they should be regulated.
Response Text
This comment was originally submitted on ODEQ's July 2019 Public Review Draft of the TMDL and
changes were made in the ODEQ November 2019 TMDL in response.
EPA recognizes that the SWCD does not have regulatory control over land that discharges into SWCD
facilities. However, as noted by ODEQ in the November Response to Comments, "The TMDL WQMP
requires water conveyance entities to implement management strategies and actions that are specific to
the parts of the system that are owned and/or operated by the water conveyance entity, for example,
implementation of best management practices to reduce sediment movement when canals and ditches
are cleaned or dredged. Water conveyance entities have the legal ability to implement best
management practices that pertain to maintenance activities on their system." EPA concurs with
ODEQ's approach in identifying water conveyances as DMAs or responsible persons.
In ODEQ's November 2019 TMDL (incorporated as Appendix A to the EPA TMDL), ODEQ removed
references to the "Decision Tree" for WCEs and instead provided a detailed list of expectations in Table
13-21, "Milestones and timelines for DEQ to work with water conveyance entities to plan and carry out
implementation of the 2019 Willamette Basin Mercury TMDL." EPA supports DEQ's responses to the
commenter.
Comment Text
The Draft TMDL does not distinguish the wasteload allocations for WCEs from upland agricultural
activities.
The TMDL is required to identify pollutant sources, estimate the amount of actual pollutant loading from
these sources and establish wasteload and load allocations for these sources. The Draft TMDL identifies
only one wasteload allocation for "General Nonpoint Source and Background" which includes Forestry,
Agriculture, Water Impoundments, Water Conveyance Entities, Non-Permitted Urban Stormwater, and
Comment ID
L28-7
Non-point Source Load Allocations
Comment Category
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Atmospheric Deposition. The Draft TMDL does not estimate the amount of pollutant loading from WCEs
as a group, or from the WCEs that deliver irrigation water to agriculture ("Irrigation Entities"). The Draft
TMDL does not distinguish among types of agricultural sources-specifically, the modeling data does not
allocate mercury between the activities of Irrigation Entities and upland agricultural activities. The Draft
TMDL modeling data also fails to separate naturally occurring and background sources of mercury from
other sources of mercury. Accordingly, Irrigation Entities are grouped with upland agricultural
operations and with non-agricultural runoff from urban non-MS4 stormwater.
The Draft TMDL states that WCEs are only responsible for their activities and not for upland return
flows. However, because the Draft TMDL does not set a load allocation for either upland exempt
agricultural activities or for Irrigation Entities' activities (whatever those may be) there is no mechanism
for determining which entities are meeting, or failing to meet, mercury reductions.
Instead, as proposed, compliance will be based on the performance of the mandated management
activities by Irrigation Entities, such as the requirement to manage "upland conveyance system
infrastructure, for example, roads, pumps, etc. to prevent soil erosion, and sediment delivery to
waterbodies." As discussed above, SWCD and other Irrigation Entities do not have the regulatory
authority to implement this management strategy. The Draft TMDL allocates mercury load so broadly
across so many sectors and activities that WCEs could never demonstrate any diminution in mercury
loading. Therefore, the Draft TMDL sets up the plan in general, and the WCEs in particular, for failure
because the Draft TMDL would impose compliance measures the agency cannot quantify and the WCEs
cannot meet.
Response Text
EPA's TMDL (Table 3) establishes load allocations for nonpoint sources as percent reductions relative to
existing loads. These percent reductions are applicable to general categories of loading pathways, such
as mercury associated with sediment erosion from agriculture. As noted at 40 CFR 130.2(g), load
allocations for nonpoint sources "...are best estimates of the loading, which may range from reasonably
accurate estimates to gross allotments, depending on the availability of data and appropriate
techniques for predicting the loading." The percent reduction targets are applicable to these land
management activities at the spatial scale of HUC8 watersheds in the Willamette River Basin. Converting
these generalized percent reduction targets to specific actions to be undertaken by DMAs and
responsible persons, including WCEs, will be accomplished through the Water Quality Management Plan
(WQMP). The WQMP is the responsibility of ODEQ and is not an EPA-reviewable component of the
TMDL itself. WQMP expectations for WCEs are described in Section 13.3.1.23 of the ODEQTMDL
document, which states that "...these systems are included as responsible persons... because
maintenance and management of these systems can impact sediment transport and erosion." In other
words, ODEQ has reserved the right to identify specific requirements for WCEs if it is determined that
they are significant contributors to mercury loading in the Willamette River Basin. As stated on p. 112 of
the ODEQTMDL, "DEQ will collaborate with watershed partners... to conduct outreach and education to
water conveyance entities over the next two years. DEQ will also work individually with owners and
operators of water conveyance systems to gather information and better characterize their potential to
discharge or have return flows to the Willamette Basin river network and determine what management
and reporting strategies are relevant to their specific operations and maintenance activities."
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Comment ID
Comment Category
L28-8
Water Quality Management Plan
Comment Text
Other agencies and jurisdictions hold regulatory authority over water quality discharged into SWCD
Facilities and those entities are the proper parties to implement TMDL management plans.
In contrast to SWCD's lack of regulatory authority over water quality, there are several state agencies
with authority to control the entities that discharge into SWCD Facilities and with authority over
activities in the SWCD Facilities. For example, Oregon Department of Agriculture ("ODA"), has regulatory
control over agricultural activities through the Agricultural Water Quality Management Act. ODA has
authority to develop Agricultural Water Quality Management Area Plans based on the load allocation to
agricultural sources. The Draft TMDL properly identifies ODA as a DMA with regulatory control over a
sector of activities. Oregon Department of State Lands ("DSL") has regulatory control over certain
activities within water conveyance systems. The Draft TMDL properly designates DSL as a DMA with
regulatory control over a sector of activities. Not only does the Draft TMDL acknowledge that water
conveyance entities do not have regulatory power, it acknowledges that their conveyance facilities are
in fact regulated by other entities designated as DMAs: "[w]ater conveyance systems, including those
that are managed for irrigation and drainage, are currently regulated by multiple state and federal
agencies, including Oregon Water Resources Department, DSL, USACE, and DEQ's own 401 water quality
certification program."
Other entities control the water quality of the non-agricultural stormwater discharged into SWCD
Facilities impacting mercury load. Marion County and DEQ issue permits for stormwater discharges into
SWCD Facilities without the permission of SWCD. SWCD Facilities also suffer the discharge of
unauthorized stormwater from other local jurisdictions. Those entities, parties discharging into SWCD
Facilities, are the proper parties for the Draft TMDL to assign responsibility for water quality
management activities and the reduction of the mercury load entering SWCD Facilities because those
entities are the source of the pollutant or have the land use controls over the source of the pollutant.
Response Text
This comment was originally submitted on ODEQ's July 2019 Public Review Draft of the TMDL and minor
changes were made in the ODEQ November 2019 TMDL in response. Determining TMDL
implementation responsibilities is outside the scope of EPA's TMDL. Through ODEQ's WQMP
implementation process, ODEQ will work with DMAs and responsible persons to determine the
appropriate roles and responsibilities of the SWCD and WCEs in implementing the TMDL.
Comment Text
The Draft TMDL management responsibilities are unduly burdensome and duplicative.
SWCD does not have the resources to implement extensive management strategies imposed on
responsible persons by the Draft TMDL. SWCD employs a district manager, an office manager, two full
time field technicians, and a part-time GIS technician. SWCD finances are limited to the assessments and
charges it imposes on its patrons. The Draft TMDL would impose an unfunded mandate on SWCD. For
example, SWCD would have to"[c]onduct education and outreach to water users and upland agricultural
and urban landowners that discharge to system." SWCD does not have the staff to organize and perform
Comment ID
L28-9
Water Quality Management Plan
Comment Category
USEPA Region 10
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regular outreach activities or to prepare educational materials. SWCD would need to hire staff or a third-
party entity to perform the educational obligations already delegated to other state entities.
The Draft TMDL's imposition of these management responsibilities on SWCD duplicates the obligations
already placed upon other agencies and jurisdictions with existing programs in place for the same target
population. For example, ODA has existing, well-developed outreach programs for agricultural water
users. Municipalities, such as Marion County, have water quality programs including stormwater
management plans and resident informational programs. These entities have the sources to develop
meaningful and effective outreach programs and the expertise with water quality controls particular to
their constituents, which are the same landowners and entities discharging mercury into SWCD
Facilities. DEQ should not reasonably expect SWCD to develop better programs than DEQ and sister
agencies charged with the very responsibility it now seeks to impose upon SWCD. DEQ should not
require SWCD to implement burdensome and duplicative actions.
Response Text
This comment was originally submitted on ODEQ's July 2019 Public Review Draft of the TMDL and
changes were made in the ODEQ November 2019 TMDL in response. Determining TMDL
implementation responsibilities is outside the scope of EPA's TMDL. ODEQ will determining the roles
and responsibilities of the SWCD and WCEs in implementing the TMDL through its WQMP process.
Comment Text
In order to resolve the issues raised above, the Draft TMDL should incorporate water conveyance
entities delivering irrigation water under ODA's DMA jurisdiction
ODA is the proper DMA to manage agriculture and Irrigation Entities. Instead of listing Irrigation Entities
as stand-alone "responsible persons, "the Draft TMDL should require ODA to manage Irrigation Entities
activities concurrently with other agricultural activities under its existing Agricultural Water Quality
Management Act and its mercury-specific DMA management authority ("ODA Management Plans").
ODA and DEQ have an existing relationship in which ODA implements water quality management plans
for agricultural areas. The two agencies work together to complete biennial reviews of ODA's
Agricultural Water Quality Management Plans in the Upper, Middle and Lower Willamette Basin
areas.12lrrigation Entities currently work with their local Soil and Water Conservation Districts to
improve water quality through the Oregon Department of Agriculture's Agricultural Water Quality
Management Program. Under that program, a Local Advisory Committee ("LAC"), or regional team of
stakeholders, meets annually to go over new water quality data, discuss areas that need improvement,
and coordinate implementation of these improvements. Irrigation Entities are part of this established
and well-developed program. In fact, many local farmers are both LAC members and Irrigation Entity
board members. Irrigation Entity staff members are also often members of the LACs. Most of the
adopted area plans include specific references to irrigation, ditch cleaning and return flows, because
these are all agricultural activities. Inclusion of the Irrigation Entities in the ODA management process
supports the argument below that the Irrigation Entities are part of ODA's jurisdiction under the
Agricultural Water Quality Management Act. The integration of ODA management, Irrigation Entities,
and farmers suggests that the most successful option to pursue water quality success is to incorporate
WCEs within the ODA Management Plans.
Comment ID
L28-10
TMDL Implementation
Comment Category
USEPA Region 10
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Effective water quality improvements cannot come from water conveyance activities alone, but from
water conveyance activities in coordination with farm and other agricultural activities. For example,
Irrigation Entities, with ODA's regulatory support, can identify areas in their systems adversely impacted
by return flows and then coordinate with the contributing agricultural sources to address the problem.
Alone, the Irrigation Entities cannot require the actual pollutant source to modify its activities.
Therefore, if Irrigation Entities are stand-alone "responsible persons", as contemplated in the Draft
TMDL, they will be ineffective at improving water quality. The Draft TMDL should instead integrate
Irrigation Entities under ODA's Management Plans.
Response Text
This comment was originally submitted on ODEQ's July 2019 Public Review Draft of the TMDL and
changes were made in the ODEQ November 2019 TMDL in response. Implementation planning is outside
the scope of EPA'sTMDL. ODEQ will determining the roles and responsibilities of the SWCD and WCEs in
implementing the TMDL through its WQMP process.
Comment ID L28-11
Comment Category Reasonable Assurance
Comment Text
The Draft TMDL fails to demonstrate "reasonable assurance" that "responsible persons" have the actual
or legal capacity to implement prescribed management plans.
The Draft TMDL's WQMP must meet the requirement of OAR 340-042-0040(4)(l) to include a
"reasonable assurance that management strategies and sector-specific or source-specific
implementation plans will be carried out through regulatory or voluntary actions." OAR 340-042-
0030(9) defines the term "Reasonable Assurance" as "a demonstration that a TMDL will be implemented
by federal, state or local governments or individuals through regulatory or voluntary actions including
management strategies or other controls." The Draft TMDL fails to meet the reasonable assurance
requirement because it relies on the implementation of sector-specific management plans by
"responsible persons" lacking regulatory authority to implement those plans. The Draft TMDL cannot
provide reasonable assurances because "responsible persons" have no legal authority to perform the
contemplated obligations and therefore, the plan will fail to achieve water quality goals.
The Reasonable Assurances section of the Draft TMDL claims that a "high likelihood of implementation
is demonstrated. . ." However, the Draft TMDL fails to cite any legal basis by water conveyance entities
(WCEs) may implement several of the required management activities. Despite the legal vacuum created
by the proposal, the Draft TMDL offers no other evidence to support the counter-intuitive "high
likelihood" conclusion. Because the "responsible person" has no legal authority to compel the
performance required to achieve compliance, there are no reasonable assurances that the sector-
specific management strategies and implementation plans dependent on WCEs will be performed.
DEQ's reliance on Santiam Water Control District (SWCD) and similarly- situated water districts to
implement management plans outside of their authority will result in the failure to attain and maintain
water quality standards. In the alternative, in order to meet the reasonable assurance requirement, the
Draft TMDL should recognize Irrigation Entities under the regulatory umbrella of the ODA Management
Plans and align obligations with parties holding the legal authority to perform those obligations.
ORS 568.912(2) grants ODA control over "landowners" (defined to include an operator, such as SWCD)
"located within an area subject to a water quality management plan to perform those actions on the
landowner's land necessary to prevent and control water pollution from agricultural activities and soil
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erosion. "The term "Agricultural Activities" may include (but are not limited to) "Construction or
maintenance of any works or facilities .... Agricultural and cropping practices; or. . .. Any other measure
or avoidance necessary for the prevention or control of water pollution of the waters of the state."
SWCD performs maintenance of irrigation facilities on the SWCD Facilities running through and serving
agricultural lands. Therefore, the maintenance of irrigation facilities is an agricultural activity. While ODA
has expressed concern that this language does not encompass Irrigation Entities, and while ODA
presently appears inclined to shift administrative responsibility, the legislature may readily clarify the
Agricultural Water Quality Management Act to expressly address ODA authority over Irrigation Entities.
If DEQ does not incorporate water conveyance entities into the ODA Management Plans, the agency
must address the Draft TMDL deficiencies in some other way. If the Draft TMDL requires water
conveyance entities to regulate mercury within their facilities, the legislature must grant the water
conveyance entities regulatory authority to do so(e.g., authority over activities on private property
discharging water (of any type) into SWCD Facilities). Alternatively, if the Draft TMDL intends water
conveyance entities to be responsible only for managing their own activities, the agency must develop a
data system that differentiates between upland agricultural activities and water conveyance
maintenance activities for the purpose of clarifying that a "responsible person" is not responsible for the
impacts of discharges made by other parties over whom the "responsible person" exercises no legal
control.
Response Text
This comment was originally submitted on July 2019 Public Review of the ODEQTMDL and reflects a
misunderstanding on the roles and responsibilities of WCEs under the WQMP. These roles and
responsibilities were clarified in modifications incorporated into the November 2019 final ODEQTMDL
(incorporated as Appendix A to the EPA TMDL).
In their November 2019 Response to Comments on the Public Review Draft of the ODEQTMDL, ODEQ
provided the following response to similar comments:
"In establishing a TMDL, OAR 340-042-0040(4)(l)(G) states that ODEQ will include a WQMP that
includes: identification of persons, including Designated Management Agencies (DMAs), responsible for
implementing the management strategies and developing and revising sector-specific or source- specific
implementation plans. This rule provides that while a WQMP can designate DMAs it can also identify
other persons with a role in implementation. Additionally OAR 340-042-0080(4) states that persons
identified in the WQMP must prepare an implementation plan. Implementation plans from sources
must provide measures to reduce pollutant loading, not to remedy pollution that the source does not
contribute to or control."
"The TMDL WQMP requires water conveyance entities to implement management strategies and
actions that are specific to the parts of the system that are owned and/or operated by the water
conveyance entity, for example implementation of best management practices to reduce sediment
movement when canals and ditches are cleaned or dredged. Water conveyance entities have the legal
ability to implement best management practices that pertain to maintenance activities on their system.
DEQ agrees that management activities already regulated for the protection of water quality, for
example dredge and fill permits administered by the USACE and DSL which have a DEQ 401 Water
Quality Certification, will comply with this TMDL."
"DEQ agrees that collaborative partnerships are an important component of TMDL implementation;
specifically, DEQ identifies in section 13.3.1.21 our commitment to collaborating with Oregon
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Department of Agriculture and Oregon Water Resources Congress to conduct outreach and education
over the next two years to water conveyance entities. These outreach and education efforts will help to
provide additional clarity about TMDL requirements for responsible persons. DEQ encourages OWRC,
their members, other water conveyance entities and watershed partners to work with DEQ to
coordinate implementation planning efforts over the next two years and then to remain implementation
partners moving forward."
"All water conveyance entities named as responsible persons in the TMDL are required to implement
the TMDL. Over the next two years DEQ will work directly with responsible persons to determine
implementation planning and reporting requirements using available information about the
characteristics of each system. DEQ believes this tailored approach will help to better define
implementation strategies and goals that include the varied attributes of water conveyance systems in
the basin."
EPA supports DEQ's collaborative approach to work with the WCEs as responsible persons to develop
and implement strategies and goals that support the overall goals of the TMDL.
Comment Text
SWCD appreciates the opportunity to comment on the Draft TMDL and to explain why DEQ should
remove SWCD and other WCEs from the list of "responsible persons" in the Draft TMDL.
Response Text
This comment was originally submitted on ODEQ's July 2019 Public Review Draft of the TMDL and minor
changes were made in the ODEQ November 2019 TMDL in response. The decision on how SWCD and
other WCEs are defined for implementing the TMDL is outside of the scope of EPA's TMDL. EPA does
recognize that the SWCD does not have regulatory control over land that discharges into SWCD facilities.
However, as noted by ODEQ in the November Response to Comments, "The TMDL WQMP requires
water conveyance entities to implement management strategies and actions that are specific to the
parts of the system that are owned and/or operated by the water conveyance entity, for example
implementation of best management practices to reduce sediment movement when canals and ditches
are cleaned or dredged. Water conveyance entities have the legal ability to implement best
management practices that pertain to maintenance activities on their system." EPA supports ODEQ's
approach to work with DMAs and "responsible persons" to help develop their TMDL implementation
plans.
Comment ID
L28-12
Water Quality Management Plan
Comment Category
USEPA Region 10
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Author Name Joy Archuleta
Organization Name
Letter ID
Comment ID
Comment Category
Name U.S. Forest Service
129
L29-1
DEQ's authority/responsibility to implement
Comment Text
We appreciate the opportunity to review and provide comment on the Environmental Protection
Agency's (EPA) Total Maximum Daily Load for Mercury in the Willamette Basin. The USDA Forest Service
(USFS) is committed to protecting and restoring Oregon's waters, as demonstrated by decades of
science-based conservation and management of some of the State's most important watersheds. We
are committed to full implementation of the Clean Water Act and appreciate the opportunity to
comment. We recognize this as an opportunity to meet State and Federal water quality rules and
regulations in a proactive and collaborative manner. Water quality protection on USFS land has
significantly improved in the last 20 years since implementation of aquatic conservation strategies
commonly known as the Northwest Forest Plan, PACFISH and INFISH, which amended the national
forest land and resource management plans in both Oregon and Washington. Water quality Best
Management Practices (BMPs) for land management activities have been a regional requirement since
the 1980s. Our updated national BMP program requires use of standardized monitoring protocols with
an emphasis on identifying corrective actions and adaptive management needed to maintain and
improve performance on water quality protection. Our 2019 Memorandum of Understanding (MOU)
with Oregon Department of Environmental Quality (DEQ) strives to meet all state water quality
standards and TMDLs. My staff has worked diligently in partnership with DEQ to develop a draft Water
Quality Management Plan (WQMP) that defines a framework of management actions to reduce runoff
and erosion from federal forest lands. We are committed to continue working hand-in-hand with DEQ
on a water quality implementation plan with measurable objectives and associated timelines for
implementing BMPs to reduce mercury transport and improve water quality.
Response Text
EPA appreciates this statement of support from the U.S. Forest Service (USFS) and acknowledges the
significant work that USFS has undertaken in protecting and restoring Oregon's waters. EPA encourages
USFS to continue to work with DEQ to develop and refine a WQMP that defines a framework of
management actions to reduce runoff and erosion from federal forest lands.
Comment Text
We are however, requesting further clarification on the EPA's sediment erosion calculations. The EPA's
TMDL establishes a 97% reduction level for five subbasins, whereas, the analysis demonstrated the
needed reductions varied between subbasins with a range from 89% to 97%. We would appreciate
further explanation on why the reduction level of 97% was extrapolated across these five subbasins as
well as the need for sediment erosion and surface runoff reductions to correlate when modeling
depicted otherwise. A 97% reduction in sediment erosion is significantly different than an 89% reduction
which was near the benchmark established in the DEQ analysis.
Comment ID
L29-2
Insufficient data and uncertainty in the process
Comment Category
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Response Text
The rationale for assigning 97% reductions to erosion-associated mercury loads in some HUC8 subbasins
is explained on page 8-9 of the EPA TMDL The reduction of 88% proposed in the ODEQTMDL is not
sufficient to attain the TMDL fish tissue targets in five HUC8 watersheds. The EPA analysis suggested
that reductions ranging from 89% to 97% would be needed to achieve targets in these watersheds. EPA
established a 97% reduction for these watersheds primarily to maintain a consistent allocation for
similar land uses across these watersheds. Having a consistent allocation goal can simplify
implementation planning, and development of specific BMPs, where land uses cross multiple
watersheds, such as in forested landscapes. It can also establish an even playing field, so to speak,
where there are different landowners in different watersheds for a particular industry. We note that the
ODEQTMDL allocations applied a consistent nonpoint source allocation across all subbasins. We have
attempted to continue that approach in the EPA TMDL, though it is challenging to do so given the
varying land uses in each subbasin, and varying subbasin mercury concentrations. Applying a 97%
reduction to these five subbasins we feel provides a consistent allocation and is protective for all.
Comment Text
Thank you for the opportunity to comment. We look forward to continuing to work collaboratively and
proactively with EPA and DEQ staff to improve water quality in the State. If you have questions please
contact Joy Archuleta, Regional Water Quality and Water Rights Program Manager at (503) 808-2696 or
joy.archuleta@usda.gov.
Response Text
EPA appreciates this statement of support from the U.S. Forest Service representative.
Comment ID
L29-3
DEQ's authority/responsibility to implement
Comment Category
USEPA Region 10
125
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