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the Agency concerning the Registration Review Problem Formulation for Coppers 

(DP386257). Comments were received from the California Stormwater Quality 

Association (CASQA), Department of Water Resources (County of Sacramento, CA), 

Physicians Committee for Responsible Medicine, American Chemistry Council (ACC)

Copper Task Force, CA Regional Water Quality Control Board, SF Bay Region, TriTAC (a technical advisory group for Publicly Owned Treatment Works), American 

Water Works Association (AWWA), and California Department of Pesticide Regulation 

(CalDPR). Comments and the Agency’s responses to comments are organized by 

common theme:

Comments on the Scope of the Risk Assessment

CASQA

Comment: “...EPA’s proposed approach should explicitly account for all important 

urban sources and transport pathways of copper compounds. Urban sources and 

associated water quality impacts are of significant concern to CASQA’s member 

agencies.

On the basis of available scientific information, we request that EPA make specific 

changes to the copper compounds registration review process to better identify and 

mitigate urban water quality impacts. We also request that EPA adopt similar changes as 

part of systematic revisions to EPA’s overall approach to the registration review process 

for all pesticides with urban use patterns.”

County of Sacramento, CA

Comment: “The copper compounds registration review must cover all common outdoor 

uses of copper in urban areas, and the common pathways by which these sources reach 

surface waters. Urban uses that are expected sources of copper in receiving waters and 

therefore should be reviewed include:

(1) Swimming pools, because when drained, pools are often discharged to urban 

gutters or storm drains

(2) Treated wood

(3) Other outdoor urban uses of copper biocides, such as roofing shingle treatments

Swimming pools are among a list of anti-microbial uses excluded from EPA’s proposed 

Analysis Plan “because they are sporadic.” However, available evidence substantiates the 

importance of swimming pool discharges as sources of copper to receiving waters. For 

example, acute water quality criteria can be exceeded in a creek when a pool is drained. 

In California, because many creeks have very low flow much of the year, the possibility 

of acute water quality impacts resulting from sporadic discharges is enhanced.”
3

ACC

Comment: “The Task Force requests that EPA clarify the antimicrobial use scenarios 

that it intends to assess in Registration Review. There are contradictory statements in 

EPA’s documentation regarding the uses to be evaluated and assessed. The scope of the 

assessments needs to be clarified at the outset of the Registration Review process and 

before any final decisions can be made on new data needs and identification of 

appropriate models for refined risk assessments.”

Comment: “The environmental risk assessment should evaluate all outdoor uses of 

copper in urban areas, and especially:

(1) Swimming pool uses, because pool water is nearly always discharged to either 

gutters/storm drains or to municipal wastewater treatment plants, and

(2) Treated wood and other outdoor urban use of biocides, such as roofing shingle 

treatments.”

Tri-TAC 

Comment: “We suggest that the uses that particularly need to be reviewed are the 

following: (1) copper-based root control products - these already appear in your 

workplan, (2) copper products that are used in swimming pool treatments because pools 

are often discharged to POTWs. In many municipalities, this discharge to POTWs during 

the cleaning of pools is a requirement. (3) Fabric treatments should receive special focus, 

because POTW discharges occur during washing.”

OPP Response: All registered uses of copper will be considered in the risk assessment 

during registration review, as well as all routes of exposure detailed in the conceptual 

model described in the problem formulation document.

The registered antimicrobial uses for copper are grouped into various use categories. The 

following are the antimicrobial uses of copper stated on currently registered labels.

o

Hard Non-Porous Surfaces: Kitchen Surfaces, Bathroom Surfaces, Soap Holders, 

Paper Towel Holders, Facial Tissue Holders, Countertops, Tabletops, Door PushPlates, Hand Rails, Stair Rails, Cash Registers, Shopping Cart Handles, Car Seats, 

ATM Machines, Elevators, Jalousie Windows, Signage, Casement, Radiator 

Covers, Office Supplies, Mass transit Facilities, Playground Equipment, Eye 

Glass Frames, Protective Eye Wear, Light Switches, Bracelets, Electrical Wall 

Plates, Headwall Systems, Knobs and Dials, IV Poles and Headrests

Residential and public access premises

o

Healthcare Facilities: Bedrails, Footboards, Toothbrush Holders, Over-bed 

Tables, Bedside Tables, Extended Care Facilities, Senior Housing, Knobs, 

Handles, Handrails, Stair Rails, Tubular Railing, Assistance Rails, Toilet Safety 

Rails, Carts, X-ray Illuminators, Operating Rooms, Corridor Hallways, 

Medical Equipment and Premises
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Automatic Door Push Plates, Computer Carts, Record Phlebotomy Carts, Sinks 

Drains, Paper Towel Holders, Shower Heads, Telephone Handsets Kitchen 

Surfaces, Floor Tiles, Ceiling Tiles and Brackets

o

Hydrotherapy Tanks

Swimming Pools

o

Ice and Water Dispensers (Outer Surface without Water Contact) and

Human Water Systems

Water Fountains 

o

Boat Hulls (Fiberglass), Boat Hulls (Aluminum), Boat/Ship Hulls/Bottoms 

(Painted/Primed) and Boat/Ship Hulls/Bottoms (Primed Metal), Boat Hulls, 

Bottoms / Ships/Yachts (Steel, Fiberglass, Aluminum, Wood, Plywood) 

Underwater Hull Surfaces, Buoys, Barges Boat Docks, Marine Structures and 

Equipment (Wood), Outboard Motors and Underwater Running Gear Ship 

Bottoms, Boat Hulls (Steel), Boat Bottoms (Fiberglass), Boat Bottoms (Wood) 

and Marine Structures (Wood)

Antifouling Coatings 

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Plastic Polymer Latex Cellulosic Products, Paints, Films, Interior Paints, 

Synthetic Fibers and Pigments and Paper/Paperboard (Coatings). Plastics, 

Coatings, Films, Laminates, Adhesives, Sealants, Household Items: Bedding, 

Mattress Cover Pads, Filling, Pillow Covers, Sheets, Blankets, Towels, Cushion 

Pads, Sleeping Bags, Clothing, Undergarments, Shoes, RV Auto Cover Plastics, 

Roof Materials, Roofing Shingles , Automotive and Vehicular Parts, Brush 

Handles, Collection and Concrete Conveyor Belts, Countertops, Floor Covering, 

Vacuum Cleaner Bags, Fire System Sprinkler Pipes and Water Filter Media 

Materials Preservatives

o

Wood Surfaces (Public, Commercial and residential Buildings Conveyances) and 

Wood Preservatives

Wood Surfaces (Fences). Landscape Ties, Fence Boards, Posts, Building Poles, 

Decks, Docks, Walkways, and Wood Boats. Wood Structures, Wood Farm 

Structures, Lumber, Timbers, Wood Fence Posts, Wood Poles/Posts, Wood 

(Construction), Wood Supports, Wood Piles (Terrestrial), Wood Products, Wood 

Shingles, Wood Structural Parts, Plywood, Rough-Sawn, Wood Protection 

Treatment to Wooden Aquatic Structures and Wood Marine Structures, Wood 

Pilings, Wood Protection Treatment to Forest Products by Pressure, Wood 

Pressure Treatment, Cooling Tower Wood and Lumber Yards (Lumber Piles)

o

Farms, Nurseries, Greenhouses, Irrigation Supply Systems, Plants, Tree and Vine 

Crops, Field and Vegetable Crops 

Agricultural Premises and Equipment

o

Lobster Pots and Crab Pots

Aquatic Areas 
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Comments on the Intersection of FIFRA and the Clean Water Act (CWA)

CASQA

CalDPR

Comment: “...municipal stormwater agencies in California have had to contend with the 

water quality impacts of registered pesticides in surface waters, and the regulatory 

consequences of those impacts. When urban receiving water impacts are discovered, the 

local stormwater agencies are typically required to conduct additional studies and 

ultimately develop programs to reduce the contribution of urban runoff discharges to the 

in-stream impairments. Because local agencies do not have authority to regulate pesticide 

uses or application patterns, they rely on federal and state regulators to control pesticide 

uses to maintain exposures at levels that prevent surface water toxicity.

The Summary Document (EPA–HQ–OPP–2010–0212-0011) notes that there are 

numerous CWA Section 303(d) listings for which the impairment is caused by copper. 

Pursuant to the requirements of the federal Clean Water Act, the Regional Water Quality 

Control Boards in Los Angeles and San Diego have already imposed deadlines and 

copper Total Maximum Daily Load (TMDL) limits on discharges of stormwater to 

California waters. Similar TMDLs are expected to be imposed on other urban watersheds 

across the state in the near future.”

Comment: “The EPA has developed water quality criteria for copper to be protective of 

aquatic life in both freshwater and saltwater surface waters. These aquatic life criteria 

should be used as risk assessment measures of effect. We anticipate that one outcome of 

the OPP/Office of Water Common Effects Assessment Methodology Project will be that 

OPP should employ water quality criteria as measures of effect in its risk assessments.”

Comment: “...USEPA needs to continue its efforts to improve integration of surface 

water quality protection into its pesticide registration and regulatory review programs. 

Coordination between USEPA’s Office of Water and Office of Pesticide Programs in 

reviewing pesticide ingredients is essential to Clean Water Act implementation; 

furthermore it provides an appropriate method of meeting FIFRA’s goal of preventing 

unreasonable adverse impacts from pesticide use.

The risk benefit standards of FIFRA require USEPA to ensure that pesticides are used in 

such a manner that mitigation under the Clean Water Act is minimal or unnecessary. 

Without a complete review of potential pesticide surface water quality impacts—

including impacts from urban uses—USEPA cannot fulfill this obligation. Properly 

implemented, USEPA’s pesticide registration process can help ensure that Clean Water 

Act water quality standards are maintained and aquatic habitats are protected. According 

to USEPA pronouncements, “When EPA approves a particular pesticide for registration, 

the Agency has assessed the chemical and found that, when used according to label 

directions, it does not pose unreasonable risk to public health and the environment.” Full 

cooperation between the Office of Water and the Office of Pesticide Programs will help 

USEPA meet this goal.”
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American Water Works Association (AWWA)

Comment: “The proposed re-registration process is the third federal regulatory 

oversight process targeting copper-based aquatic pesticides in the past four years. Each of 

these federal actions also leads to a following round of individual state actions.

These overlapping regulatory efforts are at odds with Administrator Jackson’s emphasis 

on breaking down institutional silos within the agency and utilizing available 

environmental statutes in a coordinated fashion. Drinking water systems rely on aquatic 

pesticides, particularly copper-based herbicides to assure safe and aesthetically 

acceptable drinking water. Aquatic plants, particularly algae, can impair compliance with 

drinking water standards for turbidity, affect disinfection byproduct formation, introduce 

toxins, and cause adverse taste and odors. In order to both meet drinking water treatment 

objectives and comply with all applicable federal and state requirements, water systems 

need a stable regulatory framework. In early 2011 EPA will finalize a new permit 

requirement for aquatic pesticide application under the Clean Water Act (CWA). This 

new National Pollutant Discharge Elimination Permit (NPDES) requirement is in 

addition to complying with Federal Insecticide Fungicide and Rodenticide Act (FIFRA) 

label requirements based on the FIFRA Reregistration Eligibility Decision (RED) 

(revised most recently in 2009). The current comment period opens yet another round of 

federal review of the current FIFRA requirements (e.g., applicable use rates).

AWWA encourages EPA to coordinate and share data between the NPDES and OPP 

activities in order to:

1. Maximize the value of data collection efforts,

2. Ensure compatible regulatory strategies, and

3. Minimize redundant regulatory activities.”

CalDPR

Comment: “The current risk-quotient based determination of harm or endpoints only 

serves to address Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) based 

mandates, which imply that some level of biological impacts is acceptable. While this 

may be scientifically and legally defensible under FIFRA, these types of endpoints do not 

take into consideration the protective mandates that are established under the Clean 

Water Act (CWA). We encourage that protective endpoints such as the CTR (California 

Toxics Rule) and the Biotic Ligand Model (BLM)-based fresh water quality criteria for 

copper somehow be considered by U.S. EPA as part of the risk management decision 

making under Registration Review. It is not clear whether this approach is being 

considered as part of the Office of Pesticide Programs and Office of Water harmonization 

efforts that the U.S. EPA has been undertaking.”

OPP Response: While the Registration Review assessment is being conducted under the 

regulatory authority provided by Federal Insecticide, Fungicide and Rodenticide Act 

(FIFRA), which only considers the pesticidal uses of coppers, the Office of Pesticide 
7

Programs (OPP) has initiated a planning dialogue with the Office of Water (OW), with 

the goal of coordinating regulatory efforts as much as possible to share and coordinate 

methods, models, and approaches regarding routes of pesticide exposure and effects on 

aquatic organisms. OPP welcomes further input on how to utilize information received 

from OW in future risk assessments.

The Agency acknowledges the cost of keeping in compliance with the Clean Water Act, 

and will make every effort to ensure that it adequately identifies and mitigates 

unreasonable adverse effects from pesticidal uses of copper during registration review. It 

is important to remember, however, that the ecological risk assessment for registration 

review will be nationwide in scope. The consideration of generic exposure scenarios for 

widespread applicability adds to the difficulty of estimating the relative contribution of 

the many sources of copper in individual watersheds.

The Agency determined during reregistration that use of copper could result in some risk 

to aquatic organisms in many waterbodies, and acknowledges there are many waterbodies 

listed as impaired because of copper. Many TMDLs for copper and other heavy metals, 

though, have been put in place to deal with inputs from mining operations. A small 

fraction have been caused predominantly from use of copper as a pesticide, as from the 

use as an antifoulant paint in the San Diego TMDL.

Comments on Modeling of Copper in the Environment

Comment: “The conceptual model for effects on aquatic organisms should be modified 

explicitly to account for exterior uses of biocides that are subject to rainfall runoff, where 

the runoff, after contacting the treated items, will traverse across either a) landscaped 

surfaces or b) urban impervious surfaces on the way to the storm drain and ultimately 

receiving waters.

Runoff from exterior biocide treatments may first flow either across landscaped areas, or 

directly across impervious surfaces to storm drains (e.g., from roofing shingle biocides 

and some treated wood that is placed adjacent to impervious surfaces, rather than in areas 

surrounded by landscaping). The extensive scientific literature regarding pollutant 

transport in urban runoff documents the importance of impervious surfaces to total runoff 

volume and total pollutant quantity washed into surface waters from urban watersheds. 

Runoff flow volumes relate directly to watershed impervious surface area. More 

importantly, impervious surfaces and paved/piped urban storm drainage systems facilitate 

expedient wash-off and transport of pollutants.

The conceptual model currently shows “Runoff” as a source of exposure to Surface 

Water/Sediment after exposure to “Soil”, this refers to the agricultural runoff model. To 

properly represent urban sources, two “Source” components must be added: one to 

represent “Runoff from Landscaped Areas” and one to represent “Runoff from 

Impervious Surfaces.” Both of these Sources must then have a direct connection to 

Surface Water/Sediment. The model should include a pathway through which runoff 

from copper-treated surfaces runs only through impervious gutters and storm drain 
8

systems such that it does not pass over any pervious surface prior to reaching surface 

waters.”

CA Regional Water Quality Control Board, SF Bay Region 

Comment: “Urban runoff modeling should evaluate common high-washoff scenarios, 

such as installation where runoff flows onto impervious surfaces and installation directly 

adjacent to surface waters. Agricultural modeling scenarios do not adequately represent 

urban runoff because they do not account for the importance of impervious surfaces in 

the transport of pollutants. Runoff modeling should employ computational methods that 

include realistic copper wash-off fractions.”

Comment: “It is essential to use urban runoff modeling techniques for assessment of the 

potential water quality and ecological assessments of urban pesticide sources. Typical 

agricultural soil runoff models, such as those specified in the Problem Formulation 

document, do not appropriately account for the nature of runoff from landscaped and 

impervious urban surfaces, and transport through urban storm drainage conveyance 

systems.

Computational methods that account for an appropriate washoff fraction from urban 

impervious surfaces are more appropriate than an agricultural model—and provide more 

useful estimates for risk management. CASQA does not support the use of 

PRSM/EXAMS for this purpose, because their overly conservative assumptions (such as 

100% wash-off from impervious surfaces) produce unrealistic results. EPA’s BASINS 

platform, for example, includes modeling elements designed to accommodate runoff from 

urban land uses, and has been applied to copper. A simple computational method that 

includes realistic copper wash-off fractions would be preferable to use of an agricultural 

model.”

County of Sacramento, CA

Comment: “Computational methods that account for an appropriate washoff fraction 

from urban impervious surfaces are more appropriate than an agricultural model—and 

provide more useful estimates for risk management. The County does not support the use 

of PRSM/EXAMS for this purpose, because their overly conservative assumptions (such 

as 100% wash-off from impervious surfaces) produce unrealistic results. EPA’s BASINS 

platform, for example, includes modeling elements designed to accommodate runoff from 

urban land uses, and has been applied to copper. A simple computational method that 

includes realistic copper wash-off fractions would be preferable to use of an agricultural 

model.”

Comment: “In 2008, CASQA and representatives of California’s wastewater treatment 

agencies (Tri-TAC) held a teleconference meeting with EPA’s OPP Antimicrobial 

Division staff to share information about swimming pool discharges. ... At that time, EPA 

indicated its intent to develop computational methods based on this information to use in 

modeling swimming pool discharges in future environmental risk assessments. This 
9

apparently has not been accomplished, and the Analysis Plan does not include this 

important element...”

OPP Response: It is difficult to translate from the resolution of a nationwide risk 

assessment to assess the relative input of pesticidal use of copper on a local scale. There 

are models available which can be calibrated to simulate sites and pesticides for which 

extensive flow and pollutant data have been collected in advance. Some commenters 

have suggested that the Agency use the HSPF/NPSM model, which is included in the 

EPA’s BASINS shell. This has been used to calibrate stream flow and copper pesticide 

use data to simulate loading of these pesticides consistent with concentrations measured 

in surface water monitoring. The Agency would not be able to perform such an 

assessment for all urban watersheds in the nation, and it is very unlikely that sufficient 

monitoring and flow data are available to do so, in any case.

Development of a screening model which could simulate the fate and transport of 

pesticides applied in an urban setting would require a large body of data which is 

currently unavailable. For instance, an urban landscape cannot be simulated as easily as 

an agricultural field. The PRZM model simulates runoff from an agricultural field using 

readily available data describing surface soil characteristics and laboratory data detailing 

the persistence and mobility of pesticides in these soils. The agricultural field simulated 

is homogenously planted to a single crop, and soil and water are transported from the 

field to a receiving water body with dimensions consistent with USDA farm-pond 

construction guidelines.

By contrast, an urban landscape or suburban housing development consists of impervious 

surfaces such as streets and sidewalks, and pervious surfaces such as lawns and parkland. 

One could expect much greater mobility for pesticides applied to impervious surfaces, 

but laboratory soil metabolism studies may not provide an accurate measure of the 

persistence of pesticides on these surfaces. The path runoff water and eroded sediment 

might take is less obvious for an urban setting than an agricultural field. First, an urban 

landscape cannot be considered homogeneous, as the proportion of impervious and 

pervious surfaces varies for different locations. In addition, the flow path of runoff water 

and sediment is not necessarily a direct path over land, but can pass below ground 

through storm sewer networks, be directed, or slowed by pumping stations or temporary 

holding ponds.

Currently, the Agency uses PRZM to simulate both pervious and impervious surfaces in 

an attempt to account for these different urban conditions. Because PRZM is an edge-offield model, it does not take path length into account, including potential removal of 

copper as it passes over land or through underground conveyances along with other 

sediment and organic matter. Some commenters indicated that this method is too 

conservative if it does not account for gradual washoff from treated surfaces, while others 

suggested it was not sufficiently conservative if it didn’t reflect scenarios in which 

copper-laden runoff traveled only over impervious surfaces. The Agency will attempt to 

improve its methods over the next several years leading up to the ecological risk 

assessment for registration review.
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The Agency has not previously assessed the potential for environmental exposures from 

the discharge of previously treated swimming pool water. In most cases, pesticides used 

in pools for the purpose of disinfection are dissipated in the process of providing the 

pesticidal effect (e.g., chlorine-based treatments). However, for more persistent 

chemicals, such as copper compounds, the Agency intends to enter into a dialogue with 

effected stakeholders to determine if an assessment would be needed. Also we will 

consider the possibility of the use of surrogate data. If the Agency determines that such 

an assessment is needed, it will be included in the registration review assessments.

Finally, beyond the constraints of modeling transport in an urban environment, the timing 

and magnitude of urban uses is less well defined for urban uses than agricultural uses. 

While agricultural uses would occur within a predictable window during the growing 

season, the need for urban uses could occur at different times each year, and might occur 

at different times within the same watershed. In addition, since records of how and to 

what extent copper pesticides are applied by homeowners are not well defined, it is 

harder to estimate the total load to model.

Biotic Ligand Model

CA Regional Water Quality Control Board, SF Bay Region

Comment: “The Preliminary Problem Formulation for Ecological Risk, Environmental 

Fate, and Endangered Species Assessments for copper incorporates biotic ligand model 

(BLM) based measures of effect into the exposure modeling (Page 29); this is 

inappropriate. Exposure estimates should be separated from effects assessments.

... BLM-based values are not applicable in salt water. EPA water quality criteria for 

saltwater are lower (more challenging to meet) than freshwater criteria.

The EPA established water quality standards for the state of California in a Federal 

rulemaking called the “California Toxics Rule.” This rule includes freshwater objectives 

for copper that are not based on the BLM, but rather on the previous hardness-based EPA 

copper water quality criteria. As these objectives were established by EPA, we request 

that these objectives also be used as a measure of effect in the risk assessment.”

Comment: “The environmental effects assessment should use methodologies consistent 

with those used by the Office of Water (which should be the outcome of the OPP/OW 

"Common Effects Assessment Methodology" Project). For copper, the USEPA water 

quality objectives should be used as risk assessment endpoints. U.S. EPA set California's 

copper objectives via regulation (the "California Toxics Rule"). The California fresh 

water copper objectives are not based on the biotic ligand model.”
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ACC

Comment: EPA states that the BLM will be limited to freshwater species only, but then 

lists toxicity end points for marine/estuarine organisms on p. 19 of the PF using BLM.

Comment: Recommends that OPP follow up with OW on the status of the 

estuarine/marine BLM, formal adoption is expected in 2012.

Tri-TAC

Comment: “The EPA water quality objectives should be risk assessment endpoints. 

Note that the California Toxics Rule includes an EPA-based copper water quality 

standard that is not based on the biotic ligand model.”

CalDPR

Comment: “DPR has evaluated the scientific basis of the BLM and we support its use 

for both fresh and salt water exposure and effects assessments. Since our work on copper 

AFP pollution has shown that the greatest risk to aquatic life from exposure to copper is 

in the salt water or marine marina environment, we encourage U.S. EPA to finalize the 

salt water BLM.”

OPP Response: The Office of Pesticide Programs intends to use the BLM for its 

nationwide risk assessment for copper pesticides to estimate the fraction of the modeled 

exposure of total copper species that is dissolved copper ion (Cu2+). Research has shown 

that Cu2+is the form of copper that results in the most ecological harm. Because the 

fraction of the total copper species that will be in the Cu2+ form varies with site-specific 

variations in water quality parameters and pesticidal copper discharges are likely to occur 

over much of the U.S., OPP is using a large U.S. Geological Survey (USGS) data set 

containing measured water quality parameters from across the U.S. to determine if the 

modeled exposure of total copper would result in ecological harm if it were discharged at 

any of the USGS monitored sites.

Office of Water (OW) has used the BLM to derive Aquatic Life Criteria which can 

account for the speciation and toxicity of copper as a function of local water quality 

conditions (including hardness). The Agency understands and accepts that some States 

have elected to continue using the previous hardness-based method to derive their water 

standards for copper. OW is developing a tool which will help States and localities more 

easily follow the BLM method to develop water quality criteria, perhaps more States will 

use this method once OW makes this tool available. The Office of Pesticide Programs 

will work with OW to coordinate regulatory tools and efforts.

The saltwater version of the BLM model is still under development. If the saltwater BLM 

is not completed in time for this assessment, OPP will use the best method available to 

assess saltwater exposures to copper.
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Down the Drain Assessment

ACC

Comment: The task Force does not understand these [down the drain] requirements as 

they are limited to “Copper oxide” and “antimicrobial uses”. It is unclear how EPA has 

concluded that copper oxide antimicrobial uses are those that are likely to result in 

discharges to WWTPS, while no such assumption is made about urban or agricultural 

uses. It is the Task Force’s position that antimicrobial uses of copper are not a significant 

source of copper in discharges to WWTPs and, therefore, should not be assessed for 

impact on WWTPs.

Moreover, it appears that the primary use of copper being addressed in the Registration 

Review that involves discharges clearly impacting WWTPs is root killing in sewage 

systems. This is not an antimicrobial use and it is not a use registered for copper oxide. 

Therefore, it is puzzling that EPA has premised its requirement for testing on 

antimicrobial uses of copper oxide. ...The Task Force therefore requests that EPA revise 

its PWP work plan to (1) identify the antimicrobial uses of copper that will be addressed 

in Registration Review and (2) correct its documentation of the use scenarios that drive 

the requirement for data covered by Guidelines 850.6800 and 835.1110.”

TRI-TAC

Comment: “In our view, “Down the Drain modeling” needs improvement. The 

conservative data that reflects actual POTW copper removal efficiencies should be used 

in this modeling and is available for your use from the EPA Office of Water.”

Comment: “The concerns of treatment works include not only the effluent, but also 

biological treatment processes, biosolids management, and incinerator ash management. 

In all of these cases, copper can and does act as a biocide or chemical contaminant, 

endangering the affected process and/or the affected resource (biosolids and ash). We ask 

that you consider all of these points of evaluation.”

OPP Response: The Agency will include the root-killer uses of copper in its assessment 

of potential “down-the-drain” exposures. The data requirements for down-the-drain uses 

will apply to these uses as well as to appropriate antimicrobial copper uses. The Agency 

will correct its documentation in the FWP and Problem Formulation to reflect this.

The Agency commits to using the best available data in developing input parameters for 

the down-the-drain model. As with the other models described in the Problem 

Formulation, however, the nationwide scale of the risk assessment will preclude 

consideration of the many flow regimes and removal methods that may apply at a local 

level. In addition to questions of scale, the lack of detailed usage data for indoor 

antimicrobial and root killer uses will limit the extent to which down-the-drain exposure 

assessments can be refined. The Agency will characterize the uncertainties in its risk 
13

assessment which result, as well as the range of potential vulnerabilities which could 

impact copper exposure from these uses.

The Agency appreciates the submission of this conceptual model for exposure pathways 

of biosolid-associated pollutants. Discharge of copper into the environment via effluent 

will be considered to the best degree possible in the assessment. In addition, the Agency 

is actively evaluating the extent to which ecological risk from copper via application of 

biosolids to land should be addressed in its forthcoming ecological risk assessment and, 

by extension, any additional data that may be required. As part of this evaluation, OPP is 

working closely with OW, which regulates land application of biosolids under the Clean 

Water Act.

DTD data requirements are required for all material preservative uses. The Agency 

anticipates requiring DTD data requirements for copper compounds with material 

preservative or root killer use patterns. 

Marine Antifoulant Model to Predict Environmental Concentrations (MAMPEC)

ACC

Comment: “Another issue that needs to be addressed involves the model that will be 

used to assess antifoulant uses of copper-containing compounds. EPA has stated that it 

will use MAMPEC Version 2 (Marine Antifoulant Model to Predict Environmental 

Concentrations) to evaluate antifoulants and that the “highest available leaching rate for 

Cu will be used for modeling.” First, the Task Force would like to point out that 

MAMPEC Version 3 will be available by the end of this year and believes it should be 

used in EPA’s assessment. MAMPEC 3 will address speciation of cooper and also will 

include a sediment PEC module...EPA intends to use “the highest available” rate, so it is 

of critical importance that the highest available rate is not one that so dramatically 

overestimates leaching as to render EPA risk assessments scientifically unsound.”

CalDPR

Comment: “U.S. EPA chose the commercial harbor scenario for MAM-PEC modeling 

of copper oxide antifoulant use. This is not the worst-case modeling scenario that should 

have been used. DPR have been requesting that antifoulant registrants produce MAMPEC simulations for the poorly-flushed salt water marina scenario under California 

environmental and use conditions when we evaluate new antifoulant active ingredients 

for California registration. This practice is a result of our observations that high dissolved 

copper concentrations tend to occur in large and poorly-flushed pleasure craft marinas 

along the California Coast. Note that the default emission settings for the poorly-flushed 

marinas scenario still require adjustments to better reflect California conditions. For 

example, some of our larger coastal marinas harbor thousands of pleasure crafts. The 

default marina scenario assumes that there are only 299 boats.
14

Furthermore, please note that even with the less conservative scenario that U.S. EPA 

used, the predicted Estimated Environmental Concentrations (EEC) were 1.57 μg/L for 

the average dissolved copper concentration and 4.76 μg/L for the maximum dissolved 

copper concentration. The maximum EEC value exceeds the chronic salt water ambient 

water quality standard for copper (California Toxics Rule standards promulgated by U.S. 

EPA for California) that is set at 3.1 μg/L. The acute standard of 4.8 μg/L is also very 

close to the maximum EEC. The ERA failed to point out the proximity of the EECs to 

these standards. If the poorly-flushed marina scenario under California conditions would 

have been modeled, the resulting EECs would have easily surpassed the acute standards. 

CTR standards are being vigorously imposed in California by the State’s water quality 

regulatory agencies–the State Water Resources Control Board (SWRCB) and its nine 

Regional Water Quality Control Boards (RWQCBs).

Also, please note that the ERA’s conservative assumption that all the ships are painted 

with copper oxide AFPs is not that conservative. DPR estimates that only about five 

pecent of all recreational and commercial vessels in the State’s coastal marinas use 

noncopper AFPs. Moreover, the leach rate of 50 μg/L/cm2/day is not the “highest 

possible” leach rate. Leach rate estimates submitted to DPR from copper AFP registrants 

show that environmentally-relevant leach rates (representing long-term not maximum 

rates) from a number of copper oxide products exceeded this threshold.”

Comment: “Future ERAs should also take into account the larger water body’s 

background copper levels and the impacts of underwater hull cleaning on biocide 

leaching from boat hulls. The MAM-PEC model does not factor in these sources in 

generating EECs. This hull maintenance activity is very common in California’s coastal 

marinas. Moreover, certain water bodies in California have relatively high background 

copper concentrations that could significantly contribute to a marina’s copper load. 

Brackish water areas, in particular, tend to have high background copper levels.”

Comment: “In the Registration Review document, “Preliminary Problem Formulation 

for Ecological Risk, Environmental Fate, and Endangered Species Assessments for 

Coppers,” there appears to be an error in the linkage of the antifoulant use of copper to 

the ecosystems at risk (page 25 of 106). U.S. EPA staff may be referring to the sites of 

use for the various antimicrobial uses of copper rather than the ecosystems at risk. With 

antifoulant use of copper, the ecosystems that are most at risk are those that are 

associated with marina areas, as these locations tend to exhibit high concentrations of 

copper as a result of pesticide use.”

OPP Response: The Agency agrees that most of the risk for antifoulant use of Cu is 

associated with the marina areas and we have used conservative scenarios to address this 

issue. The commercial harbor scenario used in MAMPEC model has been developed to 

be a reasonable worst case scenario for a risk assessment that must represent a large 

range of conditions nationwide. The Agency will characterize the potential for greater 

exposure in localized scenarios that may have greater vulnerability. Similarly, the 

Agency will evaluate leaching data that are available at the time of the risk assessment to 

determine which values are sufficiently conservative to drive our nationwide-scale risk 
15

assessment. The Agency welcomes the opportunity to continue working with 

stakeholders on scenarios and input parameters for the MAMPEC model which are

pertinent to the United States environmental conditions.

As with the other models described above, the Agency commits to use the best tool 

available to evaluate copper exposure from its use as an antifoulant. OPP is aware of the 

availability of the beta version 3 for MAMPEC and is in the process of evaluating its 

utility for our assessments.

Suggestions for Risk Mitigation

California Stormwater Quality Association (CASQA)

California Department of Pesticide Regulation (DPR)

Comment: “The only technically and economically feasible way for municipalities to 

comply with these looming deadlines is to eliminate copper pollution at its sources, 

which include swimming pool products, treated shingles, and treated wood. ... It is 

therefore essential that the copper registration review process adequately consider 

potential water quality impacts, including those occurring in urban areas, so that EPA can 

identify and implement risk management measures that provide controls essential for 

TMDL compliance and prevent additional copper pesticide related CWA Section 303(d) 

impaired waters listings.”

Comment: “We ask that U.S. EPA modify the labeling of copper-based root control 

products to ensure that they are not used in municipal separate storm drain systems 

(sometimes called “storm sewers”). These systems flow directly to surface water bodies 

without treatment. Discharge of copper-based root control products into storm drains 

would be environmentally harmful. We recommend that U.S. EPA required language 

below (or similar) on the labels for all copper-based root control products that might be 

applied in sewers:

“Use in storm drain systems or separate storm sewer systems is prohibited.”

OPP Response: The Agency will strive to ensure that there are no unreasonable adverse 

effects from exposure to copper after the risk assessment for registration review has been 

completed. Part of this determination involves consideration of the benefits of using 

copper for the uses described above. The Agency would appreciate further input on the 

relative importance of maintaining these tools in light of the potential treatment costs 

incurred by POTWs (for down-the-drain copper disposal) and the concerns of water 

resource agencies for copper transport to surface water via storm sewers.

The Agency would also welcome information which indicates the relative loading from 

these uses in comparison to the many other urban sources of copper with which POTWs 

and water resource agencies must contend. For instance, some commenters indicated that 

brake pads can account for more than half of urban copper loading, and existing urban 

copper TMDLs have identified natural sources, air deposition, and inputs from industry. 
16

In developing TMDLs, some States have eliminated uses such as the copper root control. 

The Agency is not aware whether other States that continue to allow this and other uses 

of copper have yet evaluated the loading attributed to them, or determined that the 

benefits are high enough or exposure relatively small enough that they should be 

maintained.

Monitoring Data

Comment: “Municipal stormwater agencies regularly submit NPDES monitoring data to 

the State of California through the NPDES permitting system. We recommend that 

USEPA contact the California Regional Water Quality Control Boards to obtain all 

relevant copper monitoring data. We suggest that it is incumbent upon EPA to take a 

more active role in identifying and acquiring pertinent monitoring data.”

OPP Response: The Office of Pesticide Programs (OPP), working with the Office of 

Water, EPA regions, and state partners, developed the “OPP Standard Operating 

Procedure: Inclusion of Water Quality & Impaired Water Body Data in OPP's 

Registration Review Risk Assessment & Management Process”. The SOP is intended to 

encourage submission and use of water quality data during registration review. Voluntary 

submission of these data to OPP for pesticide cases beginning the registration review 

process will insure that Clean Water Act Section 303(d) impaired waterbody listing data, 

and other relevant information for these and other water bodies, can be obtained and 

considered during the registration review process. Data may be submitted in advance of 

opening a pesticide case docket or during the public comment period on the initial 

docket. While data may be submitted later, EPA's ability to adequately consider latesubmitted data will be limited. The SOP described above can be found an the internet at: 

http://www.epa.gov/oppsrrd1/registration_review/water_quality.htm.

Acute Avian Oral Toxicity Requirement

Physicians Committee for Responsible Medicine

Comment: “Strongly supports the use of the newly revised OECD test guideline 

(TG223) for the acute avian oral toxicity test (passerine and non-passerine), which has 

been adopted by the OECD. The new approach could reduce the total number of animals 

by up to approximately 60%.”

OPP Response: The OECD has adopted the TG 223 guideline and has issued a 

validation report. At this time the Agency is actively evaluating the results of the OECD 

validation report to determine if the TG 223 effects endpoints and dose/response 

information adequately address the purposes of the avian acute oral data requirement as 

described in 40 CFR Part 158 and 40 CFR Part 161. Until the Agency’s evaluation of that 

validation report is completed, EPA does not expect to be able to routinely classify avian 

toxicity studies performed using the TG 223 protocol. The validation report should help 

inform the interpretation of studies performed under the TG 223 guideline, and should 
17

clarify what the Agency might find to be generally necessary for avian toxicity studies 

done under TG 223 to be acceptable to meet our data requirements.

Validation work conducted on TG 223 test guideline to date has been limited to studies 

with the upland game birds (e.g., northern bobwhite). Because no work has been done to 

date to validate this guideline for passerine species, it is doubtful that the Agency would 

have confidence in studies done under this guideline for fulfilling requirements for 

passerine acute toxicity data unless additional validation work with passerines is done, 

but the Agency recognizes that specific situations might warrant additional examination.

Potential Risk to Endangered Species

CalDPR

Comment: “Exposures to relatively low copper levels might adversely affect 

endangered salmonid populations. We request that the U.S. EPA evaluate this impact in 

its endangered species assessment.”

AWWA

Comment: “...endangered species protection measures are addressed through direct 

interaction between the relevant state agencies and the permittee. ...This approach allows 

the responsible entity to incorporate measures to avoid harm to endangered species in 

their overall IPM process.

It is possible that through the Endangered Species Act (ESA) consultation with EPA 

under Section 7(a)(2) the agency will consider significantly changing the proposed permit 

provisions. The control measures listed as appropriate for controlling impacts of algae 

and aquatic weed applications on endangered species are sound and are already reflected 

to the extent practical in the Pesticide Discharge Management Plan (PDMP) called for in 

the general permit.

AWWA strongly recommends that EPA retain the current label application rates and 

associated instructions as crafted in developing the last Coppers RED for aquatic use 

applications. These rates reflect an appropriate balance between effective application and 

concern for adverse effects. When used in the context of on-going IPM practice, state 

regulations, and new NPDES permit requirements, appropriate protection of sensitive 

species, including endangered species, will be assured.”

OPP Response: As stated in the problem formulation document, the Agency will 

conduct a risk assessment that supports a complete endangered species determination for 

copper. The ecological risk assessment planned during registration review will allow the 

Agency to determine whether copper’s use has “no effect” or “may affect” federally 

listed threatened or endangered species (listed species) or their designated critical 

habitats. When an assessment concludes that a pesticide’s use “may affect” a listed 

species or its designated critical habitat, the Agency will consult with the U.S. Fish and 
18

Wildlife Service and/or National Marine Fisheries Services (the Services), as appropriate. 

The Services may indicate that changes to copper pesticide label instructions are 

necessary after consultation with the Agency.

Copper Alloy Uses

ACC

Comment: “The ACC Task Force has no information on these [copper alloy] uses; they 

are not traditional antimicrobial uses, are not registered by any task Force members, and 

do not appear to be relevant to this Registration Review Draft Problem Formulation or 

PWP.”

OPP Response: Environmental exposure from the use of registered products such as 

doorknobs, bed rails and kick plates manufactured out of copper alloys is expected to be 

negligible since these items are designed for indoor use and release to the environment is 

very unlikely. Therefore, while the assessment to be conducted would cover these 

chemicals, no quantitative assessment for the purposes of an ecological risk assessment is 

expected to be needed.

Leaching Data Requirements – Roof Shingles, Wood Preservatives and Antifoulants

ACC

Comment: “The Task Force has provided information on copper leach rates from 

shingles. See ACC Biocides Panel Copper Reregistration Task Force, Algae-Resistant 

Roofing Granule Copper Release: White Paper, March 27, 2006, which is attached as 

Appendix B, and Determination of Copper Emission Rates for Building Materials, which 

is attached as Appendix C...Section 2.2.1 of the HydroQual Report contains a 

compilation of copper leach data from shingles weathered outdoors at four locations 

across the U.S. for periods of time ranging from four months to 15 years...

The Task Force believes that these data are reliable and should be used by EPA in its 

further risk assessment activities. It is simply impossible to conduct new long-term field 

testing in a time compatible with the Registration Review schedule. Moreover, the Task 

Force believes that laboratory data using accelerated aging techniques would not provide 

any more useful data for the Agency’s review....The Task Force does not believe that 

additional data should be required and that the Agency has adequate information and a 

reliable model to develop refined estimates of the potential exposure to result from the 

use of copper in roofing granules. In the event that EPA determines it needs more data, 

the Task Force requests that EPA explain how the requested data would be used.”

Comment: “The Task Force is extremely concerned by EPA’s requirement for leaching 

data from wood using AWPA E20-06 for soil and AWPA E11-06 for water, without any 

discussion or explanation of how the data would be evaluated, reworked, or used for risk 

assessment purposes. ...
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For aquatic exposures, when requiring the submission of AWPA-E11 studies for specific 

wood preservative systems, the Agency must recognize the limitations of the data and 

develop a methodology for adjusting the data that renders them useful for purposes of 

ecological risk assessment. The Task Force believes that EPA needs to adopt a 

methodology that would adjust the E11 data to overcome its limitations. As noted, the 

limitations include a method that vastly overestimates leach rates and the disclaimer that 

the method is not intended for environmental assessments...The Task Force proposes that 

EPA evaluate the extensive dynamic and field data available on several treatment systems 

as the basis for developing estimated exposure from a variety of treatment systems.

Similar to data generated using the E11 method; the E20 data overestimate leaching to 

soil and cannot be used for ecological risk assessment purposes without correction. The 

Task Force proposes EPA adopt a procedure similar to that for estimating aquatic 

exposures, where the results of these studies could be used to develop a correction factor 

to use with E20 data.”

Comment: While EPA has not identified leaching data from antifoulant application as a 

data gap, the Task Force believes it is essential that a dialogue be opened to determine the 

appropriate manner by which to assess leach rates from antifoulant coatings. Again, 

laboratory data that EPA has relied upon vastly overestimate actual leach rates. The Task 

Force has requested that EPA adopt an approach that is similar to the one that has been 

developed by Dr. Alistair Finnie, which provides specific correction factors for data 

generated either by the ASTM/ISO rotating cylinder method and a mass-balance 

calculation method. ..There is adequate information available to EPA to conduct reliable 

risk assessments and it is indefensible for the Agency to use leach rate data that is widely 

recognized as overstated and unreliable.

OPP Response: OPP will consider all the available data on leaching of copper from 

shingles. Some of the leaching data submitted in the HydroQual report was used in the 

previous risk assessment for copper. The roof shingle use of the Cu will be assessed using 

the emission rates reported by registrants and an assumed number of houses per Hectare. 

A ten hectare land and a standard farm will be used to calculate the concentration of Cu 

in water. The calculated concentration of Cu will be used to run BLM model to estimate 

the Risk Quotients.

The Agency will evaluate leaching data that are available at the time of the risk 

assessment to determine which values are sufficiently conservative to drive our 

nationwide-scale risk assessment. All acceptable available data will be considered and in 

cases when several acceptable leaching rates are reported for one use (such as with 

antifloulants), the highest rate will be used to conduct risk assessment. Uncertainties in 

our risk assessment, including a discussion of which assumptions are likely to be 

conservative and which are less so, will be included in the risk characterization. These 

factors will be taken into account if the risk assessment indicates a potential for risk, and 
20

could present areas of potential refinement to the risk assessment if data or methods are 

available which would allow it.

The wood preservative use of copper will be assessed using the emission rate data from 

wood provided by the registrants. The amount of Cu leached from a dock built close to 

small pond will be estimated using the surface area of the treated wood. It is assumed 

that the copper leached from wood ends in a standard pond. The concentration of Cu is 

calculated in the pond. The calculated Cu concentration is used to run the BLM model to 

calculate the Risk Quotients. OPP is aware of the issues related to the AWAPA E11-06 

methodology and is considering other approaches including the OECD methodology. 

The risk assessment will employ the best tools available at the time of the risk 

assessment. This could include methodologies other than AWAPA E11, if there are 

research and data enough to support a change.

Heavy Metal Impurities

Comment: Believes that trace heavy metal impurities in antimicrobial copper-containing 

products are so low as to be insignificant with regard to potential toxicity. They support 

this statement referencing information relating to OSHA indoor air quality standards, 

OW’s maximum drinking water contaminant levels, and average concentrations of trace 

metals in marine waters.

OPP Response: Trace heavy metal impurities in antimicrobial copper containing 

products are low and their potential toxicity may be low and in most cases insignificant. 

However, these impurities will be assessed on a case by case basis. The Agency is 

currently reviewing available heavy metal data for conventional copper-containing 

pesticides to determine if further evaulation during registration review is warranted.

Copper Oxides Environmental Fate

California Department of Pesticide Regulation (DPR)

Comment: “DPR scientists recently completed a manuscript on the environmental fate of 

copper oxide. It is currently in press and will be printed in an upcoming volume of the 

Reviews of Environmental Contamination and Toxicology. DPR would like to share this 

review with U.S. EPA once it is published.”

OPP Response: The agency will review all research that is provided to the agency prior 

to the assessment.

Registration Review’s Risk Management Decision Timeline

Comment: “DPR is concerned with the point at which risk management decisions (e.g., 

label changes, registration status changes) could be made under the currently established 
21

U.S. EPA timeline. Since the ERA is not expected until 2015, it is unlikely that any U.S. 

EPA action would occur prior to that event.

DPR has been engaged in evaluating copper AFP pollution for more than a decade ... and 

we would welcome any near-term guidance from U.S. EPA. We have conducted and 

coordinated many assessment and mitigation related activities. We have also recently 

initiated our formal reevaluation process on copper AFPs to initiate more direct 

discussions with registrants and to gather data that could be used to address high copper 

concentrations in our marinas. The reregistration process concluded without recognition 

of this issue, and subsequently no actions were taken as a result. Depending on the 

outcome of our ongoing evaluations, DPR may need to take California-specific 

regulatory or registration related measures independent of federal actions.”

OPP Response: Based on the current schedule, OPP agrees that any risk management 

decisions would not be made until after 2015. OPP will welcome the opportunity to 

engage in a dialogue with CDPR and other stake holders to discuss issues related to 

copper assessment throughout the registration review process.