NC0089621_More Information Received_20181205

December 5, 2018
Via U.S. Mail and E-Mail
Julie Grzyb
Supervisor, Complex Permitting Unit
NCDEQ - Division of Water Resources
1611 Mail Service Center
Raleigh, North Carolina 27699-1611
[e-mail]
Teresa Rodriguez
Complex Permitting Unit
NCDEQ - Division of Water Resources
1611 Mail Service Center
Raleigh, North Carolina 27699-1611
[e-mail]
Connie Brower
Classifications, Standards & Rules Review Branch
NCDEQ - Division of Water Resources
1611 Mail Service Center
Raleigh, North Carolina 27699-1611
[e-mail]
Chris Ventaloro
Classifications, Standards & Rules Review Branch
NCDEQ - Division of Water Resources
1611 Mail Service Center
Raleigh, North Carolina 27699-1611
[e-mail]
RE: NPDES Permit Application NCO089621
Novozymes North America, Inc.
Franklin County
Dear Ms. Grzyb, Ms. Rodriguez, Ms. Brower, and Mr. Ventaloro:
novozymes
Rethink Tomorrow
RECEIVEDfDENRJDWR
DEC 14 2018
Water Resources
Permitting section
Thank you for the letter dated November 6, 2018 from the Division of Water Resources (the
"Division") to Novozymes North America, Inc. ("Novozymes") regarding NPDES Permit
Application NCO089621 (the "Permit Application"). The Division's November 6 letter included
comments related to the Potassium Aquatic Life Values Study Report (Ramboll Group
September 2018) and accepted the proposed potassium aquatic life values of 17 mg/L (acute)
3028007030

RAMBOLL

POTASSIUM AQUATIC LIFE VALUES
STUDY REPORT
Project no.
1690000122
Version
Final
Date
December 2, 2018
Prepared by
Rick Lockwood and Liza Heise
Checked by
Robin Richards
Ramboll
201 Summit View Drive
Suite 300
Brentwood, TN 37027
USA
T [phone]
F [phone]
www.ramboll.com

Ramboll - Potassium AQuabC Life Values
CONTENTS
1.
Introduction
1
1.1
General
1
1.2
Problem Definition
2
1.3
Study Design
3
2.
Study Plan
5
2.1
"Site" and "Occur at the Site" Definition
5
2.2
Aquatic Life Value Development
6
2.2.1
Literature Review
6
2.2.2
Supplemental Toxicity Testing
6
2.2.3
Species -Specific Procedures
9
3.
Results and criteria Derivation
10
3.1
Literature Review
10
3.2
Toxicity Test Results
10
3.2.1
Acute Test Results
11
3.3
Potassium -Hardness Relationship
11
3.4
In -Stream Aquatic Life Value Calculations for WLHS
15
3.4.1
Final In -Stream Warm Low Hardness Surface Water of North
Carolina (WLHS) Aquatic Life Values
15
3.5
Other Considerations
16
4.
Report References
17
S.
Potassium Toxicity References
19
REFERENCE TABLES
Reference Table 1: Acute Potassium Toxicity Test Results for Lampsiiis siiiquoidea and Lai radiata
Reference Table 2: Supporting Analytical Data
Reference Table 3: Chronic Potassium Toxicity Database
Reference Table 4: Acute to Chronic Ratio Calculation
Reference Table 5: Calculation of Warm Low Hardness Surface waters of North Carolina (WLHS) Acute
Potassium Aquatic Life Values

Ramtgll - Potassium Aquabc fife Values
APPENDICES
Appendix 1
Acceptable Aquatic Acute Toxicity Database for Potassium Warm Low Hardness
Surface water of North Carolina Aquatic Life Value Derivation
Appendix 2
Freshwater Potassium Aquatic Toxicity Database Literature Search Results
Appendix 3
Review of Potassium - Hardness Toxicity Relationship for Freshwater Mussels

Ramboll - Potassium Aquatic 1He Values
1. INTRODUCTION
1.1 General
Ramboll conducted a review of potassium limits in the context of a proposed new direct discharge
of treated effluent subject to authorization as per North Carolina Department of Environmental
Quality (NCDEQ) NPDES permitting regulations. Specifically, in issuing a NPDES Permit, the state
assures that the discharge does not have a reasonable potential to cause or contribute to the
exceedance of in -stream criteria that protects the designated uses of the receiving stream. The
state, to assure protection of the designated use of the receiving stream, may develop water
quality -based effluent limits (WQBELs) that would be enforceable in the NPDES Permit. WQBELs
are developed considering a numeric in -stream criterion to protect designated use, stream design
Flow appropriate for the criterion, and statistical translation to a continuously discharging
effluent. EPA, in developing the water quality -based toxics control approaches and
methodologies, derives in -stream numerical aquatic life criteria (i.e., National Recommended
Water Quality Criteria) based on a concentration (magnitude) for a set exposure (duration) that
should not be exceeded more than once every 3 years. In -stream criteria are not considered to
protect all aquatic life under all possible conditions at all times, but are considered to protect
95% of aquatic life, whether acute or chronic exposure at a frequency of once per three years'
(equates to less than 95% of the time). These EPA approaches and methodologies are referenced
in North Carolina regulatione2.
National Recommended Water Quality Criteria can be re -developed when an aquatic ecosystem
need more or less protection for a constituent using site -specific water quality criteria (or
criterion) methods presented in the USEPA 1985 "Guidelines for Deriving Numerical National
Water Quality Criteria for Protection of Aquatic Organisms and Their Uses" (EPA Guidelines) and
the EPA "Water Quality Standards Handbook." These guidelines outline development of in -stream
site -specific acute and in -stream site -specific chronic aquatic life criteria'. Elements of the EPA
Guidelines have been updated (in 1994) and subsequently codified in 40 CFR 132 Appendix A
(regulation applicable to the Great Lakes).
As part of a water quality standards program, states present water quality criteria both as
narrative standards and numeric criteria for specific chemicals (typically similar to the National
Recommended Water Quality Criteria). In addition, some states present approaches for
interpreting a narrative criterion as a numeric assessment (e.g., using Whole Effluent Toxicity
testing) and some states present approaches to developing aquatic life criteria for a chemical if a
National Recommended Water Quality Criteria did not exist.
North Carolina presents in 15 NCAC Subchapter 02B three approaches to defining acute aquatic
toxicity for a chemical:
USEPA, 1985, "Guidelines for Deriving Numencal Nahonal Water Quality criteria for the Protection of Aquatic organisms and Their Uses" PB85-
222049.
Posthuma, Leo, GW Sutter, TP Traas, 2002, "Species Sensitivity Distributions in ECotoxi:olcgy," CRC Press.
' 15A NCAC 2B.0202(1)(a); 15A NCAC 2B.0211(11)(b); 15A NCAC 2B.0220(9)(d). Ramboll acknowledges that NCDEQ Division of Water
Resources uses a duration component for metals found at 15A NCAC 2B.0211(11) and uses a frequency component of >10% with 90%
confidence.
1/23

Ramboll - Potassium Aquatic ufe Values
• Acute Approach 1. One-half (1/2) of the Final Acute Value (FAV) determined using the EPA
Guidelines;
• Acute Approach 2. If a value cannot be determined using Acute Approach 1, then apply one-
third of lowest 'available' LC50; or
• Acute Approach 3. Conduct case -by -case statistical analyses of a dose -response curve'.
In 15 NCAC Subchapter 2B, North Carolina presents its approaches to interpreting the narrative
chronic aquatic toxicity as follows:
• Chronic Approach 1. Direct measurements of chronic toxicity°
• Chronic Approach 2a. Apply acute -to -chronic ratio (ACR) for lowest LC505,
• Chronic Approach 2b. If an ACR is not available, then 0.01 of the lowest LC50, or
• Chronic Approach 2c. 0.05 of the lowest LC50 if half-life of chemical less than 96-hr6.
The following sections walk through the steps required to validate data that will be used in acute
and chronic databases. From these databases, a Final Acute Value (FAV), ACR, and chronic value
can be calculated as described below. Ramboll utilized the approach and methodologies
presented in the EPA Guidelines and North Carolina regulations in estimating protective
potassium concentrations for acute data (North Carolina Acute Approach 1) and the North
Carolina chronic direct measurement.
1.2 Problem Definition
Potassium has been identified as a constituent of concern for mussels based on results of
analytical evaluation of the proposed Novozymes effluent. Freshwater mussels (family
Unionidae) have a demonstrated sensitivity to potassium below that of other regularly tested
freshwater taxa. Of the roughly 300 known species, only Lampsilis siliquoidea (the Fatmucket)
has a robust potassium acute toxicity data base in a range of water quality conditions that is
representative of where this species is found, generally the Mississippi River basin. The data base
for long-term sublethal (growth or reproduction) effects to mussels is very limited.
Numeric in -stream site -specific aquatic life values for potassium have previously been developed
using accepted and recognized methodology under the oversight of the Oklahoma Water
Resource Board (CP Kelco, 2016). Similarly, Ramboll proposes implementing the aquatic life
values for potassium, as presented in this study, into potassium benchmarks utilizing the
statistical procedures to relate duration of monthly average and daily maximum benchmarks for
Novozymes. This Study Report details the methods used to generate the data and information to
confidently develop valid in -stream acute and chronic potassium aquatic life values. Ramboll is
proposing acute and chronic (benchmarks), per requirements established in State rules, based on
these methods.
' 15A NCAC 2B.0202(1)
' Chromic toxicity to aquatic life means any harmful effect sustained by either resident aquatic populations or indicator species used as test
organisms in a controlled toxicity test due to long-term exposure (relative to the life cycle of the organism) or exposure during a substantial
portion of Me duration of a sensitive period of the life cycle to a specific chemical substance or mixture of chemicals (as in an effluent). In the
absence of extended periods of exposure, early life stage or reproductive toxicity tests may be used to define chronic impacts. (15A NCAC
02B. 0202(14).
s LC50 is the concentration that is lethal to 50 0 of the test organisms. Acute to Chronic Ratio (15A NCAC 28.0202(2) is the ratio of the LC50 for
a specific toxicant or an effluent to the chronic value for the same toxicant or effluent.
^ 15A NCAC 2B.0202(15), 15A NCAC 2121.0208(a)(I)
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Ramboll - Potassium Aquatic Life Values
1.3 Study Design
To develop in -stream acute and chronic potassium aquatic life values for warm lower hardness
surface waters of North Carolina (WLHS), two regulatory processes were considered: 1) aquatic
life value development and 2) WLHS modification. Potassium is not a Clean Water Act priority
pollutant or toxic pollutant, it is not listed in the EPA National Recommended Water Quality
Criteria for non -priority pollutants or nonconventional pollutants and is not listed in 15A NCAC
28.0211. Further, North Carolina has no surface water quality standard, drinking water standard,
or ground water standard for potassium. Without any type of potassium standard already in
place, it may be appropriate to use the North Carolina regulations for developing aquatic life
values for potassium. As stated above, the regulation for defining acute water quality values,
follows the EPA process of adopting water quality values for the protection of beneficial use for
aquatic life, specifically, the EPA Guidelines. Chronic values are defined in 15A NCAC 2B.0202
with procedures described in 15A NCAC 28.0208. The selected approach is dependent upon the
available validated data.
15A NCAC 2B presents approaches to developing site -specific regulatory criteria including mineral
criteria; however, these approaches are specific to heavy metals. NCDEQ regulations (15A NCAC
2B .0211 (11) (b)) reference the EPA Water Quality Standards Handbook, Second Edition, which
within Chapter 3 includes water quality criteria.' The EPA methods apply to non -regulatory
aquatic life criteria as well. Since the EPA Guidelines and Water Quality Standards Handbook are
appropriate to develop criteria, they are applicable to developing aquatic life values. Chapter 3
of the Water Quality Standards Handbook presents the following for modifying water quality
criteria:
"In the early 1980s, EPA recognized that laboratory -derived water quality criteria might not
accurately reflect site -specific conditions and, In response, created three procedures to derive
site -specific criteria. This Handbook contains the details of these procedures, referenced
below.
The Recalculation Procedure is intended to take into account relevant differences between the
sensitivities of the aquatic organisms in the national dataset and the sensitivities of
organisms that occur at the site (See Appendix L, pp. 90-97).
The Water -Effect Ratio Procedure (called the Indicator Species Procedure in USEPA, 1983a;
1984f) provided for the use of a water -effect ratio (WER) that is intended to take into
account relevant differences between the toxicities of the chemical in laboratory dilution
water and in site water (see Appendix L.).
The Resident Species Procedure intended to take into account both kinds of differences
simultaneously (see Section 3.7.6)."
The options for modifying aquatic life values are not specific to a chemical or a waterbody but do
require generation and validation of data and clarity in presenting inputs into the process of
modifying the values. Although development of an in -stream WLHS potassium standard does not
fall entirely within one of the three categories noted above, Ramboll has incorporated elements of
each of the three categories.
We have used the EPA Guidelines as the primary guidance in combination with the EPA 1994
Water Quality Standards Handbook in developing an acute potassium aquatic life value as
EPA-823-8-94-005; August 1994 with some additional new information (June 2007)
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Bamgoll - PMassium Aquabc We Values
described below. The resident species procedure was then applied to modify the acute aquatic
life value specific to the warm -water rivers found In the subject region of North Carolina.
Previous testing with mussel species, Lamplilis siliquoidea (Fatmucket mussel) (Environ, 2012)
demonstrated a relationship between potassium toxicity and hardness where the hardness of the
water utilized in the mussel testing was 100 mg/L CaCO3 or greater. The summer low -flow
hardness of the proposed receiving streams in North Carolina have median values of
approximately 33 CaCO3 (USFWS, 2017). Hence, additional aquatic toxicity testing was
performed to determine if a relationship between potassium toxicity and water quality
characteristics could be confirmed at a lower hardness. Details of the path followed to develop in -
stream acute and chronic potassium aquatic life values for WLHS are presented in the following
sections.
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Rambull- Potassium ARudUC Life Values
2. STUDY PLAN
The study plan for developing in -stream WLHS acute and chronic potassium aquatic life criteria
entailed a stepwise process presented in the following sections:
• Step 1. "Site" and "Occur at the Site" Definition
• Step 2. Criteria Development
• Literature Review
• Review Process
• Data Gap Analysis
• Supplemental Toxicity Testing
• Testing Design
• Testing Execution
• Step 3. Criteria Derivation
2.1 "Site" and "Occur at the Site" Definition
Chapter 3 of the Water Quality Standards Handbook provides guidance on defining the site as an
area. Depending on the application, a site can be defined as a state, region, watershed or
waterbody segment. For the purposes of this study, Ramboll focused on WLHS, and the in -
stream river segment chronic potassium aquatic life value is applicable to the Tar River at
Louisburg (Station #01100000) or Cedar Creek (just south of the Franklin County POTW
discharge).
The term "resident species" or "occur at the site" is defined by EPA as the following:
The phrase "occur at the site" includes the species, genera, families, orders, classes, and
phyla that:
a. Are usually present at the site.
b. Are present at the site only seasonally due to migration.
c. Are present intermittently because they periodically return to or extend their
ranges into the site.
d. Were present at the site in the past, are not currently present at the site due to
degraded conditions and are expected to return to the site when conditions
improve.
e. Are present in nearby bodies of water, are not currently present at the site due to
degraded conditions and are expected to be present at the site when conditions
improve.
The process of defining if a species occurs at the site was necessary as we suspected that two
particular species (Ceriodaphnia rigaudi, C. rigaudi) and the Rainbow trout (Oncorhynchus
mykiss) included in the potassium dataset did not occur in this region of North Carolina. An
assessment of in -stream temperature indicated the proposed receiving streams consistently
maintained temperatures that would not support Rainbow trout. The distribution of C. rigaudi in
North Carolina is uncommon. This species is known to predominately prefer ponds or lakes and
sln

Ramboll - Potassium Aquatic Life Values
climates consistent with sub -tropic like conditions. As such, it was not appropriate to consider C.
rigaudi or Rainbow trout data in the in -stream WLHS potassium criteria development.
Although the EPA Guidelines indicate that acceptable data for a fish in the family Salmonidae be
included in the calculation of criteria, this was deemed inappropriate for the proposed receiving
stream segments because fish in the family Salmonidae do not reside in the proposed receiving
streams. Therefore, to maintain the eight family MDRs, a fish species (the common carp,
Cyprinus carpio) that was known to occur in the proposed rivers was substituted.
2.2 Aquatic Life Value Development
2.2.1 LITERATURE REVIEW
2.2.1.1 Review Process
The first step of developing in -stream potassium aquatic life criteria for WLHS was to review the
published literature on the aquatic toxicity of potassium and validate the data, primarily based on
the EPA Guidelines. However, 40 CFR 132 Appendix A (Methodologies for Development of Aquatic
Life Criteria and Values) and MDEQ 1996 were also consulted as these references provide much
more rigorous guidelines for determining data validity. The initial literature search was
conducted in 2017, a second literature search was conducted in August 2018 to ensure all valid
literature was obtained and included in the analysis.
2.2.1.2 Data Gap Analysis
The next step of developing in -stream potassium aquatic life criteria for WLHS was to determine
if there were information gaps in the acceptable dataset to appropriately statistically analyze the
data. As per the EPA Guidelines, aquatic life criteria can be calculated using the eight minimum
data requirements method. Additionally, if it is determined that water quality characteristics
(e.g., hardness and alkalinity) affect toxicity, then a regression -based approach can be taken to
calculate the aquatic life criteria. Ramboll determined that the data gaps for in -stream potassium
criteria applicable to proposed receiving stream included acute data for a mussel in a low -
hardness water, and representative species indigenous (resident) to the area.
The in -stream modification process for WLHS and associated toxicity test design included
addressing the data gaps by investigating the relationship between potassium acute toxicity and
hardness using regression analysis on a low -hardness water, and utilizing an indigenous test
species.
2.2.2 SUPPLEMENTAL TOXICITY TESTING
While the existing acceptable database for potassium toxicity shows acute test results for waters
with a variety of hardness and alkalinity values, the data do not exhibit toxicity test results for a
mussel species in a low -hardness water and/or alkalinity. Thus, the existing data provide insight
to differences in sensitivity among test species to potassium and not differences in toxic response
of any single species to potassium due to changes in hardness and/or alkalinity. Additional
toxicity test results were required to investigate a relationship between potassium toxicity and
waters with low -hardness.
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Ramboll - P asslum Aquabc We Values
2.2.2.1 Testing Design
Supplemental toxicity testing in support of an in -stream potassium value for WLHS included
acute toxicity testing with mussel species exposed to a low -hardness water. Based on the
existing acute acceptable database, and organism availability, supplemental toxicity tests were
conducted with Fatmucket and Lampsilis radiata (Eastern Lampmussel). Eastern Lampmussel was
selected as a representative indigenous (resident) test species.
Although Fatmucket were not indigenous to the proposed receiving streams, other species of the
genus Lampsilis were. Furthermore, this species is artificially propagated in quantities needed for
this study; has documented performance in toxicity tests meeting test acceptability criteria; and
is considered an acceptable surrogate for other mussel species. Imlay (1973) utilized Fatmucket
in addition to other mussel species in potassium toxicity tests. His study showed similar
responses between all mussel species tested. Therefore, Fatmucket was considered an
appropriate surrogate species to represent most mussel species found in moderately hard water
rivers.
2.2.2.2 Test Execution
2.2.2.2.1 GENERAL
Potassium, in the form of potassium chloride (KCI), was added to test waters to establish
potassium test concentrations. Reagent -grade or better (98% or higher) provided the potassium
source for all tests. All potassium stock solutions were prepared in the test water to be used in
the respective acute toxicity tests and diluted with the test water appropriate to the toxicity test
to be conducted. Since potassium is stable in water and concentration correlate well to
conductivity, solution conductivity values were confirmed by measuring conductivity daily during
the testing. Actual potassium concentrations were measured only in newly prepared toxicity test
waters for the acute tests.
"Range -finding" toxicity tests were not necessary due to the availability of acute potassium
toxicity data. Potassium test concentrations were established in a dilution series (minimum of
five exposures) utilizing test concentrations of 10, 20, 40, 70, and 100 mg/L nominal potassium
to provide appropriate dose/response curves. Test design was attempted to set dilution series
increments to bracket the midpoint of mortality responses. This was done to avoid "all or
nothing" dose/response curves and develop more meaningful dose/response data. In acute
toxicity tests, every effort was made to generate dose/response data that have between 10
percent and 100 percent mortality (average of replicates) in three exposure concentrations.
Alkalinity and hardness were measured in test dilution waters and potassium was measured in all
test solutions as detailed in this section.
All toxicity testing followed the test methods with key test features as outlined below. All toxicity
tests were supported by analytical analyses, water quality assessments (i.e., pH, conductivity,
dissolved oxygen, temperature), and documentation of test water hardness and alkalinity for
each batch of dilution water prepared. Methodologies for documentation of water quality
parameters (pH, conductivity, hardness, ammonia, etc.) followed standard methodologies (i.e.,
USEPA, Standard Methods) as outlined in the laboratory SOP manual (available upon request).
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Ramboll - Potassium Aquatic life Values
2.2.2.2.2 TEST DILUTION WATER
Laboratory reconstituted dilution water was prepared at two different hardness values, 25 and 75
mg/L CaCO3. The dilution waters were prepared as described below and used in acute toxicity
tests. The following water quality parameters were documented for each batch of dilution water
used in all toxicity tests:
. Total hardness
• Total alkalinity
• Total Residual Chlorine (TRC)
The low-water hardness water generally followed the recipe of standard reconstituted
USEPA/ASTM dilution waters (USEPA, 2002a, ASTM E729). The following reagent grade salts
were added to de -ionized water to prepare the reconstituted waters listed below:
. Standard USEPA/ASTM waters - NaHCO3, MgSO4, CaSO4, KCI
De -ionized water was obtained from municipal potable water that was passed through a U.S.
Filter, Inc. (or similar) initial deionization unit equipped with five water purifying cartridges
(ultrafiltration membrane, carbon cartridge, mixed bed ion exchange, mixed bed ion polisher,
and organic scavenger). The base water for the laboratory water is tested annually to ensure it's
free of toxics. Results of the annual testing are kept on file.
2.2.2.2.3 ACUTE TESTING
Laboratory acute toxicity test protocols followed the most recent edition of ASTM (2007) and
adhered to the laboratory SOP manual. Ramboll's SOP -specified acute toxicity testing methods
are available upon request. Only tests meeting data quality requirements specified by the EPA
Guidelines, USEPA (2000, 2002a) and ASTM were used in derivation of potassium aquatic value
(i.e., only data from acute tests with 90 percent or higher control survival will be used).
Fatmucket and Eastern Lampmussel acute tests were 96-hour static daily -renewal toxicity tests.
Test durations and protocols were as follows:
• Lampsiiis siiiquoidea and Lampsiiis radiata - 96 hr test following ASTM (2006) protocol.
Mortality was the test endpoint, with mortality assessed as detailed below in the species -specific
test protocols. Water quality parameters (hardness, alkalinity, pH, dissolved oxygen,
conductivity, and temperature) were documented in accordance with specific test protocols.
2.2.2.2.4 TEST ORGANISMS
Test organism sources, culturing, and maintenance procedures adhered to American Society for
Testing and Materials (ASTM) and USEPA protocols, and laboratory Standard Operating
Procedures (SOP). Key elements of the organism culturing and handling program are
summarized below.
Fatmucket were obtained from Missouri State University and Eastern Lampmussel were obtained
from Virginia Department of Game and Inland Fisheries for toxicity testing in Ramboll's aquatic
toxicity testing laboratory. Organisms of known age were received via next -day delivery, in
culture water similar to USEPA very soft water. Upon receipt, the temperate, pH, and dissolved
oxygen content of the water were documented. Mussels are not fed at test initiation and are
placed in designated culture and holding rooms at test temperature until the time of test
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RamOoll - Potassium Aquatic We Values
initiation. Since potassium chloride is the toxicant used for routine mussel reference toxicant
testing at Ramboll, results were compared to the established data base for determination of
organism heath status.
2.2.3 SPECIES -SPECIFIC PROCEDURES
2.2.3.1 Acute test
Mussel toxicity tests were ASTM (2006) 96 hour static, daily -renewal toxicity tests conducted
under a 16:8 light:dark photoperiod at a test temperature of 25 °C. Test organisms age was
juvenile and less than 5 days post transformation at test initiation. Organisms were not fed
during acute toxicity tests. Four replicates of 5 organisms each were exposed to nominal
potassium concentrations of 0, 10, 20, 40, 70, and 100 mg/L. Water quality parameters (pH,
dissolved oxygen, conductivity, and temperature) were documented in all newly prepared and
24-hour-old test and control water exposures for the duration of the tests at test initiation, daily
renewal, and test termination. Test water temperatures were 25 +/-1 °C and pH was between
6.0-9.0 s.u.
2.2.3.2 QA/QC
The following QA/QC measures were implemented to ensure the validity of potassium analytical
results, and other supporting analyses:
• Use of only high -purity (greater than 98%) potassium chloride to establish potassium test
concentrations. Certification of analysis can be provided upon request.
• Obtaining from the manufacturer, a list of impurities in the potassium chloride used to
establish test concentrations.
• Use of a certified laboratory, and state and NELAC certified laboratory for all potassium
analyses.
• Use of a standardized sample identification and sample labeling system to ensure proper and
consistent sample identification (i.e., organism tested, test date, "new" or aged test solution,
etc.).
• Review of laboratory QA/QC data (method blanks, internal spike recoveries, etc.) to ensure
that all sample analyses are within specified control boundaries.
• Sample shipment under proper chain -of -custody.
• Daily calibration of laboratory meters (pH, dissolved oxygen, conductivity) used to measure
water quality conditions in toxicity tests. All meter calibration and related QA/QC
methodologies followed the approved toxicity testing SOPs. Any corrective measures were
implemented and documented.
• Test water hardness and alkalinity was assessed following procedures outlined in toxicity
testing SOPs. These protocols follow established EPA and ASTM methods, utilize
commercially -prepared reagents, and their accuracy is routinely evaluated using commercially
prepared standards.
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Ramtroll - Potassium Apuatit life Values
3. RESULTS AND CRITERIA DERIVATION
3.1 Literature Review
A literature search for potassium freshwater toxicity data was conducted in 2017 and again in
August 2018 to ensure all valid literature was obtained and included in the analysis. The same
data validity requirements, which are detailed in the EPA Guidelines and 15A NCAC 213, were
applied to any data resulting from the updated literature search. The August 2018 literature
search revealed a recent publication (accepted for publication Wang et al, 7/30/2018,
Environmental Toxicology and Chemistry) in which two chronic toxicity tests were conducted with
Fatmucket exposed to potassium chloride. The testing was conducted in 2013. In this chronic
study, Fatmucket were exposed to potassium concentrations with and without refugia substrate
(sand). The controls in both exposures met test acceptability criteria, however, the results of the
tests vary considerably.
Chronic (28-Day) Fatmucket data (Wang et al, 7/30/2018)
Test Aegime Uri* ibionnass t
Definition) Water -only 32.0 23.0
Refugia substrate (sand) 6.9 8.7
NOTES:
ChV - geometric mean between the NOEL and LOEC.
Testing was conducted at hardness 100 mg/L CaCO3.
In the Wang study, there is discussion of biofouling of the substrate, indicating toxicity other than
that of potassium is evident. Because of the biofouling, the general trend would suggest that the
water -only exposure yields a more valid test. After Ramboll's review of the paper, it was
determined that the water -only test was valid and should therefore be added to the acceptable
chronic database.
It should be noted that both tests were conducted under general guidance of ASTM E2455-06
(2013) which are under development and have not been subjected to extensive interlaboratory
testing and review. Also, the ASTM guidance does not include refugla substrate in the method.
3.2 Toxicity Test Results
Acute aquatic toxicity testing with potassium, as described above in Section 2, was conducted in
August 2017. Acute test results are summarized and discussed below in terms of average
measured potassium and hardness concentrations. A summary of the testing results, including
95 percent confidence intervals, is presented on Reference Table 1. Acute test results for
Fatmucket showed a greater acute sensitivity to potassium at in a low hardness water than
Eastern Lampmussel. The Eastern Lampmussel, indigenous to the North Carolina streams, is
considered a low -hardness mussel and is much more tolerant of the lower hardness than
Fatmucket. In the two tests conducted, the Eastern Lampmussel was about 1.5 percent more
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KamWll - Potassmm AVuabc the Values
tolerant to potassium than Fatmucket in the 25 mg/L CaCO3 hardness water and was
approximately twice as tolerant to potassium than Fatmucket in the 75 mg/L CaCO3 hardness
water.
3.2.1 ACUTE TEST RESULTS
Test acceptability criteria (i.e. control survival) were met for all acute tests. The 96-hour LC50
results for the testing were calculated based on measured values and are presented on Reference
Table 1. Water quality parameters (i.e., pH, temperature, dissolved oxygen, conductivity)
remained within acceptable limits for all tests. Supporting analytical analysis values measured at
the beginning of each test are presented on Reference Table 2. Since analytical measurements
(e.g., hardness, alkalinity, and potassium) were collected once at the beginning of the test,
individual analytical measurements were compared to nominal concentrations. Individual
analytical measurements were generally within 20% of the nominal test concentrations for each
test treatment.
The measured 96-hour LC50 results at hardness 25 were 37.2 mg/L for Eastern Lampmussel and
22.4 for Fatmucket. The measured 96-hour LC50 results at hardness 75 were 60.8 mg/L for
Eastern Lampmussel and 28.1 for Fatmucket. Because these data are valid, they were used in
the in -stream WLHS for North Carolina potassium benchmark development.
3.3 Potassium -Hardness Relationship
Freshwater mussels (family Unionidae) have a demonstrated sensitivity to potassium below that
of other regularly tested freshwater taxa. Of the roughly 300 known species, only Lampsilis
siliquoidea (the Fatmucket) has a robust potassium acute toxicity database in a range of water
quality conditions that is representative of where this species is found, the Mississippi River
basin. The database for long-term sublethal (growth or reproduction) effects to mussels is very
limited.
In 2017, Ramboll conducted acute testing with mussels to address the key data gaps related to
the toxicity of potassium to mussels for very soft water conditions (similar to those observed for
the Cedar Creek and Tar River). A further gap in the potassium toxicity database is a lack of
data for any Atlantic Slope (which includes the Tar/Pamlico river watershed in North Carolina)
mussel species. The testing results met the following objectives.
• Generate acute potassium toxicity test data (over a range of potassium concentrations)
for two mussel species.
o Lampsilis radiata (Eastern Lampmussel) was selected as a representative Atlantic
Slope indigenous WLHS test species.
o Lampsilis siliquoidea (Fatmucket) mussel was selected as the second species as it
is the most commonly tested species in North America and has a robust
database.
Generate data at a nominal hardness of 25 mg/L and 75 mg/L to:
o Test at the Floor hardness of 25 mg/L presented in North Carolina regulations for
hardness -based metal criteria.
o Test at 75 mg/L hardness to serve as another comparison point between the two
species and further expand the dataset of potassium toxicity in low to moderate
hardness (<100 mg/L) waters.
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Ramboll - Potassium Aquatic We Values
0 Re-evaluate the predicted toxicity results based on the established
hardness/potassium toxicity relationship for the Fatmucket mussel in waters with
hardness from 100 to 400 mg/L as CaCO3 and determine if the relationship is
appropriate for Atlantic Slope mussels such as the Eastern Lampmussel.
The results of the acute testing with the Eastern Lampmussel and Fatmucket in reduced hardness
waters indicated that mussel species of the Atlantic Slope assemblage are more tolerant of
potassium than common species in the Mississippi River drainage at equivalent hardness
concentrations (Appendix 3).
Based on the Ramboll testing in 2017 (discussed in Appendix 3) and the results of previous acute
testing (Environ, 2012), Ramboll recognized the relationship between potassium toxicity to
Fatmucket mussels and hardness. In the Environ, 2012 testing, linear regression showed a high
degree of predictability (determination) between potassium concentration and hardness (112 =
0.78) combined with a slope showing a 20% increase in the potassium LC50 concentration. Frorr
these data, a potassium -hardness toxicity relationship was developed for the Fatmucket mussel
in waters with hardness from 100 to 400 mg/L as CaCCt3 (Environ, 2012).
This relationship is defined as: LC50 (mg/L of potassium) = 0.1609(hardness)+26.872.
The relationship is used in a stepwise approach as presented below:
Potassium -Hardness
Relationship Calculation
(using Wang
et al, 2018 ChV
and Biomass
EC20)
1. Hardness
2.Test Endpoint (EC20 or
3. Ratio of Test
4. Multiply known
S. Test Endpoint
Value (mg/L
LC50) values (mg/L
Endpoint (EC20
Test Endpoint
(EC20 or LC50)
CaCO3)
potassium) at hardness
or LC50) values
(EC20 or LC50)
values (mg/L
in Step 1 as generated
values by ratio
potassium) at
from calculation
untested
hardness
25
L 0.1609 25 + 26.872 = 31
32.0 * 0.72
(Wang et al 2018
100
0.1609(100) + 26.872 = 43
31/43 = 0.72
ChV*ratio from
23.0
step 3
25
0.1609 25 + 26.872 = 31
23.0* 0.72
(Wang et al 2018
100
0.1609(100) + 26.872 = 43
31/43 = 0.72
biomass
16.5
EC20*ratio from
step 3
Though Ramboll recognizes the slope (adjustment factor), the assumption that toxicity behavior
outside of the tested hardness range is consistent was unknown. To confirm that the slope is
consistent below a hardness of 100 mg/L CaCC13, confirmatory testing of species adapted to low
hardness conditions was necessary. Because the potassium -hardness toxicity relationship
equation was not proven on low hardness waters, extrapolation to a hardness of 25 mg/L CaCO3
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Ramboll - Potassium aquatic Life values
utilizing the Fatmucket relationship between 100 mg/L and 400 mg/L CaCO3 hardness was
inappropriate.
Examples of the hardness/potassium toxicity relationship are presented below:
When the above equation is applied to the result of the Fatmucket hardness 75 mg/L CaCO3 data
point going to a lower hardness of 25 mg/L CaCO3 (data presented in Reference Table 1), the
result is:
Potassium -Hardness
Relationship Calculation
(using Reference
Table I Fatmucket
Hardness 75 mg/L
CaCO3)
1. Hardness
2. Test Endpoint (LC50)
3. Ratio of Test
4. Multiply known
5. Test Endpoint
Value (mg/L
values (mg/L potassium)
Endpoint
Test Endpoint
(LC50) value
CaCO3)
at hardness in Step 1 as
(LC50) values
(LC50) value
(mg/L
generated from
by ratio
potassium) at
calculation
untested
hardness
25
0.1609 25 + 26.872 = 31
31/38.9 = 0.7969
28.1 * 0.7969
22.4
75
0.1609 75 + 26.872 = 38.9
The value used in Step 4 is the Reference Table 1 Fatmucket 75 mg/L CaCO3 hardness result (28.1 mg/L
potassium).
In the measured data from Reference Table 1, the Fatmucket 96-hr LC50 value at hardness of 25
mg/L CaCO3 was 22.4 mg/L potassium. The result (Step 5) of the calculation immediately above
demonstrated the potassium concentration matches the test result of the measured Fatmucket at
a hardness of 25 mg/L CaCO3 (Reference Table 1).
For another example, starting with the geomean, of the Appendix 1 Fatmucket hardness 400
mg/L CaCO3 (geomean of 107, 95, 78, 72, 84 mg/L potassium) and applying the calculation for a
hardness 25 mg/L CaCO3, the result is:
Potassium -Hardness
Relationship Calculation
(using Appendix
I Fatmucket Hardness 400
1. Hardness
2. Test Endpoint (LC50) values
3. Ratio of Test
4. Multiply known 5. Test Endpoint
Value
(mg/L potassium) at
Endpoint
Test Endpoint (LC50) value
(mg/L
hardness in Step 1 as
(LC50) values
(LC50) value (mg/L potassium)
CaCO3)
generated from calculation
by ratio at untested
hardness
25
0.1609 25 + 26.872 = 31
31/91.3 = 0.3395
86 * 0.7969 29.2
400
0.1609 400 + 26.872 = 91.3
The value used in Step 4 is the geomean of the Appendix 1 Fatmucket 400 mg/L CaCO3 hardness (86 mg/L
potassium).
When the Appendix 1 Fatmucket hardness 400 mg/L CaCO3 geomean result (86 mg/L potassium)
is used in the hardness equation, the calculation at hardness 25 mg/L CaCO3 result is 29.2 mg/L
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Ramboll - PotassWm Aquatic ❑fe Values
potassium (Step 5). The calculated result in the table immediately above, although not exact, is
similar to the measured result from Reference Table 1 96-hr LCSO value at hardness of 25 mg/L
CaCO3 which is 22.4 mg/L potassium.
These examples and the results from testing with low hardness waters (Appendix 3) indicate the
potassium -hardness equation is valid for Fatmucket in waters ranging from hardness
concentrations of 25 to 400 mg/L CaCO3-
The potassium -hardness relationship, derived using acute testing, is also appropriate for use with
the chronic testing with Fatmucket as per the EPA Guidelines, Section VII. C. Notee. The EPA
Guidelines recognize the relationship between certain water quality characteristics (i.e. hardness)
and toxicity for metals and the best fit relationship is through acute toxicity. Application of
hardness derived acute relationships for metals is applied to chronic criteria noting the equation
slope for chronic criteria is either identical to or slightly less than the acute equation slope for
various metal species. This is evident in the National Ambient Water Quality Criteria - Aquatic
Life Criteria Table Appendix B (USEPA, 2018) and 15A NCAC 02B.0211 Table A. In the two
aforementioned tables, the slope for Chromium III, Lead, Nickel, and Zinc are the same for the
acute and chronic calculations, while the slope for Cadmium is slightly less in the chronic
calculation than in the acute calculation. The difference in the acute and chronic equations is
evident in the intercept values which represent the general acute to chronic ratio for these
metals.
When the potassium -hardness toxicity relationship is applied to the species mean acute value (44
mg/L potassium, Reference Table 4) for Fatmucket at a hardness of 100 mg/L CaCO3, the result
was 31.2 mg/L potassium at a hardness of 25 mg/L CaCO3. Although this value is slightly higher
than that observed in the acute testing (Reference Table 1 - 22.4 mg/L potassium), it is within
the expected range of Fatmucket testing and was on -target for the predicted result (Appendix 3).
Subsequently applying the potassium -hardness relationship to the chronic Wang et al 2018 data,
the chronic value was adjusted to 23.0 mg/L potassium and the Biomass EC20 was adjusted to
16.5 mg/L potassium, as shown in the calculation above and again presented in the table below.
EPA Guidelines Sector, VII. C Note, Because the best documented relationship I$ that between hardness and acute toxicity of metals in fresh
water and a IN IN relationship fits Mere data, geometric means and natural logarithms of both toxicity and water quality are used in the rest of
this section. For relationships based on other water quality charactenstics, such as pH, temperature, or salinity, no transformation or a different
transformation might fit the data better, and appropriate changes will be necessary throughout this section. It Is probably preferable, but not
necessary, to use the same transformation that was used with the acute values in Section V.
14/23

Ramtoll Potassium Aquatic Life Values
In addition to the previous mussel testing (Environ, 2012), three other species were tested to
determine if there was a potassium -hardness relationship. Conversely, acute tests with C. dubia,
C. tentans, and A promelas showed a poor degree of determination (maximum R2 = 0.37, 0.07,
and 0.22, respectively) combined with slopes showing an increase of 20% to 17% increase in the
potassium LC50 concentration. Although a useful relationship between hardness and potassium
toxicity was seen with only the mussel Fatmucket, a meaningful slope and relationship (112 > 70)
for at least two species is required to statistically define the potassium toxicity and hardness
relationship suitable for incorporation into criteria development (EPA Guidelines, Section V.A).
A strong relationship between potassium toxicity and hardness was observed for only the mussel,
and the two species requirement was not met. Criteria development that incorporated hardness
or alkalinity water quality conditions was not further pursued. However, because a potassium -
hardness relationship has been established for mussel species and mussels have been deemed an
important species in the proposed receiving waters, it is appropriate to use the potassium -
hardness relationship for calculating the criterion with respect to mussels, according to the EPA
Guidelines.
Refer to Appendix 3 for a more detailed description of the acute toxicity testing conducted at
Ramboll in 2017 with Fatmucket and Eastern Lampmussel, as well as observations for the
potassium -hardness relationship.
3.4 In -Stream Aquatic Life Value Calculations for WLHS
Appendix 1 presents the acceptable acute potassium toxicity database that was used to develop
the acute value for WLHS as per the EPA Guidelines. In Appendix 2, all studies reporting
potassium data are represented, however some studies were deemed unacceptable for use in
aquatic life value derivation. The acceptable acute potassium toxicity database includes data for
16 species and meets the eight family requirements. Since Salmonids are likely not residents due
to the temperatures of the proposed receiving streams, the common carp (C. carpio) was
substituted for the Salmonid family data point. The common carp has been documented to be
found in the proposed receiving streams. The Ceriodaphnia species, C. rigaudi in North Carolina
is rare as it prefers a tropical climate. Also, this species is known to predominately prefer larger
static waterbodies, such as ponds or lakes. Because the two aforementioned species are not
known to reside in the proposed WLHS, they have been removed from the acceptable acute
potassium database. Therefore, the in -stream acute value is applicable to waters where
Salmonids and C. rigaudi are not resident.
3.4.1 FINAL IN -STREAM WARM LOW HARDNESS SURFACE WATER OF NORTH CAROLINA
(WLHS) AQUATIC LIFE VALUES
The in -stream WLHS acute aquatic and chronic aquatic life values for potassium were calculated
based on the findings of the literature review, results of aquatic toxicity testing, the procedures
outlined the EPA Guidelines, and 15A NCAC 28.0208. The potassium in -stream WLHS acute
concentration calculations are presented in Reference Table 5. The chronic concentration was a
direct measurement using the data from Wang et al 2018 and adjusted for lower hardness of 25
mg/L CaCO3 using the potassium -hardness relationship discussed in Section 3.3 and Appendix 3.
Both values are presented below:
15/23

Ramboll - Potassium Aquatic ❑1e Values
Acute concentration = 17.14 mg/L (1/2 of the FAV determined using the EPA Guidelines)
Chronic concentration = 16.5 mg/L (15A NCAC 2B .0208- direct measurement (Wang et al
2018 EC20))
The Wang et al 2018 EC20 value was used in lieu of the geometric mean of the NOEC and LOEC
adjusted to a hardness of 25 mg/L CaCO3. Should the geometric mean of the NOEC and LOEC be
used, the result would be greater than the acute concentration. According to EPA Guidance
(Section XII, B), if the criterion is not consistent with sound scientific evidence, another criterion
should be derived. Because the traditional ChV for Fatmucket at a hardness of 25 mg/L CaCO3
results in a value greater than the acute criterion (23.0 mg/L potassium vs 17.14 mg/L
potassium) it makes sound scientific sense to use an alternative to the ChV, hence use of the
EC20. Using the Biomass EC20 value is not only scientifically sound, but also it is a direct
measurement of chronic toxicity.
The in -stream WLHS acute value and in -stream chronic value for potassium are applicable for the
proposed receiving waterbodies selected by Novozymes in Franklin County, North Carolina.
3.5 Other Considerations
Should there not have been enough appropriate data via direct measurement to develop
benchmark potassium values for WLHS of North Carolina, chronic values could have been
achieved through the application of an Acute -to -Chronic Ratio (ACR) using Approach 2a noted in
Section 1.1 above.
Reference Table 3 presents results from the previous chronic toxicity testing conducted at
Ramboll (Environ, 2012) along with the Wang et al 2018 data which were used to develop an
ACR as per NCDEQ guidelines. The ACR values and Final ACR value applied in derivation of the
chronic aquatic life value are presented in Reference Table 4. Chronic testing for the
Ceriodaphnia dubia (C. dubia) and Pimephales promelas (fathead minnow), and Fatmucket was
performed at the average hardness of 100 mg/L CaCO3. Previous testing indicated a minimal
relationship between hardness and potassium toxicity for C. dubia and fathead minnow,
furthermore, 100 mg/L CaCO3 is a common hardness for tests included in databases and often
results are adjusted to hardness 100 mg/L. Results from acute toxicity tests conducted at the
same hardness and alkalinity were paired with the results from the chronic tests to calculate
species specific ACR. The final ACR (FACR) was calculated as the geometric mean of the
individual species ACR (Reference Table 4).
16/23

Ramtoll - Potassium Aquatic We Values
4. REPORT REFERENCES
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Fishes. American Society for Testing and Materials. Philadelphia, PA.
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RamWil - Potassium Apuatic Life Values
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Temperate Species Daphnia magna to Seven Toxicants, Toxicol.Environ.Chem. 89(2):347-352,
2007.
Mosslacher, F. Sensitivity of Groundwater and Surface Water Crustaceans to Chemical Pollutants
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Mount, D.R., D.D. Gulley, J.R. Hockett, T.D. Garrison, and J.M. Evans, Statistical Models to Predict
the Toxicity of Major Ions to Ceriodaphnia dubia, Daphnia magna and Pimephales promelas
(Fathead Minnows), Environ.Toxicol.Chem. 16(10):2009-2019, 1997.
21/23

0.amCgll - PotassWm Aquatic We Values
Mukai, H., Effects of Chemical Pretreatment on the Germination of Statoblasts of the Freshwater
Bryozoan, Pectinatella gelatinosa, Biol.Zentralbl. 96:19-31, 1977.
Patrick, R., J. Calms Jr., and A. Scheier, The Relative Sensitivity of Diatoms, Snails, and Fish to
Twenty Common Constituents of Industrial Wastes, Prog.Fish-Cult. 30(3):137-140 (Author
Communication Used) (Publ in Part As 2406), 1968.
Pickering, Q.H., J.M. Lazorchak, and K.L. Winks, Subchronic Sensitivity of One-, Four-, and Seven -
Day -Old Fathead Minnow (Pimephales promelas) Larvae to Five Toxicants, Environ.Toxicol.Chem.
15(3):353-359, 1996.
Przytocka-Jusiak, M., Growth and Survival of Chlorella vulgaris In high Concentrations of Nitrogen,
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Purcell III, T.W., The Effects of Atrazine and Nitrate, Alone and in Combination, on a Natural
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22/23

Ramooll - Potassium Aquatic Life Values
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1998.
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23/23

RamW)l Po asslum Apuabc We Values
REFERENCE TABLES

Ramtigll - Potassium Aquatic Gfe Values
Reference Table 1. Acute Potassium Toxicity Test Results for Lamplil s/liquoidea and Lampsilis
rad/ats (8/16/17)
Measured
Conf. Int.
Lampsilis radiata (Eastern Lampmussel)
25
37.2
29.3 - 36.5
Lampsilis radiata (Eastern Lampmussei)
75
60.8
56.7 - 65.2
Lampsilis siloquoides (Fatmucket)
25
22.4
19.8 - 25.3
Lampsilis silo uoides Fatmucket
75
28.1
24.9 - 31.8
Reference Table 2. Supporting Analytical Results
for Dilution Waters
for Acute Potassium
Toxicity
Tests Lampslllsslliquoidea and Lampsillis radiate
(8/16/17)
Nominal 25 mg/L
Nominal 75 mg/L
Parameter
Hardness
Hardness
Water
24.8
Hardness
Water
75.2
Units
mg/L CaCO3
Alkalinity
22.3
39.0
mg/L
TRC
< 0.02
< 0.02
mg/L
Calcium
6.28
20.1
mg/L
Magnesium
1.61
4.80
mg/L
Potassium
< 1.0
1.72
mg/L
Sodium
6.09
4.61
mg/L
Chloride
2.64
6.93
mg/L
Sulfate
1 12.7
1 40.7
mg/L

Rampoll - Potassium Aquatic lire Values
Reference Table 3. chronic
Potassium
Test
Toxicity
Database
Hardness
Alkalinity
Test
Measured
Result -
950/0
Conf.
Genus species
Start
Test
as CaCO3
Endpoint
Survival
Duration
Endpoint
MATC
K
296
Int.
Reference
Ceriodaphnia dubia
28-Feb-12
1
220
190
Reproduction
7 days
MATC
207
ENVIRON 2012 unpublished
Reproduction
IC25
187
177-193
Survival
MATC
263
Ceriodaphnia dubia
20-Mar-12
2
208
100
Reproduction
7 days
MATC
145
ENVIRON 2012 unpublished
Reproduction
IC25
144
128-148
Survival
MATC
302
Pimephales promelas
12-3an-12
1
113
80
Growth
32 days
MATC
302
ENVIRON 2012 unpublished
Growth
IC25
232
16 - 265
Survival
MATC
139
Pimephales promelas
20-Apr-12
2
226
179
Growth
32 days
MATC
139
ENVIRON 2012 unpublished
Growth
IC25(3)
131
87 - 152
Survival
MATC
32
Lampsilis siloquoidea
2013
without
sand
100
Not given
Biomass
28 days
MATC
32
Wang et al, 2018
Biomass
EC20
23
21 - 26
Notes:
1. Hardness and Alkalinity are average measured values during test.
2. MATC = geomean of NOEC and LOEC (aka ChV)
3. K results as average measured K. Test did not meet acceptability criteria and is not used in criteria calculations.

aAi,.00, � ri,m.�w� Ae�.n�c i ee vam�s
Reference Table 4. Acute to Chronic Ratio Calculation
Acute Chronic ACR
Genus species SMAV SmCv Data Reference
Ceriodaphnia dubia 365 164 2.22 ENVIRON 2012 unpublished
Pimephales promelas 453 232 1.95 ENVIRON 2012 unpublished
Lampsilis siloquoidea 44 32 1.38 Wang et al 2018
FACR = I I 1.81

Ramboll - Potasvum Aquatic Life Values
Reference Table 5. Calculation of Warm Low Hardness Surface waters of North
Carolina (WLHS) Acute Potassium Aquatic Life Values
Aloplicable to the proposed Novoz mes North
Carolina
receiving
streams
cum
••
LN
GENUS SPECIES
RANK
.:
ROOT
Chironomus tentans
16
0.9412
0.9701
2,769
7.746
60.005
Hydroptila angusta
15
0.8824
0.9393
2,313
7.356
54.105
Cricotopus trifasciatus
14
0.8235
0.9075
1,565
7.167
51.366
Lepomis macrochirus
13
0.7647
0.8745
1,296
6.250
39.062
Pimephales promelas
12
0.7059
0.8402
518
6.201
38.446
Physella acuta
11
0.6471
0.8044
493
6.080
36.966
Cyprinus carpio
10
0.5882
0.7670
437
5.911
34.938
Ceriodaphnia dubia
9
0.5294
0.7276
369
5.429
29.478
Musculium transversum
8
0.4706
0.6860
228
5.389
29.042
Daphnia magna
7
0.4118
0.6417
219
5.147
26.497
Hyalella azteca
6
0.3529
0,5941
172
4.043
16.346
Lampsilis siloquoidea
5
0.2941
0.5423
57
4.043
16.346
Lampsilis radiata
4
0.2353
0.4851
48
3,871
14.986
Megalonaissas nervosa
3
0.1765
0.4201
47
3.850
14.824
Utterbackia imbecillis
2
0.1176
0.3430
45
3.807
14.491
Lasmi ona com Janata
1
1 0.0588
1 0.2425
34
1 3.526
1 12.435
Sum of 4 lowest Ps 0.5882
Sum of the 4 lowest square roots of Ps
1.4907
Square of the sum of the square roots of Ps
2.222
Sum of the four lowest natural logs of the GMAVs
15.05
Sum of the squared natural logs of the GMAVs
56.74
FAV CALCULATION IS AS FOLLOWS:
S' =
0.077
0.03
5' =
2.36
S =
1.5366
L =
3.1909
A =
3.5345
FAV =
34.28
Acute Concentration =
17.14
NOTES:
1. 1.Used only KCI, K504 data
2. Cyprinus carpio substituted for Salmonid data requirement.
3. Lampsilis radiata is shown as a separate mussel/data entry, because it is a representative indigenous
species and responds differently to potassium than L. siliquoidea (Appendix 3).

RamWl - Po[awum Aouao< Life Values
APPENDIX 1
ACCEPTABLE AQUATIC ACUTE TOXICITY DATABASE FOR POTASSIUM
WARM LOW HARDNESS SURFACE WATER OF NORTH CAROLINA AQUATIC
LIFE VALUE DERIVATION

DatabaseAppendix 1. Acceptable Aquatic Acute Toxicity
erio ap nia rigau i an Sa monidae eac u e as t ey o not resi a at t •e site.
Chemical
Name
Genus apKNa
Cemman Mama
Bpatlr Group
lndppint
lommassas CaCO3
(mo/L)
Alkalinity
(mp/L)
LC50 an
Conc (mp/L)
SMAV
GMAV
Reference
r ap na u a
a
u ns
r
Mount, .e W. 1997
KC
d ap nia u la
Ater
rustaceans
rL
MNPW
l
Mount, .R, e[at. l ]
KCI
Cerledaphnia dubia
Water flea
Crustaceans
48 hr LC50
113
68
415
ENVIRON 2012 unpublished
KCI
Cenodaphnla dubia
Water flea
Cusui
48 hr LCSO
Its
66
289
ENVIRON 2012 unpublished
KCI
Camodaphnla dubia
Water flea
Crustaceans
48 hr LC50
112
102
2"
ENVIRON 2012 unpublished
KCI
Cenodaphnia dubia
Water flea
CriMaceans
481u LC50
110
83
1 416
ENVIRON 2012 unpublished
KCI
Cenodaphnia dubia
Water nea
Cmstacesns
48 hr LC50
99.2
68
319
ENVIRON 2012 unpublished
KCI
CenodalIhnia dubia
Water flea
1cmetaxons
48 hr LC50
108
58
288
ENVIRON 2012 unpublished
KCI
Cerltuiphnia dubia
Water flea
Crurtawns
48 tar LC50
184
80
435
ENVIRON 2012 unpublished
KCI
Cenedaphnia dubia
Water flea
Crustaceans
48 hr LCSO
220
190
390
ENVIRON 2012 unpublished
KCI
Cenedaphma dubia
Water flea
C Mixsns
48 hr LC50
208
100
287
ENVIRON 2012 unpublished
KG
Cenodaphnia dubia
Water flea
Crustacanns
48 hr LCSO
196
BB
420
ENVIRON 2012 unpublished
KCI
Cenedaphnia dubia
Water flea
Crustaceans
48 hr LCSO
220
105
363
ENVIRON 2012 unpublished
KCI
Cerlodaphnia dubia
Water flea
Crustaceans
48 hr LC50
212
85
334
ENVIRON 2012 unpublished
KCI
Cerledephnia dubia
Water flea
Crustaceans
48 hr LC50
320
148
367
ENVIRON 2012 unpublished
KCI
Ceriedaphnia dubia
Water flea
Crustaceens
48 hr LC50
340
ISO
334
ENVIRON 2012 unpublished
KCI
CericOaphnie duels
Water flea
Crustaceans
40 hr LCSO
340
160
437
ENVIROM 2012 unpublisned
KG
Ctsiedaphnia dubla
Water ties
Crustaceans
48 hr LC50
332
132
4DO
ENVIRON 2012 unpublished
KCI
Cemix is duels
Water flea
Crustaceans
4B hr L.CSO
328
124
316
ENVIRON 2012 unpublished
KCI
Cenodaphnla duels
Water flea
Crustaceans
48 hr LCSO
312
135
458
ENVIRON 2012 unpublished
KCI
Cerlpdaphnia dubia
Water flea
Crustaceans
48 hr LC50
440
198
374
ENVIRON 2012 unpublished
KCI
Clnodaphnla dubia
Water flea
Crustaceans
48 hr LC90
456
125
514
ENVIRON 2012 unpublished
NCI
Certedaphnia dubia
Water flea
Crustaceans
48 hr LC50
426
190
377
ENVIRON 2012 unpublished
KCI
Cededaphnia dubia
Water nea
Crustaceans
48 hr LC50
440
ISO
459
ENVIRON 2012 unpublished
KCI
C rxlaphnia dubia
Water fMa
Crustaceans
48 hr LC50
H4
1%
39S
ENVIKON 2012 unpublished
KCI
Cerlodaphnla dubia
Water flea
Crustaceans
48 hr LC50
480
210
484
369
369
ENVIRON 2012 unpublished
KCI
Daphnia ma9na
Water nea
Crustacuns
46 hr LC50
90-100
40-50
219
Mphammed, A. 2007
a n a mapna
stet U
NMcwns
7FFr=
84
MHRW
346
Mount, D.R. eta . 1
KCI
Daphnia ma0na
Water Bea
Crustaceans
48 hr EC50
45.3
42.3
93
Biesinger, K.E., et al. 2972
a nia ma9na
Water ea
rpstaceans
4 r L
MM
1
1
Mount D.R. eta. 1997
KCI
Cdo topus Mfasoatus
Mid0e
Insects
48 hr LC50
unknown
unknown
1,565
1,565
1,565
MamiRnn, R.W. at al. 1975
KCI
Chlroriomus tenons
Mld0e
Insects
48 hr LCSO
100
72
2,389
ENVIRON 2012 unpublished
KCI
LTironamus tentans
Midge
Insects
N tar LC50
1"
75
2,943
ENVIRON 2012 unpublished
KCI
Ctilronomus tenons
Midge
Insects
48 hr LCSO
IOB
90
2,787
ENVIRON 2012 unpublls
PWIM13

DatabaseAppendix 1. Acceptable Aquatic Acute Toxicity
Cerio a0 nia i rigau an a moni ae esclu ed as t ey o not resi a at t iie site.
Chemical
Nam,
Ganua optic
Common Mama
Species Group
lndpolnt
Hardnra as CaCO3
(mp/L)
Alkalinity
(mp/L)
LCSO as K
Conc(mp/y
SMRV
(mp/L)
GMRV
(mp/L)
Reference
KCI
Chlronomus tentans
Midge
Insects
48 hr LC50
206
142
2,883
ENVIRON 2012 unpublished
KCI
Chlmnomus tentans
Midge
Insects
48 hr LCSO
216
155
3,098
ENVIRON 2022 unpublished!
KCI
Chlronomus renters
Midge
Insects
48 hr LC50
194
151
2,869
ENVIRON 2012 unpublished
NCI
Chimnomus tentans
Midge
Insects
48 hr LC50
292
185
2,749
ENVIRON 2022 unpublished
KU
Chirgrwmus tenbns
Midge
Insects
48 hr LC50
280
110
2,362
ENVIRON 2012 unpublished
KCI
Chlronomus tentans
Midge
insects
48 hr LCSO
304
240
1,993
ENVIRON 2012 unpublished
KCI
Chlronomus tenbns
Midge
Inserts
48 hr LC50
404
205
2,997
ENVIRON 2012 unpublished
KCI
Chlmnomus tentans
Midge
Insects
46 hr LCSO
392
200
3,443
ENVIRON 2012 unpublished
KCI
Chlronomus tentans
Midge
insects
4a hr LCSO
398
200
3,119
ENVIRON 2012 unpublished
KCI
Chlrmannus tenbns
Midge
Insects
48 hr LCSO
96.4
74
2,647
ENVIRON 2012 unpublished
KCI
Chinammus tentans
Midge
Insects
48 hr LC50
104
70
2,567
ENVIRON 2012 unpublished
KCI
Chlronomus tentens
Midge
Insects
48 hr LC50
100
Loa
3,052
ENVIRON 2012 unpublished
NCI
CMmnomus tenors
Midge
Insects
48 hr LC50
206
124
2,520
ENVIRON 2022 unpublished
KCI
Chironomus tentans
Midge
Insect
48 hr LC50
200
I00
3,298
ENVIRON 2012 unpublished
NCI
CMronomus tentans
Midge
Insects
48 hr LCSO
295
120
2,928
ENVIRON 2012 unpublished
KCI
Chhonomus tentans
Midge
Insect
48 hr LC50
300
145
3,049
ENVIRON 2012 unpublished
KCI
CNlrpnomus tenbns
Midge
Insects
48 hr LC50
312
130
2,587
ENVIRON 2012 unpublished
KCI
Chir000mus tentans
Midge
Insects
48 hr LC50
304
240
2,399
ENVISION 2012 unpublished
KCI
Chlronomus tentans
Mld0e
insects
48 hr LC50
369
140
3,076
ENVIRON 2012 unpublished
KCI
Chlmm,mus tentans
Midge
Insects
48 hr LC50
392
115
2,900
ENVIRON 2012 unpublished
KCI
Chhonomus tentans
Midge
Insects
48 hr LC50
392
110
3,329
ENVIRON 2012 unpublished
ronomus tenbns
—M
needs
WWr L
1 -
MH W
urtm eta . 1996
rgwmustenbns
17T=HRW
Burton et a. 1996
r— rn.s tenbns
ge
n—ec
r L
1 -1
MHRW
, 14
Burro. eI al. 1996
K
Irpnomus tmtans
MI a
nsect
r l
HRW
Sun. eta . 1996
K
lmnomus bnbns
ge
ns s
r L
t -1
MHRW
1,
urton eta . 1996
lmnomus tenbns
MI g-e
nsem
r
1
MM W
0
Burton eta , 1996
lmnomus tentans
Midge
Insect,
96 hr LCSO
120-130
MHRW
2,678
Burton eta . 1996
K
lmntlmustenbns
WiTge
enacts
79CR,L
I 0-1
MHRW
2,777
Burton a al. 1996
lmnomus tenbns
l e
nsects
r L
1 -1
MBurton
eta . 1996
Ironomus tenbns
MI ge
enacts
79V L
1 0-1
MHR
Burton eta . 096
K
lmnomus tenbns
MI a
nsects
r L
-1
H W
1
Burton eta . 1996
K
lmnomus tenbns
Ml ge
nsects
r L
1
,1
Burton eta . 1996
rpromustenbns
MI
nsect
r
1 -1
,
Buhton at a.
Ironomus tenbns
ge
nsects
r L
1
Burton eta . 1996
KCI
Hydropbla angusb
Caddis h,
Insects
48 hr LC50
unknown
unknown
2,313
2,313
2,313
Hamilton, R.W. et al. 1975
KCI
Cypdnus carplo
Corrrtgn Carp
Flsh
96 hr LC50
210
102
434
ENVIRON 2012 unpublished
KCI
'Anus carplo
Common Carp
Flsh
96 hr LC50
231
110
426
ENVIRON 2012 unpublished
eaaa 2 of 13

so
DerivationAppendix 1. Acceptable Aquatic Acute Toxicity Database
e ace nia rigau / an almoni ae ecc u e as t ey o not reside at the site.
CNersHral
Name
Genus species
Common Some
SpaelY Group
Endpolnt
Hardness as C.0O3
(mO/L)
alkalinity
(m0/L)
LCSO as K
Cone (m//L)
SMaV
(m0/L)
assay
Imp/L)
Reference
KCI
Cypnnus carpo
Common Carp
Fish
96 hr LCSO
209
110
451
437
437
ENVIRON 2012 unpublished
KCI
Hyalella arteca
Scud
Crustaceans
96 hr LC50
208
142
230
ENVIRON 2012 unpublished
NCI
Hyalella arteca
Scud
Cmstawns
96 hr LC50
214
155
242
ENVIRON 2012 unpublished
KCI
Hvalelia artery
ru wns
r L
1 -1
MH W
1
urton eta . 1996
KCI
Hyalella artxa
Stud
Crustaceans
96 hr LCSO
120-130
MHRW
131
urton eta . 1996
K
Hya a azteca
rus wns
r L 0
1 -1
MHRW
1"
Burton et al. 1996
K
Hya a az
cu
rustaceans
r L 0
1 -1 0
MHRW
1
Burton eta . 199
K
ya a az
Cu
mstaaans
r L 0
1 -1
MHRW
17
Burton eta . 1996
K
Hya a aztera
cu
rusbceana
r LC 0
1 -1 0
MHRW
1
Burton eta . 199
K
Hya a arteo
Cu
rost mns
r L
1 -
MH W
burion eta . 199
Hya a artem
cu
rostaceans
r L
1 =I
MHRW
1
1
-UT-
Burton eta . 199
K 4
P mep a es pro as
Fa minnow
s
r L
HRW
Mount, 0. . eta . 1997
K
Plmep es promo as
s minnow
s
r
HRW
1
Mount, D.R. eta . 1997
KCI
Mmephales promelas
Fathead minnow
Fish
96 hr LC50
113
67.9
451
ENVIRON 2012 unpublished
KCI
I Mmephales promelas
Fathead minnow
Fbh
96 hr LC50
1 104
66
SOS
I
IENVIRON 2012 unpublished
KCI
Pmephales promelas
Fathead minnow
Fish
96 hr LC50
112
102
409
ENVIRON 2012 unpublished
KCI
Mmephales promelas
Famead minnow
Fish
96 hr LC50
110
83
531
ENVIRON 2012 unpublished
KCI
Plmephales promelas
Fathead minnow
Fish
% hr LC50
99.2
68
502
ENVIRON 2012 unpublished
KCI
Pmephales promelas
Fathead minnow
Fish
% hr LC50
103
58
422
ENVIKON 2012 unpublished
KCI
Mmephales promelas
Fathead minnow
Fish
96 hr LC50
I"
SO
617
ENVIRON 2012 unpublished
KCI
Plmephales promelas
FaMead minnow
Fish
% hr LC50
220
1%
542
ENVIRON 2012 unpublished
KCI
Nmephales promelas
Fathead minnow
Fish
96 hr LC50
208
100
428
ENVIRON 2012 unpublished
KCI
Mmephales promelas
Fathead minnow
Ash
96 hr LCSO
220
105
542
ENVIRON 2012 unpublished
KCI
Pmephales bromides
Fathead minnow
Fish
96 hr LC50
212
85
469
ENVIRON 2012 unpubiished
KCI
Rmephales promelas
Fathead minnow
Ash
96 hr LC50
320
148
602
ENVIRON 2012 unpublished
KCJ
Mmephales promelas
Fathead minnow
Fish
96 hr LCSO
340
ISO
605
ENVIRON 2012 unpublished
KCI
Pmephales promelas
Fathead minnow
Ash
96 hr LC50
340
ISO
530
ENVIRON 2012 unpublished
KCI
Mmephales promelas
Fathead minnow
Fish
% hr LC50
332
132
634
ENVIRON 2012 unpublished
KCI
Pmephales promelas
Fathead minnow
Fish
96 hr LC50
328
124
620
ENVIRON 2012 unpublished
KG
Pmephales promelas
Fathead minnow
Fish
% hr LC50
312
135
514
ENVIRON 2012 unpublished
KCI
Pmephales promelas
Fathead minnow
Fish
96 hr LC50
426
190
523
ENVIRON 2012 unpublished
KCI
Mmephales promelas
Fathead minnow
Fish
96 hr LC50
440
150
636
ENVIRON 2022 unpublished
KO
Pmephales promelas
Fathead minnow
Fish
96 hr LCSO
4M
ISO
504
ENVIRON 2012 unpublished
KCI
Mmephales promelas
Fathead minnow
Fish
96 hr LC50
440
198
544
ENVIRON 2012 unpublished
KCI
Pimeprales promelas
Fathead minnow
Fish
96 hr LC50
456
125
619
ENVIRON 2012 unpublished
mice a p as
s ea minnow
S
r L
1
1
ENVIRON 2012 unpublished
KCI
Lepomis macroCHirus
Blue ill
Fish
% hr LC50
79.8
43.4
1,053
Trama, F.B. 1954 / Patrick, R.
et al. 1968
Pass 3 of l3

Cerio ap . rigau Ian Sa moni ae exd.ded as they do not reside at the site.
Chemical
Name
Genus species
fa moron Name
Species Group
[ndpolnt
Hardness as UCO3
(mq/L)
alkalinity
(rep/L)
LC66 es K
Cone (mG/L)
UMV
(mg/L)
GMV
(m0/L)
"Perann
K2504
Lepomis macrochuus
81uegdl
Fish
96 hr LC50
44.5
53.6
1,594
1,296
1,296
Trams, F.B. 1954
KCI
Umpsgls radiate
as m
Unpmussel
mussel
% hr LC50
24.8
22.3
37
Parnboll 2017 unpublished
KQ
Umpsllls radian
as m
Urrymussel
mussel
% hr LC50
75.2
39
61
Ramboll 2017 unpublished
K
Umpsl Is si w.cv
atnuc et
musu
r LCSO
24.8
22.3
22
RamboFamboll 2017 unpublished
Umpsl s sl gquoi
atnu e[
muser----
-9T-MW
Ramboli 200unpublished
ldmp5115 SI p4 of
ab9 et
-MUSS!
r L
—not repo
Wang Ivey et al 2013
KCI
Umpsllls MiNuadea
Fatrmcket
mussel
96 hr LCSO
100
77
33
ENVIRON 2012 unpublished
KCI
Umpsills sdocunldea
Fatnucket
mussel
96 hr LC50
104
72
43
ENVIRON 2012 unpublished
KCI
Umpsibs silopuadea
Fatmucket
mussel
% hr LC50
100
80
49
ENVIRON 2012 unpublished
KO
Umpsibs sd9quWdea
Fstmucket
mussel
96 hr LCSO
100
76
38
ENVIRON 2012 unpublished
NCI
Umpsilts slloqumdea
Fatsnucket
mussel
%hr LC50
100
79
47
ENVIRON 2012 unpublished
KCI
Umpsills slimuuidea
fatmucket
mussel
%hr LC50
100
75
54
ENVIRON 2012 unpublished
KCI
Umpsllls Miccluoidea
FabmuGet
morsel
%hr LC50
212
146
63
ENVIRON 2012 unpublished
KCI
Umpsllis s0oquoidea
Fatmucket
mussel
96 hr LC50
212
147
50
ENVIRON 2012 unpublished
KCI
UmpslNs siloquoidea
Fabnucket
mussel
96 hr LC50
208
146
53
ENVIRON 2012 unpublished
KCI
Ummilis siloquadea
Fatmucket
mussel
96 hr LC50
206
110
62
ENVIRON 2012 unpublished
KCI
Umpellls siloquadea
Fatmucket
mussel
96 hr LC50
200
I18
60
ENVIRON 2012 unpublished
KCI
Umpmlis sdoauomes
Fabnucket
mussel
96 hr LC50
204
130
56
ENVIRON 2012 unpublished
KCI
Umpsllls sgoqumdea
Fatmucket
mussel
96 hr LC50
300
215
55
ENVIRON 2012 unpublished
KCI
Umpsilis sitar umdea
FaMucket
mussel
96 hr LCSO
308
200
66
ENVIRON 2012 unpublished
KCI
Umpsllis sdoqumdea
Fabnucket
mussel
96 hr LCSO
304
210
79
ENVIRON 2012 unpublished
KCI
Umpsllls silo iumdea
Fatmucket
mussel
96 1u LC50
300
140
79
ENVIRON 2012 unpublished
KCI
Umpsllls Mimuoidea
Faunuact
mussel
96 hr LCSO
296
296
6o
ENVIRON 2012 unpublished
KCI
lampsllis slloquoidea
Fatmucket
mussel
% hr LCSO
296
150
92
ENVIRON 2012 unpublished
KCI
Umpful s slloquoidea
Fatmucket
mussel
% hr LC50
392
110
107
ENVIRON 2012 unpublished
KO
tampsills slloqumdea
FaMucket
mussel
% hr LC50
408
ISO
95
ENVIRON 2012 unpublished
KCI
Umpsllls slloquoidea
Fatmucket
mussel
% hr LC50
404
300
78
ENVIRON 2012 unpublished
KCI
Lamp llis snoquoldea
Fatmucket
mussel
96 hr LC50
400
275
72
ENVIRON 2012 unpublished
KCI
Umpsills siloquoidea
Fatonuatit
mussel
96 hr LC50
392
ISO
84
57
57
ENVIRON 2012 unpublished
KCI
Lasmlgons complanata
White Heelsplltter
mussel
96 hr LC50
100
not imported
34
34
M
Wang / Ivey at al 2013
KCI
Megalonalsas nervosa
Washbsurd
mussel
96 hr LC50
to0
not reported
47
47
47
Wanp / Ivey et al 2013
KCI
Utterpon:ua imbetlllis
Paper IbnOshell
morsel
96 hr LC50
100
not reported
45
45
45
Wang / Ivey et al 2013
KCI
Muuullum tansversum
np ngema
clam
Molluscs
96 hr LCSO
243
155
280
., al. see
Note 2)
Yya 4 or 13
me

DatabaseAppendix 1. Acceptable Aquatic Acute Toxicity
erio ace ma rigau0i and 611finnoni ae exc u e as [ ey o not resi a at t e site.
Chemical
Mardnra as CaCO]
Alblinky
LCSO r K
SMAV
GMAV
Mama
Grua • paelr
Common Name
Speclr Group
endpoint
(mg/L)
(mg/L)
COne(rasK
Reference
(mg/L)
(mg/L)
Ilong fingem.9
And-rion'., et ad. 1978 see
KCI
MuscWlum transversum
dam
Mallusa
96 hr LC50
263
161
185
228
228
Note 2)
KCI
Physella Mute
European physa
Molluscs
96 hr LC50
43
24
493
493
493
Patrick, R. et al. 1968
Nutr:
1. MMRW . moderately hard remnstl[u[M water. No hardness and/or alkalinity value given In paper.
2. USEPA 1985 Guidelines suggest using mxlOh data generated from Me most sensitive life stage for an organism.
Anderson 1928 demmaned
Mat Me adult life stage of the fingernail dam was more sensitive Man juvenile. Therefore, rest results for the adult life stage are presented here.
3. If endpoint value was given In paper as K, endpoint value as whole salt tested was Men ®Iculated (examples: Anderson 1978, Biminger 19]2)
Highlighted nY NtlYe
Paae 5 or 13

Ramlmll - Potassium ApuaVC We Values
APPENDIX 2
FRESHWATER POTASSIUM AQUATIC TOXICITY DATABASE LITERATURE
SEARCH RESULTS

2. Freshwater
Species Scientific Name
Potassium Aquatic
Common Name
Toxicitv
Chemical
Name
DatabaseAppendix
Endpoint
Value as
Salt
Comic
Conc
Units
Test
Duration
Verified Value
from paper as
salt
Value as K
Conc
Citation
Rejection Justification and Notes
Navlcula semmulum
Diatom
KCI
EC50
1337000
ug/L
120 hr
1337000
Academy of Natural Sciences 1960
same study as Patrick 1968
Lepomis macrochirus
Bluegill
KCI
LC50
2010000
ug/L
96 hr
2010000
Academy of Natural Sciences 1960
same study as Patrick 1968
Physastra gibbosa
Snail
KCI
LC50
940000
ug/L
96 hr
940000
Academy of Natural Sciences 1960
same study as Patrick 1968
Daphnia magna
Water Rea
KCI
EC50
204000*
ug/L
64 hr
432000
Anderson, B.G. 1948
test duraton not standard
Daphnia magna
Water Bea
KCI
TLm
176000*
ug/L
32 hr
373000
Anderson, B.G. 1944
not standard endpt, inappropriate culture
Cyclops vernalis
Cyclopoid
KCI
MATC
640000
ug/L 1
96 hr
640000
Anderson, B.G., et al. 1948
not standard endpoint statistic for acute
Daphnia magna
Water Bea
KCI
MATC
430000
u /L 1
96 hr
430000
Anderson, B.G., et al. 1948
not standard endpoint statistic for acute
Leptodora kindtii
Water flea
KCI
MATC
127000
u /L 1
96 hr
127000
Anderson, B.G., at al. 1948
not standard endpoint statistic for acute
Mesocyclo s leuckarti
Cyclopoid copepod
KCI
MATC
566000
u /L 1
96 hr
566000
Anderson B.G. et al. 1948
not standard endpoint statistic for acute
Skistodiaptomus oregonensis
Calanoid copepod
KCI
MATC
134000
ug/L 1
96 hr
134000
Anderson, B.G., et al. 1948
not standard endpoint statistic for acute
Musculium transversum
Long fingernail clam
KCI
LC50
I
we note
Anderson, K.B. 1977
data from this study is presented in Anderson 1978 Report
Musculium transversum
Lang fingernail clam
KCI
LC50
185000lug/L
96 hr
-
1850OO
Anderson, K.B., et al. 1978
For acute tests, both adults and juveniles were tested. Mortality assessed (LC50
calculated) at noted intervals. Since the 96hr LC50 Is standard endpoint, it was
deemed acceptable; other test duration endpoints not used. There is concern that
water with no food, it can
since tests were conducted in well or laboratory sed in later
not be ruled out that organisms were not stressed in later stages (alter day 10+) of
tests. Some study results also presented in Sparks and Anderson 1977, Control
mortality excessive for results marked with
Musculium transversum
Lon fingernail clam
LC50
280000
96 hr
280000
Anderson K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
1000000
96 hr
1000000
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
NCI
LC50
1825000
96 hr
-
1825000
Anderson, K.B., e[ al. 1978
Musculium transversum
Lon fingernail clam
KCI
LC50
2500000
96 hr
-
2500000
Anderson, K.B., et al. 1978
Musculium transversum
Lon fingernail clam
KCI
LC50
520000
96 or
-
520000
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
200000
30 days
-
200000
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LCSO
270000
10 days
270000
Anderson, K.B., et al. 1978
Musculium transversum
Lon fingernail clam
KCI
LC50
320000
10 da s
320000
Anderson K.B. et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
840000
10 days
840000
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
850000
u /L
10 days
850000
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
250000
ug/L
11 days
250000
Anderson, K.B., et al. 1978
Musculium transversum
Long fin email clam
KCI
LC50
250000
u /L
12 days
250000
Anderson, K.B. et al. 1978
Musculium transversum
Long fingernail dam
KCI
LC50
200000
u /L
13 days
200000
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail dam
KCI
LC50
250000
ug/L
13 days
-
250000
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail dam
KCI
LC50
310000
ug/L
13 days
310000
Anderson, K.0., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
540000
u /L
13 days
540000
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
685000
u /L
13 days
685000
Anderson, K.B., et al. 1978
Musculium transversum
Lang fingernail clam
KCI
LC50
300000
ug/L
16 days
-
300000
Anderson, K.B., a al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
495000
u /L
16 days
495000
Anderson, K.B., a al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
560000
ug/L
16 days
560000'
Anderson, K.B., et aI. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
440000
u /L
19 days
440000
Anderson K.B. et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
480000
ug/L
19 days
-
480000*
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
2700000
u /L
48 hr
2700000
Anderson, K.B. et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
3150000
u /L
48 hr
-
3150000
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
518000
ug/L
48 hr
518000
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
880000
ug/L
48 hr
880000
Anderson, K.O., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
430000
u /L
22 days
-
430000-
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
400000
ug/L
23 days
400000
Anderson, K.B., at al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
320000
ug/L
25 days
-
320000*
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
388000
u /L
27 days
388000
Anderson, K.B. et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
320000
u /L
29 days
320000'
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
K❑
LC50
1680000
u /L
72 hr
1680000
Anderson, K.B., et aI. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
1960000
u /L
72 hr
-
1960000
Anderson, K.B., et aI. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
255000
u /L
72 hr
255000
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
2700000
ug/L
72 hr
2700000
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
370000
ug/L
72 hr
370000
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
168000
u /L
120 hr
168000
Anderson, K.B., et aI. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
1800000
ug/L
120 hr
1800000
Anderson, K.B., at al. 1978
Musculium transversum
Long fingernail dam
KCI
LC50
43SO00
ug/L
120 hr
-
435000
Anderson, K.B., at al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
1070000
u /L
144 or
1070000
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
1180000
u /L
144 hr
1180000
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
228000
ug/L
144 hr
228000
Anderson, K.B., at al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
510000
u /L
144 hr
510000
Anderson K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
300000
ug/L
168 hr
300000
Anderson, K.B., at al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
980000
u /L
168 hr
980000
Anderson, K.B., at al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
1020000
ug/L
192 hr
1020000
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
212000
u /L
192 hr
212000
Anderson, K.B., at al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
350000
ug/L
192 hr
350000
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LC50
925000
u /L
192 hr
925000
Anderson, K.B., et al. 1978
Musculium transversum
Long fingernail clam
KCI
LOEC
275000
u /L
42 day
275000'
Anderson, K.B., et al. 1978
sign. Control mortality
Musculium transversum
Lon fingernail clam
KCI
NOEC
195000
u /L
42 tlay
195000*
Anderson, K.B., et al. 1978
sign. Control mortality
Musculium transversum
Long fingernail clam
KCI
NOEC
184000
u /L
42 day
184000*
Anderson K.B., et al. 1978
sign. Control mortality
Chlorella vulgaris
Green algae
KSO4
NR
—TO 12 000
ug/L
30 day
2012000
Becker, A.J.J.Jr. 1973
effects seen at all concentrations, can not calculate EC50, test media not appropriate
Salvelinus fontinalis
Brook trout
K(OH)
NR-LETH
50000
ug/L
24 for
20000000
Belding, D.L. 1927
adult fish used, no std endpt iven, just dose that caused lethality
Daphnia magna
Water Flea
KCI
LC50
405000
ug/L
48 hr
405000
Bemot, R.J., et al. 2005
study focus was testing other chemicals, KCI results are from a reftox done during the
study, No testing detads aivenfor reftox
Page 6 of 13

Species Scientific Name
Common Name
Chemical
Name
Database
Endpoint
Conc
Units
Test
Duration
Verified Value
from paper as
salt
Value as K
Conc
Citation
Rejection Justification and Notes
Value as
Salt
Conc
Daphnia magna
Water Rea
KCI
LC50
415000
ug/L
48 hr
415000
Bernot, R.J., at al. 2005
study focus was testing other chemicals, KCI results are from a reftox done during the
study. No lestinc, details divan for x
Daphnia magna
Water flea
KCI
EC50•
149000•
u /L
48 hr
?
?
Biesin er, K.E., and G.M. Christensen 1972
ECOTOX value not verified in original reference
Daphnia magna
Water Bea
KCI
EC50•
166000
ug/L
48 hr
-
166000
Biesinger, K.E., and G.M. Christensen 1972
test was fed, paper notes that presence of food affected outcome of tests; test
organisms were more tolerant of toxicant when fed. Therefore, results from fed tests
Daphnia magna
Water flea
KCI
ECSO•
83000•
ug/L
48 hr
?
?
Biesinger, K.E., and G.M. Christensen 1972
ECOTOX value not verified in original reference
Daphnia magna
Water flea
KCI
EC50'
93000
ug/L
48 hr
93000
Biesinger, K.E., and G.M. Christensen 1972
Daphnia magna
Water flea
KCI
EC50'
87000'
ug/L
21 day
7
?
Biesingeq K.E., and G.M. Christensen 1972
ECOTOX value not verified in original reference
Daphnia magna
Water flea
KCI
EC50•
97000
u /L
21 day
-
97000
Biesinger, K.E., and G.M. Christensen 1972
3wk LC50 endpoint not standard endpoint for chronic
Daphnia magna
Water flea
KCI
NR
63000'
ug/L
21 day
-
53000
Biesinger, K.E., and G.M. Christensen 1972
16% repro impairment, concentrations not measured, not standard endpoint,
inadequate information p,ovdied to calculateE
Daphnia magna
Water flea
KCI
NR
68000
ug/L
21 day
-
68000
Biesinger, K.E., and G.M. Christensen 1972
50% repro impairment, concentrations not measured, not standard endpoint,
inadeguate information omv,ded to calculateNOECILOEC
Pseudosida ramosa
Water flea
KCI
LC50
12070
u /L
48 hr
12070
Freitas E.C., and 0. Roche 2011
tropical species found in Cuba, Brazil, not resident to US
Pseudosida ramosa
Water flea
KCI
LC50
12620
u /L
48 hr
12620
Freitas,E.C., and 0. Roche 2011
tropical species not resident to US
Pseudosida ramosa
Water flea
KCI
LC50
12770
ug/L
48 hr
12770
Freitas,E.C., and 0. Roche 2011
tropical species not resident to US
Pseudosida ramosa
Water flea
KCI
LC50
12770
u /L
48 hr
12770
Freitas,E.C., and 0. Roche 2011
tropical species not resident to US
Pseudosida ramosa
Water Bea
KCI
LC50
12920
ug/L
48 hr
12920
Freitas,E.C., and 0. Roche 2011
tropical species not resident to US
Pseudosida ramosa
Water flea
KCI
LC50
12920
u /L
48 hr
12920
Freitas E.C., and 0. Roche 2011
tropical species not resident to US
Pseudosida ramosa
Water flea
KCI
LC50
13380
ug/L
48 hr
13380
Freitas,E.C., and 0. Roche 2011
tropical species not resident to US
Pseudosida ramosa
Water flea
KCI
LC50
14110
ug/L
48 hr
14110
Freitas,E.C., and 0. Roche 2011
tropical species not resident to US
Pseudosida ramosa
Water flea
KCI
LC50
14240
ug/L
48 hr
14240
Freitas,E.C., and 0. Roche 2011
tropical species not resident to US
Pseudosida ramosa
Water flea
KCI
LC50
16610
u /L
48 hr
16610
Freitas,E.C., and O. Roche 2011
tropical species not resident to US
Pseudosida ramosa
Water flea
KCI
LC50
17050
u /L
48 hr
17050
Freitas,EC., and 0. Roche 2011
tropical species not resident to US
Pseudosida ramosa
Water flea
KCI
LC50
17050
ug/L
48 hr
17050
Freitas,E.C., and 0. Roche 2011
tropical species not resident to US
Pseudosida ramosa
Water flea
KCI
LC50
18700
u /L
48 hr
18700
Freitas,E.C., and 0. Roche 2011
tropical species not resident to US
Pseudosida ramosa
Water flea
KCI
LC50
18860
u /L
48 hr
18860
Freitas,E.C., and O. Roche 2011
tropical species not resident to US
Pseudosida ramosa
W ater flea
KCI
LC50
21590
u /L
48 hr
21590
Freitas,E.C., and 0. Rothe 2011
tropical species not resident to US
Pseudosida ramosa
Water Bea
KCI
LC50
23760
ug/L
48 hr
23760
Freitas,E.C., and 0. Roche 2011
tropical species not resident to US
Pseudosida ramosa
Water flea
KCI
LC50
29710
u /L
48 hr
29710
Freitas,E.C., and 0. Racine 2011
tropical species not resident to US
Pseudosida ramosa
Water flea
KCI
LC50
31860
u /L
48 hr
31860
Freitas,E.C., and 0. Roche 2011
tropical species not resident to US
Pseudosida ramosa
Water flea
KCI
LC50
39250
ug/L
48 hr
39250
Freitas E.C., and 0. Roche 2011
tropical species not resident to US
Pseudosida ramosa
Water flea
KCI
LC50
9680
ug/L
48 hr
9680
Freitas,E.C., and 0. Roche 2011
tropical species not resident to US
Austropotamobius pallipes pa
Crayfish
KCI
LC50'
I88000'
ug/L
30 day
7
Boutet, C., and C. Chaisemartin 1973
article in french, species not resident to US, ECOTOX value not verifed in paper
Austropotamobius pallipes pa
Crayfish
KCI
LC50'
210000
ug/L
1 30 day
210000
Boutet, C., and C. Chaisemartin 1973
article in french, species not resident to US
Austropotamobius pallipes pa
Crayfish
KCI
LC50'
251000'
ug/L
30 day
?
Boutet, C., and C. Chaisemartin 1973
artide in french, species not resident to US, ECOTOX value not verifed in paper
Austropotamobius pallipes pa
Crayfish
KCI
LCSO•
280000
ug/L
30 day
280000
Boutet, C., and C. Chaisemartin 1973
article in french, species not resident to US
Austrupotamobius pallipes pa
Crayfish
KCI
LC50'
350000'
ug/L
96 hr
?
Boutet, C., and C. Chaisemartin 1973
article in french, species not resident to US, ECOTOX value not verifed in paper
Austropotamobius pallipes pa
Crayfish
KCI
LC50•
390000
u /L
96 hr
390000
Boutet C., and C. Chaisemartin 1973
article in french, species not resident to US
Orconectes Iimosus
Crayfish
KCI
LC50'
296000'
u /L
30 day
?
Boutet, C., and C. Chalsemartin 1973
article in french, ECOTOX value not verified in original reference
Orconectes Iimosus
Crayfish
KCI
LC50'
330000
ug/L
30 day
330000
Boutet, C., and C. Chaisemartin 1973
article in french, some test procedure information (organism age, control performance,
feeding during test, dilution water source) is lacking to adequately determine study
acceptabdity
Orconectes Iimosus
Crayfish
KCI
LC50•
404000•
u /L
30 day
7
Boutet, C., and C. Chaisemartin 1973
article in french, ECOTOX value not verified In original reference
Orconectes Iimosus
Crayfish
KCI
LC50•
450000
ug/L
30 day
450000
Boutet, C., and C. Chaisemartin 1973
article in french, some test procedure information (organism age, control performance,
feeding during test, dilution water source) is lacking to adequately determine study
Orconectes Iimosus
Crayfish
KCI
LC50•
574000•
ug/L
96 hr
?
Boutet, C., and C. Chalsemartin 1973
article in french, ECOTOX value not verified In original reference
Orconectes Iimosus
Crayfish
KCI
LC50'
640000
ug/L
96 hr
640000
Boutet, C., and C. Chaisemartin 1973
article in french, some test procedure information (organism age, control performance,
feeding during test, dilution water source) is lacking to adequately determine study
acceptability
Salmo trutta
Brown trout
KCI
LT50
NR
mM/L
100 hr
not given
not given
Brown D.J.A. 1981
adult brook trout tested in 0.05-2 mM/L NCI solutions. Time to 50% death recorded,
test pH = 3.5-4.0, test duration not standard
Salmo trutta
Brown trout
KCI
LT50
NR
mM/L
100 hr
not given
not given
Brown, D.J.A. 1981
Hyalella azteca
Scud
KCI
LC50
141900
ug/L
96 hr
141900
Burton, G.A.J., at al. 1996
paper notes test result was excluded from analysis as not standard test procedures
Hyalella azteca
Scud
KCI
LC50
29 3300
u /L
96 hr
297300
Burton, G.A.). at al. 1996
control failure
Hyalella azteca
Scud
KCI
LC50
232000
u /L
96 hr
232000
121568
Burton, G.A.J., at al. 1996
For Burton et al 1996; standard test procedures followed, adequate control
performance, although tests were fed at test initiation and at 48hrs, it does not appear
feeding of tests affected test results when compared to ENVIRON testing results
Hyalella azteca
Scud
KCI
LC50
250000
u /L
96 hr
250000
131000
Burton, G.A.J., at al. 1996
Hyalella azteca
Scud
KCI
LC50
275600
ug/L
96 hr
275600
144414
Burton, G.A.J., at al. 1996
Hyalella azteca
Scud
KCI
LC50
320600
ug/L
96 hr
320600
167994
Burton, G.A.J., at al. 1996
Hyalella azteca
Scud
KCI
LC50
324600
ug/L
96 hr
324600
170090
Burton, G.A.L, at al. 1996
Hyalella azteca
Scud
KCI
LC50
335600
u /L
96 hr
335600
175854
Burton G.A.J., at al. 1996
Hyalella arteca
Scud
KCI
LC50
337200
ug/L
96 hr
337200
176693
Burton, G.A.J., at al. 1996
Hyalella azteca
Scud
KCI
LC50
372400
a /L
96 hr
372400
195138
Burton, G.A.]. at al. 1996
Chironomus tentans
Midge
KCI
LC50
1250000
u /L
96 hr
12S0000
655000
Burton, G.A.J., at al. 1996
Chironomus tentans
IlAidge
LC50
200000D
u /L
96 hr
2000000
3048000
Burton G.A.J. at al. 1996
Chironomus tentans
Midge
KCIKCI
LC50
2890000
u /L
96 hr
2890000
1514360
Burton, G.A.1., et al. 1996
Chironomus tentans
Midge
I KCI
I LC50
I 317000U
I u /L
I 96 hr
3170000
r1663080
Burton, G.A.L, et al. 1996
P.ae 7 of 13

2. Freshwater
Species Scientific Name
Potassium Aquatic
Common Name
Toxicitv
Chemical
Name
DatabaseAppendix
Endpoint
Value as
Salt
Conic
Conc
Units
Test
Duration
Verified Value
from paper as
salt
Value as K
Conc
Citation
Rejection justification and Notes
Chironomus -._ss
Midge
KCI
LC50
3610000
u /L
96 hr
3610000
1891640
Burton, G.A.]., et al. 1996
Chironomo: -, IS
Midge
KCI
LC50
5000000
u /L
96 hr
5000000
2620000
Burton, G.A.J., at al. 1996
Chira" -- -.'Is
Midge
KCI
LC50
5110000
u /L
96 hr
5110000
2677640
Burton, G.A.J., at al. 1996
Ch"' .-cos
Midge
KCI
LC50
5300000
ug/L
96 hr
5300000
2777200
Burton, G.A.J., at al. 1996
Chironoln�s tentans
Midge
KCI
LC50
5360000
ug/L
96 hr
5360000
2808640
Burton, G.A.]., at al. 1996
Chironomus tentans
Midge
KCI
LC50
6200000
ug/L
96 hr
6200000
3248800
Burton, G.A.J., at al. 1996
Chironomus tentans
Midge
KCI
LC50
6280000
u /L
96 hr
6280000
3290720
Burton G.A.T. at al. 1996
Chironomus tentans
Midge
KCI
LC50
6600000
ug/L
96 hr
6600000
3458400
Burton, G.A.J., at al. 1996
Chironomus tentans
Midge
KCI
LC50
6650000
u /L
96 hr
6650000
3484600
Burton G.A.J., at al. 1996
Chironomus tentans
Midge
KCI
LC50
6835000
ug/L
96 hr
6830000
3578920
Burton, G.A.I., et al. 1996
Chironomus tentans
Midge
KCI
LC50
6190000
ug/L
96 hr
6190000
Burton, G.A.J., et al. 1996
control failure
Chironomus tentans
Midge
KCI
LC50
5300000
ug/L
96 hr
5300000
Burton, G.A.T., at al. 1996
control failure
Chironomus tentans
Midge
KCI
LC50
1770000
ug/L
96 hr
1770000
Burton, G.A.I., at al. 1996
control failure
Daphnia mains
Water Flea
KCI
EC50
7350
umol/L
24 hr
7350
Calleja, M.C., et al. 1994
test duration not standard
Streptocephalus proboscideus
Fairy shrimp
KCI
LC50
25100
umoVL
24 hr
25100
Calleja, M.C., et al. 1994
test duration not standard
Brachionus calyciflorus
Rotifer
KCI
LC50
22700
umoVL
24 hr
22700
Calleja, M.C., et al. 1994
test duration not standard
Chironomus riparius
Midge
KCI
LC50
4810000
ug/L
96 hr
4810000
Conrad, A.U., at al. 1999
study is tox test on pesticide. Ran reftox on KCI, not enough info on reftox procedures
to m'
Caenorhabditis elegans
Nematode
KCI
LC50
29839000
ug/L
24 hr
29839000
Cressman III, C.P., and P.L. Williams 1997
adults used for testing, test duration not standard
Caenorhabditis elegans
Nematode
KCI
LC50
29854000
u /L
24 hr
29854000
Creasman III, C.P., and P.L. Williams 1997
adults used for testing, tests fed, test duration not standard
Caenorhabditis elegans
Nematode
KCI
LC50
40830000
ug/L
24 hr
40830000
Creasman III, C.P., and P.L. Williams 1997
adults used for testing, tests fed, test duration not standard
Caenorhabditis elegans
Nematode
KCI
LC50
41200000
ug/L
24 hr
41200000
Cressman III, C.P., and P.L. Williams 1997
adults used for testing, test duration not standard
Caenorhabditis elegans
Nematode
KCI
LC50
42049000
ug/L
24 hr
42049000
JCressman III, C.P., and P.L. Williams 1997
adults used for testing, test duration not standard
Caenorhabditis elegans
Nematode
KCI
LC50
43609000
ug/L
24 hr
43609000
Cressman 111, C.P., and P.L. Williams 1997
adults used for testing, tests fed, test duration not standard
Caenorhabditis elegans
Nematode
KCI
LC50
29960000
ug/L
48 hr
29960000
Cressman III, C.P., and P.L. Williams 1997
adults used for testing, tests fed
Caenorhabditis elegans
Nematode
KCI
LC50
39130000
ug/L
1 48 hr
391300DO
Cressman III, C.P., and P.L. Williams 1997
adults used for testing, tests fed
Caenorhabditis elegans
Nematode
KCI
LC50
41560000
ug/L
48 hr
4156000
Cressman III, C.P., and P.L. Williams 1997
adults used for testing, tests fed
Phaeodactylum tricornutum
Diatom
KNO3
NR
1400"
ug/L
4 hr
7
Cresswell, R.C., and P.J. Syrett 1981
not std tox test, NO3 uptake
Chlorella vulgaris
Green algae
KCI
LOEC
670000
u /L
NR
670000
De long, L.E.D. 1965
test duration not reported
Chlorella vulgaris
Green algae
KCI
NOEC
600000
ug/L
NR
600000
De long, L.E.D. 1965
test duration not reported
Gammarus lacustns
Scud
Potassium
LC50
53200
ug/L
96 hr
?
De March, B.G.E. 1988
test procedures not appropriate as multiple toxicants in test solution
Tinca tinca
Tench
KNO3
NR
3400*
ug/L
NR
7
Demael, A., et al. 1980
not standard tox test, meas effect of K on blood, plasma
Daphnia magna
Water flea
KCI
LC50*
343000
ug/L
24 hr
343000
Dowden, B.F. 1961
used varying ages of 4th instar or adults for each test, 24 hr test duration not
standard, dilution water was lake water without indicatin of presence of other
Daphnia magna
Water flea
KCI
LC50-
357000
ug/L
48 hr
357000
JDowden, B.F. 1961
Daphnia magna
Water flea
KCI
LC50
343000
ug/L
24 hr
343000
Dowden, B.F., and H.J. Bennett 1965
test duration not standard, lack of test information (e.g., organism age, controls
presence/performance, feeding during test, dilution water details) prohibits
Daphnia magna
Water flea
KCI
LC50
337000
ug/L
48 hr
337000
Dowden, B.F., and H.J. Bennett 1965
lack of test information (e.g., organism age, controls presence/performance, feeding
during test, dilution water details) prohibits determination of test acceptability
Daphnia magna
Water flea
KCI
LC50
117000
ug/L
72 hr
117000
Dowden, B.F., and H.J. Bennett 1965
test duration not standard, lack of test information (e.g., organism age, controls
presence/performance, feeding during test, dilution water details) prohibits
Daphnia magna
Water flea
KCI
LC50
29000
ug/L
96 hr
29000
Dowden, B.F., and H.J. Bennett 1965
lack of test information (e.g., organism age, controls presence/performance, feeding
during test, dilution water details) prohibits determination of test acceptability
Daphnia magna
Water flea
KCI
LC50
679000
ug/L
100 hr
679000
Dowden, B.F., and H.I. Bennett 1965
test duration not standard, lack of test information (e.g., organism age, controls
presence/performance, feeding during test, dilution water details) prohibits
Lepomis macrochirus
Bluegill
KCI
LC50
5500000
ug/L
24 hr
5500000
Dowden, B.F., and H.J. Bennett 1965
test duration not standard, lack of test information (e.g., organism age, controls
presence/performance, feeding during test, dilution water details) prohibits
determination mf I— —1-hilij-
Lymnaea sp.
Pond snail
KCI
LC50
1941000
ug/L
24 hr
1941000
Dowden, B.F., and H.J. Bennett 1965
test duration not standard, lack of test information (e.g., organism acclimation since
collected from field, organism age, controls presence/performance, feeding during test,
dilution water details) prohibits determination of test acceptability
Lymnaea sp.
Pond snail
KCI
LC50
1492000
ug/L
48 hr
1492000
Dowden, B.F., and H.J. Bennett 1965
test duration not standard, lack of test information (e.g., organism acclimation since
collected from field, organism age, controls presence/performance, feeding during test,
dilution water details) prohibits determination of test acceptability
Lymnaea sp.
Pond snail
KCI
LC50
1018000
ug/L
72 hr
1018000
Dowden, B.F., and H.J. Bennett 1965
test duration not standard, lack of test information (e.g., organism acclimation since
collected from field, organism age, controls presence/performance, feeding during test,
dilution water details) prohibits determination of test acceptability
Lymnaea sp.
Pond snail
KCI
LC50
1100000
ug/L
96 hr
1100000
Dowden, B.F., and H.J. Bennett 1965
lack of test information (e.g., organism acclimation since collected from field, organism
age, controls presence/performance, feeding during test, dilution water details)
determinat on of test accentabilit,
Daphnia magna
Water flea
KNO3
LC50
490000
ug/L
24 hr
490000
Dowden, B.F., and H.J. Bennett 1965
test duration not standard, lack of test information (e.g., organism age, controls
presence/performance, feeding during test, dilution water details) prohibits
term rat on of test accentabil ty
Daphnia magna
Water flea
KNO3
LC50
490000
ug/L
48 hr
490000
Dowden, B.F., and H.J. Bennett 1965
lack of test information (e.g., organism age, controls presence/performance, feeding
during test, dilution water details) prohibits determination of test acceptability
Page 8 of 13

U
2. Freshwater
Species Scientific Name
Potassium Aquatic
Common Name
Toxicitv
Chemical
Name
DatabaseAppendix
Endpoint
Value as
Salt
Conc:
Conc
Units
Test
Duration
Verified Value
from paper as
salt
Value as K
Conc
Citation
Rejection Justification and Notes
Daphnia magna
Water Rea
KNO3
LC50
226000
ug/L
72 hr
226000
Dowden, B.F., and H.I. Bennett 1965
test duration not standard, lack of test information (e.g., organism age, controls
presence/performance, feeding during test, dilution water details) prohibits
Daphnia magna
Water Rea
KNO3
LC50
39000
ug/L
96 hr
39000
Dowden, B.F., and H.J. Bennett 1965
lack of test information (e.g., organism age, controls presence/performance, feeding
dunng test, dilution water details) prohibits determination of test acceptability
Daphnia magna
Water Rea
KNO3
LC50
900000
ug/L
100 hr
900000
Dowden, B.F., and H.J. Bennett 1965
test duration not standard, lack of test information (e.g., organism age, controls
presence/performance, feeding during test, dilution water details) prohibits
Lepomis macrochirus
Bluegill
KNO3
LC50
5500000
ug/L
24 hr
5500000
Dowden, B.F., and H.J. Bennett 1965
test duration not standard, lack of test information (e.g., organism age, controls
presence/performance, feeding during test, dilution water details) prohibits
Lymnaea sp.
Pond snail
KNO3
LC50
1941000
ug/L
24 hr
1941000
Dowden, B.F., and H.J. Bennett 1965
test duration not standard, lack of test information (e.g., organism age, controls
presence/performance, feeding during test, dilution water details) prohibits
deform nation of test Accaptahilitin,
Lymnaea sp.
Pond snail
KNO3
LC50
1492000
ug/L
48 hr
1492000
Dowden, B.F., and H.J. Bennett 1965
lack of test information (e.g., organism age, controls presence/performance, feeding
during test, dilution water details) prohibits determination of test acceptability
Lymnaea sp.
Pond snail
KNO3
LC50
1018000
ug/L
72 hr
1018000
Dowden, B.F., and H.J. Bennett 1965
test duration not standard, lack of test information (e.g., organism age, controls
presence/performance, feeding during test, dilution water details) prohibits
determiner on of test accent,hiliN
Lymnaea sp.
Pond snail
KNO3
LC50
1100000
ug/L
100 hr
1100000
Dowden, B.F., and H.J. Bennett 1965
test duration not standard, lack of test information (e.g., organism age, controls
presence/performance, feeding during test, dilution water details) prohibits
Ictalurus punctatus
Channel catfish
KCI
LC50
7338000
ug/L
24 hr
7338000
Durand -Hoffman, M.E. 1995
test duration not standard for fish
Morone saxatilis
Striped bass
KCI
LC50
3499000
ug/L
24 hr
3499000
Durand -Hoffman M.E. 1995
test duration not standard for fish
Morone saxatilis
Striped bass
KCI
LC50
508000
ug/L
24 hr
508000
Durand -Hoffman, M.E. 1995
test duration not standard for fish
Notemi onus crysoleucas
Golden shiner
KCI
LC50
816000
ug/L
24 hr
816000
Durand -Hoffman, M.E. 1995
likely adult test organism, test duration not standard for fish
Oncorhynchus mykiss
Rainbow trout
KCI
LC50
1191000
ug/L
24 hr
1191000
Durand -Hoffman, M.E. 1995
test duration not standard for fish
Pimephales promelas
Fathead minnow
KCI
LC50
2465000
ug/L
24 hr
2465000
Durand -Hoffman, M.E. 1995
likely adult test organism, test duration not standard for fish
Sander cenadense
Sauger
KCI
LC50
500000
ug/L
24 hr
500000
Durand -Hoffman, M.E. 1995
test duration not standard for fish
Sander vitreus
Walleye
KCI
LC50
724000
ug/L
24 hr
724000
Durand -Hoffman, M.E. 1995
test duration not standard for fish
Dreissena polymorpha
Zebra mussel
KCI
LC50
102000
ug/L
24 hr
102000
Durand -Hoffman, M.E. 1995
adult test organisms used, test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
116000
ug/L
24 hr
116000
Durand -Hoffman, M.E. 1995
adult test organisms used, test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
119000
ug/L
24 hr
119000
Durand -Hoffman, M.E. 1995
adult test organisms used, test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
138000
ug/L
24 hr
138000
Durand -Hoffman, M.E. 1995
adult test organisms used, test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
150000
ug/L
24 hr
150000
Durand -Hoffman, M.E. 1995
adult test organisms used, test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
281000
ug/L
24 hr
281000
Durand -Hoffman, M.E. 1995
adult test organisms used, test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
377000
ug/L
24 hr
377000
Durand -Hoffman, M.E. 1995
adult test organisms used, test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
55000
ug/L
24 hr
55000
Durand -Hoffman, M.E. 1995
adult test organisms used, test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
56000
ug/L
24 hr
56000
Durand -Hoffman, M.E. 1995
adult test organisms used, test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
587000
ug/L
24 hr
587000
Durand -Hoffman, M.E. 1995
adult test organisms used, test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
639000
ug/L
24 hr
639000
Durand -Hoffman, M.E. 1995
adult test organisms used, test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
82000
ug/L
24 hr
82000
Durand -Hoffman, M.E. 1995
adult test organisms used, test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
86000
ug/L
24 hr
86000
Durand -Hoffman, M.E. 1995
adult test organisms used, test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
87000
ug/L
24 hr
87000
Durand -Hoffman, M.E. 1995
adult test organisms used test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
88000
ug/L
24 hr
88000
Durand -Hoffman, M.E. 1995
adult test organisms used, test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
88000
ug/L
24 hr
88000
Durand -Hoffman, M.E. 1995
adult test organisms used, test tluration not stantlartl
Dreissena polymorpha
Zebra mussel
KCI
LC50
90000
ug/L
24 hr
90000
Durand -Hoffman, M.E. 1995
adult test organisms used, test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
910000
ug/L
24 fir
910000
Durand -Hoffman, M.E. 1995
adult test organisms used, test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
964000
ug/L
24 hr
964000
Durand -Hoffman, M.E. 1995
adult test organisms used, test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
98000
ug/L
24 hr
98000
Durand -Hoffman, M.E. 1995
adult test organisms used, test duration not standard
Oncorhynchus mykiss
Rainbow trout
KCI
LD50
8.1
umol/g
72 hr
7
Eales, J.G., at al. 1986
not standard tax test, fish injected with KCI, test duration not standard
Gambusia aRnis
Western mosquitofish
KCI
NR
NR
ug/L
24 hr
> 186000
Fisher, S.W., et al. 1991
test duration not standard, endpoint not reported
Anodonta imbecillis
Mussel
KCI
LC50
76000
ug/L
24 hr
76000
Fisher, S.W. at al. 1991
without sediment, test duration not standard
Dreissena polymorpha
Zebra mussel
KCI
LC50
138000
ug/L
24 hr
138000
Fisher, S.W., at al. 1991
test duration not standard
Corbicula manilensis
Asiatic clam
KCI
NR
500000
ug/L
24 hr
>500000
Fisher S.W., et al. 1991
test duration not standard, endpoint not reported
Helisoma sp.
Ramshorn snail
KCI
NR
NR
ug/L
24 hr
> 186000
Fisher, S.W., et al. 1991
test duration not standard, endpoint not reported
Dreissena polymorpha
Zebra mussel
K504
LC50
112000
ug/L
24 hr
112000
Fisher, S.W. at al. 1991
test duration not standard
Chaos carolmense
Giant Amoeba
NCI
LOEL
20
mM
NR
20
Foster, R.W., at al. 1981
single cell organism, meas membrane potential change at 20 mM KCI, test duration
unknown
Cricotopus trifasciatus
Midge
KCI
LC50'
1406000'
ug/L
48 hr
1 2987000
1565188
Hamilton, R.W., et al. 1975
used 3rd or 4th instar
Crimtopus trifasciatus
Midge
KCI
LC50.
1567000-
ug/L
48 hr
7
Hamilton, R.W., at al. 1975
used 3rd or 4th instar, ECOTOX value not verified in original reference
Hydroptila angusta
CaddisRy
KCI
LC50'
2077000'
ug/L
48 hr
4415000
2313460
Hamilton R.W., et al. 1975
used 3rd or 4th instar
H dro tila an usta
Caddisfiy
KCI
LC50'
2316000-
ug/L
48 hr
7
Hamilton R.W., at al. 1975
used 3rd or 4th Instar, ECOTOX value not verified in original reference
Nais variabilis
Oligochaete
KCI
LC50'
57000"
ug/L
48 hr
143000
Hamilton R.W. at al. 1975
control Mort 11%, used adults
Nals variabilis
Oligochaete
KCI
LC50-
75000•
ug/L
48 hr
?
Hamilton, R.W., at al. 1975
control mort 11%, used adults, ECOTOX value not verified in original reference
Amblema plicata
mussel
KCI
NOEC/LOEC
ug/L
36 d
-
1 0000 / 15000
Jmlay, M.J. 1973
tested with juveniles -adults likely mixed ages, only 8-9 organisms per chamber due [o
an I col
Page 9 of 13

2. Freshwater
Species Scientific Name
Potassium Aquatic
Common Name
Toxicitv
Chemical
Name
DatabaseAppendix
Endpoint
Value as
Salt
Canc
Canc
Units
Test
Duration
Verified Value
from paper as
salt
Value as K
Cant
Citation
Rejection Justification and Notes
Lampsilis radiate sillquoidea
mussel
KCI
NOEC/LOEC
ug/L
300 d
-
1000 / 7000
Imlay, M.J. 1973
tested with juveniles -adults likely mixed ages, feral organisms not acclimated before
testing, mixed genus/spedes in tests as paper notes test facilitators could not tell
difference between L. radiate luteola and Actinonaias ligamentina.
Actnonaias carinata
mussel
KCI
NOEC/LOEC
ug/L
36 d
-
1000 / 11000
Imlay, M.J. 1973
tested with juveniles -adults likely mixed ages, feral organisms not acclimated before
testing, mixed genus/species in tests as paper notes test facilitators could not tell
difference between L. radiate luteola and Actinonaias ligamentina.
Fusconaia Bava
mussel
KCI
NOEC/LOEC
ug/L
300 d
-
1000 / 7000
Imlay, M.J. 1973
tested with juveniles -adults likely mixed ages, no acclimation period from field
Osteichthyes
bony fishes
K(OH)
EC50
0.000014
molal
NR
?
Ishio, S. 1965
not standard tax test, test duration unknown, avoidance behavior, test substance
Osteichthyes
bony fishes
K(OH)
NR-LETH
0.00001
molal
NR
?
Ishio, S. 1965
not standard tax test endpoint, avoidance behavior, test substance, test duration
unknown
Polycelis nigra
Planarian
KCI
NR
350000
u It
48 hr
350000
Jones, J.R.E. 1940
not standard endpoint; measured avg. survival time at K conc.
Gasterosteus awleatus
Threespine stickleback
KNO3
NR-LETH
18000'
ug/L
10 days
?
Jones, J.A.E. 1939
not standard tax test duration for fish, test substance, ECOTOX result not verifed in
f
Gaaeroaeus awleatus
Threespine aickleback
KNO3
NR-LETH
50000
u /L
10 days
50000
Jones, J.R.E. 1939
not standard tax test duration for fish, test substance
Polycelis nigra
Planarian
KNO3
NR
350000
ug/L
48 hr
I
350000
Jones, J.R.E. 1940
not ad tax test, meas conc that which had avg survival time at 48 him measured, test
substance
Anabaena sp.
Blue-green algae
KNO3
NR
140000'
ug/L
20 day
7
Kanto, 5., and T.A. Sarma 1980
could not obtain original reference; test substance, test duration, endpoint unknown
Anabaena sp.
Blue-green algae
KNO3
NR
39000'
ug/L
20 day
?
Kanta, S., and T.A. Sarma 1980
could not obtain original reference; test substance, test duration, endpoint unknown
Lampsilis straminea cialborne
Southern fatmucket
KCI
LC50
13500
ug/L
96 fir
?
Keller, A.E. 2000
was not able to obtain original reference which was an EPA memo, can not confirm
testing procedures were adequate, age of test organisms unknown
Villosa vibex
S. Rainbow Mussel
KCI
LC50
26000
ug/L
96 hr
7
Keller, A.E. 2000
was not able to obtain original reference which was an EPA memo, can not confirm
testing procedures were adequate, age of test organisms unknown
Tubifex tubifex
Tubificid worm
KCI
EC50
2000000
u L
24 hr
2000000
Khangarot, B.S. 1991
test duration organism age, control performance unknown
Tubifex tubifex
Tubificid worm
KCI
EC50
1320000
ug/L
48 fir
1320000
Khangarot, B.S. 1991
test duration, or ainsism age, control performance unknown
Tubifex tubifex
Tubificid worm
KCI
EC50
812800
ug/L
96 fir
-
812800
Khangarot, B.S. 1991
age of test organisms unknown, feral organisms used, "tubewell" water used for
dilution water (hardness 245 mo/L)
Daphnia magna
Water Flea
KCI
EC50
327940
ug/L
24 fir
327940
Khangarot, B.S., and P.K. Ray 1989
test duration not standard, organism age, control performance unknown
Daphnia magna
Water flea
KCI
EC50
141460
ug/L
48 hr
-
141460
Khangarot, B.S., and P.K. Ray 1989
organism age and control pert. unknown, "tubewell" water used for dilution water
Oncorhynchus mykiss
Rainbow trout
KCI
IC25
NR
ug/L
7 day
1131000-2381000
Lazorchak I.M., and M.E. Smith 2007
test duration not standard for acute or chronic fish
Salvelinus fontinalis
Brook trout
KCI
IC25
NR
ug/L
7 day
2409000-2582000
Lazorchak, J.M., and M.E. Smith 2007
test duration not standard for acute or chronic fish
Oncorhynchus mykiss
Rainbow trout
KCI
LC50
NR
u /L
7 day
1586000
Lazorchak J.M. and M.E. Smith 2007
test duration not standard for acute or chronic fish
Oncorhynchus mykiss
Rainbow trout
KCI
LC50
NR
ug/L
7 day
2828000
Lazorchak, J.M., and M.E. Smith 2007
test duration not standard for acute or chronic fish
Oncorhynchus mykiss
Rainbow trout
KCI
I NOEC
NR
ug/L
7 day
500000-2000000
Lazorchak, J.M., and M.E. Smith 2007
test duration not standard for acute or chronic fish
Oncorhynchus mykiss
Rainbow trout
KCI
NOEC
NR
ug/L
7 day
1000000-2000000
Lazorchak, I.M., and M.E. Smith 2007
test duration not standard for acute or chronic fish
Salvelinus fontinalis
Brook trout
KCI
LC50
NR
ug/L
7 day
2,732,000
Lazorchak, I.M., and M.E. Smith 2007
test duration not standard for acute or chronic fish
Salvelinus fontinalis
Brook trout
KCI
LC50
NR
ug/L
7 day
3,007,000
Lazorchak, J.M., and M.E. Smith 2007
test duration not standard for acute or chronic fish
Salvelinus fontinalis
Brook trout
KCI
NOEC
2000000
u /L
7 day
2000000
Lazorchak, J.M., and M.E. Smith 2007
tea duration not standard for acute or chronic fish
Salvelinus fontinalis
Brook trout
KCI
NOEC
2000000
u /L
7 day
2000000
Lazorchak J.M., and M.E. Smith 2007
test duration not standard for acute or chronic fish
Daphnia magna
Water Bea
KCI
LC50
mM
24 fir
15.12
590000
Lilius, H., et al. 1995
tea duraton not standard
Daphnia magna
Water flea
KCI
EC50
15,12
mM
24 hr
15.12
590000
Wius, H., at al. 1994
tea duration not standard
Potamogeton illinoensis
Pondweed
KNO3
NR
15000
ug/L
20 day
15000
Litav, M., and Y. Lehrer 1978
not std tax test, tested one conc. and reported effects, test substance
Potamogeton illinoensis
Pondweed
KNO3
NR
42000'
ug/L
20 day
?
Litav, M., and Y. Lehrer 1978
not ad tax tea, tested one conc. and reported effects, test substance, could not verify
result m onainal source
Potamogeton illinoensis
Pondweed
KNO3
NR
15000
ug/L
20 day
15000
Litav, M., and Y. Lehrer 1978
not ad tax test, tested one conc. and reported effects test substance
Potamogeton illinoensis
Pondweed
KNO3
NR
42000'
I
ug/L
20 day
I
?
Litav, M., and Y. Lehrer 1978
not ad tax tea, tested one conc. and reported effects, test substance, could not verify
result from original source
Potamogeton illinoensis
Pondweed
KNO3
NR
15000
u /L
12 day
15000
Litav, M. and Y. Lehrer 1978
not ad tax test, tested one conc. and reported effects, test substance
Potamogeton illinoensis
Pondweed
KNO3
NR
15000
ug/L
12 day
15000
Litav, M., and Y. Lehrer 1978
not ad tax test, tested one conc. and reported effects, test substance
Potamogeton illinoensis
Pondweed
KNO3
NR
42(1
ug/L
12 day
?
Litav, M., and Y. Lehrer 1978
not ad tax tea, tested one conc. and reported effects, test substance, could not verify
result from ariainal source
Potamogeton illinoensis
Pondweed
KNO3
NR
42000'
ug/L
12 clay
?
Litav, M., and Y. Lehrer 1978
not ad tax test, tested one conc. and reported effects, test substance, could not verify
result I on i I r
Rana breviceps
Frog
KCI
NR
NR
ug/L
96 hr
1670000
Mahajan, C.L., at al. 1979
endpoint statistic CLC50) unknown, control survival unknown, adequate tea info not
Dreissena polymorpha
Zebra mussel
K(OH)
NR-LETH
10000
ug/L
several days
10000
Matisoff, G., A. et al 1991
abstract only, conc 10 ppm caused complete mortality, tea duration not known,
Dreissena polymorpha
Zebra mussel
K(OH)
NR-ZERO
1000
ug/L
several days
<I000
Matisoff, G., A. et al 1991
abstract only, conc <1 plain did not cause mortality, test duration not known, endpoint,
test substance not appropriate
Hyalella arteca
Scud
KCI
LC50
540000
ug/L
24 fir
540000
McNulty, E. W., M al. 999
24 hr tax test where organisms were starved or fed 48, 72 or 96 firs before testing,
tea was fed, 24 fir tox test where organisms were starved or fed 48, 72 or 96 him
before si r n not appropriate
Hyalella aztece
Scud
KCI
LC50
620000
ug/L
24 fir
620000
McNulty, E.W., et al. 999
Hyalella arteca
Scud
KCI
LC50
630000
ug/L
24 hr
630000
McNulty, E.W., et al. 999
test was fed, 24 hr tax tea where organisms were starved or fed 48, 72 or 96 him
Hyalella arteca
Scud
KCI
LC50
660000
ug/L
24 hr
660000
McNulty, E.W., et al. 999
24 hr tax test where organisms were starved or fed 48, 72 or 96 him before testing,
test duration not appropriate
Page 10 of 15

2. Freshwater
Species Scientific Name
Potassium Aquatic
Common Name
Toxicity
Chemical
Name
DatabaseAcipenclix
Endpoint
Value as
Salt
Cone
Conc
Units
Test
Duration
Verified Value
from paper as
salt
Value as K
Conc
Citation
Rejection justification and Notes
Hyalella azteca
Scud
NCI
LCSO
410000
ug/L
96 hr
410000
McNulty, E.W., et al. 999
organisms were "cold shocked"
Hyalella azteca
Scud
KCI
LC50
460000
u /L
96 hr
460000
McNulty, E.W., et al. 999
test was fed, study reRox
Hyalella arteca
Scud
KCI
LC50
540000
ug/L
24 hr
540000
McNulty, E.W., et al. 999
24 hr tox test where organisms were starved or fed 48, 72 or 96 firs before testing,
r nn
Hyalella azteca
Scud
KCI
LC50
620000
ug/L
24 hr
620000
McNulty, E.W., et al. 999
test was fed, 24 hr tox test where organisms were starved or fed 48, 72 or 96 hrs
beforeing. test duration not appropriate
Hyalella azteca
Scud
KCI
LC50
630000
ug/L
24 hr
630000
McNulty, E.W., at al. 999
24 hr tox test where organisms were starved or fed 48, 72 or 96 hrs before testing,
test duration not
Cenodaphnia rigaudi
Water flea
KCI
LC50
21110
ug/L
48 hr
21110
Mohammed, A. 2007
determined not resident to Deep Fork River, Genus represented by C. dubia
Daphnia magna
Water Flea
KCI
LC50
418870
u /L
48 hr
418870
219488
Mohammed, A. 2007
Diacyclops bicuspidatus
Cyclopod Copepod
KCI
LC50
ug/L
24 hr
1026000
Mohammed, A. 2007
test duraton not stantlard
Pararyclo s fimbriatus
Cyclopod Copepod
KCI
LC50
ug/L
24 hr
1004000
Mohammed, A. 2007
test duraton not standard
Proasellus slavus
Isopod
KCI
LC50
ug/L
24 hr
285000
Mohammed, A. 2007
test duraton not standard
Asellus aquaticus
Isopod
KCI
LCSO
ug/L
24 hr
355000
Mohammed, A. 2007
test tluraton not standard
Diacyclops sp.
Cyclopod Copepod
KCI
LC50
u /L
24 hr
577000
Mohammed, A. 2007
test duraton not standard
Acanthocyclocis rustus
Cyclopod Copepod
KCI
LC50
u /L
24 hr
662000
Mohammed A. 2007
test duraton not standard
Diacyclops sp. Disjunctus
Cydopod Copepod
KCI
LC50
ug/L
24 hr
698000
Mohammed, A. 2007
test duraton not standard
Megacyclops vindis
Cyclopod Copepod
KCI
LC50
a /L
24 hr
776000
Mohammed, A. 2007
test duraton notstandard
Acanthoci,clops vernalis
Cyclopod Copepod
NCI
LC50
ug/L
24 hr
1534000
Mohammed, A. 2007
test duraton not standard
Fabaeformiscandona we ellnl
Ostracoda
KCI
LC50
u /L
24 hr
1932000
Mohammed A. 2007
test duraton not standard
Pseudocandona sp.
Ostracoda
KCI
LC50
ug/L
24 hr
2018000
Mohammed, A. 2007
test duraton not standard
Acanthocyclops vemalis
Cyclopoid copepod
KNO3
LC50
1985000
u /L
24 hr
1985000
Mohammed, A. 2007
test duration, test substance
Diacyclops bicuspidatus
Cyclopod Copepod
KNO3
LC50
1459000
u /L
24 hr
1459000
Mohammed, A. 2007
test duration, test substance
Paracydo s fimbriatus
Cyclopod Copepod
KNO3
LC50
1641000
ug/L
24 hr
1641000
Mohammed, A. 2007
test duration, test substance
Proasellus slavus
Isopod
KNO3
LC50
412000
ug/L
24 hr
412000
Mohammed, A. 2007
test duration, test substance
Cenodaphnia dubia
Water flea
K2CO3
LC50
630000
u /L
24 hr
630000
Mount, D.R., et al. 1997
test duration, test substance
Cerioda hnia dubia
Water flea
K2CO3
LC50
630000
u /L
48 hr
630000
Mount D.R., et al. 1997
test substance
Daphnia magna
Water flea
K2CO3
LC50
670000
ug/L
24 hr
670000
Mount, D.R., et al. 1997
test duration, test substance
Daphnis magna
Water flea
K2CO3
LCSO
650000
u /L
48 hr
650000
Mount, D.R., at al. 1997
test substance
Pimephales promelas
Fathead minnow
K2CO3
LC50
940000
ugjL
24 hr
940000
Mount, D.R., at al. 1997
test substance, test duration
Pimephales promelas
Fathead minnow
K2CO3
LC50
820000
u /L
48 hr
820000
Mount, D.R. at al. 1997
test substance, test duration
Pimephales promelas
Fathead minnow
K2CO3
LC50
510000
u /L
96 hr
<510000
Mount, D.R., at al. 1997
test substance
Ceriodaphnia dubia
Water flea
KCI
LC50
630000
ug/L
24 hr
630000
Mount, D.A., at aI. 1997
test duraton not standard
Cenodaphnia dubia
Water flea
KCI
LC50
630000
ug/L
48 hr
630000
330120
Mount, D.R., et al. 1997
Daphnia magma
Water flea
KCI
LC50
740000
u /L
24 hr
740000
Mount, D.R., at al. 1997
test duraton not standard
Daphnia magna
Water flea
KCI
LC50
660000
ug/L
48 hr
660000
345840
Mount, D.R., et al. 1997
Pimephales promelas
Fathead minnow
KCI
LC50
950000
ug/L
24 hr
950000
Mount, D.R. at al. 1997
test duraton not Stan at
Pimephales promelas
Fathead minnow
KCI
LC50
910000
ug/L
48 hr
910000
Mount, D.R. at al. 1997
test duraton not standard
Pmephales promelas
Fathead minnow
KCI
LC50
880000
ug/L
96 hr
880000
461120
Mount, D.R., et al. 1997
Cerioda hnia dubia
Water flea
KSO4
LC50
770000
u /L
24 hr
770000
Mount, D.R., at al. 1997
test duraton not standard
Cenodaphnia dubia
Water flea
K5O4
LC50
680000
u /L
48 hr
-680000
305320
Mount, D.R., et al. 1997
Daphnis magna
Water flea
KSO4
LC50
850000
u /L
24 hr
850000
Mount, D.R. at al. 1997
test duraton not standard
Daphnia magna
Water flea
KSO4
LC50
72000D
u /L
48 hr
720000
323280
Mount, D.R., et al. 1997
Pimephales promelas
Fathead minnow
KSO4
LCSO
990000
ug/L
24 hr
990000
Mount, D.R. et al. 1997
test duraton not stantlard
Pimephales promelas
Fathead minnow
KSO4
LC50
860000
u /L
48 hr
8600DO
Mount, D.R., et al. 1997
test duraton not standard
Pimephales pramelas
Fathead minnow
K5O4
LC50
680000
ug/L
96 hr
680000
305320
Mount, D.R., et al. 1997
Pectinatella gelatmosa
Bryozoan
K(011)
NR
10
M
NR
?
Mukai, H. 1977
could not obtain original reference, could not determine endpoint, test duration
Nitzschia Iloseris
Diatom
KCI
LC50'
1337000
u L
120 hr
1337000
Patrick R., at al. 1968
single cell organism
Lepomis macrochirus
Bluegill
LC50'
2010000
u /L
96 hr
201 c
1O532 00
Patrick, R., et al. 1968
also presented in Trams at al 1954
Physella acuta
European physa
LC50'
940000
u /L
96 hr
94(
493000
Patrick, R., et al. 1968
Pimephales promelas
Fathead minnow
KCI
LOEC
1000000
ug/L
7 day
1000000
Pickering, Q.H.,et al. 1996
tested 1, 4, and 7 day old larvae. Test duration, endpoint not standard
Pimephales pramelas
Fathead minnow
KCI
NOEL
500000
ug/L
7 day
500000
Pickering, Q.H.,et al. 1996
tested 1, 4, and 7 day old larvae. Test duration, endpoint not standard
Pime hales promelas
Fathead minnow
KCI
LOEC
500000
u /L
7 day
500000
Pickering, Q.H.,et al. 1996
tested 1, 4, and 7 day old larvae. Test duration, endpoint not standard
Pimephales promelas
Fathead minnow
KCI
LOEC
500000
ug/L
7 day
500000
Pickering, Q.H.,et al. 1996
tested 1, 4, and 7 day old larvae. Test duration, endpoint not standard
PimePhales promelas
Fathead minnow
KCI
NOEC
250000
ug/L
7 day
250000
Pickering, Q.H.,et al. 1996
tested 1, 4, and 7 day old larvae. Test duration, endpoint not standard
Pimephales promelas
Fathead minnow
KCI
MATC
353000
ug/L
7 clay
353000
Pickering, Q.H.,et al. 1996
tested 1, 4, and 7 day old larvae. Test duration, endpoint not standard
Pimephales promelas
Fathead minnow
KCI
MATC
707000
u /L
7 day
707000
Pickering, Q.H.,et al. 1996
tested 1, 4, and 7 day old larvae. Test duration, endpoint not Standard
Chlorella vulgaris
Green algae
KNO3
IC50
1050000
ug/L
5 days
?
Przytocka-lusiak, M. 1976
test substance, test duration
Algae
Algae
KNO3
NR
NR
ug/L
NR
7
Purcell III, T.W. 1999
could not obtain original reference; test substance, test duration, no result reported in
Amphora ovalis
Diatom
KNO3
NR
NR
ug/L
NR
7
Purcell III, T.W. 1989
could not obtain original reference; test substance, test duration, no result reported In
FCOTOX
Chaetoceros mimmus
Diatom
KNO3
NR
NR
ug/L
NR
7
Purcell III, T.W. 1989
could not obtain original reference; test substance, test duration, no result reported in
FCOTOX
Chaetoceros sp.
Diatom
KNO3
NR
NR
ug/L
MR
?
Purcell III, T.W. 1989
could not obtain original reference; test substance, test duration, no result reported in
FCOTOX
Cryptomonas sp.
Cryptomonad
KNO3
NR
NR
ug/L
NR
?
Purcell III, T.W. 1989
could not obtain original reference; test substance, test duration, no result reported in
Page 11 of 13

2. Freshwater
Species Scientific Name
Potassium Aquatic
Common Name
Toxicitv
Chemical
Name
DatabaseAppendix
land
Endpoint
Notes
Fragilaria sp.
Diatom
KNO3
NR
, test duration, no result reported in
Fragilaria virescens
Golden algae
KNO3
NR
, test duration, no result reported in
Grammatophora sp.
Diatom
KNO3
NR
, test duration, no result reported In
Melosira vanans
Diatom
KNO3
NR
, test duration, no result reported in
Microspora sp.
Green algae
KNO3
NR
, test duration, no result reported in
Navicula angulata
Diatom
KNO3
NR
, test duration, no result reported in
Navicula sp.
Diatom
KNO3
NR
, test duration, no result reported in
Scenedesmus dimorphus
Green algae
KNO3
NR
, test duration, no result reported in
Synedra tenera
Diatom
KNO3
NR
, test duration, no result reported in
Synedra ulna
Diatom
KNO3
NR
, test duration, no result reported in
Polygonum convolvulus - con
Black Bindweed
KNO3
NR
, test duration, no result reported in
Plankton
Plankton
KNO3
NR
, test duration, no result reported in
Amphora coffeaeformis
Diatom
KNO3
NR
, test duration not standard
Amphora coffeaeformis
Diatom
KNO3
NR
, test duration not standard
Poecilia reticulata
Guppy
KNO3
LCSO
Poecilia reticulata
Guppy
KNO3
LC50
Poecilia reticulata
Guppy
KNO3
LC50
Poecilia reticulate
Guppy
KNO3
LCSO
Poecilia reticulata
Guppy
KNO3
LC50
Poecilia reticulate
Guppy
7NO3
LC50
Poecilia reticulata
Guppy
KNO3
LC50
Poecilia reticulata
Guppy
KNO3
LCSO
Poecilia reticulata
Guppy
KNO3
LCSO
Poecilia reticulata
Guppy
KNO3
LCSO
Poecilia reticulata
Guppy
KNO3
LCSO
Poecilia reticulata
Guppy
KNO3
LC50
Poecilia reticulata
Guppy
KNO3
LC50
Poecilia reticulata
Guppy
KNO3
LC50
Astacus astacus
European crayfish
KCI
NR
dipoint (LC50) and test duration
Astacus astacus
European crayfish
KCI
NR
Jpoint (LC50) and test duration
Astacus leptodactylus
Crayfish
KCI
NR
Jpoint (LCSO) and test duration
Astacus Ieptodactylus
Crayfish
KCI
NR
Jpoint (LCSO) and test duration
Hyalella azteca
Scud
KCI
LC50
Iffects of food on end result, LC50 is
not adequate for 2 of tests. Possible
Hyalella azteca
Scud
KCI
LC50
ffects of food on end result
Hyalella azteca
Scud
KCI
LC50
iffects of food on end result
Cyprinus carpio
common carp
KCI
NR
Morone chrysops
White bass
KCI
NR
Notemigonus crysoleucas
Golden shiner
KCI
NR
Notro is atherinoides
Emerald shiner
KCI
NR
Pimephales promelas
Fathead minnow
KCI
NR
Musculium transversum
Long fingernail clam
Potassium
LC50
d but data also presented in
Musculium transversum
Long fingernail clam
Potassium
LCSO
d but data also presented in
Musculium transversum
Long fingernail clam
Potassium
LC50
J but data also presented in
Musculium transversum
Long fingernail clam
Potassium
LC50
ut data also presented in Anderson
Musculium transversum
Long fingernail clam
Potassium
LC50
J but data also presented in
Musculium transversum
Long fingernail clam
Potassium
LCSO
ut data also presented in Anderson
Musculium transversum
Long fingernail clam
Potassium
LC50
presented in Anderson et al 1978

2. Freshwater
Species Scientific Name
Potassium Aquatic
Common Name
Toxicity
Chemical
Name
DatabaseAppendix
Endpoint
Value as
Salt
Conic
Conic
Units
Test
Duration
Verified Value
from paper as
salt
Value as K
Conic
Citation
Rejection justification and Notes
Musculium transversum
Long fingernail clam
Potassium
LC50
530000
ug/L
96 hr
530000
530000
Sparks, R.E., and K.B. Anderson 1977
juvenile tested,results only provided but data also presented in Anderson et al 1978
Musculium transversum
Long fingernail clam
Potassium
LC50
168000
ug/L
5 days
168000
168000
Sparks, R.E., and K.B. Anderson 1977
adults tested, test duration,results only provided but data also presented in Anderson
Pt al 7
Musculium transversum
Long fingernail clam
Potassium
LC50
435000
ug/L
5 days
435000
435000
Sparks, R.E., and K.B. Anderson 1977
juvenile tested, test duration, results only provided but data also presented in
Anderson et al 1 7
Musculium transversum
Long fingernail clam
Potassium
LC50
300000
ug/L
7 days
300000
300000
Sparks, R.E., and K.B. Anderson 1977
juvenile tested, test duration, results only provided but data also presented in
Anderson
Caenorhabditis elegans
Nematode
KNO3
LC50
479
mM
24 hr
-
479
Tatara, C.P., at al. 1998
test duration, test substance
Lepomis macrochirus
Bluegill
KCI
LC50
1060000*
u /L
96 hr
2010000
1054000
Trama F.B. 1954
Lepomis macrochirus
Bluegill
KCI
LC50
951000*
ug/L
96 hr
?
Trama, F.B. 1954
value not verified in original reference
Lepomis macrochirus
Bluegill
KNO3
LC50
1200000*
ug/L
96 hr
?
Trama, F.B. 1954
test substance not acceptable, value not verified in original reference
Lepomis macrochirus
Bluegill
KNO3
LC50
420000*
ug/L
96 hr
7
Trama, F.B. 1954
test substance not acceptable
Lepomis macrochirus
Bluegill
KSO4
LC50
3550000
ug/L
96 hr
3550000
1593950
Trama, F.B. 1954
Cyprinus carpio
common carp
KCI
NR-LETH
5910000*
ug/L
5 hr
12500000
Turoboyski, L. 1960
paper not in English, endpoint, test duration
Cyprinus carpio
common carp
KCI
NR-LETH
6590000*
ug/L
NR
7
Turoboyski, L. 1960
paper not in English, endpoint, test duration, value not verifed in original reference
Gambusia affinis
Western mosquitofish
K(OH)
LC50
85000
ug/L
24 hr
85000
Waller, I.E., et al. 1957
test water (turbid), control performance unknown, age of test organisms unknown
fiirult?l
Gambusia affinis
Western mosquitofish
K(OH)
LC50
80000
I
ug/L
48 hr
80000
Waller, I.E., et al. 1957
test water (turbid), control performance unknown, age of test organisms unknown
(adult7). test duration
Gambusia affinis
Western mosquitofish
K(OH)
LC50
80000
ug/L
96 hr
80000
Waller, I.E., a al. 1957
test water (turbid), control performance unknown, age of test organisms unknown
adult
Gambusia affinis
Western mosquitofish
KNO3
LC50
NR
ug/L
24 hr
421000
Waller, I.E., et al. 1957
test water (turbid), control performance unknown, age of test organisms unknown
fadUlt7). test
Gambusia affinis
Western mosquitofish
KNO3
LC50
NR
ug/L
48 hr
224000
Waller, I.E., et al. 1957
test water (turbid), control performance unknown, age of test organisms unknown
(adult?). test duration
Gambusia affinis
Western mosquitofish
KNO3
LC50
NR
ug/L
96 hr
162000
Waller, I.E., et al. 1957
test water (turbid), control performance unknown, age of test organisms unknown
fadult?)
Gambusia affinis
Western mosquitofish
KCI
LC50
NR
ug/L
24 hr
10000000
Waller, I.E., et al. 1957
test water (turbid), control performance unknown, age of test organisms unknown
(adult'), test duration
Gambusia affinis
Western mosquitofish
KCI
LC50
NR
ug/L
48 hr
420000
Waller, I.E., et al. 1957
test water (turbid), control performance unknown, age of test organisms unknown
test duration
Gambusia affinis
Western mosquitofish
KCI
LC50
NR
ug/L
96 hr
920000
Waller, I.E., et al. 1957
test water (turbid), control performance unknown, age of test organisms unknown
Gambusia affinis
Western mosquitofish
KCI
LC50
4700000*
ug/L
24 hr
7
Waller, I.E., et al. 1957
test in turbid water, test duration, value not verifed in original reference
Gambusia affinis
Western mosquitofish
KCI
LC50
5300000*
ug/L
24 hr
?
Waller, I.E., et al. 1957
test in turbid water, test duration, value not verifed in original reference
Gambusia affinis
Western mosquitofish
KCI
LC50
1990000*
ug/L
48 hr
?
Waller, I.E., et al. 1957
test in turbid water, test duration, value not verifed in original reference
Gambusia affinis
Western mosquitofish
KCI
LC50
2200000*
ug/L
48 hr
?
Waller, I.E., at al. 1957
test in turbid water, test duration, value not verifed in original reference
Gambusia affinis
Western mosquitofish
KCI
LC50
435000*
ug/L
96 hr
Wallen, I.E., et al. 1957
test in turbid water, value not verifed in original reference
Gambusia affinis
Western mosquitofish
KCI
LC50
485000*
ug/L
96 hr
7
Waller, I.E., et al. 1957
test in turbid water, value not verifed in original reference
Gambusia affinis
Western mosquitofish
KCI
NR
265000*
u /L
96 hr
?
Waller, I.E., et al. 1957
test in turbid water, value not venfed in original reference
Gambusia affinis
Western mosquitofish
KCI
NR
295000*
ug/L
96 hr
?
Waller, I.E., et al. 1957
test in turbid water, value not verifed in original reference
Gambusia affinis
Western mosquitofish
KNO3
LC50
162000*
ug/L
24 he
?
Waller, LE., et al. 1957
test in turbid water, test duration, value not verifed in original reference
Gambusia affinis
Western mosquitofish
KNO3
LC50
58500*
ug/L
24 hr
?
Waller, ICE., et al. 1957
test in turbid water, test duration, value not verifed in original reference
Gambusia affinis
Western mosquitofish
KNO3
LC50
31100*
ug/L
48 hr
7
Waller, I.E., et al. 1957
test in turbid water, value not verifed in original reference
Gambusia affinis
Western mosquitofish
KNO3
LC50
865000*
ug/L
48 hr
7
Waller, I.E., et al. 1957
test in turbid water, test duration, value not verifed in original reference
Gambusia affinis
Western mosquitofish
KNO3
LC50
22500*
ug/L
96 hr
?
Waller, I.E., at al. 1957
test in turbid water, value not verifed in original reference
Gambusia affinis
Western mosquitofish
KNO3
LC50
62000*
ug/L
96 hr
7
Waller, I.E., at al. 1957
test In turbid water, value not verifed in original reference
Gambusia affinis
Western mosquitofish
KNO3
NR
14000*
ug/L
96 hr
?
Waller, I.E., et al. 1957
test in turbid water, value not verifed in original reference
Gambusia affinis
Western mosquitofish
KNO3
NR
39000*
ug/L
96 hr
?
Waller, I.E., et al. 1957
test in turbid water, value not verifed in original reference
Ictalurus punctatus
Channel catfish
KCI
LC50
720000
ug/L
48 he
720000
Waller, D.L., et al. 1993
test duration not appropriate for fish
Oncorhynchus mykiss
Rainbow trout
KCI
LC50
1610000
ug/L
48 hr
1610000
Waller, D.L., et aI. 1993
Is was agreed by EPA that trout likely do not occur at the site due to warm water
"conditions,n
Dreissena polymorpha
Zebra mussel
KCI
LC50
147000
ug/L
48 hr
147000
Waller D.L., et al. 1993
adult test organisms used, invasive species
Dreissena polymorpha
Zebra mussel
KCI
LC50
150000
ug/L
48 hr
150000
Waller, D.L., at al. 1993
adult test organisms used, invasive species
Obliquaria refiexa
Three -homed wartyback
KCI
LC50
1000000
ug/L
48 hr
a2000000
Waller, D.L., et al. 1993
adults used for testing, determined 96hr test duration more appropriate for mussels
Dreissena polymorpha
Zebra mussel
KCI
LC50
ug/L
24 hr
-
3460000
Wildridge, P.J., et al. 1998
tested at 12 deg C, adults used, invasive species
Dreissena Dolymorpha
Zebra mussel
KCI
LC50
ug/L
24 hr
-
400000
Wildridge, P.7., et al. 1998
tested at 22 deg C, adults used, invasive species
Dreissena polymorpha
Zebra mussel
Potassium
NOEC / LOEC
NR
mmol/L
24 hr
0.12 / 0.25
Wildridge, PJ., et al. 1998
measured filtration rate when exposed to different K conc. for 24 hrs, test duration,
n in ri for acute
Poecilia reticulate
Guppy
K(OH)
LC50
165000
ug/L
24 hr
165000
lYamhombek, A.A.,et al 1991
test duration not standard
Notes:
1. EPA ECOTOK/AQUIRE data search conducted July 2009
Updated data search conducted May 2012
Database table revised (formatting and addition of notes only, no additional data search performed) January 2014
2. Blue Text indicated acceptable study result and used in calculation
3. Only data generated from KCI or KSO4 were deemed appropriate for use in development of K criteria.
Page 13 of 13

Ramboll - Potassium Aquatic b/e Values
APPENDIX 3
REVIEW OF POTASSIUM - HARDNESS TOXICITY RELATIONSHIP FOR
FRESHWATER MUSSELS

I MEMO
Project no. 1690000122
F.om Rick Lockwood, Liza Heise, and Robin Richards, REM
REVIEW OF POTASSIUM - HARDNESS TOXICITY RELATIONSHIP
FOR FRESHWATER MUSSELS
INTRODUCTION
Freshwater mussels (family Unionidae) have a demonstrated sensitivity to
potassium below that of other regularly tested freshwater taxa. Of the roughly
300 known species, only Lampsilis siliquoidea (the Fatmucket) has a robust
potassium acute toxicity database in a range of water quality conditions that is
representative of where this species is found, the Mississippi River basin. The
database for long-term sublethal (growth or reproduction) effects to mussels is
very limited.
In 2017, Ramboll conducted testing with mussels to address the key data gaps
related to the toxicity of potassium to mussels for very soft water conditions
(similar to those observed for the Cedar Creek and Tar River). A further gap in
the potassium toxicity database is a lack of data for any Atlantic Slope (which
includes the Tar/Pamlico river watershed in North Carolina) mussel species. The
testing results met the following objectives.
1) Generate acute potassium toxicity test data (over a range of potassium
concentrations) for two mussel species.
a) A mussel species indigenous to the Atlantic Slope. Related to availability
and culture suitability. Lampsilis radiata (Eastern Lampmussel) was
selected as a representative Atlantic Slope indigenous test species.
b) For comparative purposes, the second species selected was Lampsilis
siliquoidea (Fatmucket) mussel. The most commonly tested species in
North America.
2) Generate data at a nominal hardness of 25 mg/L and 75 mg/L to:
a) Test at the floor hardness of 25 mg/L presented in North Carolina
regulations for hardness -based metal criteria.
Ramboll
201 Summit view Drive
Suite 300
Brentwood, TN 37027
USA
T [phone]
F [phone]
wwwxamboll.com
1/4

b) Test at 75 mg/L hardness to serve as another comparison point between the two species and
further expand the dataset of potassium toxicity in low to moderate hardness (<100 mg/L)
waters.
c) Re-evaluate the predicted toxicity results based on the established hardness/potassium toxicity
relationship for the Fatmucket mussel in waters with hardness from 100 to 400 mg/L as CaCO3,
and determine if the relationship is appropriate for Atlantic Slope mussels such as the Eastern
Lampmussel.
The results of the acute testing with the Eastern Lampmussel and Fatmucket in reduced hardness
waters indicated that mussel species of the Atlantic Slope assemblage are more tolerant of potassium
than common species in the Mississippi River drainage at equivalent hardness concentrations. Applying
this finding to derivation of chronic (sublethal) potassium limits is the focus of this memo.
ACUTE TOXICITY RESULTS FOR 25 MG/L AND 75 MG/L HARDNESS WATERS
The main observations and conclusions from the toxicity testing conducted in August 2017 are as
follows:
The Eastern Lampmussel is less sensitive (as indicated by LC50) to potassium than the Fatmucket
mussel at both the 25 mg/L and 75 mg/L hardness (as CaCO3) levels.
0 25 mg/L Hardness Results
- Eastern Lampmussel measured LC50: 37.2 mg/L K
- Fatmucket measured LC50: 22.4 mg/L K
0 75 mg/L Hardness Results
- Eastern Lampmussel measured LC50: 60.8 mg/L K
- Fatmucket measured LC50: 28.1 mg/L K
For the Eastern Lampmussel, actual LC50 values were higher than predicted values'.
For the Fatmucket mussel, actual LC50 values were equal or lower than predicted values.
For both species, the 95 percent Confidence Intervals around the measured LC50 values are small,
for example the single test percent span confidence interval compared to the LC50 values range
from 14 to 32 (calculation not shown). These results indicate good quality data and a high level of
certainty associated with the measured LC50 values.
The predicted LC50 values based on the Fatmucket derived models for a hardness 25 mg/L as CaCO3
are 31mg/L K for the Ramboll model and 30 mg/L K for the Wang model. The Eastern Lamp mussel
demonstrated 20 - 23 percent less sensitivity to K compared to model predictions at hardness 25. The
predicted LC50 values based on the Fatmucket derived models for a hardness 75 mg/L as CaCO3 are 40
mg/L K for the Ramboll model and 38 mg/L K for the Wang model. The Eastern Lamp mussel
demonstrated 52 - 60 percent less sensitivity to K compared to model predictions at hardness 75.
MUSSEL CHRONIC TOXICITY DATA -
A recent publication (accepted for publication Wang et al, 7/30/2018) details two chronic toxicity tests
conducted with mussels exposed to potassium chloride. It should be noted that both tests were
A hardness/potassium toxicity relationship was developed for the Fatmucket mussel in waters with hardness from 100 to 400 mg/L
as CaCO3. This relationship is defined as: LC50 (mg/L of potassium) = 0.1609(hardness)+26.872. Wang 2017 developed a similar
function LC50 (mg/L of potassium) = 0.146(hardness)+26.7
2/4

conducted under general guidance of ASTM E2455-06 (2013) which are under development and have
not been subjected to extensive interlaboratory testing and review. Both were conducted by USGS in
2013 (Wang et al, 2018), and used Fatmucket mussels. The results are summarized below:
• A 28-day study (2013) conducted in hardness 100 laboratory water with no refugia substrate (no -
sand or water only) and,
• A 28-day study (2013) conducted in hardness 100 laboratory water with refugia substrate (sand).
The significant difference between the two side by side tests introduces a large degree of uncertainty for
interpretation. The control performance for both tests (with and without sand) differs by less than 1
percent indicating that the sand substrate compounded the potassium toxicity in these exposures. This
would suggest that the water only results are more valid with fewer uncontrolled variables in the study,
and the results from the sand substrate test should not be used solely as the basis for determining the
chronic toxicity of potassium to mussels.
• ACR calculations are based on the corresponding Fatmucket hardness 100 database 96-hour LC50 =
44 mg/L K.
The chronic values (ChV) and EC20 values for the water only 28-day test at hardness 100 without sand
are:
• Biomass ChV = 32 mg/L K (ACR = 1.38)
• Biomass EC20 = 23 mg/L K (ACR = 1.91)
These results can be adjusted to hardness of 25 mg/L using same equation as for in footnote 1 above:
ACR calculations are based on the corresponding Fatmucket hardness 25 adjustment of the database
96-hour LC50 = 31.7 mg/L K
The adjusted chronic values (ChV) or EC20 values for the water only 28-day test at hardness 25 without
sand are:
• Biomass ChV = 23.1 mg/L K (ACR = 1.37)
• Biomass EC20 = 16.6 mg/L K (ACR = 1.91)
Chronic Criteria Derivations and Use of Indigenous Species and Ambient Site
Conditions
The hardness based acute sensitivity to potassium demonstrated by the indigenous Eastern Lampmussel
is significantly less than for surrogate mussel species in the data base. Therefore, it is appropriate to
assume that chronic tolerance will also be greater, especially since ambient potassium levels in Atlantic
slope streams are comparable to streams supporting mussels in other parts of the US where hardness is
greater. Furthermore, there is precedent for using resident or locally indigenous species for deriving
water quality criteria.
Given the level of uncertainty for the present database of chronic potassium toxicity to mussels, use of
the water only 28-day biomass results is considered the best available data for development of a
chronic potassium criteria for surface waters in Franklin County, NC. However, because of the
3/4

uncertainty of the chronic toxicity database, multiple options for derivation are appropriate and
defensible.
1) NCDEQ regulatory definition (15A NCAC 2B.202(15)) - Direct use of hardness adjusted ChV (23.1
mg/LK) or EC20 value (16.6 mg/L K).
2) Indigenous mussel acute at site hardness and average of 3 representative ACR's (fathead minnow,
C. dubia, and 28-day Fatmucket water only result) - Eastern Lampmussel LC50 of 37.2 mg/L K /
ACR of 1.815 = 20.5 mg/L2 K.
' Using the chronic geometric mean of the Fatmucket NOEC and LOEC in the ACR calculation would yield results greater than the
acute concentration. Therefore, the value of 16.6 mg/L K is recommended as the chronic concentration.
4/4